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Sample records for tough2 multiphase flow

  1. TOUGH2: A general-purpose numerical simulator for multiphase nonisothermal flows

    Energy Technology Data Exchange (ETDEWEB)

    Pruess, K. [Lawrence Berkeley Lab., CA (United States)

    1991-06-01

    Numerical simulators for multiphase fluid and heat flows in permeable media have been under development at Lawrence Berkeley Laboratory for more than 10 yr. Real geofluids contain noncondensible gases and dissolved solids in addition to water, and the desire to model such `compositional` systems led to the development of a flexible multicomponent, multiphase simulation architecture known as MULKOM. The design of MULKOM was based on the recognition that the mass-and energy-balance equations for multiphase fluid and heat flows in multicomponent systems have the same mathematical form, regardless of the number and nature of fluid components and phases present. Application of MULKOM to different fluid mixtures, such as water and air, or water, oil, and gas, is possible by means of appropriate `equation-of-state` (EOS) modules, which provide all thermophysical and transport parameters of the fluid mixture and the permeable medium as a function of a suitable set of primary thermodynamic variables. Investigations of thermal and hydrologic effects from emplacement of heat-generating nuclear wastes into partially water-saturated formations prompted the development and release of a specialized version of MULKOM for nonisothermal flow of water and air, named TOUGH. TOUGH is an acronym for `transport of unsaturated groundwater and heat` and is also an allusion to the tuff formations at Yucca Mountain, Nevada. The TOUGH2 code is intended to supersede TOUGH. It offers all the capabilities of TOUGH and includes a considerably more general subset of MULKOM modules with added capabilities. The paper briefly describes the simulation methodology and user features.

  2. Using TOUGH2 to model the coupled effects of gas generation, repository consolidation, and multiphase brine and gas flow at the Waste Isolation Pilot Plant

    International Nuclear Information System (INIS)

    Freeze, G.A.; Larson, K.W.; Davies, P.B.; Webb, S.W.

    1995-01-01

    The Waste Isolation Pilot Plant (WIPP) is a US Department of Energy facility designed to demonstrate the safe underground disposal of transuranic waste. Following waste emplacement, each room will be backfilled with crushed salt. Due to deviatoric stress introduced by excavation, the walls of the waste disposal rooms in the repository will deform over time, consolidating waste containers and salt backfill, thereby decreasing the void volume of the repository. Long-term repository assessment must consider the processes of gas generation, room closure and expansion due to salt creep, and multiphase (brine and gas) fluid flow, as well as the complex coupling between these three processes. Stone (1992) used the mechanical creep closure code SANCHO to simulate the closure of a single, perfectly sealed disposal room filled with waste and backfill. The results of the SANCHO f-series simulations provide a relationship between gas generation, room closure, and room pressure. Several methods for coupling this relationship with multiphase fluid flow into and out of a room were examined by Freeze et al. TOUGH2 was employed to couple the processes of gas generation, room closure/consolidation, and multiphase brine and gas flow. Two empirically-based methods for approximating salt creep and room consolidation were implemented in TOUGH2: the pressure-time-porosity line interpolation approach and the fluid-phase-salt approach. Both approaches utilized links to the SANCHO f-series simulation results to calculate room-void-volume changes with time during a simulation

  3. EOS7Cm: An improved TOUGH2 module for simulating non-isothermal multiphase and multicomponent flow in CO2-H2S-CH4-brine systems with high pressure, temperature and salinity

    Science.gov (United States)

    Lei, Hongwu; Li, Jun; Li, Xiaochun; Jiang, Zhenjiao

    2016-09-01

    Understanding the non-isothermal multiphase and multicomponent flow in a CO2-H2S-CH4-brine system is of critical importance in projects such as CO2 storage in deep saline aquifers, natural gas extraction using CO2 as the displacement fluid, and heat extraction from hot dry rocks using CO2 as the working fluid. Numerical simulation is a necessary tool to evaluate the chemical evolution in these systems. However, an accurate thermodynamic model for CO2-H2S-CH4-brine systems appropriate for high pressure, temperature, and salinity is still lacking. This study establishes the mutual solubility model for CO2-H2S-CH4-brine systems based on the fugacity-activity method for phase equilibrium. The model can predict mutual solubilities for pressure up to 1000 bar for CO2 and CH4, and 200 bar for H2S, for temperature up to 200 °C, and for salinity up to 6 mol/kg water. We incorporated the new model into TOUGH2/EOS7C, forming a new improved module we call EOS7Cm. Compared to the original EOS7C, EOS7Cm considers the effects of H2S and covers a larger range of temperature and salinity. EOS7Cm is employed in five examples, including CO2 injection with and without impurities (CH4 and/or H2S) into deep aquifers, CH4 extraction from aquifers by CO2 injection, and heat extraction from hot dry rock. The results are compared to those from TOUGH2/ECO2N, EOS7C and CMG, agreement among which serves to verify EOS7Cm.

  4. Flow and transport simulations using T2CG1, a package of conjugate gradient solvers for the TOUGH2 family of codes

    Energy Technology Data Exchange (ETDEWEB)

    Moridis, G.; Pruess, K.

    1995-04-01

    This report discusses the details of modifications made to the TOUGH2 family of codes to complement its direct solver which significantly increases the size of problems solved by the TOUGH2 code. With this modification, the TOUGH2 system is being tested in multiphase, multicomponent fluid and heat flow problems related to vadose zone hydrology, nuclear waste disposal, and environmental remediation.

  5. iTOUGH2 Command Reference

    Energy Technology Data Exchange (ETDEWEB)

    Finsterle, Stefan

    2002-06-18

    iTOUGH2 is a program for parameter estimation, sensitivity analysis, and uncertainty propagation analysis. It is based on the TOUGH2 simulator for non-isothermal multiphase flow in fractured and porous media. This report contains a detailed description of all iTOUGH2 commands.

  6. TOUGH2 software qualification

    Energy Technology Data Exchange (ETDEWEB)

    Pruess, K.; Simmons, A.; Wu, Y.S.; Moridis, G.

    1996-02-01

    TOUGH2 is a numerical simulation code for multi-dimensional coupled fluid and heat flow of multiphase, multicomponent fluid mixtures in porous and fractured media. It belongs to the MULKOM ({open_quotes}MULti-KOMponent{close_quotes}) family of codes and is a more general version of the TOUGH simulator. The MULKOM family of codes was originally developed with a focus on geothermal reservoir simulation. They are suited to modeling systems which contain different fluid mixtures, with applications to flow problems arising in the context of high-level nuclear waste isolation, oil and gas recovery and storage, and groundwater resource protection. TOUGH2 is essentially a subset of MULKOM, consisting of a selection of the better tested and documented MULKOM program modules. The purpose of this package of reports is to provide all software baseline documents necessary for the software qualification of TOUGH2.

  7. TOUGH2 software qualification

    International Nuclear Information System (INIS)

    Pruess, K.; Simmons, A.; Wu, Y.S.; Moridis, G.

    1996-02-01

    TOUGH2 is a numerical simulation code for multi-dimensional coupled fluid and heat flow of multiphase, multicomponent fluid mixtures in porous and fractured media. It belongs to the MULKOM (open-quotes MULti-KOMponentclose quotes) family of codes and is a more general version of the TOUGH simulator. The MULKOM family of codes was originally developed with a focus on geothermal reservoir simulation. They are suited to modeling systems which contain different fluid mixtures, with applications to flow problems arising in the context of high-level nuclear waste isolation, oil and gas recovery and storage, and groundwater resource protection. TOUGH2 is essentially a subset of MULKOM, consisting of a selection of the better tested and documented MULKOM program modules. The purpose of this package of reports is to provide all software baseline documents necessary for the software qualification of TOUGH2

  8. Enhancements to the TOUGH2 Simulator as Implemented in iTOUGH2

    Energy Technology Data Exchange (ETDEWEB)

    Finsterle, Stefan [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2015-03-01

    iTOUGH2 is a program for parameter estimation, sensitivity analysis, and uncertainty propagation analysis. It is based on the TOUGH2 simulator for non-isothermal multiphase, multicomponent flow and transport in fractured and porous media [Pruess, 1987, 1991, 2005, 2011; Falta et al., 1995; Pruess et al., 1999, 2002, 2012; Doughty, 2013]. The core of iTOUGH2 contains slightly modified versions of TOUGH2 modules. Most code modifications are editorial and do not affect the simulation results. As a result, standard TOUGH2 input files can be used in iTOUGH2, and identical results are obtained if iTOUGH2 is run in forward mode. However, a number of modifications have been made as described in this report. They enhance the functionality, flexibilitu, and eas-of-use of the forward simulator. This report complements the reports iTOUGH2 User's Guide, iTOUGH2 Command Referecne, and the collection of tutorial examples in iTOUGH2 Sample Problems.

  9. Tomographic multiphase flow measurement

    International Nuclear Information System (INIS)

    Sætre, C.; Johansen, G.A.; Tjugum, S.A.

    2012-01-01

    Measurement of multiphase flow of gas, oil and water is not at all trivial and in spite of considerable achievements over the past two decades, important challenges remain (). These are related to reducing measurement uncertainties arising from variations in the flow regime, improving long term stability and developing new means for calibration, adjustment and verification of the multiphase flow meters. This work focuses on the first two issues using multi gamma beam (MGB) measurements for identification of the type of flow regime. Further gamma ray tomographic measurements are used for reference of the gas/liquid distribution. For the MGB method one Am-241 source with principal emission at 59.5 keV is used because this relatively low energy enables efficient collimation and thereby shaping of the beams, as well as compact detectors. One detector is placed diametrically opposite the source whereas the second is positioned to the side so that this beam is close to the pipe wall. The principle is then straight forward to compare the measured intensities of these detectors and through that identify the flow pattern, i.e. the instantaneous cross-sectional gas-liquid distribution. The measurement setup also includes Compton scattering measurements, which can provide information about the changes in the water salinity for flow segments with high water liquid ratio and low gas fractions. By measuring the transmitted intensity in short time slots (<100ms), rapid regime variations are revealed. From this we can select the time sections suitable for salinity measurements. Since the salinity variations change at the time scale of hours, a running average can be performed to increase the accuracy of the measurements. Recent results of this work will be presented here. - Highlights: ► Multiphase flow gas-fraction and flow regime measurements by multi gamma ray beams. ► High-speed gamma ray tomograph as reference for the flow pattern and gas fraction. ► Dual modality

  10. Multiphase Flow Dynamics 1 Fundamentals

    CERN Document Server

    Kolev, Nikolay Ivanov

    2012-01-01

    Multi-phase flows are part of our natural environment such as tornadoes, typhoons, air and water pollution and volcanic activities as well as part of industrial technology such as power plants, combustion engines, propulsion systems, or chemical and biological industry. The industrial use of multi-phase systems requires analytical and numerical strategies for predicting their behavior. In its fourth extended edition the successful monograph package “Multiphase Flow Dynmics” contains theory, methods and practical experience for describing complex transient multi-phase processes in arbitrary geometrical configurations, providing a systematic presentation of the theory and practice of numerical multi-phase fluid dynamics. In the present first volume the local volume and time averaging is used to derive a complete set of conservation equations for three fluids each of them having multi components as constituents. Large parts of the book are devoted on the design of successful numerical methods for solving the...

  11. Multiphase flow dynamics 1 fundamentals

    CERN Document Server

    Kolev, Nikolay Ivanov

    2004-01-01

    Multi-phase flows are part of our natural environment such as tornadoes, typhoons, air and water pollution and volcanic activities as well as part of industrial technology such as power plants, combustion engines, propulsion systems, or chemical and biological industry. The industrial use of multi-phase systems requires analytical and numerical strategies for predicting their behavior. In its third extended edition this monograph contains theory, methods and practical experience for describing complex transient multi-phase processes in arbitrary geometrical configurations, providing a systematic presentation of the theory and practice of numerical multi-phase fluid dynamics. In the present first volume the fundamentals of multiphase dynamics are provided. This third edition includes various updates, extensions and improvements in all book chapters.

  12. Multiphase flow dynamics 1 fundamentals

    CERN Document Server

    Kolev, Nikolay Ivanov

    2007-01-01

    Multi-phase flows are part of our natural environment such as tornadoes, typhoons, air and water pollution and volcanic activities as well as part of industrial technology such as power plants, combustion engines, propulsion systems, or chemical and biological industry. The industrial use of multi-phase systems requires analytical and numerical strategies for predicting their behavior. In its third extended edition this monograph contains theory, methods and practical experience for describing complex transient multi-phase processes in arbitrary geometrical configurations, providing a systematic presentation of the theory and practice of numerical multi-phase fluid dynamics. In the present first volume the fundamentals of multiphase dynamics are provided. This third edition includes various updates, extensions and improvements in all book chapters.

  13. Multiphase flow dynamics 1 fundamentals

    CERN Document Server

    Kolev, Nikolay Ivanov

    2015-01-01

    In its fifth extended edition the successful monograph package “Multiphase Flow Dynamics” contains theory, methods and practical experience for describing complex transient multi-phase processes in arbitrary geometrical configurations, providing a systematic presentation of the theory and practice of numerical multi-phase fluid dynamics. In the present first volume the local volume and time averaging is used to derive a complete set of conservation equations for three fluids each of them having multi components as constituents. Large parts of the book are devoted on the design of successful numerical methods for solving the obtained system of partial differential equations. Finally the analysis is repeated for boundary fitted curvilinear coordinate systems designing methods applicable for interconnected multi-blocks. This fifth edition includes various updates, extensions, improvements and corrections, as well as  a completely new chapter containing the basic physics describing the multi-phase flow in tu...

  14. TOUGH2 User's Guide Version 2

    International Nuclear Information System (INIS)

    Pruess, K.; Oldenburg, C.M.; Moridis, G.J.

    1999-01-01

    TOUGH2 is a numerical simulator for nonisothermal flows of multicomponent, multiphase fluids in one, two, and three-dimensional porous and fractured media. The chief applications for which TOUGH2 is designed are in geothermal reservoir engineering, nuclear waste disposal, environmental assessment and remediation, and unsaturated and saturated zone hydrology. TOUGH2 was first released to the public in 1991; the 1991 code was updated in 1994 when a set of preconditioned conjugate gradient solvers was added to allow a more efficient solution of large problems. The current Version 2.0 features several new fluid property modules and offers enhanced process modeling capabilities, such as coupled reservoir-wellbore flow, precipitation and dissolution effects, and multiphase diffusion. Numerous improvements in previously released modules have been made and new user features have been added, such as enhanced linear equation solvers, and writing of graphics files. The T2VOC module for three-phase flows of water, air and a volatile organic chemical (VOC), and the T2DM module for hydrodynamic dispersion in 2-D flow systems have been integrated into the overall structure of the code and are included in the Version 2.0 package. Data inputs are upwardly compatible with the previous version. Coding changes were generally kept to a minimum, and were only made as needed to achieve the additional functionalities desired. TOUGH2 is written in standard FORTRAN77 and can be run on any platform, such as workstations, PCs, Macintosh, mainframe and supercomputers, for which appropriate FORTRAN compilers are available. This report is a self-contained guide to application of TOUGH2 to subsurface flow problems. It gives a technical description of the TOUGH2 code, including a discussion of the physical processes modeled, and the mathematical and numerical methods used. Illustrative sample problems are presented along with detailed instructions for preparing input data

  15. Multiphase flows with phase change

    Indian Academy of Sciences (India)

    Multiphase flows with phase change are ubiquitous in many industrial sectors ranging from energy and infra-structure to specialty chemicals and pharmaceuticals. My own interest in mul- tiphase flows with phase change started more than 15 years ago when I had initiated work on riser reactor for fluid catalytic cracking and ...

  16. Software qualification of selected TOUGH2 modules

    International Nuclear Information System (INIS)

    Wu, Y.S.; Ahlers, C.F.; Fraser, P.; Simmons, A.; Pruess, K.

    1996-10-01

    The purpose of this package of reports is to provide all software baseline documents necessary for the software qualification of the single-phase Gas (EOS1G), Effective Continuum Method (ECM), Saturated/Unsaturated Flow (EOS9), and Radionuclide Transport (T2R3D) modules of TOUGH2, a numerical simulation code for multi-dimensional coupled fluid and heat flow of multiphase, multicomponent fluid mixtures in porous and fractured media. This report contains the following sections: (1) Requirements Specification, (2) Design Description, (3) Software Validation Test Plan and Report, (4) Software User Documentation, and (5) Appendices. These sections comprise sequential parts of the Software Life Cycle, and are not intended to stand alone but should be used in conjunction with the TOUGH User's Guide (Pruess, 1987), TOUGH2--A General Purpose Numerical Simulator for Multiphase Fluid and Heat Flow (Pruess, 1991), and the above-referenced TOUGH2 software qualification document. The qualification package is complete with the attached Software Identification Form and executable source code for the single-phase Gas, Effective Continuum method, Saturated/Unsaturated Flow, and Radionuclide Transport modules of TOUGH2

  17. TOUGH2-GRS version 1. User manual

    Energy Technology Data Exchange (ETDEWEB)

    Navarro, Martin; Eckel, Jens

    2016-07-15

    TOUGH2 is a code for the simulation of multi-phase flow processes in porous media that has been developed by the Lawrence Berkeley National Laboratory, California, USA. Since 1991, GRS has been using the code for process analyses and safety assessments for deep geological repositories and has extended the code by several processes that are relevant for repository systems. The TOUGH2 source code that has been developed further by GRS is referred to as TOUGH2-GRS. The present report presents code version 1.1.g, which was developed in project UM13 A 03400 sponsored by the German Federal Ministry for the Environment, Nature Conservation, Building and Nuclear Safety (BMUB).

  18. Modifications and additions to selected TOUGH2 modules

    International Nuclear Information System (INIS)

    Wu, Y.S.; Mishra, A.K.

    1998-01-01

    The purpose of this report is to provide all software baseline documents necessary for the software qualification of the revised versions of the selected TOUGH2 modules, which include single-phase gas (EOS1G), effective continuum method (EOS3/ECM), saturated/unsaturated flow (EOS9), and radionuclide transport (T2R3D) modules of the TOUGH2 code. TOUGH2 is a numerical simulation code for multi-dimensional, coupled fluid and heat flow of multiphase, multicomponent fluid mixtures in porous and fractured media. This report augments the document Software Qualification of Selected TOUGH2 modules. This report contains the following sections: (1) requirement specifications and code development and (2) software validation test plan and results. These sections comprise sequential parts of Software Lifecycle, and should be used in conjunction with the TOUGH User's Guide, TOUGH2 documentation, TOUGH2 Software Qualification, and Software Qualification of Selected TOUGH2 modules. The version of TOUGH2 used with the software being qualified herein is the October 1996 Standard Version 1.2, as qualified in Wu et al. (1996) and housed at the Department of Energy's Energy Science and Technology Software Center (ESTSC) in Oak Ridge, Tennessee

  19. iTOUGH2 Universal Optimization Using the PEST Protocol

    International Nuclear Information System (INIS)

    Finsterle, S.A.

    2010-01-01

    iTOUGH2 (http://www-esd.lbl.gov/iTOUGH2) is a computer program for parameter estimation, sensitivity analysis, and uncertainty propagation analysis [Finsterle, 2007a, b, c]. iTOUGH2 contains a number of local and global minimization algorithms for automatic calibration of a model against measured data, or for the solution of other, more general optimization problems (see, for example, Finsterle [2005]). A detailed residual and estimation uncertainty analysis is conducted to assess the inversion results. Moreover, iTOUGH2 can be used to perform a formal sensitivity analysis, or to conduct Monte Carlo simulations for the examination for prediction uncertainties. iTOUGH2's capabilities are continually enhanced. As the name implies, iTOUGH2 is developed for use in conjunction with the TOUGH2 forward simulator for nonisothermal multiphase flow in porous and fractured media [Pruess, 1991]. However, iTOUGH2 provides FORTRAN interfaces for the estimation of user-specified parameters (see subroutine USERPAR) based on user-specified observations (see subroutine USEROBS). These user interfaces can be invoked to add new parameter or observation types to the standard set provided in iTOUGH2. They can also be linked to non-TOUGH2 models, i.e., iTOUGH2 can be used as a universal optimization code, similar to other model-independent, nonlinear parameter estimation packages such as PEST [Doherty, 2008] or UCODE [Poeter and Hill, 1998]. However, to make iTOUGH2's optimization capabilities available for use with an external code, the user is required to write some FORTRAN code that provides the link between the iTOUGH2 parameter vector and the input parameters of the external code, and between the output variables of the external code and the iTOUGH2 observation vector. While allowing for maximum flexibility, the coding requirement of this approach limits its applicability to those users with FORTRAN coding knowledge. To make iTOUGH2 capabilities accessible to many application models

  20. iTOUGH2 Universal Optimization Using the PEST Protocol

    Energy Technology Data Exchange (ETDEWEB)

    Finsterle, S.A.

    2010-07-01

    iTOUGH2 (http://www-esd.lbl.gov/iTOUGH2) is a computer program for parameter estimation, sensitivity analysis, and uncertainty propagation analysis [Finsterle, 2007a, b, c]. iTOUGH2 contains a number of local and global minimization algorithms for automatic calibration of a model against measured data, or for the solution of other, more general optimization problems (see, for example, Finsterle [2005]). A detailed residual and estimation uncertainty analysis is conducted to assess the inversion results. Moreover, iTOUGH2 can be used to perform a formal sensitivity analysis, or to conduct Monte Carlo simulations for the examination for prediction uncertainties. iTOUGH2's capabilities are continually enhanced. As the name implies, iTOUGH2 is developed for use in conjunction with the TOUGH2 forward simulator for nonisothermal multiphase flow in porous and fractured media [Pruess, 1991]. However, iTOUGH2 provides FORTRAN interfaces for the estimation of user-specified parameters (see subroutine USERPAR) based on user-specified observations (see subroutine USEROBS). These user interfaces can be invoked to add new parameter or observation types to the standard set provided in iTOUGH2. They can also be linked to non-TOUGH2 models, i.e., iTOUGH2 can be used as a universal optimization code, similar to other model-independent, nonlinear parameter estimation packages such as PEST [Doherty, 2008] or UCODE [Poeter and Hill, 1998]. However, to make iTOUGH2's optimization capabilities available for use with an external code, the user is required to write some FORTRAN code that provides the link between the iTOUGH2 parameter vector and the input parameters of the external code, and between the output variables of the external code and the iTOUGH2 observation vector. While allowing for maximum flexibility, the coding requirement of this approach limits its applicability to those users with FORTRAN coding knowledge. To make iTOUGH2 capabilities accessible to many

  1. Multiphase Flow Dynamics 2 Mechanical Interactions

    CERN Document Server

    Kolev, Nikolay Ivanov

    2012-01-01

    Multi-phase flows are part of our natural environment such as tornadoes, typhoons, air and water pollution and volcanic activities as well as part of industrial technology such as power plants, combustion engines, propulsion systems, or chemical and biological industry. The industrial use of multi-phase systems requires analytical and numerical strategies for predicting their behavior. .In its fourth extended edition the successful monograph package “Multiphase Flow Daynmics” contains theory, methods and practical experience for describing complex transient multi-phase processes in arbitrary geometrical configurations, providing a systematic presentation of the theory and practice of numerical multi-phase fluid dynamics. In the present second volume the methods for describing the mechanical interactions in multiphase dynamics are provided. This fourth edition includes various updates, extensions, improvements and corrections.   "The literature in the field of multiphase flows is numerous. Therefore, it i...

  2. Coupling LaGrit unstructured mesh generation and model setup with TOUGH2 flow and transport: A case study

    Science.gov (United States)

    Sentís, Manuel Lorenzo; Gable, Carl W.

    2017-11-01

    There are many applications in science and engineering modeling where an accurate representation of a complex model geometry in the form of a mesh is important. In applications of flow and transport in subsurface porous media, this is manifest in models that must capture complex geologic stratigraphy, structure (faults, folds, erosion, deposition) and infrastructure (tunnels, boreholes, excavations). Model setup, defined as the activities of geometry definition, mesh generation (creation, optimization, modification, refine, de-refine, smooth), assigning material properties, initial conditions and boundary conditions requires specialized software tools to automate and streamline the process. In addition, some model setup tools will provide more utility if they are designed to interface with and meet the needs of a particular flow and transport software suite. A control volume discretization that uses a two point flux approximation is for example most accurate when the underlying control volumes are 2D or 3D Voronoi tessellations. In this paper we will present the coupling of LaGriT, a mesh generation and model setup software suite and TOUGH2 (Pruess et al., 1999) to model subsurface flow problems and we show an example of how LaGriT can be used as a model setup tool for the generation of a Voronoi mesh for the simulation program TOUGH2. To generate the MESH file for TOUGH2 from the LaGriT output a standalone module Lagrit2Tough2 was developed, which is presented here and will be included in a future release of LaGriT. In this paper an alternative method to generate a Voronoi mesh for TOUGH2 with LaGriT is presented and thanks to the modular and command based structure of LaGriT this method is well suited to generating a mesh for complex models.

  3. Multiphase Flow Dynamics 3 Thermal Interactions

    CERN Document Server

    Kolev, Nikolay Ivanov

    2012-01-01

    Multi-phase flows are part of our natural environment such as tornadoes, typhoons, air and water pollution and volcanic activities as well as part of industrial technology such as power plants, combustion engines, propulsion systems, or chemical and biological industry. The industrial use of multi-phase systems requires analytical and numerical strategies for predicting their behavior. .In its fourth extended edition the successful monograph package “Multiphase Flow Daynmics” contains theory, methods and practical experience for describing complex transient multi-phase processes in arbitrary geometrical configurations, providing a systematic presentation of the theory and practice of numerical multi-phase fluid dynamics. In the present third volume methods for describing of the thermal interactions in multiphase dynamics are provided. In addition a large number of valuable experiments is collected and predicted using the methods introduced in this monograph. In this way the accuracy of the methods is reve...

  4. User's Guide for TOUGH2-MP - A Massively Parallel Version of the TOUGH2 Code

    Energy Technology Data Exchange (ETDEWEB)

    Earth Sciences Division; Zhang, Keni; Zhang, Keni; Wu, Yu-Shu; Pruess, Karsten

    2008-05-27

    TOUGH2-MP is a massively parallel (MP) version of the TOUGH2 code, designed for computationally efficient parallel simulation of isothermal and nonisothermal flows of multicomponent, multiphase fluids in one, two, and three-dimensional porous and fractured media. In recent years, computational requirements have become increasingly intensive in large or highly nonlinear problems for applications in areas such as radioactive waste disposal, CO2 geological sequestration, environmental assessment and remediation, reservoir engineering, and groundwater hydrology. The primary objective of developing the parallel-simulation capability is to significantly improve the computational performance of the TOUGH2 family of codes. The particular goal for the parallel simulator is to achieve orders-of-magnitude improvement in computational time for models with ever-increasing complexity. TOUGH2-MP is designed to perform parallel simulation on multi-CPU computational platforms. An earlier version of TOUGH2-MP (V1.0) was based on the TOUGH2 Version 1.4 with EOS3, EOS9, and T2R3D modules, a software previously qualified for applications in the Yucca Mountain project, and was designed for execution on CRAY T3E and IBM SP supercomputers. The current version of TOUGH2-MP (V2.0) includes all fluid property modules of the standard version TOUGH2 V2.0. It provides computationally efficient capabilities using supercomputers, Linux clusters, or multi-core PCs, and also offers many user-friendly features. The parallel simulator inherits all process capabilities from V2.0 together with additional capabilities for handling fractured media from V1.4. This report provides a quick starting guide on how to set up and run the TOUGH2-MP program for users with a basic knowledge of running the (standard) version TOUGH2 code, The report also gives a brief technical description of the code, including a discussion of parallel methodology, code structure, as well as mathematical and numerical methods used

  5. User's Guide for TOUGH2-MP - A Massively Parallel Version of the TOUGH2 Code

    International Nuclear Information System (INIS)

    Earth Sciences Division; Zhang, Keni; Zhang, Keni; Wu, Yu-Shu; Pruess, Karsten

    2008-01-01

    TOUGH2-MP is a massively parallel (MP) version of the TOUGH2 code, designed for computationally efficient parallel simulation of isothermal and nonisothermal flows of multicomponent, multiphase fluids in one, two, and three-dimensional porous and fractured media. In recent years, computational requirements have become increasingly intensive in large or highly nonlinear problems for applications in areas such as radioactive waste disposal, CO2 geological sequestration, environmental assessment and remediation, reservoir engineering, and groundwater hydrology. The primary objective of developing the parallel-simulation capability is to significantly improve the computational performance of the TOUGH2 family of codes. The particular goal for the parallel simulator is to achieve orders-of-magnitude improvement in computational time for models with ever-increasing complexity. TOUGH2-MP is designed to perform parallel simulation on multi-CPU computational platforms. An earlier version of TOUGH2-MP (V1.0) was based on the TOUGH2 Version 1.4 with EOS3, EOS9, and T2R3D modules, a software previously qualified for applications in the Yucca Mountain project, and was designed for execution on CRAY T3E and IBM SP supercomputers. The current version of TOUGH2-MP (V2.0) includes all fluid property modules of the standard version TOUGH2 V2.0. It provides computationally efficient capabilities using supercomputers, Linux clusters, or multi-core PCs, and also offers many user-friendly features. The parallel simulator inherits all process capabilities from V2.0 together with additional capabilities for handling fractured media from V1.4. This report provides a quick starting guide on how to set up and run the TOUGH2-MP program for users with a basic knowledge of running the (standard) version TOUGH2 code. The report also gives a brief technical description of the code, including a discussion of parallel methodology, code structure, as well as mathematical and numerical methods used

  6. Frontiers and progress in multiphase flow

    CERN Document Server

    2014-01-01

    This volume presents state-of-the-art of reviews in the field of multiphase flow. In focusses on nonlinear aspects of multiphase flow networks as well as visualization experiments. The first chapter presents nonlinear aspects or deterministic chaos issues in the systems of multi-phase reactors.  The second chapter reviews two-phase flow dynamics in combination with complex network theory. The third chapter discusses evaporation mechanism in the wick of copper heat pipes. The last chapter investigates numerically the flow dynamics and heat and mass transfer in the laminar and turbulent boundary layer on the flat vertical plate.

  7. TOUGH2 User's Guide Version 2

    Energy Technology Data Exchange (ETDEWEB)

    Pruess, K.; Oldenburg, C.M.; Moridis, G.J.

    1999-11-01

    TOUGH2 is a numerical simulator for nonisothermal flows of multicomponent, multiphase fluids in one, two, and three-dimensional porous and fractured media. The chief applications for which TOUGH2 is designed are in geothermal reservoir engineering, nuclear waste disposal, environmental assessment and remediation, and unsaturated and saturated zone hydrology. TOUGH2 was first released to the public in 1991; the 1991 code was updated in 1994 when a set of preconditioned conjugate gradient solvers was added to allow a more efficient solution of large problems. The current Version 2.0 features several new fluid property modules and offers enhanced process modeling capabilities, such as coupled reservoir-wellbore flow, precipitation and dissolution effects, and multiphase diffusion. Numerous improvements in previously released modules have been made and new user features have been added, such as enhanced linear equation solvers, and writing of graphics files. The T2VOC module for three-phase flows of water, air and a volatile organic chemical (VOC), and the T2DM module for hydrodynamic dispersion in 2-D flow systems have been integrated into the overall structure of the code and are included in the Version 2.0 package. Data inputs are upwardly compatible with the previous version. Coding changes were generally kept to a minimum, and were only made as needed to achieve the additional functionalities desired. TOUGH2 is written in standard FORTRAN77 and can be run on any platform, such as workstations, PCs, Macintosh, mainframe and supercomputers, for which appropriate FORTRAN compilers are available. This report is a self-contained guide to application of TOUGH2 to subsurface flow problems. It gives a technical description of the TOUGH2 code, including a discussion of the physical processes modeled, and the mathematical and numerical methods used. Illustrative sample problems are presented along with detailed instructions for preparing input data.

  8. Design of Multiphase Flow Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Urkedal, Hege

    1998-12-31

    This thesis proposes an experimental design procedure for multiphase experiments. The two-phase functions can be determined using data from a single experiment, while the three-phase relative permeabilities must be determined using data from multiple experiments. Various three-phase experimental designs have been investigated and the accuracy with which the flow functions may be determined using the corresponding data have been computed. Analytical sensitivity coefficients were developed from two-phase to three-phase flow. Sensitivity coefficients are the derivative of the model output with respect to the model parameters. They are obtained by a direct method that takes advantage of the fact that the model equations are solved using the Newton-Raphson method, and some of the results from this solution can be used directly when solving the sensitivity equation. Numerical derivatives are avoided, which improves accuracy. The thesis uses an inverse methodology for determination of two- and three-phase relative permeability and capillary pressure functions. The main work has been the development of analytical sensitivity coefficients for two-and three-phase flow. This technical contribution has improved the accuracy both in parameter estimation and accuracy assessment of the estimates and reduced the computer time requirements. The proposed experimental design is also dependent on accurate sensitivity coefficients to give the right guidelines for how two- and three-phase experiments should be conducted. Following the proposed experimental design, three-phase relative permeability and capillary pressure functions have been estimated when multiple sets of experimental data have been reconciled by simulations. 74 refs., 69 figs., 18 tabs.

  9. Accurate solution algorithms for incompressible multiphase flows

    International Nuclear Information System (INIS)

    Rider, W.J.; Kothe, D.B.; Mosso, S.J.; Cerutti, J.H.; Hochstein, J.I.

    1994-01-01

    A number of advances in modeling multiphase incompressible flow are described. These advances include high-order Godunov projection methods, piecewise linear interface reconstruction and tracking and the continuum surface force model. Examples are given

  10. Measurement in multiphase reacting flows

    Science.gov (United States)

    Chigier, N. A.

    1979-01-01

    A survey is presented of diagnostic techniques and measurements made in multiphase reacting flows. The special problems encountered by the presence of liquid droplets, soot and solid particles in high temperature chemically reacting turbulent environments are outlined. The principal measurement techniques that have been tested in spray flames are spark photography, laser anemometry, thermocouples and suction probes. Spark photography provides measurement of drop size, drop size distribution, drop velocity, and angle of flight. Photographs are analysed automatically by image analysers. Photographic techniques are reliable, inexpensive and proved. Laser anemometers have been developed for simultaneous measurement of velocity and size of individual particles in sprays under conditions of vaporization and combustion. Particle/gas velocity differentials, particle Reynolds numbers, local drag coefficients and direct measurement of vaporization rates can be made by laser anemometry. Gas temperature in sprays is determined by direct in situ measurement of time constants immediately prior to measurement with compensation and signal analysis by micro-processors. Gas concentration is measured by suction probes and gas phase chromatography. Measurements of particle size, particle velocity, gas temperature, and gas concentration made in airblast and pressure atomised liquid spray flames are presented.

  11. Simulation of multiphase flow in hydrocyclone

    Directory of Open Access Journals (Sweden)

    Rudolf P.

    2013-04-01

    Full Text Available Multiphase gas-liquid-solid swirling flow within hydrocyclone is simulated. Geometry and boundary conditions are based on Hsieh's 75 mm hydrocyclone. Extensive simulations point that standard mixture model with careful selection of interphase drag law is suitable for correct prediction of particle classification in case of dilute suspensions. However this approach fails for higher mass loading. It is also confirmed that Reynolds stress model is the best choice for multiphase modeling of the swirling flow on relatively coarse grids.

  12. The simulation of multidimensional multiphase flows

    International Nuclear Information System (INIS)

    Lahey, Richard T.

    2005-01-01

    This paper presents an assessment of various models which can be used for the multidimensional simulation of multiphase flows, such as may occur in nuclear reactors. In particular, a model appropriate for the direct numerical simulation (DNS) of multiphase flows and a mechanistically based, three-dimensional, four-field, turbulent, two-fluid computational multiphase fluid dynamics (CMFD) model are discussed. A two-fluid bubbly flow model, which was derived using potential flow theory, can be extended to other flow regimes, but this will normally involve ensemble-averaging the results from direct numerical simulations (DNS) of various flow regimes to provide the detailed numerical data necessary for the development of flow-regime-specific interfacial and wall closure laws

  13. Simulation approaches for the two-phase flow in saline repositories using the code TOUGH2-GRS. Report in the frame of the project ZIESEL. Two-phase flow in a saline repository using the example ERAM; Ansaetze zur Simulation der Zweiphasenstroemung in salinaren Endlagern mit dem Code TOUGH2-GRS. Bericht im Vorhaben ZIESEL. Zweiphasenfluss in einem salinaren Endlager am Beispiel des ERAM

    Energy Technology Data Exchange (ETDEWEB)

    Navarro, Martin; Fischer, Heidemarie; Seher, Holger; Weyand, Torben

    2016-10-15

    The simulation approaches for the two-phase flow in saline repositories using the code TOUGH2-GRS cover the following issues: simulation of gravitational flows in horizontal galleries without vertical discretization, homogenization approach for the simulation of the two-phase flow in converging partly backfilled galleries, qualification of the convergence approach implemented by GRS into the code TOUGH2-GRS, discretization effects during replacement of liquid by gas, consequences for the system analyses in the frame of the project ZIESEL.

  14. Multiphase reacting flows modelling and simulation

    CERN Document Server

    Marchisio, Daniele L

    2007-01-01

    The papers in this book describe the most widely applicable modeling approaches and are organized in six groups covering from fundamentals to relevant applications. In the first part, some fundamentals of multiphase turbulent reacting flows are covered. In particular the introduction focuses on basic notions of turbulence theory in single-phase and multi-phase systems as well as on the interaction between turbulence and chemistry. In the second part, models for the physical and chemical processes involved are discussed. Among other things, particular emphasis is given to turbulence modeling strategies for multiphase flows based on the kinetic theory for granular flows. Next, the different numerical methods based on Lagrangian and/or Eulerian schemes are presented. In particular the most popular numerical approaches of computational fluid dynamics codes are described (i.e., Direct Numerical Simulation, Large Eddy Simulation, and Reynolds-Averaged Navier-Stokes approach). The book will cover particle-based meth...

  15. EDITORIAL: Measurement techniques for multiphase flows Measurement techniques for multiphase flows

    Science.gov (United States)

    Okamoto, Koji; Murai, Yuichi

    2009-11-01

    Research on multiphase flows is very important for industrial applications, including power stations, vehicles, engines, food processing and so on. Multiphase flows originally have nonlinear features because of multiphase systems. The interaction between the phases plays a very interesting role in the flows. The nonlinear interaction causes the multiphase flows to be very complicated. Therefore techniques for measuring multiphase flows are very useful in helping to understand the nonlinear phenomena. The state-of-the-art measurement techniques were presented and discussed at the sixth International Symposium on Measurement Techniques for Multiphase Flows (ISMTMF2008) held in Okinawa, Japan, on 15-17 December 2008. This special feature of Measurement Science and Technology includes selected papers from ISMTMF2008. Okinawa has a long history as the Ryukyus Kingdom. China, Japan and many western Pacific countries have had cultural and economic exchanges through Okinawa for over 1000 years. Much technical and scientific information was exchanged at the symposium in Okinawa. The proceedings of ISMTMF2008 apart from these special featured papers were published in Journal of Physics: Conference Series vol. 147 (2009). We would like to express special thanks to all the contributors to the symposium and this special feature. This special feature will be a milestone in measurement techniques for multiphase flows.

  16. A multiphase compressible model for the simulation of multiphase flows

    International Nuclear Information System (INIS)

    Caltagirone, J.P.; Vincent, St.; Caruyer, C.

    2011-01-01

    A compressible model able to manage incompressible two-phase flows as well as compressible motions is proposed. After a presentation of the multiphase compressible concept, the new model and related numerical methods are detailed on fixed structured grids. The presented model is a 1-fluid model with a reformulated mass conservation equation which takes into account the effects of compressibility. The coupling between pressure and flow velocity is ensured by introducing mass conservation terms in the momentum and energy equations. The numerical model is then validated with four test cases involving the compression of an air bubble by water, the liquid injection in a closed cavity filled with air, a bubble subjected to an ultrasound field and finally the oscillations of a deformed air bubble in melted steel. The numerical results are compared with analytical results and convergence orders in space are provided. (authors)

  17. Multiphase flow in porous media using CFD

    DEFF Research Database (Denmark)

    Hemmingsen, Casper Schytte; Walther, Jens Honore

    We present results from a new Navier-Stokes model for multiphase flow in porous media implemented in Ansys Fluent 16.2 [1]. The model includes the Darcy-Forchheimer source terms in the momentum equations and proper account for relative permeability and capillary pressure in the porous media...

  18. EOS9nT: A TOUGH2 module for the simulation of flow and solute/colloid transport

    International Nuclear Information System (INIS)

    Moridis, G.J.; Wu, Y.S.; Pruess, K.

    1998-04-01

    EOS9nT is a new TOUGH2 module for the simulation of flow and transport of an arbitrary number n of tracers (solutes and/or colloids) in the subsurface. The module first solves the flow-related equations, which are comprised of (a) the Richards equation and, depending on conditions, may also include (b) the flow equation of a dense brine or aqueous suspension and/or (c) the heat equation. A second set of transport equations, corresponding to the n tracers, are then solved sequentially. The low concentrations of the n tracers are considered to have no effect on the liquid phase, thus making possible the decoupling of their equations. The first set of equations in EOS9nT provides the flow regime and account for fluid density variations due to thermal and/or solute concentration effects. The n tracer transport equations account for sorption, radioactive decay, advection, hydrodynamic dispersion, molecular diffusion, as well as filtration (for colloids only). EOS9nT can handle gridblocks or irregular geometry in three-dimensional domains. Preliminary results from four 1-D verification problems show an excellent agreement between the numerical predictions and the known analytical solutions

  19. Visualization of multiphase flow by neutron radiography

    International Nuclear Information System (INIS)

    Mishima, Kaichiro; Takenaka, Nobuyuki.

    1991-01-01

    Neutron radiography (NRG) is a technique which produces images of the internal structure of a body, making use of the attenuation characteristics of neutrons in the materials being observed. Recently, attempts have been made to expand the application of this technique not only to non-destructive testing but also to a variety of industrial and basic research fields. The attenuation of neutrons is large in a light material like water and small in ordinary metals, which difference may make it possible to visualize a multiphase flow in a metallic container. Particularly, the neutron television, which is one of the applied techniques of NRG, is expected to be a useful tool for observing the behavior of two-phase flow, since it produces images in real time. In this paper the basic idea and the method of NRG are presented along with examples of visualization of multiphase flow by NRG. (author)

  20. A development of multiphase flow facility

    International Nuclear Information System (INIS)

    Ismail Mustapha; Jaafar Abdullah

    2004-01-01

    Multiphase liquid flow facility shall be enabling to transport of oil/gas/water in pipelines. In horizontal pipelines, the different flow patterns that could be observed. The flow pattern will depend mainly on the gas and liquid velocities, and gas liquid ratio. For very high liquid velocities and low gas liquid ratios, the dispersed bubble flow is observed. For low flow rates of liquid and gas, a smooth or wavy stratified flow is expected. For intermediate liquid velocities, rolling waves of liquids are formed. The rolling waves increase to the point of forming a plug flow and a slug flow. For very high gas velocities, the annular flow is observed Also include a tillable test section allowing for testing at any angle between 0 0 degree from horizontal, lowering the measurement uncertainties and increased capabilities with respect to flow rates and gas fractions. (Author)

  1. iTOUGH2-EOS1SC. Multiphase Reservoir Simulator for Water under Sub- and Supercritical Conditions. User's Guide

    Energy Technology Data Exchange (ETDEWEB)

    Magnusdottir, Lilja [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Finsterle, Stefan [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2015-03-01

    Supercritical fluids exist near magmatic heat sources in geothermal reservoirs, and the high enthalpy fluid is becoming more desirable for energy production with advancing technology. In geothermal modeling, the roots of the geothermal systems are normally avoided but in order to accurately predict the thermal behavior when wells are drilled close to magmatic intrusions, it is necessary to incorporate the heat sources into the modeling scheme. Modeling supercritical conditions poses a variety of challenges due to the large gradients in fluid properties near the critical zone. This work focused on using the iTOUGH2 simulator to model the extreme temperature and pressure conditions in magmatic geothermal systems.

  2. Non-Equilibrium Thermodynamics in Multiphase Flows

    CERN Document Server

    Mauri, Roberto

    2013-01-01

    Non-equilibrium thermodynamics is a general framework that allows the macroscopic description of irreversible processes. This book introduces non-equilibrium thermodynamics and its applications to the rheology of multiphase flows. The subject is relevant to graduate students in chemical and mechanical engineering, physics and material science. This book is divided into two parts. The first part presents the theory of non-equilibrium thermodynamics, reviewing its essential features and showing, when possible, some applications. The second part of this book deals with how the general theory can be applied to model multiphase flows and, in particular, how to determine their constitutive relations. Each chapter contains problems at the end, the solutions of which are given at the end of the book. No prior knowledge of statistical mechanics is required; the necessary prerequisites are elements of transport phenomena and on thermodynamics. “The style of the book is mathematical, but nonetheless it remains very re...

  3. Modeling variability in porescale multiphase flow experiments

    Energy Technology Data Exchange (ETDEWEB)

    Ling, Bowen; Bao, Jie; Oostrom, Mart; Battiato, Ilenia; Tartakovsky, Alexandre M.

    2017-07-01

    Microfluidic devices and porescale numerical models are commonly used to study multiphase flow in biological, geological, and engineered porous materials. In this work, we perform a set of drainage and imbibition experiments in six identical microfluidic cells to study the reproducibility of multiphase flow experiments. We observe significant variations in the experimental results, which are smaller during the drainage stage and larger during the imbibition stage. We demonstrate that these variations are due to sub-porescale geometry differences in microcells (because of manufacturing defects) and variations in the boundary condition (i.e.,fluctuations in the injection rate inherent to syringe pumps). Computational simulations are conducted using commercial software STAR-CCM+, both with constant and randomly varying injection rate. Stochastic simulations are able to capture variability in the experiments associated with the varying pump injection rate.

  4. Modeling variability in porescale multiphase flow experiments

    Science.gov (United States)

    Ling, Bowen; Bao, Jie; Oostrom, Mart; Battiato, Ilenia; Tartakovsky, Alexandre M.

    2017-07-01

    Microfluidic devices and porescale numerical models are commonly used to study multiphase flow in biological, geological, and engineered porous materials. In this work, we perform a set of drainage and imbibition experiments in six identical microfluidic cells to study the reproducibility of multiphase flow experiments. We observe significant variations in the experimental results, which are smaller during the drainage stage and larger during the imbibition stage. We demonstrate that these variations are due to sub-porescale geometry differences in microcells (because of manufacturing defects) and variations in the boundary condition (i.e., fluctuations in the injection rate inherent to syringe pumps). Computational simulations are conducted using commercial software STAR-CCM+, both with constant and randomly varying injection rates. Stochastic simulations are able to capture variability in the experiments associated with the varying pump injection rate.

  5. Modeling reproducibility of porescale multiphase flow experiments

    Science.gov (United States)

    Ling, B.; Tartakovsky, A. M.; Bao, J.; Oostrom, M.; Battiato, I.

    2017-12-01

    Multi-phase flow in porous media is widely encountered in geological systems. Understanding immiscible fluid displacement is crucial for processes including, but not limited to, CO2 sequestration, non-aqueous phase liquid contamination and oil recovery. Microfluidic devices and porescale numerical models are commonly used to study multiphase flow in biological, geological, and engineered porous materials. In this work, we perform a set of drainage and imbibition experiments in six identical microfluidic cells to study the reproducibility of multiphase flow experiments. We observe significant variations in the experimental results, which are smaller during the drainage stage and larger during the imbibition stage. We demonstrate that these variations are due to sub-porescale geometry differences in microcells (because of manufacturing defects) and variations in the boundary condition (i.e.,fluctuations in the injection rate inherent to syringe pumps). Computational simulations are conducted using commercial software STAR-CCM+, both with constant and randomly varying injection rate. Stochastic simulations are able to capture variability in the experiments associated with the varying pump injection rate.

  6. iTOUGH2-IFC: An Integrated Flow Code in Support of Nagra's Probabilistic Safety Assessment: User's Guide and Model Description

    International Nuclear Information System (INIS)

    Finsterle, Stefan A.

    2009-01-01

    uncertainty, parametric uncertainty) is handled by the outer shell of the PSA model; it is not further discussed in this report. Moreover, justifications for the inclusion or exclusion of FEPs as well as for certain simplifying assumptions are available or can be obtained using detailed process models and other supporting information. The IFC is both a numerical code and a model of a repository system. The numerical code is a modification of the multiphase, multicomponent simulator TOUGH2 (Pruess et al., 1999), as implemented within the iTOUGH2 (Finsterle, 2007abc) framework. The code modifications are mainly concerned with the implementation of relevant FEPs as outlined in Nagra (2007a, AN 07-115), as well as removal of processes and features that are not needed within the IFC; the modifications are summarized in Appendix A1. In addition, the IFC includes a model, i.e., a simplified representation of the repository system. Specifically, a computational grid was generated, which includes the emplacement tunnels for spent fuel, high-level wastes, as well as long-lived intermediate-level wastes. Moreover, the model represents engineered barriers (backfill, seals, plugs, etc.), various tunnels and other underground facilities, and includes a simplified representation of the geological structure, i.e., the host rock (including the excavation disturbed zone (EDZ) around the underground openings), confining units, local aquifers, and a highly transmissive zone. The IFC model was designed in close collaboration with Nagra. This report describes all functional requirements of the IFC and how they are implemented in the IFC. The input formats needed to invoke added modeling capabilities are documented. Finally, the IFC model grid is described, and results from a test simulation are presented

  7. Multiphase flows with phase change

    Indian Academy of Sciences (India)

    odic dry-out/rewetting were observed. The presented data will be useful to provide insights into boiling in diverging micro-channels. ... discuss the development of a computational tool for simulating condensation processes. CFD models were used to understand flow and condensation as well as deposition of ice in the con-.

  8. Solving iTOUGH2 simulation and optimization problems using the PEST protocol

    Energy Technology Data Exchange (ETDEWEB)

    Finsterle, S.A.; Zhang, Y.

    2011-02-01

    The PEST protocol has been implemented into the iTOUGH2 code, allowing the user to link any simulation program (with ASCII-based inputs and outputs) to iTOUGH2's sensitivity analysis, inverse modeling, and uncertainty quantification capabilities. These application models can be pre- or post-processors of the TOUGH2 non-isothermal multiphase flow and transport simulator, or programs that are unrelated to the TOUGH suite of codes. PEST-style template and instruction files are used, respectively, to pass input parameters updated by the iTOUGH2 optimization routines to the model, and to retrieve the model-calculated values that correspond to observable variables. We summarize the iTOUGH2 capabilities and demonstrate the flexibility added by the PEST protocol for the solution of a variety of simulation-optimization problems. In particular, the combination of loosely coupled and tightly integrated simulation and optimization routines provides both the flexibility and control needed to solve challenging inversion problems for the analysis of multiphase subsurface flow and transport systems.

  9. Soft-sensing, non-intrusive multiphase flow meter

    NARCIS (Netherlands)

    Wrobel, K.; Schiferli, W.

    2009-01-01

    For single phase flow meters more and better non-intrusive or even clamp-on meters become available. This allows for a wider use of meters and for easier flow control. As the demand for multiphase meters is increasing, the current aim is to develop a non-intrusive multiphase flow meter. The

  10. Multiphase flow dynamics 5 nuclear thermal hydraulics

    CERN Document Server

    Kolev, Nikolay Ivanov

    2015-01-01

    This Volume 5 of the successful book package "Multiphase Flow Dynamics" is devoted to nuclear thermal hydraulics which is a substantial part of nuclear reactor safety. It provides knowledge and mathematical tools for adequate description of the process of transferring the fission heat released in materials due to nuclear reactions into its environment. It step by step introduces into the heat release inside the fuel, temperature fields in the fuels, the "simple" boiling flow in a pipe described using ideas of different complexity like equilibrium, non equilibrium, homogeneity, non homogeneity. Then the "simple" three-fluid boiling flow in a pipe is described by gradually involving the mechanisms like entrainment and deposition, dynamic fragmentation, collisions, coalescence, turbulence. All heat transfer mechanisms are introduced gradually discussing their uncertainty. Different techniques are introduced like boundary layer treatments or integral methods. Comparisons with experimental data at each step demons...

  11. Multiphase Flow Dynamics 5 Nuclear Thermal Hydraulics

    CERN Document Server

    Kolev, Nikolay Ivanov

    2012-01-01

    The present Volume 5 of the successful book package "Multiphase Flow Dynamics" is devoted to nuclear thermal hydraulics which is a substantial part of nuclear reactor safety. It provides knowledge and mathematical tools for adequate description of the process of transferring the fission heat released in materials due to nuclear reactions into its environment. It step by step introduces into the heat release inside the fuel, temperature fields in the fuels, the "simple" boiling flow in a pipe described using ideas of different complexity like equilibrium, non equilibrium, homogeneity, non homogeneity. Then the "simple" three-fluid boiling flow in a pipe is described by gradually involving the mechanisms like entrainment and deposition, dynamic fragmentation, collisions, coalescence, turbulence. All heat transfer mechanisms are introduced gradually discussing their uncertainty. Different techniques are introduced like boundary layer treatments or integral methods. Comparisons with experimental data at each step...

  12. Quantitative tomographic measurements of opaque multiphase flows

    Energy Technology Data Exchange (ETDEWEB)

    GEORGE,DARIN L.; TORCZYNSKI,JOHN R.; SHOLLENBERGER,KIM ANN; O' HERN,TIMOTHY J.; CECCIO,STEVEN L.

    2000-03-01

    An electrical-impedance tomography (EIT) system has been developed for quantitative measurements of radial phase distribution profiles in two-phase and three-phase vertical column flows. The EIT system is described along with the computer algorithm used for reconstructing phase volume fraction profiles. EIT measurements were validated by comparison with a gamma-densitometry tomography (GDT) system. The EIT system was used to accurately measure average solid volume fractions up to 0.05 in solid-liquid flows, and radial gas volume fraction profiles in gas-liquid flows with gas volume fractions up to 0.15. In both flows, average phase volume fractions and radial volume fraction profiles from GDT and EIT were in good agreement. A minor modification to the formula used to relate conductivity data to phase volume fractions was found to improve agreement between the methods. GDT and EIT were then applied together to simultaneously measure the solid, liquid, and gas radial distributions within several vertical three-phase flows. For average solid volume fractions up to 0.30, the gas distribution for each gas flow rate was approximately independent of the amount of solids in the column. Measurements made with this EIT system demonstrate that EIT may be used successfully for noninvasive, quantitative measurements of dispersed multiphase flows.

  13. Modification and application of TOUGH2 as a variable-density, saturated-flow code and comparison to SWIFT II results

    International Nuclear Information System (INIS)

    Christian-Frear, T.L.; Webb, S.W.

    1995-01-01

    Human intrusion scenarios at the Waste Isolation Pilot Plant (WIPP) involve penetration of the repository and an underlying brine reservoir by a future borehole. Brine and gas from the brine reservoir and the repository may flow up the borehole and into the overlying Culebra formation, which is saturated with water containing different amounts of dissolved 'solids resulting in a spatially varying density. Current modeling approaches involve perturbing a steady-state Culebra flow field by inflow of gas and/or brine from a breach borehole that has passed through the repository. Previous studies simulating steady-state flow in the Culebra have been done. One specific study by LaVenue et al. (1990) used the SWIFT 2 code, a single-phase flow and transport code, to develop the steady-state flow field. Because gas may also be present in the fluids from the intrusion borehole, a two-phase code such as TOUGH2 can be used to determine the effect that emitted fluids may have on the steady-state Culebra flow field. Thus a comparison between TOUGH2 and SWIFT2 was prompted. In order to compare the two codes and to evaluate the influence of gas on flow in the Culebra, modifications were made to TOUGH2. Modifications were performed by the authors to allow for element-specific values of permeability, porosity, and elevation. The analysis also used a new equation of state module for a water-brine-air mixture, EOS7 (Pruess, 1991), which was developed to simulate variable water densities by assuming a miscible mixture of water and brine phases and allows for element-specific brine concentration in the INCON file

  14. Dan Joseph's contributions to disperse multiphase flow

    Science.gov (United States)

    Prosperetti, Andrea

    2012-11-01

    During his distinguished career, Dan Joseph worked on a vast array of problems. One of these, which occupied him off and on over the last two decades of his life, was that of flows with suspended finite-size particles at finite Reynolds numbers. He realized early on that progress in this field had to rely on the insight gained from numerical simulation, an area in which he was a pioneer. On the basis of the early numerical results he recognized the now famous ``drafting, kissing and tumbling'' mechanism of particle-particle interaction, the possibility of fluidization by lift and many others. With a number of colleagues and a series of gifted students he produced a significant body of work summarized in his on-line book Interrogations of Direct Numerical Simulation of Solid-Liquid Flows available from http://www.efluids.com/efluids/books/joseph.htm. This presentation will describe Joseph's contribution to the understanding of disperse multiphase flow and conclude with some examples from the author's recent work in this area. Supported by NSF.

  15. Workshop on Scientific Issues in Multiphase Flow

    Energy Technology Data Exchange (ETDEWEB)

    Hanratty, Thomas J. [Univ. of Illinois, Urbana, IL (United States)

    2003-01-02

    This report outlines scientific issues whose resolution will help advance and define the field of multiphase flow. It presents the findings of four study groups and of a workshop sponsored by the Program on Engineering Physics of the Department of Energy. The reason why multiphase flows are much more difficult to analyze than single phase flows is that the phases assume a large number of complicated configurations. Therefore, it should not be surprising that the understanding of why the phases configure in a certain way is the principal scientific issue. Research is needed which identifies the microphysics controlling the organization of the phases, which develops physical models for the resultant multi-scale interactions and which tests their validity in integrative experiments/theories that look at the behavior of a system. New experimental techniques and recently developed direct numerical simulations will play important roles in this endeavor. In gas-liquid flows a top priority is to develop an understanding of why the liquid phase in quasi fully-developed pipe flow changes from one configuration to another. Mixing flows offer a more complicated situation in which several patterns can exist at the same time. They introduce new physical challenges. A second priority is to provide a quantitative description of the phase distribution for selected fully-developed flows and for simple mixing flows (that could include heat transfer and phase change). Microphysical problems of interest are identified – including the coupling of molecular and macroscopic behavior that can be observed in many situations and the formation/destruction of interfaces in the coalescence/breakup of drops and bubbles. Solid-fluid flows offer a simpler system in that interfaces are not changing. However, a variety of patterns exist, that depend on the properties of the particles, their concentration and the Reynolds number characterizing the relative velocity. A top priority is the

  16. 2nd International Conference on Multiphase Flow - ICMF '95

    CERN Document Server

    Fukano, T; Bataille, Jean

    1995-01-01

    There is increasing world-wide interest in obtaining an understanding of various multiphase flow phenomena and problems in terms of a common language of multiphase flow. This volume contains state-of-the-art papers which have been contributed from all over the world by experts working on all aspects of multiphase flows. The volume also highlights international technology-sharing in the fields of energy, environment and public health, in order to create a brighter and sustainable future for man and for all life in the next century. It is intended that this volume will serve as a major source of

  17. Multiphase Flow and Fluidization Continuum and Kinetic Theory Descriptions

    CERN Document Server

    Gidaspow, Dimitri

    1994-01-01

    Useful as a reference for engineers in industry and as an advanced level text for graduate engineering students, Multiphase Flow and Fluidization takes the reader beyond the theoretical to demonstrate how multiphase flow equations can be used to provide applied, practical, predictive solutions to industrial fluidization problems. Written to help advance progress in the emerging science of multiphase flow, this book begins with the development of the conservation laws and moves on through kinetic theory, clarifying many physical concepts (such as particulate viscosity and solids pressure) and i

  18. Multiphase flow models for hydraulic fracturing technology

    Science.gov (United States)

    Osiptsov, Andrei A.

    2017-10-01

    drift-flux approaches. The derivation of the drift-flux model from conservation olaws is criticall revisited in order to define the list of underlying assumptions and to mark the applicability margins of the model. All these fundamental problems share the same technological application (hydraulic fracturing) and the same method of research, namely, the multi-fluid approach to multiphase flow modeling and the consistent use of asymptotic methods. Multi-fluid models are then discussed in comparison with semi-empirical (often postulated) models widely used in the industry.

  19. Application of neutron radiography to visualization of multiphase flows

    International Nuclear Information System (INIS)

    Takenaka, N.; Fujii, T.; Nishizaki, K.; Asano, H.; Ono, A.; Sonoda, K.; Akagawa, K.

    1990-01-01

    Visualizations by real-time neutron radiography are demonstrated of various flow patterns of nitrogen gas-water two-phase flow in a stainless-steel tube, water inverted annular flow in a stainless-steel tube, flashing flow in an aluminium nozzle and fluidized bed in aluminium tube and vessels. Photographs every 1/60 s are presented by an image processing method to show the dynamic behaviours of the various flow patterns. It is shown that this visualization method can be applied efficiently to multiphase flow researches and will be applicable to multiphase flows in industrial machines. (author)

  20. Multiphase flow metering: 4 years on

    Energy Technology Data Exchange (ETDEWEB)

    Falcone, G.; Hewitt, G.F.; Alimonti, C.; Harrison, B.

    2005-07-01

    Since the authors' last review in 2001 [1], the use of Multiphase Flow Metering (MFM) within the oil and gas industry continues to grow apace, being more popular in some parts of the world than others. Since the early 1990's, when the first commercial meters started to appear, there have been more than 1,600 field applications of MFM for field allocation, production optimisation and mobile well testing. As the authors predicted, wet gas metering technology has improved to such an extent that its use has rapidly increased worldwide. A ''who's who'' of the MFM sector is provided, which highlights the mergers in the sector and gives an insight into the meters and measurement principles available today. Cost estimates, potential benefits and reliability in the field of the current MFM technologies are revisited and brought up to date. Several measurements technologies have resurfaced, such as passive acoustic energy patterns, infrared wavelengths, Nuclear Magnetic Resonance (NMR) and Electrical Capacitance Tomography (ECT), and they are becoming commercial. The concept of ''virtual metering'', integrated with ''classical MFM'', is now widely accepted. However, sometimes the principles of the MFM measurements themselves are forgotten, submerged in the sales and marketing hype. (author) (tk)

  1. A multi-phase flow model for electrospinning process

    Directory of Open Access Journals (Sweden)

    Xu Lan

    2013-01-01

    Full Text Available An electrospinning process is a multi-phase and multi-physicical process with flow, electric and magnetic fields coupled together. This paper deals with establishing a multi-phase model for numerical study and explains how to prepare for nanofibers and nanoporous materials. The model provides with a powerful tool to controlling over electrospinning parameters such as voltage, flow rate, and others.

  2. International Symposium of Cavitation and Multiphase Flow (ISCM 2014)

    International Nuclear Information System (INIS)

    Wu, Yulin

    2015-01-01

    The International Symposium on Cavitation and Multiphase Flow (ISCM 2014) was held in Beijing, China during 18th-21st October, 2014, which was jointly organized by Tsinghua University, Beijing, China and Jiangsu University, Zhenjiang, China. The co-organizer was the State Key Laboratory of Hydroscience and Engineering, Beijing, China. Cavitation and multiphase flow is one of paramount topics of fluid mechanics with many engineering applications covering a broad range of topics, e.g. hydraulic machinery, biomedical engineering, chemical and process industry. In order to improve the performances of engineering facilities (e.g. hydraulic turbines) and to accelerate the development of techniques for medical treatment of serious diseases (e.g. tumors), it is essential to improve our understanding of cavitation and Multiphase Flow. For example, the present development towards the advanced hydrodynamic systems (e.g. space engine, propeller, hydraulic machinery system) often requires that the systems run under cavitating conditions and the risk of cavitation erosion needs to be controlled. The purpose of the ISCM 2014 was to discuss the state-of-the-art cavitation and multiphase flow research and their up-to-date applications, and to foster discussion and exchange of knowledge, and to provide an opportunity for the researchers, engineers and graduate students to report their latest outputs in these fields. Furthermore, the participants were also encouraged to present their work in progress with short lead time and discuss the encountered problems. ISCM 2014 covers all aspects of cavitation and Multiphase Flow, e.g. both fundamental and applied research with a focus on physical insights, numerical modelling and applications in engineering. Some specific topics are: Cavitating and Multiphase Flow in hydroturbines, pumps, propellers etc. Numerical simulation techniques Cavitation and multiphase flow erosion and anti-erosion techniques Measurement techniques for cavitation and

  3. FOREWORD: International Symposium of Cavitation and Multiphase Flow (ISCM 2014)

    Science.gov (United States)

    Wu, Yulin

    2015-01-01

    The International Symposium on Cavitation and Multiphase Flow (ISCM 2014) was held in Beijing, China during 18th-21st October, 2014, which was jointly organized by Tsinghua University, Beijing, China and Jiangsu University, Zhenjiang, China. The co-organizer was the State Key Laboratory of Hydroscience and Engineering, Beijing, China. Cavitation and multiphase flow is one of paramount topics of fluid mechanics with many engineering applications covering a broad range of topics, e.g. hydraulic machinery, biomedical engineering, chemical and process industry. In order to improve the performances of engineering facilities (e.g. hydraulic turbines) and to accelerate the development of techniques for medical treatment of serious diseases (e.g. tumors), it is essential to improve our understanding of cavitation and Multiphase Flow. For example, the present development towards the advanced hydrodynamic systems (e.g. space engine, propeller, hydraulic machinery system) often requires that the systems run under cavitating conditions and the risk of cavitation erosion needs to be controlled. The purpose of the ISCM 2014 was to discuss the state-of-the-art cavitation and multiphase flow research and their up-to-date applications, and to foster discussion and exchange of knowledge, and to provide an opportunity for the researchers, engineers and graduate students to report their latest outputs in these fields. Furthermore, the participants were also encouraged to present their work in progress with short lead time and discuss the encountered problems. ISCM 2014 covers all aspects of cavitation and Multiphase Flow, e.g. both fundamental and applied research with a focus on physical insights, numerical modelling and applications in engineering. Some specific topics are: Cavitating and Multiphase Flow in hydroturbines, pumps, propellers etc. Numerical simulation techniques Cavitation and multiphase flow erosion and anti-erosion techniques Measurement techniques for cavitation and

  4. Development of Next Generation Multiphase Pipe Flow Prediction Tools

    Energy Technology Data Exchange (ETDEWEB)

    Cem Sarica; Holden Zhang

    2006-05-31

    The developments of oil and gas fields in deep waters (5000 ft and more) will become more common in the future. It is inevitable that production systems will operate under multiphase flow conditions (simultaneous flow of gas, oil and water possibly along with sand, hydrates, and waxes). Multiphase flow prediction tools are essential for every phase of hydrocarbon recovery from design to operation. Recovery from deep-waters poses special challenges and requires accurate multiphase flow predictive tools for several applications, including the design and diagnostics of the production systems, separation of phases in horizontal wells, and multiphase separation (topside, seabed or bottom-hole). It is crucial for any multiphase separation technique, either at topside, seabed or bottom-hole, to know inlet conditions such as flow rates, flow patterns, and volume fractions of gas, oil and water coming into the separation devices. Therefore, the development of a new generation of multiphase flow predictive tools is needed. The overall objective of the proposed study is to develop a unified model for gas-oil-water three-phase flow in wells, flow lines, and pipelines to predict flow characteristics such as flow patterns, phase distributions, and pressure gradient encountered during petroleum production at different flow conditions (pipe diameter and inclination, fluid properties and flow rates). In the current multiphase modeling approach, flow pattern and flow behavior (pressure gradient and phase fractions) prediction modeling are separated. Thus, different models based on different physics are employed, causing inaccuracies and discontinuities. Moreover, oil and water are treated as a pseudo single phase, ignoring the distinct characteristics of both oil and water, and often resulting in inaccurate design that leads to operational problems. In this study, a new model is being developed through a theoretical and experimental study employing a revolutionary approach. The

  5. User's guide of TOUGH2-EGS-MP: A Massively Parallel Simulator with Coupled Geomechanics for Fluid and Heat Flow in Enhanced Geothermal Systems VERSION 1.0

    Energy Technology Data Exchange (ETDEWEB)

    Xiong, Yi [Colorado School of Mines, Golden, CO (United States); Fakcharoenphol, Perapon [Colorado School of Mines, Golden, CO (United States); Wang, Shihao [Colorado School of Mines, Golden, CO (United States); Winterfeld, Philip H. [Colorado School of Mines, Golden, CO (United States); Zhang, Keni [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Wu, Yu-Shu [Colorado School of Mines, Golden, CO (United States)

    2013-12-01

    TOUGH2-EGS-MP is a parallel numerical simulation program coupling geomechanics with fluid and heat flow in fractured and porous media, and is applicable for simulation of enhanced geothermal systems (EGS). TOUGH2-EGS-MP is based on the TOUGH2-MP code, the massively parallel version of TOUGH2. In TOUGH2-EGS-MP, the fully-coupled flow-geomechanics model is developed from linear elastic theory for thermo-poro-elastic systems and is formulated in terms of mean normal stress as well as pore pressure and temperature. Reservoir rock properties such as porosity and permeability depend on rock deformation, and the relationships between these two, obtained from poro-elasticity theories and empirical correlations, are incorporated into the simulation. This report provides the user with detailed information on the TOUGH2-EGS-MP mathematical model and instructions for using it for Thermal-Hydrological-Mechanical (THM) simulations. The mathematical model includes the fluid and heat flow equations, geomechanical equation, and discretization of those equations. In addition, the parallel aspects of the code, such as domain partitioning and communication between processors, are also included. Although TOUGH2-EGS-MP has the capability for simulating fluid and heat flows coupled with geomechanical effects, it is up to the user to select the specific coupling process, such as THM or only TH, in a simulation. There are several example problems illustrating applications of this program. These example problems are described in detail and their input data are presented. Their results demonstrate that this program can be used for field-scale geothermal reservoir simulation in porous and fractured media with fluid and heat flow coupled with geomechanical effects.

  6. On convergence of multigrid method in multiphase flow problems

    Science.gov (United States)

    Filatov, M.; Maksimov, D.

    2013-12-01

    Standard multigrid methods often become inefficient in multiphase flow problems because the coarse grid operators are constructed disregarding heterogeneous saturation distribution. This may lead to inefficient residual smoothing and significantly reduce convergence rate. Here we study the convergence behavior of geometric multigrid method in case when the upscaling methods (incl. multiphase) are employed in construction of coarse grid operators. The application for nonlinear multigrid method is also discussed.

  7. Multiphase flow in micro- and nanochannels

    NARCIS (Netherlands)

    Shui, Lingling; Eijkel, Jan C.T.; van den Berg, Albert

    2007-01-01

    Fluids that are of interest in nature, biotechnology and chemistry are rarely either simple single-phase or non-confined (open system) fluids. It is therefore not surprising that recently a surge of interest has arisen in multiphase confined fluid manipulation. This paper aims at reviewing

  8. Multiscale Modeling of Multiphase Fluid Flow

    Science.gov (United States)

    2016-08-01

    interactions within a molecular system are approximated by intramolecular (bonded) interactions: bond stretching, bond bending , and torsions , and...2, harmonic bond bending ( − )2, and the torsional energy for a dihedral angle defined by...many more. The combination of multiphase heat transfer and nano-technology, thus, opens up a wide range of possibilities for cooling technologies

  9. Direct numerical simulations of gas-liquid multiphase flows

    CERN Document Server

    Tryggvason, Grétar; Zaleski, Stéphane

    2011-01-01

    Accurately predicting the behaviour of multiphase flows is a problem of immense industrial and scientific interest. Modern computers can now study the dynamics in great detail and these simulations yield unprecedented insight. This book provides a comprehensive introduction to direct numerical simulations of multiphase flows for researchers and graduate students. After a brief overview of the context and history the authors review the governing equations. A particular emphasis is placed on the 'one-fluid' formulation where a single set of equations is used to describe the entire flow field and

  10. Multiphase Flow of Immiscible Fluids on Unstructured Moving Meshes

    DEFF Research Database (Denmark)

    Misztal, Marek Krzysztof; Erleben, Kenny; Bargteil, Adam

    2013-01-01

    In this paper, we present a method for animating multiphase flow of immiscible fluids using unstructured moving meshes. Our underlying discretization is an unstructured tetrahedral mesh, the deformable simplicial complex (DSC), that moves with the flow in a Lagrangian manner. Mesh optimization op...

  11. Electrification of particulates in industrial and natural multiphase flows

    CERN Document Server

    Gu, Zhaolin

    2017-01-01

    This book introduces comprehensive fundamentals, numerical simulations and experimental methods of electrification of particulates entrained multiphase flows. The electrifications of two particulate forms, liquid droplets and solid particles, are firstly described together. Liquid droplets can be charged under preset or associated electric fields, while solid particles can be charged through contact. Different charging ways in gas (liquid)-liquid or gas-solid multiphase flows are summarized, including ones that are beneficial to industrial processes, such as electrostatic precipitation, electrostatic spraying, and electrostatic separation, etc., ones harmful for shipping and powder industry, and ones occurring in natural phenomenon, such as wind-blown sand and thunderstorm. This book offers theoretical references to the control and utilization of the charging or charged particulates in multiphase flows as well.

  12. Multiphase flow parameter estimation based on laser scattering

    International Nuclear Information System (INIS)

    Vendruscolo, Tiago P; Fischer, Robert; Martelli, Cicero; Da Silva, Marco J; Rodrigues, Rômulo L P; Morales, Rigoberto E M

    2015-01-01

    The flow of multiple constituents inside a pipe or vessel, known as multiphase flow, is commonly found in many industry branches. The measurement of the individual flow rates in such flow is still a challenge, which usually requires a combination of several sensor types. However, in many applications, especially in industrial process control, it is not necessary to know the absolute flow rate of the respective phases, but rather to continuously monitor flow conditions in order to quickly detect deviations from the desired parameters. Here we show how a simple and low-cost sensor design can achieve this, by using machine-learning techniques to distinguishing the characteristic patterns of oblique laser light scattered at the phase interfaces. The sensor is capable of estimating individual phase fluxes (as well as their changes) in multiphase flows and may be applied to safety applications due to its quick response time. (paper)

  13. Multiphase flow parameter estimation based on laser scattering

    Science.gov (United States)

    Vendruscolo, Tiago P.; Fischer, Robert; Martelli, Cicero; Rodrigues, Rômulo L. P.; Morales, Rigoberto E. M.; da Silva, Marco J.

    2015-07-01

    The flow of multiple constituents inside a pipe or vessel, known as multiphase flow, is commonly found in many industry branches. The measurement of the individual flow rates in such flow is still a challenge, which usually requires a combination of several sensor types. However, in many applications, especially in industrial process control, it is not necessary to know the absolute flow rate of the respective phases, but rather to continuously monitor flow conditions in order to quickly detect deviations from the desired parameters. Here we show how a simple and low-cost sensor design can achieve this, by using machine-learning techniques to distinguishing the characteristic patterns of oblique laser light scattered at the phase interfaces. The sensor is capable of estimating individual phase fluxes (as well as their changes) in multiphase flows and may be applied to safety applications due to its quick response time.

  14. A mass-conserving multiphase lattice Boltzmann model for simulation of multiphase flows

    Science.gov (United States)

    Niu, Xiao-Dong; Li, You; Ma, Yi-Ren; Chen, Mu-Feng; Li, Xiang; Li, Qiao-Zhong

    2018-01-01

    In this study, a mass-conserving multiphase lattice Boltzmann (LB) model is proposed for simulating the multiphase flows. The proposed model developed in the present study is to improve the model of Shao et al. ["Free-energy-based lattice Boltzmann model for simulation of multiphase flows with density contrast," Phys. Rev. E 89, 033309 (2014)] by introducing a mass correction term in the lattice Boltzmann model for the interface. The model of Shao et al. [(the improved Zheng-Shu-Chew (Z-S-C model)] correctly considers the effect of the local density variation in momentum equation and has an obvious improvement over the Zheng-Shu-Chew (Z-S-C) model ["A lattice Boltzmann model for multiphase flows with large density ratio," J. Comput. Phys. 218(1), 353-371 (2006)] in terms of solution accuracy. However, due to the physical diffusion and numerical dissipation, the total mass of each fluid phase cannot be conserved correctly. To solve this problem, a mass correction term, which is similar to the one proposed by Wang et al. ["A mass-conserved diffuse interface method and its application for incompressible multiphase flows with large density ratio," J. Comput. Phys. 290, 336-351 (2015)], is introduced into the lattice Boltzmann equation for the interface to compensate the mass losses or offset the mass increase. Meanwhile, to implement the wetting boundary condition and the contact angle, a geometric formulation and a local force are incorporated into the present mass-conserving LB model. The proposed model is validated by verifying the Laplace law, simulating both one and two aligned droplets splashing onto a liquid film, droplets standing on an ideal wall, droplets with different wettability splashing onto smooth wax, and bubbles rising under buoyancy. Numerical results show that the proposed model can correctly simulate multiphase flows. It was found that the mass is well-conserved in all cases considered by the model developed in the present study. The developed

  15. Dynamic effects in multiphase flow: A pore-scale network approach

    NARCIS (Netherlands)

    Gielen, T.; Hassanizadeh, S.M.; Leijnse, A.; Nordhaug, H.F.

    2005-01-01

    Current theories of multiphase flow rely on capillary pressure and saturation relationships that are commonly measured under static conditions. To incorporate transient behaviour, new multiphase flow theories have been proposed. These include an extended capillary pressure-saturation relationship

  16. New Turbulent Multiphase Flow Facilities for Simulation Benchmarking

    Science.gov (United States)

    Teoh, Chee Hau; Salibindla, Ashwanth; Masuk, Ashik Ullah Mohammad; Ni, Rui

    2017-11-01

    The Fluid Transport Lab at Penn State has devoted last few years on developing new experimental facilities to unveil the underlying physics of coupling between solid-gas and gas-liquid multiphase flow in a turbulent environment. In this poster, I will introduce one bubbly flow facility and one dusty flow facility for validating and verifying simulation results. Financial support for this project was provided by National Science Foundation under Grant Number: 1653389 and 1705246.

  17. Analytical modeling of pipeline failure in multiphase flow due to ...

    African Journals Online (AJOL)

    This research focuses on the development of a model that can predict pipeline failure due to corrosion in multiphase flows. The role that velocity, density, water cut and other parameters play in predicting corrosion is critically analyzed with Norsok Model. The result shows that velocity plays a key role in corrosion prediction.

  18. TOUGH+CO 2: A multiphase fluid-flow simulator for CO 2 geologic sequestration in saline aquifers

    Science.gov (United States)

    Zhang, Keni; Moridis, George; Pruess, Karsten

    2011-06-01

    TOUGH+CO 2 is a new simulator for modeling of CO 2 geologic sequestration in saline aquifers. It is a member of TOUGH+, the successor to the TOUGH2 family of codes for multicomponent, multiphase fluid and heat flow simulation. The code accounts for heat and up to 3 mass components, which are partitioned into three possible phases. In the code, the thermodynamics and thermophysical properties of H 2O-NaCl-CO 2 mixtures are determined based on system status and subdivided into six different phase combinations. By solving coupled mass and heat balance equations, TOUGH+CO 2 can model non-isothermal or isothermal CO 2 injection, phase behavior and flow of fluids and heat under typical conditions of temperature, pressure and salinity in CO 2 geologic storage projects. The code takes into account effects of salt precipitation on porosity and permeability changes, and the wettability phenomena. The new simulator inherits all capabilities of TOUGH2 in handling fractured media and using unstructured meshes for complex simulation domains. The code adds additional relative permeability and capillary pressure functions. The FORTRAN 95 OOP architecture and other new language features have been extensively used to enhance memory use and computing efficiency. In addition, a domain decomposition approach has been implemented for parallel simulation. All these features lead to increased computational efficiency, and allow applicability of the code to multi-core/processor parallel computing platforms with excellent scalability.

  19. Parameter estimation from flowing fluid temperature logging data in unsaturated fractured rock using multiphase inverse modeling

    Energy Technology Data Exchange (ETDEWEB)

    Mukhopadhyay, S.; Tsang, Y.; Finsterle, S.

    2009-01-15

    A simple conceptual model has been recently developed for analyzing pressure and temperature data from flowing fluid temperature logging (FFTL) in unsaturated fractured rock. Using this conceptual model, we developed an analytical solution for FFTL pressure response, and a semianalytical solution for FFTL temperature response. We also proposed a method for estimating fracture permeability from FFTL temperature data. The conceptual model was based on some simplifying assumptions, particularly that a single-phase airflow model was used. In this paper, we develop a more comprehensive numerical model of multiphase flow and heat transfer associated with FFTL. Using this numerical model, we perform a number of forward simulations to determine the parameters that have the strongest influence on the pressure and temperature response from FFTL. We then use the iTOUGH2 optimization code to estimate these most sensitive parameters through inverse modeling and to quantify the uncertainties associated with these estimated parameters. We conclude that FFTL can be utilized to determine permeability, porosity, and thermal conductivity of the fracture rock. Two other parameters, which are not properties of the fractured rock, have strong influence on FFTL response. These are pressure and temperature in the borehole that were at equilibrium with the fractured rock formation at the beginning of FFTL. We illustrate how these parameters can also be estimated from FFTL data.

  20. Wettability control on multiphase flow in patterned microfluidics

    Science.gov (United States)

    Juanes, R.; Zhao, B.; MacMinn, C. W.

    2016-12-01

    Multiphase flow in porous media is important in many natural and industrial processes, including geologic CO2 sequestration, enhanced oil recovery, and water infiltration into soil. Although it is well known that the wetting properties of porous media can vary drastically depending on the type of media and pore fluids, the effect of wettability on multiphase flow continues to challenge our microscopic and macroscopic descriptions. Here, we study the impact of wettability on viscously unfavorable fluid-fluid displacement in disordered media by means of high-resolution imaging in microfluidic flow cells patterned with vertical posts. By systematically varying the wettability of the flow cell over a wide range of contact angles, we find that increasing the substrate's affinity to the injected fluid results in more efficient displacement of the defending fluid up to a critical wetting transition, beyond which the trend is reversed. We identify the pore-scale mechanisms—cooperative pore filling (increasing displacement efficiency) and corner flow (decreasing displacement efficiency)—responsible for this macroscale behavior, and show that they rely on the inherent 3D nature of interfacial flows, even in quasi-2D media. Our results demonstrate the powerful control of wettability on multiphase flow in porous media, and show that the markedly different invasion protocols that emerge—from pore-filling to post-bridging—are determined by physical mechanisms that are missing from current pore-scale and continuum-scale descriptions.

  1. Development of Next Generation Multiphase Pipe Flow Prediction Tools

    Energy Technology Data Exchange (ETDEWEB)

    Tulsa Fluid Flow

    2008-08-31

    The developments of fields in deep waters (5000 ft and more) is a common occurrence. It is inevitable that production systems will operate under multiphase flow conditions (simultaneous flow of gas-oil-and water possibly along with sand, hydrates, and waxes). Multiphase flow prediction tools are essential for every phase of the hydrocarbon recovery from design to operation. The recovery from deep-waters poses special challenges and requires accurate multiphase flow predictive tools for several applications including the design and diagnostics of the production systems, separation of phases in horizontal wells, and multiphase separation (topside, seabed or bottom-hole). It is very crucial to any multiphase separation technique that is employed either at topside, seabed or bottom-hole to know inlet conditions such as the flow rates, flow patterns, and volume fractions of gas, oil and water coming into the separation devices. The overall objective was to develop a unified model for gas-oil-water three-phase flow in wells, flow lines, and pipelines to predict the flow characteristics such as flow patterns, phase distributions, and pressure gradient encountered during petroleum production at different flow conditions (pipe diameter and inclination, fluid properties and flow rates). The project was conducted in two periods. In Period 1 (four years), gas-oil-water flow in pipes were investigated to understand the fundamental physical mechanisms describing the interaction between the gas-oil-water phases under flowing conditions, and a unified model was developed utilizing a novel modeling approach. A gas-oil-water pipe flow database including field and laboratory data was formed in Period 2 (one year). The database was utilized in model performance demonstration. Period 1 primarily consisted of the development of a unified model and software to predict the gas-oil-water flow, and experimental studies of the gas-oil-water project, including flow behavior description and

  2. Multiphase flow of immiscible fluids on unstructured moving meshes

    DEFF Research Database (Denmark)

    Misztal, Marek Krzysztof; Erleben, Kenny; Bargteil, Adam

    2012-01-01

    In this paper, we present a method for animating multiphase flow of immiscible fluids using unstructured moving meshes. Our underlying discretization is an unstructured tetrahedral mesh, the deformable simplicial complex (DSC), that moves with the flow in a Lagrangian manner. Mesh optimization...... operations improve element quality and avoid element inversion. In the context of multiphase flow, we guarantee that every element is occupied by a single fluid and, consequently, the interface between fluids is represented by a set of faces in the simplicial complex. This approach ensures...... that the underlying discretization matches the physics and avoids the additional book-keeping required in grid-based methods where multiple fluids may occupy the same cell. Our Lagrangian approach naturally leads us to adopt a finite element approach to simulation, in contrast to the finite volume approaches adopted...

  3. Measurement Of Multiphase Flow Water Fraction And Water-cut

    Science.gov (United States)

    Xie, Cheng-gang

    2007-06-01

    This paper describes a microwave transmission multiphase flow water-cut meter that measures the amplitude attenuation and phase shift across a pipe diameter at multiple frequencies using cavity-backed antennas. The multiphase flow mixture permittivity and conductivity are derived from a unified microwave transmission model for both water- and oil-continuous flows over a wide water-conductivity range; this is far beyond the capability of microwave-resonance-based sensors currently on the market. The water fraction and water cut are derived from a three-component gas-oil-water mixing model using the mixture permittivity or the mixture conductivity and an independently measured mixture density. Water salinity variations caused, for example, by changing formation water or formation/injection water breakthrough can be detected and corrected using an online water-conductivity tracking technique based on the interpretation of the mixture permittivity and conductivity, simultaneously measured by a single-modality microwave sensor.

  4. Multiphase flow in geometrically simple fracture intersections

    Science.gov (United States)

    Basagaoglu, H.; Meakin, P.; Green, C.T.; Mathew, M.; ,

    2006-01-01

    A two-dimensional lattice Boltzmann (LB) model with fluid-fluid and solid-fluid interaction potentials was used to study gravity-driven flow in geometrically simple fracture intersections. Simulated scenarios included fluid dripping from a fracture aperture, two-phase flow through intersecting fractures and thin-film flow on smooth and undulating solid surfaces. Qualitative comparisons with recently published experimental findings indicate that for these scenarios the LB model captured the underlying physics reasonably well.

  5. Mixing and reactions in multiphase flow through porous media

    Science.gov (United States)

    Jimenez-Martinez, J.; Le Borgne, T.; Meheust, Y.; Porter, M. L.; De Anna, P.; Hyman, J.; Tabuteau, H.; Turuban, R.; Carey, J. W.; Viswanathan, H. S.

    2016-12-01

    The understanding and quantification of flow and transport processes in multiphase systems remains a grand scientific and engineering challenge in natural and industrial systems (e.g., soils and vadose zone, CO2 sequestration, unconventional oil and gas extraction, enhanced oil recovery). Beyond the kinetic of the chemical reactions, mixing processes in porous media play a key role in controlling both fluid-fluid and fluid-solid reactions. However, conventional continuum-scale models and theories oversimplify and/or ignore many important pore-scale processes. Multiphase flows, with the creation of highly heterogeneous fluid velocity fields (i.e., low velocities regions or stagnation zones, and high velocity regions or preferential paths), makes conservative and reactive transport more complex. We present recent multi-scale experimental developments and theoretical approaches to quantify transport, mixing, and reaction and their coupling with multiphase flows. We discuss our main findings: i) the sustained concentration gradients and enhanced reactivity in a two-phase system for a continuous injection, and the comparison with a pulse line injection; ii) the enhanced mixing by a third mobile-immiscible phase; and iii) the role that capillary forces play in the localization of the fluid-solid reactions. These experimental results are for highly-idealized geometries, however, the proposed models are related to basic porous media and unsaturated flow properties, and could be tested on more complex systems.

  6. Multiphase flow modeling in centrifugal partition chromatography.

    Science.gov (United States)

    Adelmann, S; Schwienheer, C; Schembecker, G

    2011-09-09

    The separation efficiency in Centrifugal Partition Chromatography (CPC) depends on selection of a suitable biphasic solvent system (distribution ratio, selectivity factor, sample solubility) and is influenced by hydrodynamics in the chambers. Especially the stationary phase retention, the interfacial area for mass transfer and the flow pattern (backmixing) are important parameters. Their relationship with physical properties, operating parameters and chamber geometry is not completely understood and predictions are hardly possible. Experimental flow visualization is expensive and two-dimensional only. Therefore we simulated the flow pattern using a volume-of-fluid (VOF) method, which was implemented in OpenFOAM®. For the three-dimensional simulation of a rotating FCPC®-chamber, gravitational centrifugal and Coriolis forces were added to the conservation equation. For experimental validation the flow pattern of different solvent systems was visualized with an optical measurement system. The amount of mobile phase in a chamber was calculated from gray scale values of videos recorded by an image processing routine in ImageJ®. To visualize the flow of the stationary phase polyethylene particles were used to perform a qualitative particle image velocimetry (PIV) analysis. We found a good agreement between flow patterns and velocity profiles of experiments and simulations. By using the model we found that increasing the chamber depth leads to higher specific interfacial area. Additionally a circular flow in the stationary phase was identified that lowers the interfacial area because it pushes the jet of mobile phase to the chamber wall. The Coriolis force alone gives the impulse for this behavior. As a result the model is easier to handle than experiments and allows 3D prediction of hydrodynamics in the chamber. Additionally it can be used for optimizing geometry and operating parameters for given physical properties of solvent systems. Copyright © 2011 Elsevier B

  7. Impact of normal stress on multiphase flow through rough fractures

    Science.gov (United States)

    Alves da Silva Junior, J.; Kang, P. K.; Yang, Z.; Cueto-Felgueroso, L.; Juanes, R.

    2015-12-01

    Fluid flow and transport through geologic fractures plays a key role in several areas such as groundwater hydrology, geothermal energy, oil and gas production, CO2 sequestration and nuclear waste disposal. High-permeability zones associated with fracture corridors often serve as fast fluid conduits for both single and multiphase flow in otherwise low-permeability media. When multiphase flow occurs, the presence of one phase interferes with the flow of the other phase, resulting in complex displacement patterns through the fracture, and macroscopic descriptors (such as fracture-scale capillary pressure and relative permeability) that depend on the phase concentration of both phases. Here, we investigate the impact of normal stress on single and multiphase flow through rough-walled fractures: (1) we generate synthetic aperture fields that honor the fractal roughness structure observed in real fractures; (2) we model the effect of normal stress on the fracture aperture geometry by solving the contact problem between fracture walls; and (3) we use invasion percolation with trapping to model immiscible fluid displacement and then compute relative permeability numerically for each stress scenario. Our results indicate that normal stress increases the amount of contact area in the fracture wall, which results in an increase of the tortuosity of the available path for fluid displacement. Increasing normal stress results in low relative permeability for the wetting phase due to a decrease of the available path for fluid flow, and therefore a small amount of non-wetting fluid has a large impact on the flow of the wetting fluid. We find that the relative permeability of the non-wetting fluid shows less variation with stress than the wetting fluid, and that both fluids exhibit strong phase interference at intermediate saturations. Finally, we show early results from our experimental work currently underway to validate the modeling results.

  8. CONTINOUS MULTI-PHASE FLOW REACTOR FOR SMALL AND LARGE FLOW CAPACITIES THAN L/MIN

    NARCIS (Netherlands)

    Al-Rawashdeh, Ma'moun; Schouten, Jaap; Nijhuis, T. Alexander; Yue, Jun

    2014-01-01

    Multiphase flow processing in flow reactors holds great promises for diverse applications in fine chemicals and materials synthesis primarily due to its precise control over the flow, mixing and reaction inside or between each phase. Even though, flow reactors have shown superior performance, so far

  9. Seeking simplicity for the understanding of multiphase flows

    Science.gov (United States)

    Stone, Howard A.

    2017-10-01

    Fluid mechanics is a discipline with rich phenomena, with motions occurring over an enormous range of length scales, and spanning a wide range of laminar and turbulent flows, instabilities, and applications in industry, nature, biology, and medicine. The subfield of complex fluids typically refers to those flows where the complexity is introduced, for example, by the presence of suspended particles, multiple phases, soft boundaries, and electrokinetic effects; several distinct multiphase flows of Newtonian fluids make up the examples in this article. Interfaces play a significant role and modify the flow with feedback that further changes the shapes of the interfaces. I will provide examples of our work highlighting (i) new features of classical instabilities triggered by changes in geometry, (ii) multiphase flows relevant to the design of liquid-infused substrates exhibiting effective slip while retaining the trapped liquid, and (iii) unexpected dynamics in flow at a T-junction. The interplay of experiments and mathematical models and/or simulations is critical to the new understanding developed.

  10. Stability Analysis of Reactive Multiphase Slug Flows in Microchannels

    Directory of Open Access Journals (Sweden)

    Alejandro A. Munera Parra

    2014-05-01

    Full Text Available Conducting multiphase reactions in micro-reactors is a promising strategy for intensifying chemical and biochemical processes. A major unresolved challenge is to exploit the considerable benefits offered by micro-scale operation for industrial scale throughputs by numbering-up whilst retaining the underlying advantageous flow characteristics of the single channel system in multiple parallel channels. Fabrication and installation tolerances in the individual micro-channels result in different pressure losses and, thus, a fluid maldistribution. In this work, an additional source of maldistribution, namely the flow multiplicities, which can arise in a multiphase reactive or extractive flow in otherwise identical micro-channels, was investigated. A detailed experimental and theoretical analysis of the flow stability with and without reaction for both gas-liquid and liquid-liquid slug flow has been developed. The model has been validated using the extraction of acetic acid from n-heptane with the ionic liquid 1-Ethyl-3-methylimidazolium ethyl sulfate. The results clearly demonstrate that the coupling between flow structure, the extent of reaction/extraction and pressure drop can result in multiple operating states, thus, necessitating an active measurement and control concept to ensure uniform behavior and optimal performance.

  11. Approaching multiphase flows from the perspective of computational fluid dynamics

    International Nuclear Information System (INIS)

    Banas, A.O.

    1992-01-01

    Thermalhydraulic simulation methodologies based on subchannel and porous-medium concepts are briefly reviewed and contrasted with the general approach of Computational Fluid Dynamics (CFD). An outline of the advanced CFD methods for single-phase turbulent flows is followed by a short discussion of the unified formulation of averaged equations for turbulent and multiphase flows. Some of the recent applications of CFD at Chalk River Laboratories are discussed, and the complementary role of CFD with regard to the established thermalhydraulic methods of analysis is indicated. (author). 8 refs

  12. Multiphase flows in complex geometries: a UQ perspective

    KAUST Repository

    Icardi, Matteo

    2015-01-07

    Nowadays computer simulations are widely used in many multiphase flow applications involving interphases, dispersed particles, and complex geometries. Most of these problems are solved with mixed models composed of fundamental physical laws, rigorous mathematical upscaling, and empirical correlations/closures. This means that classical inference techniques or forward parametric studies, for example, becomes computationally prohibitive and must take into account the physical meaning and constraints of the equations. However mathematical techniques commonly used in Uncertainty Quantification can come to the aid for the (i) modeling, (ii) simulation, and (iii) validation steps. Two relevant applications for environmental, petroleum, and chemical engineering will be presented to highlight these aspects and the importance of bridging the gaps between engineering applications, computational physics and mathematical methods. The first example is related to the mathematical modeling of sub-grid/sub-scale information with Probability Density Function (PDF) models in problems involving flow, mixing, and reaction in random environment. After a short overview of the research field, some connections and similarities with Polynomial Chaos techniques, will be investigated. In the second example, averaged correlations laws and effective parameters for multiphase flow and their statistical fluctuations, will be considered and efficient computational techniques, borrowed from high-dimensional stochastic PDE problems, will be applied. In presence of interfacial flow, where small spatial scales and fast time scales are neglected, the assessment of robustness and predictive capabilities are studied. These illustrative examples are inspired by common problems arising, for example, from the modeling and simulation of turbulent and porous media flows.

  13. Applied multiphase flow in pipes and flow assurance oil and gas production

    CERN Document Server

    Al-Safran, Eissa M

    2017-01-01

    Applied Multiphase Flow in Pipes and Flow Assurance - Oil and Gas Production delivers the most recent advancements in multiphase flow technology while remaining easy to read and appropriate for undergraduate and graduate petroleum engineering students. Responding to the need for a more up-to-the-minute resource, this highly anticipated new book represents applications on the fundamentals with new material on heat transfer in production systems, flow assurance, transient multiphase flow in pipes and the TUFFP unified model. The complex computation procedure of mechanistic models is simplified through solution flowcharts and several example problems. Containing over 50 solved example problems and 140 homework problems, this new book will equip engineers with the skills necessary to use the latest steady-state simulators available.

  14. User's Guide of TOUGH2-EGS. A Coupled Geomechanical and Reactive Geochemical Simulator for Fluid and Heat Flow in Enhanced Geothermal Systems Version 1.0

    Energy Technology Data Exchange (ETDEWEB)

    Fakcharoenphol, Perapon [Colorado School of Mines, Golden, CO (United States); Xiong, Yi [Colorado School of Mines, Golden, CO (United States); Hu, Litang [Colorado School of Mines, Golden, CO (United States); Winterfeld, Philip H. [Colorado School of Mines, Golden, CO (United States); Xu, Tianfu [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Wu, Yu-Shu [Colorado School of Mines, Golden, CO (United States)

    2013-05-01

    TOUGH2-EGS is a numerical simulation program coupling geomechanics and chemical reactions for fluid and heat flows in porous media and fractured reservoirs of enhanced geothermal systems. The simulator includes the fully-coupled geomechanical (THM) module, the fully-coupled geochemical (THC) module, and the sequentially coupled reactive geochemistry (THMC) module. The fully-coupled flow-geomechanics model is developed from the linear elastic theory for the thermo-poro-elastic system and is formulated with the mean normal stress as well as pore pressure and temperature. The chemical reaction is sequentially coupled after solution of flow equations, which provides the flow velocity and phase saturation for the solute transport calculation at each time step. In addition, reservoir rock properties, such as porosity and permeability, are subjected to change due to rock deformation and chemical reactions. The relationships between rock properties and geomechanical and chemical effects from poro-elasticity theories and empirical correlations are incorporated into the simulator. This report provides the user with detailed information on both mathematical models and instructions for using TOUGH2-EGS for THM, THC or THMC simulations. The mathematical models include the fluid and heat flow equations, geomechanical equation, reactive geochemistry equations, and discretization methods. Although TOUGH2-EGS has the capability for simulating fluid and heat flows coupled with both geomechanical and chemical effects, it is up to the users to select the specific coupling process, such as THM, THC, or THMC in a simulation. There are several example problems illustrating the applications of this program. These example problems are described in details and their input data are presented. The results demonstrate that this program can be used for field-scale geothermal reservoir simulation with fluid and heat flow, geomechanical effect, and chemical reaction in porous and fractured media.

  15. Multiphase flow of immiscible fluids on unstructured moving meshes.

    Science.gov (United States)

    Misztal, Marek Krzysztof; Erleben, Kenny; Bargteil, Adam; Fursund, Jens; Christensen, Brian Bunch; Bærentzen, Jakob Andreas; Bridson, Robert

    2014-01-01

    In this paper, we present a method for animating multiphase flow of immiscible fluids using unstructured moving meshes. Our underlying discretization is an unstructured tetrahedral mesh, the deformable simplicial complex (DSC), that moves with the flow in a Lagrangian manner. Mesh optimization operations improve element quality and avoid element inversion. In the context of multiphase flow, we guarantee that every element is occupied by a single fluid and, consequently, the interface between fluids is represented by a set of faces in the simplicial complex. This approach ensures that the underlying discretization matches the physics and avoids the additional book-keeping required in grid-based methods where multiple fluids may occupy the same cell. Our Lagrangian approach naturally leads us to adopt a finite element approach to simulation, in contrast to the finite volume approaches adopted by a majority of fluid simulation techniques that use tetrahedral meshes. We characterize fluid simulation as an optimization problem allowing for full coupling of the pressure and velocity fields and the incorporation of a second-order surface energy. We introduce a preconditioner based on the diagonal Schur complement and solve our optimization on the GPU. We provide the results of parameter studies as well as a performance analysis of our method, together with suggestions for performance optimization.

  16. Modelling of transit-time ultrasonic flow meters under multi-phase flow conditions

    DEFF Research Database (Denmark)

    Simurda, Matej; Duggen, Lars; Lassen, Benny

    2016-01-01

    of the background flow are included. Spatial derivatives are calculated by a Fourier collocation scheme allowing the use of the Fast Fourier transform. The method is compared against analytical solutions and experimental measurements. Additionally, a study of clamp-on and in-line ultrasonic flowmeters operating......A pseudospectral model for transit time ultrasonic flowmeters under multiphase flow conditions is presented. The method solves first order stress-velocity equations of elastodynamics, with acoustic media being modelled by setting shear modulus to zero. Additional terms to account for the effect...... under multiphase flow conditions is carried out....

  17. 4. Workshop - Measurement techniques of stationary and transient multiphase flow

    Energy Technology Data Exchange (ETDEWEB)

    Prasser, H.M. (ed.)

    2001-05-01

    In November 2000, the 4th Workshop on Measurement Techniques for Stationary and Transient Multiphase Flows took place in Rossendorf. Three previous workshops of this series were national meetings; this time participants from different countries took part. The programme comprised 14 oral presentations, 9 of which are included in these proceedings in full length. A special highlight of the meeting was the main lecture ''Ultrasonic doppler method for bubbly flow measurement'' of Professor Masanori Aritomi, Dr. Hiroshige Kikura and Dr. Yumiko Suzuki. The workshop again dealt with high-resolution phase distribution and phase velocity measurement techniques based on electrical conductivity, ultrasound, laser light and high-speed cinematography. A number of presentations were dedicated to the application of wire-mesh sensors developed by FZR for different applications used by the Technical Universities of Delft and Munich and the Tokyo Institute of Technology. (orig.)

  18. 4. Workshop - Measurement techniques of stationary and transient multiphase flow

    International Nuclear Information System (INIS)

    Prasser, H.M.

    2001-05-01

    In November 2000, the 4th Workshop on Measurement Techniques for Stationary and Transient Multiphase Flows took place in Rossendorf. Three previous workshops of this series were national meetings; this time participants from different countries took part. The programme comprised 14 oral presentations, 9 of which are included in these proceedings in full length. A special highlight of the meeting was the main lecture ''Ultrasonic doppler method for bubbly flow measurement'' of Professor Masanori Aritomi, Dr. Hiroshige Kikura and Dr. Yumiko Suzuki. The workshop again dealt with high-resolution phase distribution and phase velocity measurement techniques based on electrical conductivity, ultrasound, laser light and high-speed cinematography. A number of presentations were dedicated to the application of wire-mesh sensors developed by FZR for different applications used by the Technical Universities of Delft and Munich and the Tokyo Institute of Technology. (orig.)

  19. Linear Power-Flow Models in Multiphase Distribution Networks: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Bernstein, Andrey; Dall' Anese, Emiliano

    2017-05-26

    This paper considers multiphase unbalanced distribution systems and develops approximate power-flow models where bus-voltages, line-currents, and powers at the point of common coupling are linearly related to the nodal net power injections. The linearization approach is grounded on a fixed-point interpretation of the AC power-flow equations, and it is applicable to distribution systems featuring (i) wye connections; (ii) ungrounded delta connections; (iii) a combination of wye-connected and delta-connected sources/loads; and, (iv) a combination of line-to-line and line-to-grounded-neutral devices at the secondary of distribution transformers. The proposed linear models can facilitate the development of computationally-affordable optimization and control applications -- from advanced distribution management systems settings to online and distributed optimization routines. Performance of the proposed models is evaluated on different test feeders.

  20. Multiphase flow in lab on chip devices: A real tool for the future

    NARCIS (Netherlands)

    Shui, Lingling; Pennathur, S.; Pennathur, Sumita; Eijkel, Jan C.T.; van den Berg, Albert

    2008-01-01

    Many applications for lab on a chip (LOC) devices require the use of two or more fluids that are either not chemically related (e.g. oil and water) or in different phases (e.g. liquid and gas). Utilizing multiphase flow in LOC devices allows for both the fundamental study of multiphase flow and the

  1. Multiphase flow dynamics 2 thermal and mechanical interactions

    CERN Document Server

    Kolev, Nikolay I

    2007-01-01

    The industrial use of multi-phase systems requires analytical and numerical strategies for predicting their behavior. This book contains theory, methods and practical experience for describing complex transient multi-phase processes. It provides a systematic presentation of the theory and practice of numerical multi-phase fluid dynamics.

  2. Multicomponent, multiphase flow in porous media with temperature variation

    Energy Technology Data Exchange (ETDEWEB)

    Wingard, J.S.; Orr, F.M. Jr.

    1990-10-01

    Recovery of hydrocarbons from porous media is an ongoing concern. Advanced techniques augment conventional recovery methods by injecting fluids that favorably interact with the oil. These fluids interact with the oil by energy transfer, in the case of steam injection, or by mass transfer, as in a miscible gas flood. Often both thermal and compositional considerations are important. An understanding of these injection methods requires knowledge of how temperature variations, phase equilibrium and multiphase flow in porous media interact. The material balance for each component and energy balance are cast as a system of non-strictly hyperbolic partial differential equations. This system of equations is solved using the method of characteristics. The model takes into account the phase behavior by using the Peng-Robinson equation of state to partition the individual components into different phases. Temperature effects are accounted for by the energy balance. Flow effects are modelled by using fractional flow curves and a Stone's three phase relative permeability model. Three problems are discussed. The first problem eliminates the phase behavior aspect of the problem by studying the flow of a single component as it undergoes an isothermal phase change. The second couples the effects of temperature and flow behavior by including a second component that is immiscible with the original component. Phase behavior is added by using a set of three partially miscible components that partition into two or three separate phases. 66 refs., 54 figs., 14 tabs.

  3. Modelling the Multiphase Flow in Dense Medium Cyclones

    Directory of Open Access Journals (Sweden)

    Kaiwei Chu

    2010-12-01

    Full Text Available Dense medium cyclone (DMC is widely used in mineral industry to separate solids by density. It is simple in design but the flow pattern within it is complex due to the size and density distributions of the feed and process medium solids, and the turbulent vortex formed. Recently, the so-called combined computational fluid dynamics (CFD and discrete element method (DEM (CFD-DEM was extended from two-phase flow to model the flow in DMCs at the University of New South Wales (UNSW. In the CFD-DEM model, the flow of coal particles is modelled by DEM and that of medium flow by CFD, allowing consideration of medium-coal mutual interaction and particle-particle collisions. In the DEM model, Newton's laws of motion are applied to individual particles, and in the CFD model the local-averaged Navier-Stokes equations combined with the volume of fluid (VOF and mixture multiphase flow models are solved. The application to the DMC studies requires intensive computational effort. Therefore, various simplified versions have been proposed, corresponding to the approaches such as Lagrangian particle tracking (LPT method where dilute phase flow is assumed so that the interaction between particles can be ignored, one-way coupling where the effect of particle flow on fluid flow is ignored, and the use of the concept of parcel particles whose properties are empirically determined. In this paper, the previous works on the modelling of DMCs at UNSW are summarized and the features and applicability of the models used are discussed.

  4. RF sensor for multiphase flow measurement through an oil pipeline

    Science.gov (United States)

    Wylie, S. R.; Shaw, A.; Al-Shamma'a, A. I.

    2006-08-01

    We have developed, in conjunction with Solartron ISA, an electromagnetic cavity resonator based sensor for multiphase flow measurement through an oil pipeline. This sensor is non-intrusive and transmits low power (10 mW) radio frequencies (RF) in the range of 100-350 MHz and detects the pipeline contents using resonant peaks captured instantaneously. The multiple resonances from each captured RF spectrum are analysed to determine the phase fractions in the pipeline. An industrial version of the sensor for a 102 mm (4 inch) diameter pipe has been constructed and results from this sensor are compared to those given by simulations performed using the electromagnetic high frequency structure simulator software package HFSS. This paper was presented at the 13th International Conference on Sensors and held in Chatham, Kent, on 6-7 September 2005.

  5. Thermodynamic framework for discrete optimal control in multiphase flow systems

    Science.gov (United States)

    Sieniutycz, Stanislaw

    1999-08-01

    Bellman's method of dynamic programming is used to synthesize diverse optimization approaches to active (work producing) and inactive (entropy generating) multiphase flow systems. Thermal machines, optimally controlled unit operations, nonlinear heat conduction, spontaneous relaxation processes, and self-propagating wave fronts are all shown to satisfy a discrete Hamilton-Jacobi-Bellman equation and a corresponding discrete optimization algorithm of Pontryagin's type, with the maximum principle for a Hamiltonian. The extremal structures are always canonical. A common unifying criterion is set for all considered systems, which is the criterion of a minimum generated entropy. It is shown that constraints can modify the entropy functionals in a different way for each group of the processes considered; thus the resulting structures of these functionals may differ significantly. Practical conclusions are formulated regarding the energy savings and energy policy in optimally controlled systems.

  6. Multiphase flow processing in microreactors combined with heterogeneous catalysis for efficient and sustainable chemical synthesis

    NARCIS (Netherlands)

    Yue, Jun

    2017-01-01

    The convergence of continuous flow chemistry and microreactor technology creates numerous possibilities towards the development of an efficient and sustainable chemical synthesis. In this field, the combination of heterogeneous catalysis and multiphase flow processing in microreactors represents an

  7. Multiphase Flow Technology Impacts on Thermal Control Systems for Exploration

    Science.gov (United States)

    McQuillen, John; Sankovic, John; Lekan, Jack

    2006-01-01

    The Two-Phase Flow Facility (TPHIFFy) Project focused on bridging the critical knowledge gap by developing and demonstrating critical multiphase fluid products for advanced life support, thermal management and power conversion systems that are required to enable the Vision for Space Exploration. Safety and reliability of future systems will be enhanced by addressing critical microgravity fluid physics issues associated with flow boiling, condensation, phase separation, and system stability. The project included concept development, normal gravity testing, and reduced gravity aircraft flight campaigns, in preparation for the development of a space flight experiment implementation. Data will be utilized to develop predictive models that could be used for system design and operation. A single fluid, two-phase closed thermodynamic loop test bed was designed, assembled and tested. The major components in this test bed include: a boiler, a condenser, a phase separator and a circulating pump. The test loop was instrumented with flow meters, thermocouples, pressure transducers and both high speed and normal speed video cameras. A low boiling point surrogate fluid, FC-72, was selected based on scaling analyses using preliminary designs for operational systems. Preliminary results are presented which include flow regime transitions and some observations regarding system stability.

  8. On the predictive capabilities of multiphase Darcy flow models

    KAUST Repository

    Icardi, Matteo

    2016-01-09

    Darcy s law is a widely used model and the limit of its validity is fairly well known. When the flow is sufficiently slow and the porosity relatively homogeneous and low, Darcy s law is the homogenized equation arising from the Stokes and Navier- Stokes equations and depends on a single effective parameter (the absolute permeability). However when the model is extended to multiphase flows, the assumptions are much more restrictive and less realistic. Therefore it is often used in conjunction with empirical models (such as relative permeability and capillary pressure curves), derived usually from phenomenological speculations and experimental data fitting. In this work, we present the results of a Bayesian calibration of a two-phase flow model, using high-fidelity DNS numerical simulation (at the pore-scale) in a realistic porous medium. These reference results have been obtained from a Navier-Stokes solver coupled with an explicit interphase-tracking scheme. The Bayesian inversion is performed on a simplified 1D model in Matlab by using adaptive spectral method. Several data sets are generated and considered to assess the validity of this 1D model.

  9. Compositional multiphase flow and transport in heterogeneous porous media

    Energy Technology Data Exchange (ETDEWEB)

    Huber, R.U.

    2000-07-01

    This work first treats the conceptual models for the description of multiphase flow processes in porous media. The thermodynamic laws are explained and the description and quantification of multi-fluid equilibria are discussed in order to account for fluid composition. The fully and weakly coupled approaches for the mathematical description of such flow processes with respect to systems consisting of two and three fluid phases as well as with respect to compositional single and multiphase systems are assessed. For the discretization of the two-phase flow equations node- and cell-centered finite volume methods and mixed and mixed-hybrid finite element approaches are applied. Based upon these methods five solution algorithms are developed. Four of these algorithms are based on the simultaneous solution of the discretized equations in combination with the Newton-Raphson technique. Methods 1 and 2 treat two- three-phase flow processes, Method 3 applies to the solution of partially miscible three-component systems while Method 4 is created for three-phase three-component systems. The latter method uses a variable substitution dependent on the local presence of the fluid phases. Method 5 is based on the IMPES/IMPESC concept. The time-implicit pressure equation is discretized with the mixed-hybrid finite element method. The saturation and concentration equations, respectively, are solved with a cell-centered finite volume scheme. The developed algorithms are applied to the two- and three-phase Buckley-Leverett problems. A partitioning interwell tracer test is simulated. The propagation behavior of nonaqueous phase liquids (NAPLs) in the saturated and unsaturated ground zone under the influence of heterogeneities are examined. In addition, a larger-scale experiment is simulated, which involves an injection of trichloroethylene into the subsurface and the subsequent distribution. Here, the development of a dissolved contaminant plume as well as the behavior of organic

  10. Investigation of hydrate formation and transportability in multiphase flow systems

    Science.gov (United States)

    Grasso, Giovanny A.

    The oil and gas industry is moving towards offshore developments in more challenging environments, where evaluating hydrate plugging risks to avoid operational/safety hazards becomes more difficult (Sloan, 2005). Even though mechanistic models for hydrate plug formation have been developed, components for a full comprehensive model are still missing. Prior to this work, research efforts were focused on flowing hydrate particles with relatively little research on hydrate accumulation, leaving hydrate deposition in multiphase flow an unexplored subject. The focus of this thesis was to better understand hydrate deposition as a form of accumu- lation in pipelines. To incorporate the multiphase flow effect, hydrate formation experiments were carried out at varying water cut (WC) from 15 to 100 vol.%, liquid loading (LL) from 50 to 85 vol.%, mixture velocity (vmix) from 0.75 to 3 m/s, for three fluids systems (100 % WC, water in Conroe crude oil emulsions and King Ranch condensate + water) on the ExxonMobil flowloop (4 in. nominal size and 314 ft. long) at Friendswood, TX. For the 100 % WC flowloop tests, hydrate particle distribution transitions beyond a critical hydrate volume concentration, observed values were between 8.2 to 29.4 vol.%, causing a sudden increase in pressure drop (DP). A revised correlation of the transition as a function of Reynolds number and liquid loading was developed. For Conroe emulsions, DP starts increasing at higher hydrate concentrations than King Ranch condensate, many times at 10 vol.%. Experiments with King Ranch show higher relative DP (10 to 25) than Conroe (2 to 10) performed at the same vmix and LL. Cohesive force measurements between cyclopentane hydrate particles were reduced from a value of 3.32 mN/m to 1.26 mN/m when 6 wt.% Conroe was used and to 0.41 mN/m when 5 wt.% Caratinga crude oil was used; similar values were obtained when extracted asphaltenes were used. King Ranch condensate (11 wt.%) did not significantly change the

  11. Dual domain material point method for multiphase flows

    Science.gov (United States)

    Zhang, Duan

    2017-11-01

    Although the particle-in-cell method was first invented in the 60's for fluid computations, one of its later versions, the material point method, is mostly used for solid calculations. Recent development of the multi-velocity formulations for multiphase flows and fluid-structure interactions requires the Lagrangian capability of the method be combined with Eulerian calculations for fluids. Because of different numerical representations of the materials, additional numerical schemes are needed to ensure continuity of the materials. New applications of the method to compute fluid motions have revealed numerical difficulties in various versions of the method. To resolve these difficulties, the dual domain material point method is introduced and improved. Unlike other particle based methods, the material point method uses both Lagrangian particles and Eulerian mesh, therefore it avoids direct communication between particles. With this unique property and the Lagrangian capability of the method, it is shown that a multiscale numerical scheme can be efficiently built based on the dual domain material point method. In this talk, the theoretical foundation of the method will be introduced. Numerical examples will be shown. Work sponsored by the next generation code project of LANL.

  12. Load Balancing Strategies for Multiphase Flows on Structured Grids

    Science.gov (United States)

    Olshefski, Kristopher; Owkes, Mark

    2017-11-01

    The computation time required to perform large simulations of complex systems is currently one of the leading bottlenecks of computational research. Parallelization allows multiple processing cores to perform calculations simultaneously and reduces computational times. However, load imbalances between processors waste computing resources as processors wait for others to complete imbalanced tasks. In multiphase flows, these imbalances arise due to the additional computational effort required at the gas-liquid interface. However, many current load balancing schemes are only designed for unstructured grid applications. The purpose of this research is to develop a load balancing strategy while maintaining the simplicity of a structured grid. Several approaches are investigated including brute force oversubscription, node oversubscription through Message Passing Interface (MPI) commands, and shared memory load balancing using OpenMP. Each of these strategies are tested with a simple one-dimensional model prior to implementation into the three-dimensional NGA code. Current results show load balancing will reduce computational time by at least 30%.

  13. Statistical analysis on the signals monitoring multiphase flow patterns in pipeline-riser system

    Science.gov (United States)

    Ye, Jing; Guo, Liejin

    2013-07-01

    The signals monitoring petroleum transmission pipeline in offshore oil industry usually contain abundant information about the multiphase flow on flow assurance which includes the avoidance of most undesirable flow pattern. Therefore, extracting reliable features form these signals to analyze is an alternative way to examine the potential risks to oil platform. This paper is focused on characterizing multiphase flow patterns in pipeline-riser system that is often appeared in offshore oil industry and finding an objective criterion to describe the transition of flow patterns. Statistical analysis on pressure signal at the riser top is proposed, instead of normal prediction method based on inlet and outlet flow conditions which could not be easily determined during most situations. Besides, machine learning method (least square supported vector machine) is also performed to classify automatically the different flow patterns. The experiment results from a small-scale loop show that the proposed method is effective for analyzing the multiphase flow pattern.

  14. Evaluation of 3D Mapping Experimental Non-Intrusive Methods for Multiphase Flows

    Directory of Open Access Journals (Sweden)

    C Poette

    2016-09-01

    Full Text Available The present contribution focuses on the evaluation of non-intrusive 3D mapping experimental methods for the investigation of multiphase flows during tank sloshing. This problem is a key issue for launchers and satellites since the feeding in propellants has to be ensured during flight and manoeuvres. At first, an extensive survey of non-intrusive experimental techniques of interest for multiphase flows has been carried out. This task has accounted for new innovative methods developed for space and non-space applications with a focus on the methods used in medicine and other fields such as ultrasound techniques. A particular care has been given to electrical and ultrasonic tomography techniques since they are both non-intrusive, non-invasive, low cost, fast and simple to operate, and suitable for real time measurements. Electrical tomography techniques have demonstrated convincing capabilities for multiphase flow visualization and present numerous advantages for industrial processes and multiphase flow measurements. Ultrasound experimental techniques are extensively used in medicine for a wide range of investigations. They are also largely used for material analysis and fluid mechanics. As a consequence since several years, ultrasound tomography has been applied to multiphase flows. Application of the method to annular, sludge, slug and bubbly flows has demonstrated the potential of this technique for multiphase flow investigations. Additionally, in the context of launchers this technique presents an advantage in term of safety. Using the available results, the advantages and disadvantages of ultrasonic and electrical methods have been identified and this leads to the conclusion that the ultrasonic tomography possesses the best potential for the final application. Finally, using the available experimental results obtained using ultrasound tomography for the mapping of multiphase flows, numerical simulations have been performed to proceed to their

  15. Prediction of Separation Length of Turbulent Multiphase Flow Using Radiotracer and Computational Fluid Dynamics Simulation

    Directory of Open Access Journals (Sweden)

    S. Sugiharto1

    2013-04-01

    Full Text Available Multiphase flow modeling presents great challenges due to its extreme importance in various industrial and environmental applications. In the present study, prediction of separation length of multiphase flow is examined experimentally by injection of two kinds of iodine-based radiotracer solutions into a hydrocarbon transport pipeline (HCT having an inner diameter of 24 in (60,96 m. The main components of fluids in the pipeline are water 95%, crude oil 3% and gas 2%. A radiotracing experiment was carried out at the segment of pipe which is located far from branch points with assumptions that stratified flows in such segment were achieved. Two radiation detectors located at 80 and 100 m from injection point were used to generate residence time distribution (RTD curve resulting from injection of radiotracer solutions. Multiphase computational fluid dynamics (CFD simulations using Eulerian-Eulerian control volume and commercial CFD package Fluent 6.2 were employed to simulate separation length of multiphase flow. The results of study shows that the flow velocity of water is higher than the flow rate of crude oil in water-dominated system despite the higher density of water than the density of the crude oil. The separation length in multiphase flow predicted by Fluent mixture model is approximately 20 m, measured from injection point. This result confirms that the placement of the first radiation detector at the distance 80 m from the injection point was correct

  16. Prediction of Separation Length of Turbulent Multiphase Flow Using Radiotracer and Computational Fluid Dynamics Simulation

    International Nuclear Information System (INIS)

    Sugiharto, S.; Kurniadi, R.; Abidin, Z.; Stegowski, Z.; Furman, L.

    2013-01-01

    Multiphase flow modeling presents great challenges due to its extreme importance in various industrial and environmental applications. In the present study, prediction of separation length of multiphase flow is examined experimentally by injection of two kinds of iodine-based radiotracer solutions into a hydrocarbon transport pipeline (HCT) having an inner diameter of 24 in (60,96 m). The main components of fluids in the pipeline are water 95%, crude oil 3% and gas 2%. A radiotracing experiment was carried out at the segment of pipe which is located far from branch points with assumptions that stratified flows in such segment were achieved. Two radiation detectors located at 80 and 100 m from injection point were used to generate residence time distribution (RTD) curve resulting from injection of radiotracer solutions. Multiphase computational fluid dynamics (CFD) simulations using Eulerian-Eulerian control volume and commercial CFD package Fluent 6.2 were employed to simulate separation length of multiphase flow. The results of study shows that the flow velocity of water is higher than the flow rate of crude oil in water-dominated system despite the higher density of water than the density of the crude oil. The separation length in multiphase flow predicted by Fluent mixture model is approximately 20 m, measured from injection point. This result confirms that the placement of the first radiation detector at the distance 80 m from the injection point was correct. (author)

  17. Nanoscale multi-phase flow and its application to control nanofiber diameter

    Directory of Open Access Journals (Sweden)

    Liu Yan-Qing

    2018-01-01

    Full Text Available Nanoscale flows appear widely in nanofiber fabrication especially in electro-spinning, where a nanoscale jet is a multi-phase fluid including solvents and additives. This paper shows that the fiber morphology can be effectively controlled by adjusting the density of the multi-phase jet. TiO2 is used as an additive to produce polyacrylonitrile nanofibers by electrospinning; the results elucidate that uniform nanofiber can be obtained, and this phenomenon is explained theoretically.

  18. Multiphase Flow Dynamics 4 Turbulence, Gas Adsorption and Release, Diesel Fuel Properties

    CERN Document Server

    Kolev, Nikolay Ivanov

    2012-01-01

    The present Volume 4 of the successful monograh package “Multiphase Flow Dynamics”is devoted to selected Chapters of the multiphase fluid dynamics that are important for practical applications but did not find place in the previous volumes. The state of the art of the turbulence modeling in multiphase flows is presented. As introduction, some basics of the single phase boundary layer theory including some important scales and flow oscillation characteristics in pipes and rod bundles are presented. Then the scales characterizing the dispersed flow systems are presented. The description of the turbulence is provided at different level of complexity: simple algebraic models for eddy viscosity, simple algebraic models based on the Boussinesq hypothesis, modification of the boundary layer share due to modification of the bulk turbulence, modification of the boundary layer share due to nucleate boiling. The role of the following forces on the mathematical description of turbulent flows is discussed: the lift fo...

  19. Pattern recognition techniques for horizontal and vertically upward multiphase flow measurement

    Science.gov (United States)

    Arubi, Tesi I. M.; Yeung, Hoi

    2012-03-01

    The oil and gas industry need for high performing and low cost multiphase meters is ever more justified given the rapid depletion of conventional oil reserves that has led oil companies to develop smaller and marginal fields and reservoirs in remote locations and deep offshore, thereby placing great demands for compact and more cost effective solutions of on-line continuous multiphase flow measurement for well testing, production monitoring, production optimisation, process control and automation. The pattern recognition approach for clamp-on multiphase measurement employed in this study provides one means for meeting this need. High speed caesium-137 radioisotope-based densitometers were installed vertically at the top of a 50.8mm and 101.6mm riser as well as horizontally at the riser base in the Cranfield University multiphase flow test facility. A comprehensive experimental campaign comprising flow conditions typical of operating conditions found in the Petroleum Industry was conducted. The application of a single gamma densitometer unit, in conjunction with pattern recognition techniques to determine both the phase volume fractions and velocities to yield the individual phase flow rates of horizontal and vertically upward multiphase flows was investigated. The pattern recognition systems were trained to map the temporal fluctuations in the multiphase mixture density with the individual phase flow rates using statistical features extracted from the gamma counts signals as their inputs. Initial results yielded individual phase flow rate predictions to within ±5% relative error for the two phase airwater flows and ±10% for three phase air-oil-water flows data.

  20. PREFACE: The 6th International Symposium on Measurement Techniques for Multiphase Flows

    Science.gov (United States)

    Okamoto, Koji; Murai, Yuichi

    2009-02-01

    Research on multi-phase flows is very important for industrial applications, including power stations, vehicles, engines, food processing, and so on. Also, from the environmental viewpoint, multi-phase flows need to be investigated to overcome global warming. Multi-phase flows originally have non-linear features because they are multi-phased. The interaction between the phases plays a very interesting role in the flows. The non-linear interaction causes the multi-phase flows to be very difficult to understand phenomena. The International Symposium on Measurement Techniques for Multi-phase Flows (ISMTMF) is a unique symposium. The target of the symposium is to exchange the state-of-the-art knowledge on the measurement techniques for non-linear multi-phase flows. Measurement technique is the key technology to understanding non-linear phenomena. The ISMTMF began in 1995 in Nanjing, China. The symposium has continuously been held every two or three years. The ISMTMF-2008 was held in Okinawa, Japan as the 6th symposium of ISMTMF on 15-17 December 2008. Okinawa has a long history as the Ryukyus Kingdom. China and Japan have had cultural and economic exchanges through Okinawa for more than 1000 years. Please enjoy Okinawa and experience its history to enhance our international communication. The present symposium was attended by 124 participants, the program included 107 contributions with 5 plenary lectures, 2 keynote lectures, and 100 oral regular paper presentations. The topics include, besides the ordinary measurement techniques for multiphase flows, acoustic and electric sensors, bubbles and microbubbles, computed tomography, gas-liquid interface, laser-imaging and PIV, oil/coal/drop and spray, solid and powder, spectral and multi-physics. This volume includes the presented papers at ISMTMF-2008. In addition to this volume, ten selected papers will be published in a special issue of Measurement Science and Technology. We would like to express special thanks to all

  1. Application of the level set method for multi-phase flow computation in fusion engineering

    International Nuclear Information System (INIS)

    Luo, X-Y.; Ni, M-J.; Ying, A.; Abdou, M.

    2006-01-01

    Numerical simulation of multi-phase flow is essential to evaluate the feasibility of a liquid protection scheme for the power plant chamber. The level set method is one of the best methods for computing and analyzing the motion of interface among the multi-phase flow. This paper presents a general formula for the second-order projection method combined with the level set method to simulate unsteady incompressible multi-phase flow with/out phase change flow encountered in fusion science and engineering. The third-order ENO scheme and second-order semi-implicit Crank-Nicholson scheme is used to update the convective and diffusion term. The numerical results show this method can handle the complex deformation of the interface and the effect of liquid-vapor phase change will be included in the future work

  2. Smoothed Particle Hydrodynamics: A consistent model for interfacial multiphase fluid flow simulations

    Science.gov (United States)

    Krimi, Abdelkader; Rezoug, Mehdi; Khelladi, Sofiane; Nogueira, Xesús; Deligant, Michael; Ramírez, Luis

    2018-04-01

    In this work, a consistent Smoothed Particle Hydrodynamics (SPH) model to deal with interfacial multiphase fluid flows simulation is proposed. A modification to the Continuum Stress Surface formulation (CSS) [1] to enhance the stability near the fluid interface is developed in the framework of the SPH method. A non-conservative first-order consistency operator is used to compute the divergence of stress surface tensor. This formulation benefits of all the advantages of the one proposed by Adami et al. [2] and, in addition, it can be applied to more than two phases fluid flow simulations. Moreover, the generalized wall boundary conditions [3] are modified in order to be well adapted to multiphase fluid flows with different density and viscosity. In order to allow the application of this technique to wall-bounded multiphase flows, a modification of generalized wall boundary conditions is presented here for using the SPH method. In this work we also present a particle redistribution strategy as an extension of the damping technique presented in [3] to smooth the initial transient phase of gravitational multiphase fluid flow simulations. Several computational tests are investigated to show the accuracy, convergence and applicability of the proposed SPH interfacial multiphase model.

  3. Numerical Simulation of the Multiphase Flow in the Rheinsahl-Heraeus (RH) System

    Science.gov (United States)

    Geng, Dian-Qiao; Lei, Hong; He, Ji-Cheng

    2010-02-01

    Knowledge of gas-liquid multiphase flow behavior in the Rheinsahl-Heraeus (RH) system is of great significance to clarify the circulation flow rate, decarburization, and inclusion removal with a reliable description. Thus, based on the separate model of injecting gas behavior, a novel mathematical model of multiphase flow has been developed to give the distribution of gas holdup in the RH system. The numerical results show that the predicted circulation flow rates, the predicted flow velocities, and the predicted mixing times agree with the measured results in a water model and that the predicted tracer concentration curve agrees with the results obtained in an actual RH system. With a lower lifting gas flow rate, the rising gas bubbles are concentrated near the wall; with a higher lifting gas flow rate, gas bubbles can reach the center of the up-snorkel. A critical lifting gas flow rate is used to obtain the maximum circulation flow rate.

  4. Multi-phase flow modeling of soil contamination and soil remediation

    NARCIS (Netherlands)

    Dijke, van M.I.J.

    1997-01-01


    In this thesis multi-phase flow models are used to study the flow behavior of liquid contaminants in aquifers and of gases that are injected below the groundwater table for remediation purposes. Considered problems are redistribution of a lens of light nonaqueous phase

  5. Paradigm for Subgrid Scale Closure Modeling in Multiphase Geophysical Flows

    Science.gov (United States)

    Calantoni, J.; Simeonov, J.; Penko, A. M.; Bateman, S. P.; Palmsten, M. L.; Holland, K.

    2012-12-01

    We present a new paradigm for modeling multiphase geophysical flows to produce highly accurate and highly efficient forecasting of the complexity of the natural environment across the full range of relevant length and time scales. The assumption that computing technology will never allow us to perform direct numerical simulations (DNS) of the natural environment often limits our ambition in forward thinking model development and produces only incremental improvements in the state-of-the-art technology. Regional and global forecasting models for earth, ocean, and atmospheric processes based on averaged equations (e.g. RANS) must advance beyond simple closures relations obtained for single-phase fluid turbulence (e.g., k-epsilon, k-omega, and Mellor-Yamada). We propose using a hierarchy of computationally intensive, high fidelity simulations to resolve subgrid processes across a range of cascading length and time scales in the model domain to generate numerical interpolations for the unresolved physical processes. Further, we believe that it is possible to use the cumulative results of these subgrid scale simulations to develop a Bayesian network, for example, which may eventually replace the computationally intensive simulations with a highly efficient probabilistic closure model for the unresolved physical processes. The success of our approach will be greatly enhanced through rigorous validation of our subgrid scale models using three-dimensional laboratory and field measurements of fluid-particle turbulence at the scales of interest. Recent advances in optical imaging techniques have made it possible to make highly resolved three-dimensional measurements of fluid-particle turbulent interactions in the laboratory with spatial and temporal resolutions at or near the Kolmogorov scales. Additional work must be done to transition these technologies for use in the field. As a pilot test case we introduce our new paradigm using a hierarchy of models we have developed

  6. Using a multiphase flow code to model the coupled effects of repository consolidation and multiphase brine and gas flow at the Waste Isolation Pilot Plant

    International Nuclear Information System (INIS)

    Freeze, G.A.; Larson, K.W.; Davies, P.B.; Webb, S.W.

    1995-01-01

    Long-term repository assessment must consider the processes of (1) gas generation, (2) room closure and expansions due to salt creep, and (3) multiphase (brine and gas) fluid flow, as well as the complex coupling between these three processes. The mechanical creep closure code SANCHO was used to simulate the closure of a single, perfectly sealed disposal room filled with water and backfill. SANCHO uses constitutive models to describe salt creep, waste consolidation, and backfill consolidation, Five different gas-generation rate histories were simulated, differentiated by a rate multiplier, f, which ranged from 0.0 (no gas generation) to 1.0 (expected gas generation under brine-dominated conditions). The results of the SANCHO f-series simulations provide a relationship between gas generation, room closure, and room pressure for a perfectly sealed room. Several methods for coupling this relationship with multiphase fluid flow into and out of a room were examined. Two of the methods are described

  7. SITA version 0. A simulation and code testing assistant for TOUGH2 and MARNIE

    Energy Technology Data Exchange (ETDEWEB)

    Seher, Holger; Navarro, Martin

    2016-06-15

    High quality standards have to be met by those numerical codes that are applied in long-term safety assessments for deep geological repositories for radioactive waste. The software environment SITA (''a simulation and code testing assistant for TOUGH2 and MARNIE'') has been developed by GRS in order to perform automated regression testing for the flow and transport simulators TOUGH2 and MARNIE. GRS uses the codes TOUGH2 and MARNIE in order to assess the performance of deep geological repositories for radioactive waste. With SITA, simulation results of TOUGH2 and MARNIE can be compared to analytical solutions and simulations results of other code versions. SITA uses data interfaces to operate with codes whose input and output depends on the code version. The present report is part of a wider GRS programme to assure and improve the quality of TOUGH2 and MARNIE. It addresses users as well as administrators of SITA.

  8. Progress in the Development of Compressible, Multiphase Flow Modeling Capability for Nuclear Reactor Flow Applications

    Energy Technology Data Exchange (ETDEWEB)

    R. A. Berry; R. Saurel; F. Petitpas; E. Daniel; O. Le Metayer; S. Gavrilyuk; N. Dovetta

    2008-10-01

    In nuclear reactor safety and optimization there are key issues that rely on in-depth understanding of basic two-phase flow phenomena with heat and mass transfer. Within the context of multiphase flows, two bubble-dynamic phenomena – boiling (heterogeneous) and flashing or cavitation (homogeneous boiling), with bubble collapse, are technologically very important to nuclear reactor systems. The main difference between boiling and flashing is that bubble growth (and collapse) in boiling is inhibited by limitations on the heat transfer at the interface, whereas bubble growth (and collapse) in flashing is limited primarily by inertial effects in the surrounding liquid. The flashing process tends to be far more explosive (and implosive), and is more violent and damaging (at least in the near term) than the bubble dynamics of boiling. However, other problematic phenomena, such as crud deposition, appear to be intimately connecting with the boiling process. In reality, these two processes share many details.

  9. Technical Report on NETL's Non Newtonian Multiphase Slurry Workshop: A path forward to understanding non-Newtonian multiphase slurry flows

    Energy Technology Data Exchange (ETDEWEB)

    Guenther, Chris [National Energy Technology Lab. (NETL), Morgantown, WV (United States); Garg, Rahul [National Energy Technology Lab. (NETL), Morgantown, WV (United States)

    2013-08-19

    The Department of Energy’s (DOE) National Energy Technology Laboratory (NETL) sponsored a workshop on non-Newtonian multiphase slurry at NETL’s Morgantown campus August 19 and 20, 2013. The objective of this special two-day meeting of 20-30 invited experts from industry, National Labs and academia was to identify and address technical issues associated with handling non-Newtonian multiphase slurries across various facilities managed by DOE. Particular emphasis during this workshop was placed on applications managed by the Office of Environmental Management (EM). The workshop was preceded by two webinars wherein personnel from ORP and NETL provided background information on the Hanford WTP project and discussed the critical design challenges facing this project. In non-Newtonian fluids, viscosity is not constant and exhibits a complex dependence on applied shear stress or deformation. Many applications under EM’s tank farm mission involve non-Newtonian slurries that are multiphase in nature; tank farm storage and handling, slurry transport, and mixing all involve multiphase flow dynamics, which require an improved understanding of the mechanisms responsible for rheological changes in non-Newtonian multiphase slurries (NNMS). To discuss the issues in predicting the behavior of NNMS, the workshop focused on two topic areas: (1) State-of-the-art in non-Newtonian Multiphase Slurry Flow, and (2) Scaling up with Confidence and Ensuring Safe and Reliable Long-Term Operation.

  10. An experimental investigation of the multiphase flows in a photobioreactor for algae cultivation

    Science.gov (United States)

    Yang, Zifeng; Hu, Hui; Del Ninno, Matteo; Wen, Zhiyou

    2011-11-01

    Algal biomass is a promising feedstock for biofuels production, with photobioreactors being one of the major cultivation systems for algal cells. Light absorption, fluid dynamics, and algal metabolism are three key factors in determining the overall performance of a photobioreactor. The behavior of the multiphase flow (i.e., liquid phase - water, gas phase - CO2 and O2, and solid phase - algal cells) and turbulent mixing inside the reactor are the core connecting the three factors together. One of the major challenges in the optimal design of photobioreactors for algae cultivation is the lack of in-depth understanding of the characteristics of the multiphase flows and turbulent mixing. In this study, we present a comprehensive experimental study to investigate the effects of turbulent mixing in photobioreactors on the performance of a photobioreactor for algae cultivation. A high-resolution particle image velocity (PIV) system is used to achieve time-resolved, in-situ flow field measurements to quantify the turbulent mixing of the multiphase flows inside the bioreactor, while algal cultures are also grown in the same reactor with the same experimental settings. The mixing characteristics of the multiphase flow are correlated with the algal growth performance in the bioreactors to elucidate the underlying physics to explore/optimize design paradigms for the optimization of photobioreactor designs for algae cultivation.

  11. Coupled multiphase flow and closure analysis of repository response to waste-generated gas at the Waste Isolation Pilot Plant (WIPP)

    International Nuclear Information System (INIS)

    Freeze, G.A.; Larson, K.W.; Davies, P.B.

    1995-10-01

    A long-term assessment of the Waste Isolation Pilot Plant (WIPP) repository performance must consider the impact of gas generation resulting from the corrosion and microbial degradation of the emplaced waste. A multiphase fluid flow code, TOUGH2/EOS8, was adapted to model the processes of gas generation, disposal room creep closure, and multiphase (brine and gas) fluid flow, as well as the coupling between the three processes. System response to gas generation was simulated with a single, isolated disposal room surrounded by homogeneous halite containing two anhydrite interbeds, one above and one below the room. The interbeds were assumed to have flow connections to the room through high-permeability, excavation-induced fractures. System behavior was evaluated by tracking four performance measures: (1) peak room pressure; (2) maximum brine volume in the room; (3) total mass of gas expelled from the room; and (4) the maximum gas migration distance in an interbed. Baseline simulations used current best estimates of system parameters, selected through an evaluation of available data, to predict system response to gas generation under best-estimate conditions. Sensitivity simulations quantified the effects of parameter uncertainty by evaluating the change in the performance measures in response to parameter variations. In the sensitivity simulations, a single parameter value was varied to its minimum and maximum values, representative of the extreme expected values, with all other parameters held at best-estimate values. Sensitivity simulations identified the following parameters as important to gas expulsion and migration away from a disposal room: interbed porosity; interbed permeability; gas-generation potential; halite permeability; and interbed threshold pressure. Simulations also showed that the inclusion of interbed fracturing and a disturbed rock zone had a significant impact on system performance

  12. Coupled multiphase flow and closure analysis of repository response to waste-generated gas at the Waste Isolation Pilot Plant (WIPP)

    Energy Technology Data Exchange (ETDEWEB)

    Freeze, G.A.; Larson, K.W. [INTERA Inc., Austin, TX (United States); Davies, P.B. [Sandia National Laboratories, Albuquerque, NM (United States)

    1995-10-01

    A long-term assessment of the Waste Isolation Pilot Plant (WIPP) repository performance must consider the impact of gas generation resulting from the corrosion and microbial degradation of the emplaced waste. A multiphase fluid flow code, TOUGH2/EOS8, was adapted to model the processes of gas generation, disposal room creep closure, and multiphase (brine and gas) fluid flow, as well as the coupling between the three processes. System response to gas generation was simulated with a single, isolated disposal room surrounded by homogeneous halite containing two anhydrite interbeds, one above and one below the room. The interbeds were assumed to have flow connections to the room through high-permeability, excavation-induced fractures. System behavior was evaluated by tracking four performance measures: (1) peak room pressure; (2) maximum brine volume in the room; (3) total mass of gas expelled from the room; and (4) the maximum gas migration distance in an interbed. Baseline simulations used current best estimates of system parameters, selected through an evaluation of available data, to predict system response to gas generation under best-estimate conditions. Sensitivity simulations quantified the effects of parameter uncertainty by evaluating the change in the performance measures in response to parameter variations. In the sensitivity simulations, a single parameter value was varied to its minimum and maximum values, representative of the extreme expected values, with all other parameters held at best-estimate values. Sensitivity simulations identified the following parameters as important to gas expulsion and migration away from a disposal room: interbed porosity; interbed permeability; gas-generation potential; halite permeability; and interbed threshold pressure. Simulations also showed that the inclusion of interbed fracturing and a disturbed rock zone had a significant impact on system performance.

  13. Modelling multiphase flow inside the porous media of a polymer electrolyte membrane fuel cell

    DEFF Research Database (Denmark)

    Berning, Torsten; Kær, Søren Knudsen

    2011-01-01

    Transport processes inside polymer electrolyte membrane fuel cells (PEMFC’s) are highly complex and involve convective and diffusive multiphase, multispecies flow through porous media along with heat and mass transfer and electrochemical reactions in conjunction with water transport through...... emerge and be entrained into the gas stream....

  14. Towards advanced one-dimensional numerical models for multiphase flow in pipelines

    NARCIS (Netherlands)

    Van Zwieten, J.S.B.

    2013-01-01

    In this report we give an overview of models and discretisation techniques for the simulation of multiphase flow in long pipelines. Due to the size of the pipelines we focus on one-dimensional models, which are derived from three-dimensional conservation laws for mass, momentum and energy. All

  15. Some Specific CASL Requirements for Advanced Multiphase Flow Simulation of Light Water Reactors

    Energy Technology Data Exchange (ETDEWEB)

    R. A. Berry

    2010-11-01

    Because of the diversity of physical phenomena occuring in boiling, flashing, and bubble collapse, and of the length and time scales of LWR systems, it is imperative that the models have the following features: • Both vapor and liquid phases (and noncondensible phases, if present) must be treated as compressible. • Models must be mathematically and numerically well-posed. • The models methodology must be multi-scale. A fundamental derivation of the multiphase governing equation system, that should be used as a basis for advanced multiphase modeling in LWR coolant systems, is given in the Appendix using the ensemble averaging method. The remainder of this work focuses specifically on the compressible, well-posed, and multi-scale requirements of advanced simulation methods for these LWR coolant systems, because without these are the most fundamental aspects, without which widespread advancement cannot be claimed. Because of the expense of developing multiple special-purpose codes and the inherent inability to couple information from the multiple, separate length- and time-scales, efforts within CASL should be focused toward development of a multi-scale approaches to solve those multiphase flow problems relevant to LWR design and safety analysis. Efforts should be aimed at developing well-designed unified physical/mathematical and high-resolution numerical models for compressible, all-speed multiphase flows spanning: (1) Well-posed general mixture level (true multiphase) models for fast transient situations and safety analysis, (2) DNS (Direct Numerical Simulation)-like models to resolve interface level phenmena like flashing and boiling flows, and critical heat flux determination (necessarily including conjugate heat transfer), and (3) Multi-scale methods to resolve both (1) and (2) automatically, depending upon specified mesh resolution, and to couple different flow models (single-phase, multiphase with several velocities and pressures, multiphase with single

  16. EOS3nn: An iTOUGH2 module for non-Newtonian liquid and gasflow

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Yu-Shu; Finsterle, Stefan; Pruess, Karsten

    2002-08-01

    This report documents the iTOUGH2 module EOS3nn, developed for modeling two-phase isothermal flow of a non-Newtonian liquid and a non-condensible gas in multidimensional, porous and fractured geologic media. This document supplements the TOUGH2 and iTOUGH2 user s guides and is therefore not a self-contained manual. It presents information on the physical processes modeled and the mathematical and numerical methods used. Also included are two sample problems for code testing and benchmarking. Modeling scenarios and approaches are discussed to illustrate problem setup and usage of the EOS3nn module.

  17. The use of TOUGH2/iTOUGH2 in support of the Yucca Mountain Project: Successes and limitations

    International Nuclear Information System (INIS)

    Bodvarsson, G.S.; Birkholzer, J.T.; Finsterle, S.; Liu, H.H.; Rutqvist, J.; Wu, Y.S.

    2003-01-01

    The TOUGH2/iTOUGH2 family of codes is being used to analyze various processes and phenomena in the unsaturated zone at the proposed high-level nuclear waste repository at Yucca Mountain, Nevada. Various models have been developed that help quantify properties of the volcanic tuffs, water flow, seepage into drifts, and thermally driven coupled processes arising from the heat emitted by radioactive waste. These models are based on various assumptions and approximations that are generally accepted in the literature, but can give rise to different degrees of uncertainty. Some of the key approaches utilized include the continuum approximation, the van Genuchten formulation, the active fracture model, and homogeneous sublayers. These and other approximations are presented separately for the five different models considered, and the resulting levels of uncertainty are discussed

  18. Experimental and computational analysis of pressure response in a multiphase flow loop

    Science.gov (United States)

    Morshed, Munzarin; Amin, Al; Rahman, Mohammad Azizur; Imtiaz, Syed

    2016-07-01

    The characteristics of multiphase fluid flow in pipes are useful to understand fluid mechanics encountered in the oil and gas industries. In the present day oil and gas exploration is successively inducing subsea operation in the deep sea and arctic condition. During the transport of petroleum products, understanding the fluid dynamics inside the pipe network is important for flow assurance. In this case the information regarding static and dynamic pressure response, pressure loss, optimum flow rate, pipe diameter etc. are the important parameter for flow assurance. The principal aim of this research is to represents computational analysis and experimental analysis of multi-phase (L/G) in a pipe network. This computational study considers a two-phase fluid flow through a horizontal flow loop with at different Reynolds number in order to determine the pressure distribution, frictional pressure loss profiles by volume of fluid (VOF) method. However, numerical simulations are validated with the experimental data. The experiment is conducted in 76.20 mm ID transparent circular pipe using water and air in the flow loop. Static pressure transducers are used to measure local pressure response in multiphase pipeline.

  19. Is it possible to design universal multi-phase flow analyzer?

    International Nuclear Information System (INIS)

    Ivanov Kolev, N.

    2005-01-01

    Transient 3D-multiphase flows consisting of many chemical constituents in nature and technology (Figs. 1 and 2) are the common case of flows. In many technical applications we have to do with particular realization of the multi-phase flows like steady state flows, or single component flows or single phase flows etc. Engineers and scientists created hundreds of computer codes for description of more or less specific realizations of multi-phase flows. If one compares the structure of these codes one is astonished by the waste of the human resources for programming repeating model elements like equations of state, friction lows in variety of geometry, heat transfer coefficients, mathematical equation solvers, data handling procedures, graphical environment etc. It is hardly to expect, that the best solution for the specific sub-phenomenon is available in all codes. Looking in other branches of the technology like computer chips production we realize that the revolutionary idea of having common ''chips'' within complex applications is very far from its practical realization in the computational multi-phase flow dynamics. Following this line of arguments I expressed several times in my publications explicitly or implicitly the idea, that it is possible to create a universal multi-phase flow analyzer in the sense of computer architecture, that is capable to absorb the adequate multi-phase knowledge data base specified in Appendix 1. The subject of this paper is to summarize some of the main ideas, some of them already realized by this author, on the way of creating such computer code architecture, to illustrate haw they work, and to make an outlook regarding what are the challenges in the future developments. We confine deliberately our attention to the solution of the so called local volume and time averaged system of PDE's for a simple reason: Direct numerical resolution of interacting fluids is possible as demonstrated for small scales by many researchers, but for

  20. An efficient numerical approach for transient simulation of multiphase flow behavior in centrifuges

    OpenAIRE

    Hammerich, Simon; Nirschl, Hermann

    2016-01-01

    The separation process of particles and liquids in centrifuge is a widely used operation in industry. In spite of the long term usage of centrifuges, the knowledge for a detailed characterization of the interaction of the macroscopic processes due the separation is lacking. Reason for this is the complex multiphase flow and the sediment built-up within the machines. The sediment shape influences the flow behavior. The shape is dependent of the rheological behavior of the sediment. Computation...

  1. Lattice-gas models for multiphase flows and magnetohydrodynamics

    International Nuclear Information System (INIS)

    Chen, H.; Chen, S.; Doolen, G.D.; Matthaeus, W.H.

    1990-01-01

    Lattice-gas automata are many-body dynamical systems described by discrete space and time variables. The microscopic state of such a system is completely specified by a few integer quantities at each lattice site. The system is updated according to the dynamics of the lattice-gas particles, which are usually determined only by local information. The first lattice-gas model was introduced by Frisch, Hasslacher, and Pomeau (FHP). The FHP model simulates fluid behavior and, in the low-Mach-number limit, obeys the incompressible Navier-Stokes equations. Since the creation of the FHP model, lattice-gas research has developed rapidly, providing not only further insight into the relation between microscopic processes and macroscopic properties but also new procedures for fast computation. Recent improvements and extensions of the FHP model have opened up brand-new fields. Already such research has had some impact on the understanding of the macroscopic properties of physics, in particular, the properties of multiple-fluid systems. Moreover, some potential industrial applications are now being explored. Lattice-gas models for single-phase fluids, multiphase fluids, and magnetohydrodynamic fluids are briefly described. 22 refs., 2 figs

  2. Non-isothermal effects on multi-phase flow in porous medium

    DEFF Research Database (Denmark)

    Singh, Ashok; Wang, W; Park, C. H.

    2010-01-01

    In this paper a ppT -formulation for non-isothermal multi-phase flow is given including diffusion and latent heat effects. Temperature and pressure dependencies of governing parameters are considered, in particular surface tension variation on phase interfaces along with temperature changes. A we...... geotechnical areas. The classic benchmark for two-phase flow by McWhorter and Sunada1 is used as a reference case on which non-isothermal effects and non-linear material behavior are studied.......In this paper a ppT -formulation for non-isothermal multi-phase flow is given including diffusion and latent heat effects. Temperature and pressure dependencies of governing parameters are considered, in particular surface tension variation on phase interfaces along with temperature changes. A weak...

  3. Nonequilibrium Physics and Phase-Field Modeling of Multiphase Flow in Porous Media

    Energy Technology Data Exchange (ETDEWEB)

    Juanes, Ruben [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

    2016-09-01

    The overarching goal of this project was to develop a new continuum theory of multiphase flow in porous media. The theory follows a phase-field modeling approach, and therefore has a sound thermodynamical basis. It is a phenomenological theory in the sense that its formulation is driven by macroscopic phenomena, such as viscous instabilities during multifluid displacement. The research agenda was organized around a set of hypothesis on hitherto unexplained behavior of multiphase flow. All these hypothesis are nontrivial, and testable. Indeed, a central aspect of the project was testing each hypothesis by means of carefully-designed laboratory experiments, therefore probing the validity of the proposed theory. The proposed research places an emphasis on the fundamentals of flow physics, but is motivated by important energy-driven applications in earth sciences, as well as microfluidic technology.

  4. Influence of the multiphase flow patterns on the transport properties

    Science.gov (United States)

    Markicevic, Bojan

    2016-11-01

    The capillary network model with the dynamic boundary condition at free interface for displacement flow in porous media is developed, in which the net flow into each pore at the free interface can be less, equal to or greater than zero. The spread of the liquid and form of the liquid flow patterns are resolved in the networks of different sizes and heterogeneity and for two types of the boundary conditions, the constant inlet pressure or constant flow rate. It has been shown that for the constant flow rate boundary condition, the pressure drop throughout the network remains constant due to the pressure increase at the inlet boundary. The constant pressure drop produces the similar flow patterns during the displacement flow, and the saturation remains constant in the flow direction. The liquid saturation in the network is varied gradually by increasing the liquid flow rate at network inlet. For each distinct flow rate, the sizes of the repeating flow pattern and corresponding pressure drop change accordingly. This implies that for sufficiently large networks in which the flow pattern is fully developed, the transport parameters do not depend on the network size. The flow pattern and transport parameters depend on the network heterogeneity, as the dynamic boundary condition changes at the free interface producing a different distribution of the liquid. A continuous development of the flow pattern is also observed for the constant inlet pressure boundary condition, where the pressure drop decreases as liquid advances into the network. Finally, a summary in changes of transport parameters, relative permeability and capillary pressure, is elaborated.

  5. Discrete fracture modeling of multiphase flow and hydrocarbon production in fractured shale or low permeability reservoirs

    Science.gov (United States)

    Hao, Y.; Settgast, R. R.; Fu, P.; Tompson, A. F. B.; Morris, J.; Ryerson, F. J.

    2016-12-01

    It has long been recognized that multiphase flow and transport in fractured porous media is very important for various subsurface applications. Hydrocarbon fluid flow and production from hydraulically fractured shale reservoirs is an important and complicated example of multiphase flow in fractured formations. The combination of horizontal drilling and hydraulic fracturing is able to create extensive fracture networks in low permeability shale rocks, leading to increased formation permeability and enhanced hydrocarbon production. However, unconventional wells experience a much faster production decline than conventional hydrocarbon recovery. Maintaining sustainable and economically viable shale gas/oil production requires additional wells and re-fracturing. Excessive fracturing fluid loss during hydraulic fracturing operations may also drive up operation costs and raise potential environmental concerns. Understanding and modeling processes that contribute to decreasing productivity and fracturing fluid loss represent a critical component for unconventional hydrocarbon recovery analysis. Towards this effort we develop a discrete fracture model (DFM) in GEOS (LLNL multi-physics computational code) to simulate multiphase flow and transfer in hydraulically fractured reservoirs. The DFM model is able to explicitly account for both individual fractures and their surrounding rocks, therefore allowing for an accurate prediction of impacts of fracture-matrix interactions on hydrocarbon production. We apply the DFM model to simulate three-phase (water, oil, and gas) flow behaviors in fractured shale rocks as a result of different hydraulic stimulation scenarios. Numerical results show that multiphase flow behaviors at the fracture-matrix interface play a major role in controlling both hydrocarbon production and fracturing fluid recovery rates. The DFM model developed in this study will be coupled with the existing hydro-fracture model to provide a fully integrated

  6. Benchmark initiative on coupled multiphase flow and geomechanical processes during CO2 injection

    Science.gov (United States)

    Benisch, K.; Annewandter, R.; Olden, P.; Mackay, E.; Bauer, S.; Geiger, S.

    2012-12-01

    CO2 injection into deep saline aquifers involves multiple strongly interacting processes such as multiphase flow and geomechanical deformation, which threat to the seal integrity of CO2 repositories. Coupled simulation codes are required to establish realistic prognoses of the coupled process during CO2 injection operations. International benchmark initiatives help to evaluate, to compare and to validate coupled simulation results. However, there is no published code comparison study so far focusing on the impact of coupled multiphase flow and geomechanics on the long-term integrity of repositories, which is required to obtain confidence in the predictive capabilities of reservoir simulators. We address this gap by proposing a benchmark study. A wide participation from academic and industrial institutions is sought, as the aim of building confidence in coupled simulators become more plausible with many participants. Most published benchmark studies on coupled multiphase flow and geomechanical processes have been performed within the field of nuclear waste disposal (e.g. the DECOVALEX project), using single-phase formulation only. As regards CO2 injection scenarios, international benchmark studies have been published comparing isothermal and non-isothermal multiphase flow processes such as the code intercomparison by LBNL, the Stuttgart Benchmark study, the CLEAN benchmark approach and other initiatives. Recently, several codes have been developed or extended to simulate the coupling of hydraulic and geomechanical processes (OpenGeoSys, ELIPSE-Visage, GEM, DuMuX and others), which now enables a comprehensive code comparison. We propose four benchmark tests of increasing complexity, addressing the coupling between multiphase flow and geomechanical processes during CO2 injection. In the first case, a horizontal non-faulted 2D model consisting of one reservoir and one cap rock is considered, focusing on stress and strain regime changes in the storage formation and the

  7. The application of single particle hydrodynamics in continuum models of multiphase flow

    Science.gov (United States)

    Decker, Rand

    1988-01-01

    A review of the application of single particle hydrodynamics in models for the exchange of interphase momentum in continuum models of multiphase flow is presented. Considered are the equations of motion for a laminar, mechanical two phase flow. Inherent to this theory is a model for the interphase exchange of momentum due to drag between the dispersed particulate and continuous fluid phases. In addition, applications of two phase flow theory to de-mixing flows require the modeling of interphase momentum exchange due to lift forces. The applications of single particle analysis in deriving models for drag and lift are examined.

  8. Laboratory setup and results of experiments on two-dimensional multiphase flow in porous media

    International Nuclear Information System (INIS)

    McBride, J.F.; Graham, D.N.

    1990-10-01

    In the event of an accidental release into earth's subsurface of an immiscible organic liquid, such as a petroleum hydrocarbon or chlorinated organic solvent, the spatial and temporal distribution of the organic liquid is of great interest when considering efforts to prevent groundwater contamination or restore contaminated groundwater. An accurate prediction of immiscible organic liquid migration requires the incorporation of relevant physical principles in models of multiphase flow in porous media; these physical principles must be determined from physical experiments. This report presents a series of such experiments performed during the 1970s at the Swiss Federal Institute of Technology (ETH) in Zurich, Switzerland. The experiments were designed to study the transient, two-dimensional displacement of three immiscible fluids in a porous medium. This experimental study appears to be the most detailed published to date. The data obtained from these experiments are suitable for the validation and test calibration of multiphase flow codes. 73 refs., 140 figs

  9. Laboratory setup and results of experiments on two-dimensional multiphase flow in porous media

    Energy Technology Data Exchange (ETDEWEB)

    McBride, J.F. (ed.) (Pacific Northwest Lab., Richland, WA (USA)); Graham, D.N. (ed.); Schiegg, H.O. (SIMULTEC Ltd., Meilen/Zurich (Switzerland))

    1990-10-01

    In the event of an accidental release into earth's subsurface of an immiscible organic liquid, such as a petroleum hydrocarbon or chlorinated organic solvent, the spatial and temporal distribution of the organic liquid is of great interest when considering efforts to prevent groundwater contamination or restore contaminated groundwater. An accurate prediction of immiscible organic liquid migration requires the incorporation of relevant physical principles in models of multiphase flow in porous media; these physical principles must be determined from physical experiments. This report presents a series of such experiments performed during the 1970s at the Swiss Federal Institute of Technology (ETH) in Zurich, Switzerland. The experiments were designed to study the transient, two-dimensional displacement of three immiscible fluids in a porous medium. This experimental study appears to be the most detailed published to date. The data obtained from these experiments are suitable for the validation and test calibration of multiphase flow codes. 73 refs., 140 figs.

  10. Microgravity Multi-Phase Flow Experiment for Suborbital Testing (MFEST)

    Data.gov (United States)

    National Aeronautics and Space Administration — The primary objective is to conduct a pathfinder, suborbital flight experiment for two-phase fluid flow and separator operations.The primary purpose of this test...

  11. THE WORK SIMULATION OF FLOW RATE FOR CARRIAGES' REPAIR AS A MULTIPHASE, MULTIPLEX AND MULTIDISCIPLINARY SYSTEM OF MASS SERVICE

    Directory of Open Access Journals (Sweden)

    V. V. Myamlin

    2011-04-01

    Full Text Available The algorithm of computer simulation of the flexible flow for repair of cars as a multiphase polychannel manyobject queuing system is presented. The basic operators of the model are given and their work is described.

  12. Development of an Efficient Meso- scale Multi-phase Flow Solver in Nuclear Applications

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Taehun [City Univ. (CUNY), NY (United States)

    2015-10-20

    The proposed research aims at formulating a predictive high-order Lattice Boltzmann Equation for multi-phase flows relevant to nuclear energy related application - namely, saturated and sub-cooled boiling in reactors, and liquid- liquid mixing and extraction for fuel cycle separation. An efficient flow solver will be developed based on the Finite Element based Lattice Boltzmann Method (FE- LBM), accounting for phase-change heat transfer and capable of treating multiple phases over length scales from the submicron to the meter. A thermal LBM will be developed in order to handle adjustable Prandtl number, arbitrary specific heat ratio, a wide range of temperature variations, better numerical stability during liquid-vapor phase change, and full thermo-hydrodynamic consistency. Two-phase FE-LBM will be extended to liquid–liquid–gas multi-phase flows for application to high-fidelity simulations building up from the meso-scale up to the equipment sub-component scale. While several relevant applications exist, the initial applications for demonstration of the efficient methods to be developed as part of this project include numerical investigations of Critical Heat Flux (CHF) phenomena in nuclear reactor fuel bundles, and liquid-liquid mixing and interfacial area generation for liquid-liquid separations. In addition, targeted experiments will be conducted for validation of this advanced multi-phase model.

  13. Smoothed Particle Hydrodynamics model for multiphase flow in porous media

    Energy Technology Data Exchange (ETDEWEB)

    Tartakovsky, Alexandre M.; Meakin, Paul; Ward, Anderson L.

    2007-07-07

    A numerical model based on smoothed particle hydrodynamics (SPH) was used to simulate pore-scale liquid and gas flow in synthetic two-dimensional porous media consisting of non-overlapping grains. The model was used to study effects of pore scale heterogeneity and anisotropy on relationship between the average saturation and the Bond number. The effect of the wetting fluid properties on drainage was also investigated. It is shown that pore-scale heterogeneity and anisotropy can cause saturation/Bond number and entry (bubbling) pressures to be dependent on the flow direction suggesting that these properties should be described by tensor rather than scalar quantities.

  14. Surface Tension of Multi-phase Flow with Multiple Junctions Governed by the Variational Principle

    International Nuclear Information System (INIS)

    Matsutani, Shigeki; Nakano, Kota; Shinjo, Katsuhiko

    2011-01-01

    We explore a computational model of an incompressible fluid with a multi-phase field in three-dimensional Euclidean space. By investigating an incompressible fluid with a two-phase field geometrically, we reformulate the expression of the surface tension for the two-phase field found by Lafaurie et al. (J Comput Phys 113:134–147, 1994) as a variational problem related to an infinite dimensional Lie group, the volume-preserving diffeomorphism. The variational principle to the action integral with the surface energy reproduces their Euler equation of the two-phase field with the surface tension. Since the surface energy of multiple interfaces even with singularities is not difficult to be evaluated in general and the variational formulation works for every action integral, the new formulation enables us to extend their expression to that of a multi-phase (N-phase, N ≥ 2) flow and to obtain a novel Euler equation with the surface tension of the multi-phase field. The obtained Euler equation governs the equation for motion of the multi-phase field with different surface tension coefficients without any difficulties for the singularities at multiple junctions. In other words, we unify the theory of multi-phase fields which express low dimensional interface geometry and the theory of the incompressible fluid dynamics on the infinite dimensional geometry as a variational problem. We apply the equation to the contact angle problems at triple junctions. We computed the fluid dynamics for a two-phase field with a wall numerically and show the numerical computational results that for given surface tension coefficients, the contact angles are generated by the surface tension as results of balances of the kinematic energy and the surface energy.

  15. Complexity Reduction of Multiphase Flows in Heterogeneous Porous Media

    KAUST Repository

    Ghommem, Mehdi

    2015-04-22

    In this paper, we apply mode decomposition and interpolatory projection methods to speed up simulations of two-phase flows in heterogeneous porous media. We propose intrusive and nonintrusive model-reduction approaches that enable a significant reduction in the size of the subsurface flow problem while capturing the behavior of the fully resolved solutions. In one approach, we use the dynamic mode decomposition. This approach does not require any modification of the reservoir simulation code but rather post-processes a set of global snapshots to identify the dynamically relevant structures associated with the flow behavior. In the second approach, we project the governing equations of the velocity and the pressure fields on the subspace spanned by their proper-orthogonal-decomposition modes. Furthermore, we use the discrete empirical interpolation method to approximate the mobility-related term in the global-system assembly and then reduce the online computational cost and make it independent of the fine grid. To show the effectiveness and usefulness of the aforementioned approaches, we consider the SPE-10 benchmark permeability field, and present a numerical example in two-phase flow. One can efficiently use the proposed model-reduction methods in the context of uncertainty quantification and production optimization.

  16. Heat and mass transfer in turbulent multiphase channel flow

    NARCIS (Netherlands)

    Bukhvostova, A.

    2015-01-01

    Direct numerical simulation is used to assess the importance of compressibility in turbulent channel flow of a mixture of air and water vapor with dispersed water droplets. The dispersed phase is allowed to undergo phase transition, which leads to heat and mass transfer between the phases. We

  17. Stochastic Rotation Dynamics simulations of wetting multi-phase flows

    Science.gov (United States)

    Hiller, Thomas; Sanchez de La Lama, Marta; Brinkmann, Martin

    2016-06-01

    Multi-color Stochastic Rotation Dynamics (SRDmc) has been introduced by Inoue et al. [1,2] as a particle based simulation method to study the flow of emulsion droplets in non-wetting microchannels. In this work, we extend the multi-color method to also account for different wetting conditions. This is achieved by assigning the color information not only to fluid particles but also to virtual wall particles that are required to enforce proper no-slip boundary conditions. To extend the scope of the original SRDmc algorithm to e.g. immiscible two-phase flow with viscosity contrast we implement an angular momentum conserving scheme (SRD+mc). We perform extensive benchmark simulations to show that a mono-phase SRDmc fluid exhibits bulk properties identical to a standard SRD fluid and that SRDmc fluids are applicable to a wide range of immiscible two-phase flows. To quantify the adhesion of a SRD+mc fluid in contact to the walls we measure the apparent contact angle from sessile droplets in mechanical equilibrium. For a further verification of our wettability implementation we compare the dewetting of a liquid film from a wetting stripe to experimental and numerical studies of interfacial morphologies on chemically structured surfaces.

  18. Analysis of multiphase flows using dual-energy gamma densitometry and neural networks

    International Nuclear Information System (INIS)

    Bishop, C.M.; James, G.D.

    1993-01-01

    Dual-energy gamma densitometry offers a powerful technique for the non-intrusive analysis of multiphase flows. By employing multiple beam lines, information on the phase configuration can be obtained. Once the configuration is known, it then becomes possible in principle to determine the phase fractions. In practice, however, the extraction of the phase fractions from the densitometer data is complicated by the wide variety of phase configurations which can arise, and by the considerable difficulties of modelling multiphase flows. In this paper we show that neural network techniques provide a powerful approach to the analysis of data from dual-energy gamma densitometers, allowing both the phase configuration and the phase fractions to be determined with high accuracy, whilst avoiding the uncertainties associated with modelling. The technique is well suited to the determination of oil, water and gas fractions in multiphase oil pipelines. Results from linear and non-linear network models are compared, and a new technique for validating the network output is described. (orig.)

  19. Load-Flow in Multiphase Distribution Networks: Existence, Uniqueness, Non-Singularity, and Linear Models

    Energy Technology Data Exchange (ETDEWEB)

    Bernstein, Andrey [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Dall-Anese, Emiliano [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Zhao, Changhong [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Wang, Cong [Ecole Polytechnique Federale de Lausanne (EPFL); Le Boudec, Jean-Yves [Ecole Polytechnique Federale de Lausanne (EPFL)

    2018-04-06

    This paper considers unbalanced multiphase distribution systems with generic topology and different load models, and extends the Z-bus iterative load-flow algorithm based on a fixed-point interpretation of the AC load-flow equations. Explicit conditions for existence and uniqueness of load-flow solutions are presented. These conditions also guarantee convergence of the load-flow algorithm to the unique solution. The proposed methodology is applicable to generic systems featuring (i) wye connections; (ii) ungrounded delta connections; (iii) a combination of wye-connected and delta-connected sources/loads; and, (iv) a combination of line-to-line and line-to-grounded-neutral devices at the secondary of distribution transformers. Further, a sufficient condition for the non-singularity of the load-flow Jacobian is proposed. Finally, linear load-flow models are derived, and their approximation accuracy is analyzed. Theoretical results are corroborated through experiments on IEEE test feeders.

  20. Multiphase flow problems on thermofluid safety for fusion reactors

    International Nuclear Information System (INIS)

    Takase, Kazuyuki

    2003-01-01

    As the thermofluid safety study for the International Thermonuclear Experimental Reactor (ITER), thermal-hydraulic characteristics of Tokamak fusion reactors under transient events were investigated experimentally and analyzed numerically. As severe transient events an ingress-of-coolant event (ICE) and a loss-of-vacuum event (LOVA) were considered. An integrated ICE test facility was constructed to demonstrate that the ITER safety design approach and parameters are adequate. Water-vapor two-phase flow behavior and performance of the ITER pressure suppression system during the ICE were clarified by the integrated ICE experiments. The TRAC was modified to specify the two-phase flow behavior under the ICE. The ICE experimental results were verified using the modified TRAC code. On the other hand, activated dust mobilization and air ingress characteristics in the ITER vacuum vessel during the LOVA were analyzed using a newly developed analysis code. Some physical models on the motion of dust were considered. The rate of dust released from the vacuum vessel through breaches to the outside was characterized quantitatively. The predicted average pressures in the vacuum vessel during the LOVA were in good agreement with the experimental results. Moreover, direct-contact condensation characteristics between water and vapor inside the ITER suppression tank were observed visually and simulated by the direct two-phase flow analysis. Furthermore, chemical reaction characteristics between vapor and ITER plasma-facing component materials were predicted numerically in order to obtain qualitative estimation on generation of inflammable gases such as hydrogen and methane. The experimental and numerical results of the present studies were reflected in the ITER thermofluid safety design. (author)

  1. Research on Underwater Vehicle Based on Multiphase Flow Control

    Directory of Open Access Journals (Sweden)

    Zhang Xiaoshi

    2015-01-01

    Full Text Available The commercial software ANSYS CFX is used for modeling the hydrodynamic characteristics of submarine-launched vehicle. In the numerical simulations, the SST (Shear Stress Transport turbulence model is employed to describe the turbulence phenomenon occurring in the continuous fluid. The Rayleigh-Plesset equations are applied to analyze the cavitation phenomenon. Three-dimensional numerical simulation was carried out to study the cavity shape, the surface pressure distribution and the drag force with different flow control. The result shows that the gas and the number of ventilation holes control to show any significant impact on the cavity shape and the surface pressure are effective measures to decrease resistance.

  2. Mathematical modelling of ultrasound propagation in multi-phase flow

    DEFF Research Database (Denmark)

    Simurda, Matej

    violates the repeatability of the measurements and thus impairs the device accuracy. Development of new flow meter designs for these conditions based on a purely experimental approach is expensive both in terms of time and economy. An attractive alternative is the employment of a mathematical model...... is further extended by mesh adaptation techniques to accurately resolve acoustic scattering in complex geometries. The presented numerical model is, to the best of the author's knowledge, the only pseudospectral model available in the open literature that solves propagation of acoustic waves in moving...

  3. Modeling the multiphase flows in deformable porous media

    Directory of Open Access Journals (Sweden)

    Perepechko Lyudmila

    2017-01-01

    Full Text Available This work proposes the nonlinear model for the flow of mixture of compressible liquids in a porous medium with consideration of finite deformations and thermal effects. Development of this model is based on the method of thermodynamically consistent systems of conservation laws. Numerical analysis of the model is based on the WENO-Runge-Kutta method of the high accuracy. The model is developed to solve the problems arising when studying the different-scale fluid dynamic processes. Evolution of the wave fields in inhomogeneous saturated porous media is considered.

  4. Modeling studies of multiphase fluid and heat flow processes in nuclear waste isolation

    International Nuclear Information System (INIS)

    Pruess, K.

    1989-01-01

    Multiphase fluid and heat flow plays an important role in many problems relating to the disposal of nuclear wastes in geologic media. Examples include boiling and condensation processes near heat-generating wastes, flow of water and formation gas in partially saturated formations, evolution of a free gas phase from waste package corrosion in initially water-saturated environments, and redistribution (dissolution, transport and precipitation) of rock minerals in non-isothermal flow fields. Such processes may strongly impact upon waste package and repository design considerations and performance. This paper summarizes important physical phenomena occurring in multiphase and nonisothermal flows, as well as techniques for their mathematical modeling and numerical simulation. Illustrative applications are given for a number of specific fluid and heat flow problems, including: thermohydrologic conditions near heat-generating waste packages in the unsaturated zone; repositorywide convection effects in the unsaturated zone; effects of quartz dissolution and precipitation for disposal in the saturated zone; and gas pressurization and flow effects from corrosion of low-level waste packages

  5. Modeling studies for multiphase fluid and heat flow processes in nuclear waste isolation

    International Nuclear Information System (INIS)

    Pruess, K.

    1988-07-01

    Multiphase fluid and heat flow plays an important role in many problems relating to the disposal of nuclear wastes in geologic media. Examples include boiling and condensation processes near heat-generating wastes, flow of water and formation gas in partially saturated formations, evolution of a free gas phase from waste package corrosion in initially water-saturated environments, and redistribution (dissolution, transport, and precipitation) of rock minerals in non-isothermal flow fields. Such processes may strongly impact upon waste package and repository design considerations and performance. This paper summarizes important physical phenomena occurring in multiphase and nonisothermal flows, as well as techniques for their mathematical modeling and numerical simulation. Illustrative applications are given for a number of specific fluid and heat flow problems, including: thermohydrologic conditions near heat-generating waste packages in the unsaturated zone; repository-wide convection effects in the unsaturated zone; effects of quartz dissolution and precipitation for disposal in the saturated zone; and gas pressurization and flow corrosion of low-level waste packages. 34 refs; 7 figs; 2 tabs

  6. Massively parallel simulations of multiphase flows using Lattice Boltzmann methods

    Science.gov (United States)

    Ahrenholz, Benjamin

    2010-03-01

    In the last two decades the lattice Boltzmann method (LBM) has matured as an alternative and efficient numerical scheme for the simulation of fluid flows and transport problems. Unlike conventional numerical schemes based on discretizations of macroscopic continuum equations, the LBM is based on microscopic models and mesoscopic kinetic equations. The fundamental idea of the LBM is to construct simplified kinetic models that incorporate the essential physics of microscopic or mesoscopic processes so that the macroscopic averaged properties obey the desired macroscopic equations. Especially applications involving interfacial dynamics, complex and/or changing boundaries and complicated constitutive relationships which can be derived from a microscopic picture are suitable for the LBM. In this talk a modified and optimized version of a Gunstensen color model is presented to describe the dynamics of the fluid/fluid interface where the flow field is based on a multi-relaxation-time model. Based on that modeling approach validation studies of contact line motion are shown. Due to the fact that the LB method generally needs only nearest neighbor information, the algorithm is an ideal candidate for parallelization. Hence, it is possible to perform efficient simulations in complex geometries at a large scale by massively parallel computations. Here, the results of drainage and imbibition (Degree of Freedom > 2E11) in natural porous media gained from microtomography methods are presented. Those fully resolved pore scale simulations are essential for a better understanding of the physical processes in porous media and therefore important for the determination of constitutive relationships.

  7. Supercomputing with TOUGH2 family codes for coupled multi-physics simulations of geologic carbon sequestration

    Science.gov (United States)

    Yamamoto, H.; Nakajima, K.; Zhang, K.; Nanai, S.

    2015-12-01

    Powerful numerical codes that are capable of modeling complex coupled processes of physics and chemistry have been developed for predicting the fate of CO2 in reservoirs as well as its potential impacts on groundwater and subsurface environments. However, they are often computationally demanding for solving highly non-linear models in sufficient spatial and temporal resolutions. Geological heterogeneity and uncertainties further increase the challenges in modeling works. Two-phase flow simulations in heterogeneous media usually require much longer computational time than that in homogeneous media. Uncertainties in reservoir properties may necessitate stochastic simulations with multiple realizations. Recently, massively parallel supercomputers with more than thousands of processors become available in scientific and engineering communities. Such supercomputers may attract attentions from geoscientist and reservoir engineers for solving the large and non-linear models in higher resolutions within a reasonable time. However, for making it a useful tool, it is essential to tackle several practical obstacles to utilize large number of processors effectively for general-purpose reservoir simulators. We have implemented massively-parallel versions of two TOUGH2 family codes (a multi-phase flow simulator TOUGH2 and a chemically reactive transport simulator TOUGHREACT) on two different types (vector- and scalar-type) of supercomputers with a thousand to tens of thousands of processors. After completing implementation and extensive tune-up on the supercomputers, the computational performance was measured for three simulations with multi-million grid models, including a simulation of the dissolution-diffusion-convection process that requires high spatial and temporal resolutions to simulate the growth of small convective fingers of CO2-dissolved water to larger ones in a reservoir scale. The performance measurement confirmed that the both simulators exhibit excellent

  8. Viscosity and surface tension effects during multiphase flow in propped fractures

    Science.gov (United States)

    Dzikowski, Michał; Dąbrowski, Marcin

    2017-04-01

    Geological sequestration of CO2 was proposed as an important mechanism to reduce its emission into atmosphere. CO2 exhibits a higher affinity to organic matter than methane molecules and, potentially, it could be pumped and stored in shale reservoirs while enhancing late stage shale gas production. A successful analysis of CO2 sequestration in low matrix permeability rocks such as shales requires a thorough understanding of multiphase flow in stimulated rock fractures, which provide most significant pathways for fluids in such systems. Multiphase fracture flows are also of great relevance to brine, oil and gas migration in petroleum systems, water and stream circulation in geothermal reservoirs, and chemical transport of non-aqueous phase liquids in shallow hydrogeological systems, particularly in partially saturated zones. There are various physical models that describe phenomena taking place during multiphase flow through porous media. One of key aspects that need to be considered are pore-scale effects related to capillarity. Unfortunately, detailed models that describe motion and evolution of phase or component boundary require direct numerical simulations and spatial resolutions that are hard to reach when considering industrial relevant systems. Main aim of the presented work was the development of reduced 2.5D models based on Brinkman approximation of thin domain flow that would be able to capture local scale phenomena without expensive 3D simulations. Presented approach was designed specifically to tackle incompressible and immiscible systems and is based on Continuous Surface Force approach presented by Brackbill et al., implemented using Lattice Boltzmann Method. Presented approach where firstly validated against standard test cases with known classical solution and known experimental data. In the second part, we present and discuss two component, immiscible permeability data for rough and propped fracture obtained with our code for a rage of proppants

  9. Complementary Constrains on Component based Multiphase Flow Problems, Should It Be Implemented Locally or Globally?

    Science.gov (United States)

    Shao, H.; Huang, Y.; Kolditz, O.

    2015-12-01

    Multiphase flow problems are numerically difficult to solve, as it often contains nonlinear Phase transition phenomena A conventional technique is to introduce the complementarity constraints where fluid properties such as liquid saturations are confined within a physically reasonable range. Based on such constraints, the mathematical model can be reformulated into a system of nonlinear partial differential equations coupled with variational inequalities. They can be then numerically handled by optimization algorithms. In this work, two different approaches utilizing the complementarity constraints based on persistent primary variables formulation[4] are implemented and investigated. The first approach proposed by Marchand et.al[1] is using "local complementary constraints", i.e. coupling the constraints with the local constitutive equations. The second approach[2],[3] , namely the "global complementary constrains", applies the constraints globally with the mass conservation equation. We will discuss how these two approaches are applied to solve non-isothermal componential multiphase flow problem with the phase change phenomenon. Several benchmarks will be presented for investigating the overall numerical performance of different approaches. The advantages and disadvantages of different models will also be concluded. References[1] E.Marchand, T.Mueller and P.Knabner. Fully coupled generalized hybrid-mixed finite element approximation of two-phase two-component flow in porous media. Part I: formulation and properties of the mathematical model, Computational Geosciences 17(2): 431-442, (2013). [2] A. Lauser, C. Hager, R. Helmig, B. Wohlmuth. A new approach for phase transitions in miscible multi-phase flow in porous media. Water Resour., 34,(2011), 957-966. [3] J. Jaffré, and A. Sboui. Henry's Law and Gas Phase Disappearance. Transp. Porous Media. 82, (2010), 521-526. [4] A. Bourgeat, M. Jurak and F. Smaï. Two-phase partially miscible flow and transport modeling in

  10. The Pore-scale modeling of multiphase flows in reservoir rocks using the lattice Boltzmann method

    Science.gov (United States)

    Mu, Y.; Baldwin, C. H.; Toelke, J.; Grader, A.

    2011-12-01

    Digital rock physics (DRP) is a new technology to compute the physical and fluid flow properties of reservoir rocks. In this approach, pore scale images of the porous rock are obtained and processed to create highly accurate 3D digital rock sample, and then the rock properties are evaluated by advanced numerical methods at the pore scale. Ingrain's DRP technology is a breakthrough for oil and gas companies that need large volumes of accurate results faster than the current special core analysis (SCAL) laboratories can normally deliver. In this work, we compute the multiphase fluid flow properties of 3D digital rocks using D3Q19 immiscible LBM with two relaxation times (TRT). For efficient implementation on GPU, we improved and reformulated color-gradient model proposed by Gunstensen and Rothmann. Furthermore, we only use one-lattice with the sparse data structure: only allocate memory for pore nodes on GPU. We achieved more than 100 million fluid lattice updates per second (MFLUPS) for two-phase LBM on single Fermi-GPU and high parallel efficiency on Multi-GPUs. We present and discuss our simulation results of important two-phase fluid flow properties, such as capillary pressure and relative permeabilities. We also investigate the effects of resolution and wettability on multiphase flows. Comparison of direct measurement results with the LBM-based simulations shows practical ability of DRP to predict two-phase flow properties of reservoir rock.

  11. Optimal Power Flow in Multiphase Radial Networks with Delta Connections: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Changhong [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Dall-Anese, Emiliano [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Low, Steven H. [California Institute of Technology

    2017-11-27

    This paper focuses on multiphase radial distribution networks with mixed wye and delta connections, and proposes a semidefinite relaxation of the AC optimal power flow (OPF) problem. Two multiphase power-flow models are developed to facilitate the integration of delta-connected generation units/loads in the OPF problem. The first model extends traditional branch flow models - and it is referred to as extended branch flow model (EBFM). The second model leverages a linear relationship between per-phase power injections and delta connections, which holds under a balanced voltage approximation (BVA). Based on these models, pertinent OPF problems are formulated and relaxed to semidefinite programs (SDPs). Numerical studies on IEEE test feeders show that SDP relaxations can be solved efficiently by a generic optimization solver. Numerical evidences indicate that solving the resultant SDP under BVA is faster than under EBFM. Moreover, both SDP solutions are numerically exact with respect to voltages and branch flows. It is also shown that the SDP solution under BVA has a small optimality gap, while the BVA model is accurate in the sense that it reflects actual system voltages.

  12. Examples of the Potential of DNS for the Understanding of Reactive Multiphase Flows

    Directory of Open Access Journals (Sweden)

    J. Reveillon

    2011-03-01

    Full Text Available The objective of this article is to point out the ability of the multiphase flow DNS (Direct Numerical Simulation to help to understand basic physics and to interpret some experimental observations. To illustrate the DNS' potential to give access to key phenomena involved in reactive multiphase flows, several recent results obtained by the authors are summed up with a bridge to experimental results. It includes droplet dispersion, laminar spray flame instability, spray combustion regimes or acoustic modulation effect on a two-phase flow Bunsen burner. As a perspective, two-phase flow DNS auto-ignition is considered thanks to a skeletal mechanism for the n-heptane chemistry involving 29 species and 52 reactions. Results highlight evaporating droplet effects on the auto-ignition process that is generally dramatically modified by spray distribution resulting from the turbulent fluid motion. This paper shows that DNS is a powerful tool to understand the intricate coupling between the evaporating spray, the turbulent fluid motion and the detailed chemistry, inseparable in the experimental context.

  13. An open-source toolbox for multiphase flow in porous media

    Science.gov (United States)

    Horgue, P.; Soulaine, C.; Franc, J.; Guibert, R.; Debenest, G.

    2015-02-01

    Multiphase flow in porous media provides a wide range of applications: from the environmental understanding (aquifer, site-pollution) to industrial process improvements (oil production, waste management). Modeling of such flows involves specific volume-averaged equations and therefore specific computational fluid dynamics (CFD) tools. In this work, we develop a toolbox for modeling multiphase flow in porous media with OpenFOAM®, an open-source platform for CFD. The underlying idea of this approach is to provide an easily adaptable tool that can be used in further studies to test new mathematical models or numerical methods. The package provides the most common effective properties models of the literature (relative permeability, capillary pressure) and specific boundary conditions related to porous media flows. To validate this package, solvers based on the IMplicit Pressure Explicit Saturation (IMPES) method are developed in the toolbox. The numerical validation is performed by comparison with analytical solutions on academic cases. Then, a satisfactory parallel efficiency of the solver is shown on a more complex configuration.

  14. Investigation of Multiscale and Multiphase Flow, Transport and Reaction in Heavy Oil Recovery Processes

    Energy Technology Data Exchange (ETDEWEB)

    Yortsos, Y.C.

    2001-05-29

    This report is an investigation of various multi-phase and multiscale transport and reaction processes associated with heavy oil recovery. The thrust areas of the project include the following: Internal drives, vapor-liquid flows, combustion and reaction processes, fluid displacements and the effect of instabilities and heterogeneities and the flow of fluids with yield stress. These find respective applications in foamy oils, the evolution of dissolved gas, internal steam drives, the mechanics of concurrent and countercurrent vapor-liquid flows, associated with thermal methods and steam injection, such as SAGD, the in-situ combustion, the upscaling of displacements in heterogeneous media and the flow of foams, Bingham plastics and heavy oils in porous media and the development of wormholes during cold production.

  15. Lagrangian evolution of deformation of finite-size bubbles in turbulent multiphase flow

    Science.gov (United States)

    Masuk, Ashik Ullah Mohammad; Salibindla, Ashwanth; Ni, Rui

    2017-11-01

    Finite-size bubbles tend to deform in a strong turbulent environment because of the complex interfacial momentum transfer between them. We have utilized the new V-ONSET turbulence multiphase flow facility to track the deformation and the couplings between two phases in a 3D Lagrangian framework. This rich dataset allows us to understand the roles played by the dynamic pressure and viscous stress, as well as different forces that contribute to the interfacial momentum transfer. Financial support for this project was provided by National Science Foundation under Grant Number: 1653389 and 1705246.

  16. Numerical models of caldera deformation: Effects of multiphase and multicomponent hydrothermal fluid flow

    Science.gov (United States)

    Hutnak, M.; Hurwitz, S.; Ingebritsen, S.E.; Hsieh, P.A.

    2009-01-01

    Ground surface displacement (GSD) in large calderas is often interpreted as resulting from magma intrusion at depth. Recent advances in geodetic measurements of GSD, notably interferometric synthetic aperture radar, reveal complex and multifaceted deformation patterns that often require complex source models to explain the observed GSD. Although hydrothermal fluids have been discussed as a possible deformation agent, very few quantitative studies addressing the effects of multiphase flow on crustal mechanics have been attempted. Recent increases in the power and availability of computing resources allow robust quantitative assessment of the complex time-variant thermal interplay between aqueous fluid flow and crustal deformation. We carry out numerical simulations of multiphase (liquid-gas), multicomponent (H 2O-CO2) hydrothermal fluid flow and poroelastic deformation using a range of realistic physical parameters and processes. Hydrothermal fluid injection, circulation, and gas formation can generate complex, temporally and spatially varying patterns of GSD, with deformation rates, magnitudes, and geometries (including subsidence) similar to those observed in several large calderas. The potential for both rapid and gradual deformation resulting from magma-derived fluids suggests that hydrothermal fluid circulation may help explain deformation episodes at calderas that have not culminated in magmatic eruption.

  17. Salinity independent volume fraction prediction in water-gas-oil multiphase flows using artificial neural networks

    Energy Technology Data Exchange (ETDEWEB)

    Salgado, C.M.; Pereira, Claudio M.N.A.; Brandao, Luis E.B., E-mail: otero@ien.gov.b, E-mail: cmnap@ien.gov.b, E-mail: brandao@ien.gov.b [Instituto de Engenharia Nuclear (DIRA/IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Div. de Radiofarmacos

    2011-07-01

    This work investigates the response of a volume fraction prediction system for water-gas-oil multiphase flows considering variations on water salinity. The approach is based on gamma-ray pulse height distributions pattern recognition by means the artificial neural networks (ANNs). The detection system uses appropriate fan beam geometry, comprised of a dual-energy gamma-ray source and two NaI(Tl) detectors adequately positioned outside the pipe in order measure transmitted and scattered beams. An ideal and static theoretical model for annular flow regime have been developed using MCNP-X code, which was used to provide training, test and validation data for the ANN. More than 500 simulations have been done, in which water salinity have been ranged from 0 to 16% in order to cover a most practical situations. Validation tests have included values of volume fractions and water salinity different from those used in ANN training phase. The results presented here show that the proposed approach may be successfully applied to material volume fraction prediction on watergas- oil multiphase flows considering practical (real) levels of variations in water salinity. (author)

  18. Salinity independent volume fraction prediction in water-gas-oil multiphase flows using artificial neural networks

    International Nuclear Information System (INIS)

    Salgado, C.M.; Pereira, Claudio M.N.A.; Brandao, Luis E.B.

    2011-01-01

    This work investigates the response of a volume fraction prediction system for water-gas-oil multiphase flows considering variations on water salinity. The approach is based on gamma-ray pulse height distributions pattern recognition by means the artificial neural networks (ANNs). The detection system uses appropriate fan beam geometry, comprised of a dual-energy gamma-ray source and two NaI(Tl) detectors adequately positioned outside the pipe in order measure transmitted and scattered beams. An ideal and static theoretical model for annular flow regime have been developed using MCNP-X code, which was used to provide training, test and validation data for the ANN. More than 500 simulations have been done, in which water salinity have been ranged from 0 to 16% in order to cover a most practical situations. Validation tests have included values of volume fractions and water salinity different from those used in ANN training phase. The results presented here show that the proposed approach may be successfully applied to material volume fraction prediction on watergas- oil multiphase flows considering practical (real) levels of variations in water salinity. (author)

  19. Joint numerical microscale simulations of multi-phase flow and NMR relaxation behaviour in porous media

    Science.gov (United States)

    Mohnke, O.; Ahrenholz, B.

    2011-12-01

    Nuclear Magnetic Resonance (NMR) is a useful tool for analyzing gas (methane) and fluids (water, oil) in rock formations in order to derive transport and storage properties such as pore-size distributions or relative permeability. Even though there is considerable NMR data available about hydraulic properties of rock formations, this information is only empirical. Thus, the aim of this paper is to present joint NMR and multi-phase flow simulations in micro-scale pore systems derived from micro-CT images to quantify relationships between NMR parameters and transport and storage properties of partially saturated rocks. Hereby, the NMR differential equations were implemented using an advection/diffusion lattice-Boltzmann method (LBM) where the flow field is computed by a coupled LBM CFD solver. The results of numerical imbibition and drainage experiments quantitatively agree with laboratory experiments with regard to frequently found peak shifts and bimodal NMR decay time distributions related to residual water in films and corners as well as to fluids/gases trapped in large pores. This numerical framework enables one to quantitatively describe NMR surface and bulk relaxation processes, diffusive coupling along with the multi-phase flow properties of partially saturated porous systems. Furthermore, it is a viable alternative to the more time-consuming and less controllable laboratory experiments. Such virtual experimental setups can considerably help to benchmark and validate statistical network models to better understand hydraulic properties of partially saturated rocks by using experimentally obtained NMR data.

  20. Development of high-frame rate neutron radiography and quantitative measurement method for multiphase flow research

    International Nuclear Information System (INIS)

    Mishima, K.; Hibiki, T.

    1998-01-01

    Neutron radiography (NR) is one of the radiographic techniques which makes use of the difference in attenuation characteristics of neutrons in materials. Fluid measurement using the NR technique is a non-intrusive method which enables visualization of dynamic images of multiphase flow of opaque fluids and/or in a metallic duct. To apply the NR technique to multiphase flow research, high frame-rate NR was developed by combining up-to-date technologies for neutron sources, scintillator, high-speed video and image intensifier. This imaging system has several advantages such as a long recording time (up to 21 minutes), high-frame-rate (up to 1000 frames/s) imaging and there is no need for a triggering signal. Visualization studies of air-water two-phase flow in a metallic duct and molten metal-water interaction were performed at recording speeds of 250, 500 and 1000 frames/s. The qualities of the consequent images were sufficient to observe the flow pattern and behavior. It was also demonstrated that some characteristics of two-phase flow could be measured from these images in collaboration with image processing techniques. By utilizing geometrical information extracted from NR images, data on flow regime, bubble rise velocity, and wave height and interfacial area in annular flow were obtained. By utilizing attenuation characteristics of neutrons in materials, measurements of void profile and average void fraction were performed. It was confirmed that this new technique may have significant advantages both in visualizing and measuring high-speed fluid phenomena when other methods, such as an optical method and X-ray radiography, cannot be applied. (author)

  1. A discontinuous control volume finite element method for multi-phase flow in heterogeneous porous media

    Science.gov (United States)

    Salinas, P.; Pavlidis, D.; Xie, Z.; Osman, H.; Pain, C. C.; Jackson, M. D.

    2018-01-01

    We present a new, high-order, control-volume-finite-element (CVFE) method for multiphase porous media flow with discontinuous 1st-order representation for pressure and discontinuous 2nd-order representation for velocity. The method has been implemented using unstructured tetrahedral meshes to discretize space. The method locally and globally conserves mass. However, unlike conventional CVFE formulations, the method presented here does not require the use of control volumes (CVs) that span the boundaries between domains with differing material properties. We demonstrate that the approach accurately preserves discontinuous saturation changes caused by permeability variations across such boundaries, allowing efficient simulation of flow in highly heterogeneous models. Moreover, accurate solutions are obtained at significantly lower computational cost than using conventional CVFE methods. We resolve a long-standing problem associated with the use of classical CVFE methods to model flow in highly heterogeneous porous media.

  2. A Coupled Model of Multiphase Flow, Reactive Biogeochemical Transport, Thermal Transport and Geo-Mechanics.

    Science.gov (United States)

    Tsai, C. H.; Yeh, G. T.

    2015-12-01

    In this investigation, a coupled model of multiphase flow, reactive biogeochemical transport, thermal transport and geo-mechanics in subsurface media is presented. It iteratively solves the mass conservation equation for fluid flow, thermal transport equation for temperature, reactive biogeochemical transport equations for concentration distributions, and solid momentum equation for displacement with successive linearization algorithm. With species-based equations of state, density of a phase in the system is obtained by summing up concentrations of all species. This circumvents the problem of having to use empirical functions. Moreover, reaction rates of all species are incorporated in mass conservation equation for fluid flow. Formation enthalpy of all species is included in the law of energy conservation as a source-sink term. Finite element methods are used to discretize the governing equations. Numerical experiments are presented to examine the accuracy and robustness of the proposed model. The results demonstrate the feasibility and capability of present model in subsurface media.

  3. Two-Fluid Models for Simulating Dispersed Multiphase Flows-A Review

    Directory of Open Access Journals (Sweden)

    L.X. Zhou

    2009-01-01

    Full Text Available The development of two-fluid models for simulating dispersed multiphase flows (gas-particle, gas-droplet, bubble-liquid, liquid-particle flows by the present author within the last 20 years is systematically reviewed. The two-fluid models based on Reynolds expansion, time averaging and mass-weighed averaging, and also PDF transport equations are described. Different versions of two-phase turbulence models, including the unified second-order moment (USM and k-ε-kp models, the DSM-PDF model, the SOM-MC model, the nonlinear k-e-kp model, and the USM-Θ model for dense gas-particle flows and their application and experimental validation are discussed.

  4. DENSE MULTIPHASE FLOW SIMULATION: CONTINUUM MODEL FOR POLY-DISPERSED SYSTEMS USING KINETIC THEORY

    Energy Technology Data Exchange (ETDEWEB)

    Moses Bogere

    2011-08-31

    The overall objective of the project was to verify the applicability of the FCMOM approach to the kinetic equations describing the particle flow dynamics. For monodispersed systems the fundamental equation governing the particle flow dynamics is the Boltzmann equation. During the project, the FCMOM was successfully applied to several homogeneous and in-homogeneous problems in different flow regimes, demonstrating that the FCMOM has the potential to be used to solve efficiently the Boltzmann equation. However, some relevant issues still need to be resolved, i.e. the homogeneous cooling problem (inelastic particles cases) and the transition between different regimes. In this report, the results obtained in homogeneous conditions are discussed first. Then a discussion of the validation results for in-homogeneous conditions is provided. And finally, a discussion will be provided about the transition between different regimes. Alongside the work on development of FCMOM approach studies were undertaken in order to provide insights into anisotropy or particles kinetics in riser hydrodynamics. This report includes results of studies of multiphase flow with unequal granular temperatures and analysis of momentum re-distribution in risers due to particle-particle and fluid-particle interactions. The study of multiphase flow with unequal granular temperatures entailed both simulation and experimental studies of two particles sizes in a riser and, a brief discussion of what was accomplished will be provided. And finally, a discussion of the analysis done on momentum re-distribution of gas-particles flow in risers will be provided. In particular a discussion of the remaining work needed in order to improve accuracy and predictability of riser hydrodynamics based on two-fluid models and how they can be used to model segregation in risers.

  5. Fundamentals of multiphase, gas-solid and gas-liquid flows in porous media

    Science.gov (United States)

    Mazaheri, Ali Reza

    This thesis is concerned with fundamentals and applications of multiphase and particulate flows. The study contains three parts covering gas-liquid flows through porous media, gas-solid flows and Chemical-Mechanical Polishing (CMP). A continuum model for multiphase fluid flows through poro-elastic media is developed. It is shown that the present theory leads to the extended Darcy's law and contains, as its special case, Biot's theory of saturated poro-elastic media. The capillary pressure formulation derived from the new model is used and the equation governing the evolution of the saturation and its temporal variation in porous media is derived. The resulting nonlinear diffusion equation is then solved numerically. The results show that the capillary hysteresis occurs when the temporal variation of saturation is included. Application of the developed model to CO2 sequestration is discussed. Computer simulations of dilute Gas-Solid flows in complex geometry regions are studied. A procedure for handling particle trajectory analysis in unstructured grid is developed. Examples of particle transport and removal in human lung and hot-gas cleaning systems are presented. The simulation results for the human lung show that the capture efficiency is affected by the turbulence in the upper three bifurcation airways. Computer simulations of gas-solid flows in hot-gas cleaning for a demonstration scale filtration system is studied in details. Alternative designs of the filter vessel are proposed. The corresponding vessel performance are numerically simulated. Chemical mechanical polishing (CMP) has become critical to the fabrication of advanced multilevel integrated circuit in microelectronic industry. The effect of course surface roughness of abrasive particles on the polishing rate in CMP is studied. The effects of slurry pH and double layer attraction and repulsion on chemical-mechanical polishing are also studied. It is shown that the slurry pH and colloidal forces

  6. A multiphase flow meter for the on-line determination of the flow rates of oil, water and gas

    International Nuclear Information System (INIS)

    Roach, G.J.; Watt, J.S.

    1997-01-01

    Multiphase mixtures of crude oil, formation water and gas are carried in pipelines from oil wells to production facilities. Multiphase flow meters (MFMs) are being developed to determine the flow rates of each component of the heterogeneous mixture in the pipeline. CSIRO Minerals has developed and field tested a gamma-ray MFM for the on-line determination of the flow rates of heterogeneous mixtures of oil, water and gas in pipelines. It consists of two specialised gamma-ray transmission gauges, and pressure and temperature sensors, mounted on the pipeline carrying the full flow of the production stream. The MFM separately measures liquids and gas flow rates, and the volume ratio of water and liquids (water cut). The MFM has been trialled at three offshore production facilities in Australia. In each, the MFM was mounted on the pipeline between the test manifold and the test separator. The multiphase streams from the various wells feeding to the platform were sequentially routed past the MFM. The MFM and test separator outputs were compared using regression analysis. The flow rates of oil, water and gas were each determined to relative errors in the range of 5-10% . The MFM has been in routine use on the West Kingfish platform in the Bass Strait since November 1994. The MFM was recently tested over a wide range of flow conditions at a Texaco flow facility near Houston. Water cut, based on pre-trial calibration, was determined to 2% rms over the range 0-100% water cut. The liquids and gas flow results were interpreted based on slip correlations obtained from comparison of the MFM and Texaco flows. Using these, the relative errors were respectively 6.6% for liquid flow, 6.2% for gas, 8% for oil and 8% for water. The MFM is licensed to Kvaerner FSSL of Aberdeen. Kvaerner will supply the gamma-ray MFM for both platform and subsea use. Technology transfer commenced in December 1996, and Kvaerner completed the manufacture of the first MFM in August 1997

  7. A multiphase flow meter for the on-line determination of the flow rates of oil, water and gas

    Energy Technology Data Exchange (ETDEWEB)

    Roach, G.J.; Watt, J.S. [Commonwealth Scientific and Industrial Research Organisation (CSIRO), Menai, NSW (Australia). Divsion of Minerals

    1997-10-01

    Multiphase mixtures of crude oil, formation water and gas are carried in pipelines from oil wells to production facilities. Multiphase flow meters (MFMs) are being developed to determine the flow rates of each component of the heterogeneous mixture in the pipeline. CSIRO Minerals has developed and field tested a gamma-ray MFM for the on-line determination of the flow rates of heterogeneous mixtures of oil, water and gas in pipelines. It consists of two specialised gamma-ray transmission gauges, and pressure and temperature sensors, mounted on the pipeline carrying the full flow of the production stream. The MFM separately measures liquids and gas flow rates, and the volume ratio of water and liquids (water cut). The MFM has been trialled at three offshore production facilities in Australia. In each, the MFM was mounted on the pipeline between the test manifold and the test separator. The multiphase streams from the various wells feeding to the platform were sequentially routed past the MFM. The MFM and test separator outputs were compared using regression analysis. The flow rates of oil, water and gas were each determined to relative errors in the range of 5-10% . The MFM has been in routine use on the West Kingfish platform in the Bass Strait since November 1994. The MFM was recently tested over a wide range of flow conditions at a Texaco flow facility near Houston. Water cut, based on pre-trial calibration, was determined to 2% rms over the range 0-100% water cut. The liquids and gas flow results were interpreted based on slip correlations obtained from comparison of the MFM and Texaco flows. Using these, the relative errors were respectively 6.6% for liquid flow, 6.2% for gas, 8% for oil and 8% for water. The MFM is licensed to Kvaerner FSSL of Aberdeen. Kvaerner will supply the gamma-ray MFM for both platform and subsea use. Technology transfer commenced in December 1996, and Kvaerner completed the manufacture of the first MFM in August 1997 4 refs., 7 figs.

  8. A novel consistent and well-balanced algorithm for simulations of multiphase flows on unstructured grids

    Science.gov (United States)

    Patel, Jitendra Kumar; Natarajan, Ganesh

    2017-12-01

    We discuss the development and assessment of a robust numerical algorithm for simulating multiphase flows with complex interfaces and high density ratios on arbitrary polygonal meshes. The algorithm combines the volume-of-fluid method with an incremental projection approach for incompressible multiphase flows in a novel hybrid staggered/non-staggered framework. The key principles that characterise the algorithm are the consistent treatment of discrete mass and momentum transport and the similar discretisation of force terms appearing in the momentum equation. The former is achieved by invoking identical schemes for convective transport of volume fraction and momentum in the respective discrete equations while the latter is realised by representing the gravity and surface tension terms as gradients of suitable scalars which are then discretised in identical fashion resulting in a balanced formulation. The hybrid staggered/non-staggered framework employed herein solves for the scalar normal momentum at the cell faces, while the volume fraction is computed at the cell centroids. This is shown to naturally lead to similar terms for pressure and its correction in the momentum and pressure correction equations respectively, which are again treated discretely in a similar manner. We show that spurious currents that corrupt the solution may arise both from an unbalanced formulation where forces (gravity and surface tension) are discretised in dissimilar manner and from an inconsistent approach where different schemes are used to convect the mass and momentum, with the latter prominent in flows which are convection-dominant with high density ratios. Interestingly, the inconsistent approach is shown to perform as well as the consistent approach even for high density ratio flows in some cases while it exhibits anomalous behaviour for other scenarios, even at low density ratios. Using a plethora of test problems of increasing complexity, we conclusively demonstrate that the

  9. THC-MP: High performance numerical simulation of reactive transport and multiphase flow in porous media

    Science.gov (United States)

    Wei, Xiaohui; Li, Weishan; Tian, Hailong; Li, Hongliang; Xu, Haixiao; Xu, Tianfu

    2015-07-01

    The numerical simulation of multiphase flow and reactive transport in the porous media on complex subsurface problem is a computationally intensive application. To meet the increasingly computational requirements, this paper presents a parallel computing method and architecture. Derived from TOUGHREACT that is a well-established code for simulating subsurface multi-phase flow and reactive transport problems, we developed a high performance computing THC-MP based on massive parallel computer, which extends greatly on the computational capability for the original code. The domain decomposition method was applied to the coupled numerical computing procedure in the THC-MP. We designed the distributed data structure, implemented the data initialization and exchange between the computing nodes and the core solving module using the hybrid parallel iterative and direct solver. Numerical accuracy of the THC-MP was verified through a CO2 injection-induced reactive transport problem by comparing the results obtained from the parallel computing and sequential computing (original code). Execution efficiency and code scalability were examined through field scale carbon sequestration applications on the multicore cluster. The results demonstrate successfully the enhanced performance using the THC-MP on parallel computing facilities.

  10. A hybrid interface tracking - level set technique for multiphase flow with soluble surfactant

    Science.gov (United States)

    Shin, Seungwon; Chergui, Jalel; Juric, Damir; Kahouadji, Lyes; Matar, Omar K.; Craster, Richard V.

    2018-04-01

    A formulation for soluble surfactant transport in multiphase flows recently presented by Muradoglu and Tryggvason (JCP 274 (2014) 737-757) [17] is adapted to the context of the Level Contour Reconstruction Method, LCRM, (Shin et al. IJNMF 60 (2009) 753-778, [8]) which is a hybrid method that combines the advantages of the Front-tracking and Level Set methods. Particularly close attention is paid to the formulation and numerical implementation of the surface gradients of surfactant concentration and surface tension. Various benchmark tests are performed to demonstrate the accuracy of different elements of the algorithm. To verify surfactant mass conservation, values for surfactant diffusion along the interface are compared with the exact solution for the problem of uniform expansion of a sphere. The numerical implementation of the discontinuous boundary condition for the source term in the bulk concentration is compared with the approximate solution. Surface tension forces are tested for Marangoni drop translation. Our numerical results for drop deformation in simple shear are compared with experiments and results from previous simulations. All benchmarking tests compare well with existing data thus providing confidence that the adapted LCRM formulation for surfactant advection and diffusion is accurate and effective in three-dimensional multiphase flows with a structured mesh. We also demonstrate that this approach applies easily to massively parallel simulations.

  11. Modeling compressible multiphase flows with dispersed particles in both dense and dilute regimes

    Science.gov (United States)

    McGrath, T.; St. Clair, J.; Balachandar, S.

    2017-06-01

    Many important explosives and energetics applications involve multiphase formulations employing dispersed particles. While considerable progress has been made toward developing mathematical models and computational methodologies for these flows, significant challenges remain. In this work, we apply a mathematical model for compressible multiphase flows with dispersed particles to existing shock and explosive dispersal problems from the literature. The model is cast in an Eulerian framework, treats all phases as compressible, is hyperbolic, and satisfies the second law of thermodynamics. It directly applies the continuous-phase pressure gradient as a forcing function for particle acceleration and thereby retains relaxed characteristics for the dispersed particle phase that remove the constituent material sound velocity from the eigenvalues. This is consistent with the expected characteristics of dispersed particle phases and can significantly improve the stable time-step size for explicit methods. The model is applied to test cases involving the shock and explosive dispersal of solid particles and compared to data from the literature. Computed results compare well with experimental measurements, providing confidence in the model and computational methods applied.

  12. Numerical Simulation of Transient Multiphase Flow in a Five-Strand Bloom Tundish during Ladle Change

    Directory of Open Access Journals (Sweden)

    Hua Zhang

    2018-02-01

    Full Text Available The steel-slag-air multiphase flow in a bloom tundish with five strands during the transient casting of the ladle change was simulated using the Volume of Fluid (VOF model, and the formation mechanisms of macro-inclusions and the behavior of the steel-slag-air interface during the filling process were investigated. Water model experiments were conducted to validate the multiphase model. The results showed that the numerical results of slag entrapment behavior and the exposed area of steel are basically consistent with the experimental results. The flow of molten steel in the tundish is weak except for the region around the stopper rods at the end of the emptying process. Strong fluctuations in liquid level were formed during the filling process, showing two wave crests in front of and behind the shroud in the impact zone, which intensified with the increase in filling time and then declined gradually. Entrapment phenomena and exposure of liquid steel could not be observed before the filling stage. While the entrapped slag droplets mostly float up and can be removed within 40 s during the filling process, the remainder enters the casting zone through the baffle. The maximum exposed area of molten steel is 252 cm2 when the filling time is 4.0 s.

  13. A relaxation-projection method for compressible flows. Part II: Artificial heat exchanges for multiphase shocks

    International Nuclear Information System (INIS)

    Petitpas, Fabien; Franquet, Erwin; Saurel, Richard; Le Metayer, Olivier

    2007-01-01

    The relaxation-projection method developed in Saurel et al. [R. Saurel, E. Franquet, E. Daniel, O. Le Metayer, A relaxation-projection method for compressible flows. Part I: The numerical equation of state for the Euler equations, J. Comput. Phys. (2007) 822-845] is extended to the non-conservative hyperbolic multiphase flow model of Kapila et al. [A.K. Kapila, Menikoff, J.B. Bdzil, S.F. Son, D.S. Stewart, Two-phase modeling of deflagration to detonation transition in granular materials: reduced equations, Physics of Fluids 13(10) (2001) 3002-3024]. This model has the ability to treat multi-temperatures mixtures evolving with a single pressure and velocity and is particularly interesting for the computation of interface problems with compressible materials as well as wave propagation in heterogeneous mixtures. The non-conservative character of this model poses however computational challenges in the presence of shocks. The first issue is related to the Riemann problem resolution that necessitates shock jump conditions. Thanks to the Rankine-Hugoniot relations proposed and validated in Saurel et al. [R. Saurel, O. Le Metayer, J. Massoni, S. Gavrilyuk, Shock jump conditions for multiphase mixtures with stiff mechanical relaxation, Shock Waves 16 (3) (2007) 209-232] exact and approximate 2-shocks Riemann solvers are derived. However, the Riemann solver is only a part of a numerical scheme and non-conservative variables pose extra difficulties for the projection or cell average of the solution. It is shown that conventional Godunov schemes are unable to converge to the exact solution for strong multiphase shocks. This is due to the incorrect partition of the energies or entropies in the cell averaged mixture. To circumvent this difficulty a specific Lagrangian scheme is developed. The correct partition of the energies is achieved by using an artificial heat exchange in the shock layer. With the help of an asymptotic analysis this heat exchange takes a similar form as

  14. A relaxation-projection method for compressible flows. Part II: Artificial heat exchanges for multiphase shocks

    Science.gov (United States)

    Petitpas, Fabien; Franquet, Erwin; Saurel, Richard; Le Metayer, Olivier

    2007-08-01

    The relaxation-projection method developed in Saurel et al. [R. Saurel, E. Franquet, E. Daniel, O. Le Metayer, A relaxation-projection method for compressible flows. Part I: The numerical equation of state for the Euler equations, J. Comput. Phys. (2007) 822-845] is extended to the non-conservative hyperbolic multiphase flow model of Kapila et al. [A.K. Kapila, Menikoff, J.B. Bdzil, S.F. Son, D.S. Stewart, Two-phase modeling of deflagration to detonation transition in granular materials: reduced equations, Physics of Fluids 13(10) (2001) 3002-3024]. This model has the ability to treat multi-temperatures mixtures evolving with a single pressure and velocity and is particularly interesting for the computation of interface problems with compressible materials as well as wave propagation in heterogeneous mixtures. The non-conservative character of this model poses however computational challenges in the presence of shocks. The first issue is related to the Riemann problem resolution that necessitates shock jump conditions. Thanks to the Rankine-Hugoniot relations proposed and validated in Saurel et al. [R. Saurel, O. Le Metayer, J. Massoni, S. Gavrilyuk, Shock jump conditions for multiphase mixtures with stiff mechanical relaxation, Shock Waves 16 (3) (2007) 209-232] exact and approximate 2-shocks Riemann solvers are derived. However, the Riemann solver is only a part of a numerical scheme and non-conservative variables pose extra difficulties for the projection or cell average of the solution. It is shown that conventional Godunov schemes are unable to converge to the exact solution for strong multiphase shocks. This is due to the incorrect partition of the energies or entropies in the cell averaged mixture. To circumvent this difficulty a specific Lagrangian scheme is developed. The correct partition of the energies is achieved by using an artificial heat exchange in the shock layer. With the help of an asymptotic analysis this heat exchange takes a similar form as

  15. Persistent Homology to describe Solid and Fluid Structures during Multiphase Flow

    Science.gov (United States)

    Herring, A. L.; Robins, V.; Liu, Z.; Armstrong, R. T.; Sheppard, A.

    2017-12-01

    The question of how to accurately and effectively characterize essential fluid and solid distributions and structures is a long-standing topic within the field of porous media and fluid transport. For multiphase flow applications, considerable research effort has been made to describe fluid distributions under a range of conditions; including quantification of saturation levels, fluid-fluid pressure differences and interfacial areas, and fluid connectivity. Recent research has effectively used topological metrics to describe pore space and fluid connectivity, with researchers demonstrating links between pore-scale nonwetting phase topology to fluid mobilization and displacement mechanisms, relative permeability, fluid flow regimes, and thermodynamic models of multiphase flow. While topology is clearly a powerful tool to describe fluid distribution, topological metrics by definition provide information only on the connectivity of a phase, not its geometry (shape or size). Physical flow characteristics, e.g. the permeability of a fluid phase within a porous medium, are dependent on the connectivity of the pore space or fluid phase as well as the size of connections. Persistent homology is a technique which provides a direct link between topology and geometry via measurement of topological features and their persistence from the signed Euclidean distance transform of a segmented digital image (Figure 1). We apply persistent homology analysis to measure the occurrence and size of pore-scale topological features in a variety of sandstones, for both the dry state and the nonwetting phase fluid during two-phase fluid flow (drainage and imbibition) experiments, visualized with 3D X-ray microtomography. The results provide key insights into the dominant topological features and length scales of a media which control relevant field-scale engineering properties such as fluid trapping, absolute permeability, and relative permeability.

  16. Dripping and jetting in microfluidic multiphase flows applied to particle and fiber synthesis

    Science.gov (United States)

    Nunes, J K; Tsai, S S H; Wan, J; Stone, H A

    2013-01-01

    Dripping and jetting regimes in microfluidic multiphase flows have been investigated extensively, and this review summarizes the main observations and physical understandings in this field to date for three common device geometries: coaxial, flow-focusing and T-junction. The format of the presentation allows for simple and direct comparison of the different conditions for drop and jet formation, as well as the relative ease and utility of forming either drops or jets among the three geometries. The emphasis is on the use of drops and jets as templates for microparticle and microfiber syntheses, and a description is given of the more common methods of solidification and strategies for achieving complex multicomponent microparticles and microfibers. PMID:23626378

  17. Mathematical Models of Electro-Magnetohydrodynamic Multiphase Flows Synthesis with Nano-Sized Hafnium Particles

    Directory of Open Access Journals (Sweden)

    Farooq Hussain

    2018-02-01

    Full Text Available The multiphase fluid flow under the influence of electro-magnetohydrodynamics (EHD is investigated in this study. The base fluid contains hafnium particles. Two illustrative models namely fluid phase and particulate phase are considered for three different geometries having great importance in both industrial and mechanical usage. The impact of pertinent parameters from different aspects is illustrated graphically with requisite discussion keeping in view their physical aspects. The stream lines are also erected to highlight their physical importance regarding the flow patterns. In addition, the paper is terminated by making a comparison with the existing literature as a limiting case of considered problem to confirm the validations of achieved results and hence found in excellent agreement. This model can be used to design and engineer for nozzle or diffuser type of injectors in the latest models of automobiles to improve their performance and reduce the consumption of fuel.

  18. Adaptive mesh refinement and multilevel iteration for multiphase, multicomponent flow in porous media

    Energy Technology Data Exchange (ETDEWEB)

    Hornung, R.D. [Duke Univ., Durham, NC (United States)

    1996-12-31

    An adaptive local mesh refinement (AMR) algorithm originally developed for unsteady gas dynamics is extended to multi-phase flow in porous media. Within the AMR framework, we combine specialized numerical methods to treat the different aspects of the partial differential equations. Multi-level iteration and domain decomposition techniques are incorporated to accommodate elliptic/parabolic behavior. High-resolution shock capturing schemes are used in the time integration of the hyperbolic mass conservation equations. When combined with AMR, these numerical schemes provide high resolution locally in a more efficient manner than if they were applied on a uniformly fine computational mesh. We will discuss the interplay of physical, mathematical, and numerical concerns in the application of adaptive mesh refinement to flow in porous media problems of practical interest.

  19. New multiphase choke correlations for a high flow rate Iranian oil field

    Directory of Open Access Journals (Sweden)

    M. Safar Beiranvand

    2012-06-01

    Full Text Available The multiphase flow through wellhead restrictions of an offshore oil field in Iran is investigated and two sets of new correlations are presented for high flow rate and water cut conditions. The both correlations are developed by using 748 actual data points, corresponding to critical flow conditions of gas-liquid mixtures through wellhead chokes. The first set of correlations is a modified Gilbert equation and predicts liquid flow rates as a function of flowing wellhead pressure, gas-liquid ratio and surface wellhead choke size. To minimize error in such condition, in the second correlation, free water, sediment and emulsion (BS & W is also considered as an effective parameter. The predicted oil flow rates by the new sets of correlations are in the excellent agreement with the measured ones. These results are found to be statistically superior to those predicted by other relevant published correlations. The both proposed correlations exhibit more accuracy (only 2.95% and 2.0% average error, respectively than the existent correlations. These results should encourage the production engineer which works at such condition to utilize the proposed correlations for future practical answers when a lack of available information, time, and calculation capabilities arises.

  20. CFD analysis of multiphase blood flow within aorta and its thoracic branches of patient with coarctation of aorta using multiphase Euler-Euler approach

    International Nuclear Information System (INIS)

    Ostrowski, Z; Melka, B; Adamczyk, W; Rojczyk, M; Nowak, A J; Golda, A

    2016-01-01

    In the research a numerical Computational Fluid Dynamics (CFD) model of the pulsatile blood flow was created and analyzed. A real geometry of aorta and its thoracic branches of 8-year old patient diagnosed with a congenital heart defect - coarctation of aorta was used. The inlet boundary condition were implemented as the User Define Function according to measured values of volumetric blood flow. The blood flow was treated as multiphase: plasma, set as the primary fluid phase, was dominant with volume fraction of 0.585 and morphological elements of blood were treated in Euler-Euler approach as dispersed phases (with 90% Red Blood Cells and White Blood Cells as remaining solid volume fraction). (paper)

  1. Theoretical analysis of multiphase flow during oil-well drilling by a conservative model

    Science.gov (United States)

    Nicolas-Lopez, Ruben

    2005-11-01

    In order to decrease cost and improve drilling operations is necessary a better understood of the flow mechanisms. Therefore, it was carried out a multiphase conservative model that includes three mass equations and a momentum equation. Also, the measured geothermal gradient is utilized by state equations for estimating physical properties of the phases flowing. The mathematical model is solved by numerical conservative schemes. It is used to analyze the interaction among solid-liquid-gas phases. The circulating system consists as follow, the circulating fluid is pumped downward into the drilling pipe until the bottom of the open hole then it flows through the drill bit, and at this point formation cuttings are incorporated to the circulating fluid and carried upward to the surface. The mixture returns up to the surface by an annular flow area. The real operational conditions are fed to conservative model and the results are matched up to field measurements in several oil wells. Mainly, flow rates, drilling rate, well and tool geometries are data to estimate the profiles of pressure, mixture density, equivalent circulating density, gas fraction and solid carrying capacity. Even though the problem is very complex, the model describes, properly, the hydrodynamics of drilling techniques applied at oil fields. *Authors want to thank to Instituto Mexicano del Petroleo and Petroleos Mexicanos for supporting this research.

  2. Multiphase flow dynamics and control; Dynamique et controle des ecoulements polyphasiques

    Energy Technology Data Exchange (ETDEWEB)

    Duret, E.

    2005-02-01

    Production in the petroleum industry requires a better knowledge of multiphase flow, as the design of pipelines may cause the flow to become strongly unstable. For instance, for low flow rates and when a sea line ends at a riser, the riser base may accumulate liquid and stop the flow of gas. Then, the upstream gas is compressed until its pressure is large enough to push the liquid slug downstream. Under such conditions, a cyclic process occurs which is called severe slugging, generating large and fast fluctuations in pressure and flow rates. This thesis is devoted to two methods to stabilize this undesirable phenomenon. Using the pipeline's ability to separate phases to pick-up the gas upstream the riser base, they are mainly based on the perturbation theory (fast proportional effect, slow integral effect). The first one uses a secondary riser to transport the gas to the surface facilities. A stability study worked out with the phase diagrams technique shows that it is a good method to control this phenomenon. However, it imposes a high pressure in all the system. Thus, the second controller re-injects the gas at a determined height in the riser to decrease the hydrostatic pressure. A first stability study in open loop give a criterion on the minimal reinjection height. Then, the controller is developed by using the two-time scale control techniques. Finally, let us denote that these two controllers have been validated with a small size experimental set up. (author)

  3. Application of the numerical density-enthalpy method to the multi-phase flow through a porous medium

    NARCIS (Netherlands)

    Ibrahim, D.; Vermolen, F.J.; Vuik, C.

    2010-01-01

    In this paper we apply a new method to solve multi-phase fluid flow problem for 1D1D and 2D2D fluid systems. This method is developed at TNO and presented in [1] for spatially homogeneous systems. We call this method the numerical density-enthalpy method (or ??-hh method) because density-enthalpy

  4. CFD Applied for the Identification of Stiffness and Damping Properties for Smooth Annular Turbomachinery Seals in Multiphase Flow

    DEFF Research Database (Denmark)

    Voigt, Andreas Jauernik; Ludiciani, Piero; Nielsen, Kenny Krogh

    2016-01-01

    This paper presents a first venture into quantifying stiffness and damping coefficients for turbomachinery seals in multiphase flow using Computational Fluid Dynamics (CFD). The study focusses on the simplest seal type: the smooth annular seal. The investigation is conducted for both wet-gas and ...

  5. Particle methods for simulation of subsurface multiphase fluid flow and biogeochemical processes

    International Nuclear Information System (INIS)

    Meakin, Paul; Tartakovsky, Alexandre; Scheibe, Tim; Tartakovsky, Daniel; Redden, George; Long, Philip E; Brooks, Scott C; Xu Zhijie

    2007-01-01

    A number of particle models that are suitable for simulating multiphase fluid flow and biogeochemical processes have been developed during the last few decades. Here we discuss three of them: a microscopic model - molecular dynamics; a mesoscopic model - dissipative particle dynamics; and a macroscopic model - smoothed particle hydrodynamics. Particle methods are robust and versatile, and it is relatively easy to add additional physical, chemical and biological processes into particle codes. However, the computational efficiency of particle methods is low relative to continuum methods. Multiscale particle methods and hybrid (particle-particle and particle-continuum) methods are needed to improve computational efficiency and make effective use of emerging computational capabilities. These new methods are under development

  6. Adverse Condition and Critical Event Prediction in Cranfield Multiphase Flow Facility

    DEFF Research Database (Denmark)

    Egedorf, Søren; Shaker, Hamid Reza

    2017-01-01

    Today's complex processes and plants are vulnerable to different faults, misconfiguration, non-holistic and improper control and management which cause abnormal behavior and might eventually result in poor and sub-optimal operation, dissatisfaction, damage to the plant, to personnel and resources......, or even to the environment. To cope with these, adverse condition and critical event prediction plays an important role. Adverse Condition and Critical Event Prediction Toolbox (ACCEPT) is a tool which has been recently developed by NASA to allow for a timely prediction of an adverse event, with low false...... alarm and missed detection rates. While ACCEPT has shown to be an effective tool in some applications, its performance has not yet been evaluated on practical well-known benchmark examples. In this paper, ACCEPT is used for adverse condition and critical event prediction in a multiphase flow facility...

  7. EOS7CA Version 1.0: TOUGH2 Module for Gas Migration in Shallow Subsurface Porous Media Systems

    Energy Technology Data Exchange (ETDEWEB)

    Oldenburg, Curtis M.

    2015-03-06

    EOS7CA is a TOUGH2 module for mixtures of a non-condensible gas (NCG) and air with or without a gas tracer, an aqueous phase, and water vapor. The user can select the NCG as being CO2, N2, or CH4. EOS7CA uses a cubic equation of state with a multiphase version of Darcy’s Law to model flow and transport of gas and aqueous phase mixtures over a range of pressures and temperatures appropriate to shallow subsurface porous media systems. The limitation to shallow systems arises from the use of Henry’s Law for gas solubility which is appropriate for low pressures but begins to over-predict solubility starting at pressures greater than approximately 1 MPa (10 bar). The components modeled in EOS7CA are water, brine, NCG, gas tracer, air, and optional heat. The real gas properties module (ZEVCA) has options for Peng-Robinson, Redlich-Kwong, or Soave-Redlich-Kwong equations of state to calculate gas mixture density, enthalpy departure, and viscosity. Transport of the gaseous and dissolved components is by advection and Fickian molecular diffusion. This user guide provides instructions for use and two sample problems as verification and demonstration of EOS7CA.

  8. A robust and accurate approach to computing compressible multiphase flow: Stratified flow model and AUSM+-up scheme

    International Nuclear Information System (INIS)

    Chang, Chih-Hao; Liou, Meng-Sing

    2007-01-01

    In this paper, we propose a new approach to compute compressible multifluid equations. Firstly, a single-pressure compressible multifluid model based on the stratified flow model is proposed. The stratified flow model, which defines different fluids in separated regions, is shown to be amenable to the finite volume method. We can apply the conservation law to each subregion and obtain a set of balance equations. Secondly, the AUSM + scheme, which is originally designed for the compressible gas flow, is extended to solve compressible liquid flows. By introducing additional dissipation terms into the numerical flux, the new scheme, called AUSM + -up, can be applied to both liquid and gas flows. Thirdly, the contribution to the numerical flux due to interactions between different phases is taken into account and solved by the exact Riemann solver. We will show that the proposed approach yields an accurate and robust method for computing compressible multiphase flows involving discontinuities, such as shock waves and fluid interfaces. Several one-dimensional test problems are used to demonstrate the capability of our method, including the Ransom's water faucet problem and the air-water shock tube problem. Finally, several two dimensional problems will show the capability to capture enormous details and complicated wave patterns in flows having large disparities in the fluid density and velocities, such as interactions between water shock wave and air bubble, between air shock wave and water column(s), and underwater explosion

  9. Numerical modelling of multiphase liquid-vapor-gas flows with interfaces and cavitation

    Science.gov (United States)

    Pelanti, Marica

    2017-11-01

    We are interested in the simulation of multiphase flows where the dynamical appearance of vapor cavities and evaporation fronts in a liquid is coupled to the dynamics of a third non-condensable gaseous phase. We describe these flows by a single-velocity three-phase compressible flow model composed of the phasic mass and total energy equations, the volume fraction equations, and the mixture momentum equation. The model includes stiff mechanical and thermal relaxation source terms for all the phases, and chemical relaxation terms to describe mass transfer between the liquid and vapor phases of the species that may undergo transition. The flow equations are solved by a mixture-energy-consistent finite volume wave propagation scheme, combined with simple and robust procedures for the treatment of the stiff relaxation terms. An analytical study of the characteristic wave speeds of the hierarchy of relaxed models associated to the parent model system is also presented. We show several numerical experiments, including two-dimensional simulations of underwater explosive phenomena where highly pressurized gases trigger cavitation processes close to a rigid surface or to a free surface. This work was supported by the French Government Grant DGA N. 2012.60.0011.00.470.75.01, and partially by the Norwegian Grant RCN N. 234126/E30.

  10. Towards a new method for modeling multicomponent, multiphase flow and transport in porous media

    Science.gov (United States)

    Kong, X. Z.; Schaedle, P.; Leal, A. M. M.; Saar, M. O.

    2016-12-01

    The ability to computationally simulate multiphase-multicomponent fluid flow, coupled with geochemical reactions between fluid species and rock minerals, in porous and/or fractured subsurface systems is of major importance to a vast number of applications. These include (1) carbon dioxide storage in geologic formations, (2) geothermal energy extraction, (3) combinations of the latter two applications during CO2-Plume Geothermal energy extraction, (4) waste fluid and waste storage, as well as (5) groundwater and contaminant transport. Modeling these systems with such a wide variety of coupled physical and chemical processes is both challenging and computationally expensive. In this work we present a new approach to develop a simulator for multicomponent-multiphase flow and reactive transport in porous media by using state of the art numerical tools, namely FEniCS (fenicsproject.org) and Reaktoro (reaktoro.org). The governing partial differential equations for fluid flow and transport are solved using FEniCS, which enables fast and efficient implementation of computer codes for the simulation of complex physical phenomena using finite element methods on unstructured meshes. FEniCS supports a wide range of finite element schemes of special interest to porous media flow. In addition, FEniCS interfaces with many sparse linear solvers and provides convenient tools for adaptive mesh refinement and the capability of massively parallel calculations. A fundamental component of our contribution is the coupling of our FEniCS based flow and transport solver with our chemical reaction simulator, Reaktoro, which implements efficient, robust, and accurate methods for chemical equilibrium and kinetics calculations at every node of the mesh, at every time step. These numerical methods for reaction modeling have been especially developed for performance-critical applications such as reactive transport modeling. Furthermore, Reaktoro is also used for the calculation of thermodynamic

  11. Coupling Analysis of Low-Speed Multiphase Flow and High-Frequency Electromagnetic Field in a Complex Pipeline Structure

    OpenAIRE

    Huo, Xiaokai; Sun, Weitao; He, Fengjiang; Yang, Zhe; Peng, Yuanping

    2014-01-01

    Accurate estimation of water content in an oil-water mixture is a key technology in oil exploration and production. Based on the principles of the microwave transmission line (MTL), the logging probe is an important water content measuring apparatus. However, the effects of mixed fluid flow on the measurement of electromagnetic field parameters are rarely considered. This study presents the coupling model for low-speed multiphase flow and high-frequency electromagnetic field in a complex pipe...

  12. A simple mass-conserved level set method for simulation of multiphase flows

    Science.gov (United States)

    Yuan, H.-Z.; Shu, C.; Wang, Y.; Shu, S.

    2018-04-01

    In this paper, a modified level set method is proposed for simulation of multiphase flows with large density ratio and high Reynolds number. The present method simply introduces a source or sink term into the level set equation to compensate the mass loss or offset the mass increase. The source or sink term is derived analytically by applying the mass conservation principle with the level set equation and the continuity equation of flow field. Since only a source term is introduced, the application of the present method is as simple as the original level set method, but it can guarantee the overall mass conservation. To validate the present method, the vortex flow problem is first considered. The simulation results are compared with those from the original level set method, which demonstrates that the modified level set method has the capability of accurately capturing the interface and keeping the mass conservation. Then, the proposed method is further validated by simulating the Laplace law, the merging of two bubbles, a bubble rising with high density ratio, and Rayleigh-Taylor instability with high Reynolds number. Numerical results show that the mass is a well-conserved by the present method.

  13. TOUGHREACT User's Guide: A Simulation Program for Non-isothermal Multiphase Reactive geochemical Transport in Variably Saturated Geologic Media

    International Nuclear Information System (INIS)

    Xu, Tianfu; Sonnenthal, Eric; Spycher, Nicolas; Pruess, Karsten

    2004-01-01

    Coupled modeling of subsurface multiphase fluid and heat flow, solute transport and chemical reactions can be used for the assessment of mineral alteration in hydrothermal systems, waste disposal sites, acid mine drainage remediation, contaminant transport, and groundwater quality. A comprehensive non-isothermal multi-component reactive fluid flow and geochemical transport simulator, TOUGHREACT, has been developed. A wide range of subsurface thermo-physical-chemical processes is considered under various thermohydrological and geochemical conditions of pressure, temperature, water saturation, and ionic strength. The program can be applied to one-, two- or three-dimensional porous and fractured media with physical and chemical heterogeneity. The model can accommodate any number of chemical species present in liquid, gas and solid phases. A variety of equilibrium chemical reactions are considered, such as aqueous complexation, gas dissolution/exsolution, and cation exchange. Mineral dissolution/precipitation can proceed either subject to local equilibrium or kinetic conditions. Changes in porosity and permeability due to mineral dissolution and precipitation can be considered. Linear adsorption and decay can be included. For the purpose of future extensions, surface complexation by double layer model is coded in the program. Xu and Pruess (1998) developed a first version of a non-isothermal reactive geochemical transport model, TOUGHREACT, by introducing reactive geochemistry into the framework of the existing multi-phase fluid and heat flow code TOUGH2 (Pruess, 1991). Xu, Pruess, and their colleagues have applied the program to a variety of problems such as: (1) supergene copper enrichment (Xu et al, 2001), (2) caprock mineral alteration in a hydrothermal system (Xu and Pruess, 2001a), and (3) mineral trapping for CO 2 disposal in deep saline aquifers (Xu et al, 2003b and 2004a). For modeling the coupled thermal, hydrological, and chemical processes during heater

  14. Multiphase Flow in Porous Media with Emphasis on Co2 Sequestration

    Energy Technology Data Exchange (ETDEWEB)

    Be, Alif

    2011-07-01

    Numerical simulation has been used to predict multiphase flow in porous media. It is of great importance to incorporate accurate flow properties to obtain a proper simulation result thus reducing the risk of making wrong decision. Relative permeability and capillary pressure are important key parameters in multiphase flow as they describe how different fluid will interact in porous media. It is even more important in the case of three-phase flow as there are more fluid phases interact in the system. In most of the three-phase flow studies, capillary pressure has been neglected due to the lack of measured data and assumption that its effect is negligible. In other cases, two-phase capillary pressure has been used instead to describe the process in the system. This study will try to show how significant the impact of three-phase capillary pressure using different rock wettability. The three-phase capillary pressure surfaces are generated using a network model. Prior research shows that rock wettability is altered during Co2 sequestration due to the formation of carbonic acid (H2CO3) which leads to lower ph. In this study the effect of wettability alteration is incorporated to assess the safety of Johansen formation which is a good candidate for Co2 sequestration project. In addition, the wettability alteration effect to different flow parameters such as heterogeneity, solubility and diffusion is investigated. This thesis consists of two parts; the first part presents a theoretical background for the work, and the second part is a collection of papers. The papers are grouped into two main topics. The first three papers are discussing about three-phase flow simulation in porous media. The rest are discussing about wettability alteration during Co2 sequestration. Chapter 2 and 3 of the theoretical background include definitions and descriptions of interfacial tension, wettability, capillary pressure, relative permeability and hysteresis. Network model and technique for

  15. Multiphase Flow in Porous Media with Emphasis on Co2 Sequestration

    International Nuclear Information System (INIS)

    Be, Alif

    2011-01-01

    Numerical simulation has been used to predict multiphase flow in porous media. It is of great importance to incorporate accurate flow properties to obtain a proper simulation result thus reducing the risk of making wrong decision. Relative permeability and capillary pressure are important key parameters in multiphase flow as they describe how different fluid will interact in porous media. It is even more important in the case of three-phase flow as there are more fluid phases interact in the system. In most of the three-phase flow studies, capillary pressure has been neglected due to the lack of measured data and assumption that its effect is negligible. In other cases, two-phase capillary pressure has been used instead to describe the process in the system. This study will try to show how significant the impact of three-phase capillary pressure using different rock wettability. The three-phase capillary pressure surfaces are generated using a network model. Prior research shows that rock wettability is altered during Co2 sequestration due to the formation of carbonic acid (H2CO3) which leads to lower ph. In this study the effect of wettability alteration is incorporated to assess the safety of Johansen formation which is a good candidate for Co2 sequestration project. In addition, the wettability alteration effect to different flow parameters such as heterogeneity, solubility and diffusion is investigated. This thesis consists of two parts; the first part presents a theoretical background for the work, and the second part is a collection of papers. The papers are grouped into two main topics. The first three papers are discussing about three-phase flow simulation in porous media. The rest are discussing about wettability alteration during Co2 sequestration. Chapter 2 and 3 of the theoretical background include definitions and descriptions of interfacial tension, wettability, capillary pressure, relative permeability and hysteresis. Network model and technique for

  16. Multiphase integral reacting flow computer code (ICOMFLO): User`s guide

    Energy Technology Data Exchange (ETDEWEB)

    Chang, S.L.; Lottes, S.A.; Petrick, M.

    1997-11-01

    A copyrighted computational fluid dynamics computer code, ICOMFLO, has been developed for the simulation of multiphase reacting flows. The code solves conservation equations for gaseous species and droplets (or solid particles) of various sizes. General conservation laws, expressed by elliptic type partial differential equations, are used in conjunction with rate equations governing the mass, momentum, enthalpy, species, turbulent kinetic energy, and turbulent dissipation. Associated phenomenological submodels of the code include integral combustion, two parameter turbulence, particle evaporation, and interfacial submodels. A newly developed integral combustion submodel replacing an Arrhenius type differential reaction submodel has been implemented to improve numerical convergence and enhance numerical stability. A two parameter turbulence submodel is modified for both gas and solid phases. An evaporation submodel treats not only droplet evaporation but size dispersion. Interfacial submodels use correlations to model interfacial momentum and energy transfer. The ICOMFLO code solves the governing equations in three steps. First, a staggered grid system is constructed in the flow domain. The staggered grid system defines gas velocity components on the surfaces of a control volume, while the other flow properties are defined at the volume center. A blocked cell technique is used to handle complex geometry. Then, the partial differential equations are integrated over each control volume and transformed into discrete difference equations. Finally, the difference equations are solved iteratively by using a modified SIMPLER algorithm. The results of the solution include gas flow properties (pressure, temperature, density, species concentration, velocity, and turbulence parameters) and particle flow properties (number density, temperature, velocity, and void fraction). The code has been used in many engineering applications, such as coal-fired combustors, air

  17. MODELING COUPLED PROCESSES OF MULTIPHASE FLOW AND HEAT TRANSFER IN UNSATURATED FRACTURED ROCK

    International Nuclear Information System (INIS)

    Y. Wu; S. Mukhopadhyay; K. Zhang; G.S. Bodvarsson

    2006-01-01

    A mountain-scale, thermal-hydrologic (TH) numerical model is developed for investigating unsaturated flow behavior in response to decay heat from the radioactive waste repository at Yucca Mountain, Nevada, USA. The TH model, consisting of three-dimensional (3-D) representations of the unsaturated zone, is based on the current repository design, drift layout, and thermal loading scenario under estimated current and future climate conditions. More specifically, the TH model implements the current geological framework and hydrogeological conceptual models, and incorporates the most updated, best-estimated input parameters. This mountain-scale TH model simulates the coupled TH processes related to mountain-scale multiphase fluid flow, and evaluates the impact of radioactive waste heat on the hydrogeological system, including thermally perturbed liquid saturation, gas- and liquid-phase fluxes, and water and rock temperature elevations, as well as the changes in water flux driven by evaporation/condensation processes and drainage between drifts. For a better description of the ambient geothermal condition of the unsaturated zone system, the TH model is first calibrated against measured borehole temperature data. The ambient temperature calibration provides the necessary surface and water table boundary as well as initial conditions. Then, the TH model is used to obtain scientific understanding of TH processes in the Yucca Mountain unsaturated zone under the designed schedule of repository thermal load

  18. An incompressible two-dimensional multiphase particle-in-cell model for dense particle flows

    Energy Technology Data Exchange (ETDEWEB)

    Snider, D.M. [SAIC, Albuquerque, NM (United States); O`Rourke, P.J. [Los Alamos National Lab., NM (United States); Andrews, M.J. [Texas A and M Univ., College Station, TX (United States). Dept. of Mechanical Engineering

    1997-06-01

    A two-dimensional, incompressible, multiphase particle-in-cell (MP-PIC) method is presented for dense particle flows. The numerical technique solves the governing equations of the fluid phase using a continuum model and those of the particle phase using a Lagrangian model. Difficulties associated with calculating interparticle interactions for dense particle flows with volume fractions above 5% have been eliminated by mapping particle properties to a Eulerian grid and then mapping back computed stress tensors to particle positions. This approach utilizes the best of Eulerian/Eulerian continuum models and Eulerian/Lagrangian discrete models. The solution scheme allows for distributions of types, sizes, and density of particles, with no numerical diffusion from the Lagrangian particle calculations. The computational method is implicit with respect to pressure, velocity, and volume fraction in the continuum solution thus avoiding courant limits on computational time advancement. MP-PIC simulations are compared with one-dimensional problems that have analytical solutions and with two-dimensional problems for which there are experimental data.

  19. An Incompressible Three-Dimensional Multiphase Particle-in-Cell Model for Dense Particle Flows

    Science.gov (United States)

    Snider, D. M.

    2001-07-01

    A three-dimensional, incompressible, multiphase particle-in-cell method is presented for dense particle flows. The numerical technique solves the governing equations of the fluid phase using a continuum model and those of the particle phase using a Lagrangian model. Difficulties associated with calculating interparticle interactions for dense particle flows with volume fractions above 5% have been eliminated by mapping particle properties to an Eulerian grid and then mapping back computed stress tensors to particle positions. A subgrid particle, normal stress model for discrete particles which is robust and eliminates the need for an implicit calculation of the particle normal stress on the grid is presented. Interpolation operators and their properties are defined which provide compact support, are conservative, and provide fast solution for a large particle population. The solution scheme allows for distributions of types, sizes, and density of particles, with no numerical diffusion from the Lagrangian particle calculations. Particles are implicitly coupled to the fluid phase, and the fluid momentum and pressure equations are implicitly solved, which gives a robust solution.

  20. A multi-phase ferrofluid flow model with equation of state for thermomagnetic pumping and heat transfer

    Energy Technology Data Exchange (ETDEWEB)

    Aursand, Eskil, E-mail: eskil.aursand@sintef.no; Gjennestad, Magnus Aa.; Yngve Lervåg, Karl; Lund, Halvor

    2016-03-15

    A one-dimensional multi-phase flow model for thermomagnetically pumped ferrofluid with heat transfer is proposed. The thermodynamic model is a combination of a simplified particle model and thermodynamic equations of state for the base fluid. The magnetization model is based on statistical mechanics, taking into account non-uniform particle size distributions. An implementation of the proposed model is validated against experiments from the literature, and found to give good predictions for the thermomagnetic pumping performance. However, the results reveal a very large sensitivity to uncertainties in heat transfer coefficient predictions. - Highlights: • A multi-phase flow model for thermomagnetically pumped ferrofluid is proposed. • An implementation is validated against experiments from the literature. • Predicted thermomagnetic pumping effect agrees with experiments. • However, a very large sensitivity to heat transfer coefficient is revealed.

  1. Grain scale simulation of multiphase flow through porous media; Simulacao em escala granular do escoamento multifasico em meio poroso

    Energy Technology Data Exchange (ETDEWEB)

    Domingos, Ricardo Golghetto; Cheng, Liang-Yee [Universidade de Sao Paulo (USP), SP (Brazil). Escola Politecnica

    2012-07-01

    Since the grain scale modeling of multi-phase flow in porous media is of great interest for the oil industry, the aim of the present research is to show an implementation of Moving Particle Semi-Implicit (MPS) method for the grain scale simulation of multi-phase flow in porous media. Geometry data obtained by a high-resolution CT scan of a sandstone sample has been used as input for the simulations. The results of the simulations performed considering different resolutions are given, the head loss and permeability obtained numerically, as well as the influence of the wettability of the fluids inside the sample of the reservoir's sandstone. (author)

  2. AOI 1— COMPUTATIONAL ENERGY SCIENCES:MULTIPHASE FLOW RESEARCH High-fidelity multi-phase radiation module for modern coal combustion systems

    Energy Technology Data Exchange (ETDEWEB)

    Modest, Michael

    2013-11-15

    The effects of radiation in particle-laden flows were the object of the present research. The presence of particles increases optical thickness substantially, making the use of the “optically thin” approximation in most cases a very poor assumption. However, since radiation fluxes peak at intermediate optical thicknesses, overall radiative effects may not necessarily be stronger than in gas combustion. Also, the spectral behavior of particle radiation properties is much more benign, making spectral models simpler (and making the assumption of a gray radiator halfway acceptable, at least for fluidized beds when gas radiation is not large). On the other hand, particles scatter radiation, making the radiative transfer equation (RTE) much more di fficult to solve. The research carried out in this project encompassed three general areas: (i) assessment of relevant radiation properties of particle clouds encountered in fluidized bed and pulverized coal combustors, (ii) development of proper spectral models for gas–particulate mixtures for various types of two-phase combustion flows, and (iii) development of a Radiative Transfer Equation (RTE) solution module for such applications. The resulting models were validated against artificial cases since open literature experimental data were not available. The final models are in modular form tailored toward maximum portability, and were incorporated into two research codes: (i) the open-source CFD code OpenFOAM, which we have extensively used in our previous work, and (ii) the open-source multi-phase flow code MFIX, which is maintained by NETL.

  3. Single layer porous media with entrapped minerals for microscale studies of multiphase flow.

    Science.gov (United States)

    Liefferink, R W; Naillon, A; Bonn, D; Prat, M; Shahidzadeh, N

    2018-03-27

    The behaviour of minerals (i.e. salts) such as sodium chloride and calcite in porous media is very important in various applications such as weathering of artworks, oil recovery and CO2 sequestration. We report a novel method for manufacturing single layer porous media in which minerals can be entrapped in a controlled way in order to study their dissolution and recrystallization. In addition, our manufacturing method is a versatile tool for creating monomodal, bimodal or multimodal pore size microporous media with controlled porosity ranging from 25% to 50%. These micromodels allow multiphase flows to be quantitatively studied with different microscopy techniques and can serve to validate numerical models that can subsequently be extended to the 3D situation where visualization is experimentally difficult. As an example of their use, deliquescence (dissolution by moisture absorption) of entrapped NaCl crystals is studied; our results show that the invasion of the resulting salt solution is controlled by the capillary pressure within the porous network. For hydrophilic porous media, the liquid preferentially invades the small pores whereas in a hydrophobic network the large pores are filled. Consequently, after several deliquescence/drying cycles in the hydrophilic system, the salt is transported towards the outside of the porous network via small pores; in hydrophobic micromodels, no salt migration is observed. Numerical simulations based on the characteristics of our single layer pore network agree very well with the experimental results and give more insight into the dynamics of salt transport through porous media.

  4. A Multiphase Flow in the Antroduodenal Portion of the Gastrointestinal Tract: A Mathematical Model

    Directory of Open Access Journals (Sweden)

    P. V. Trusov

    2016-01-01

    Full Text Available A group of authors has developed a multilevel mathematical model that focuses on functional disorders in a human body associated with various chemical, physical, social, and other factors. At this point, the researchers have come up with structure, basic definitions and concepts of a mathematical model at the “macrolevel” that allow describing processes in a human body as a whole. Currently we are working at the “mesolevel” of organs and systems. Due to complexity of the tasks, this paper deals with only one meso-fragment of a digestive system model. It describes some aspects related to modeling multiphase flow in the antroduodenal portion of the gastrointestinal tract. Biochemical reactions, dissolution of food particles, and motor, secretory, and absorbing functions of the tract are taken into consideration. The paper outlines some results concerning influence of secretory function disorders on food dissolution rate and tract contents acidity. The effect which food density has on inflow of food masses from a stomach to a bowel is analyzed. We assume that the future development of the model will include digestive enzymes and related reactions of lipolysis, proteolysis, and carbohydrates breakdown.

  5. A hybrid interface tracking-level set technique for multiphase flow with soluble surfactant in Blue

    Science.gov (United States)

    Matar, Omar K.; Shin, Seungwon; Chergui, Jalel; Juric, Damir; Kahouadji, Lyes; Craster, Richard V.

    2017-11-01

    We adapt a formulation for surfactant transport in multiphase flows presented by Muradoglu & Tryggvason to the context of the Level Contour Reconstruction Method, a hybrid method that combines the front-tracking and level-set methods. Attention is paid to the formulation and numerical implementation of the surface gradients of surfactant concentration and surface tension. Various benchmark tests are performed to demonstrate the accuracy of different elements of the algorithm. To verify surfactant mass conservation, values for surfactant diffusion along the interface are compared with the exact solution for the problem of uniform expansion of a sphere. The numerical implementation of the discontinuous boundary condition for the source term in the bulk concentration is compared with the approximate solution. Surface tension forces are tested for Marangoni drop translation. Our numerical results for drop deformation in simple shear are compared with previous experimental and numerical results yielding good agreement. We also demonstrate that our approach applies easily to massively-parallel simulations. EPSRC, UK, MEMPHIS program Grant (EP/K003976/1), RAEng Research Chair (OKM), Basic Science Research Program through the National Research Foundation of Korea (NRF-2014R1A2A1A11051346), computing time at IDRIS of the CNRS in France.

  6. KIVA-hpFE. Predictive turbulent reactive and multiphase flow in engines - An Overview

    Energy Technology Data Exchange (ETDEWEB)

    Carrington, David Bradley [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-05-23

    Research and development of KIVA-hpFE for turbulent reactive and multiphase flow particularly as related to engine modeling program has relevance to National energy security and climate change. Climate change is a source problem, and energy national security is consumption of petroleum products problem. Accurately predicting engine processes leads to, lower greenhouse gas (GHG) emission, where engines in the transportation sector currently account for 26% of the U.S. GHG emissions. Less dependence on petroleum products leads to greater energy security. By Environmental Protection Agency standards, some vehicles are now reaching 42 to the 50 mpg mark. These are conventional gasoline engines. Continued investment and research into new technical innovations, the potential exists to save more than 4 million barrels of oil per day or approximately $200 to $400 million per day. This would be a significant decrease in emission and use of petroleum and a very large economic stimulus too! It is estimated with further advancements in combustion, the current emissions can be reduced up to 40%. Enabling better understanding of fuel injection and fuel-air mixing, thermodynamic combustion losses, and combustion/emission formation processes enhances our ability to help solve both problems. To provide adequate capability for accurately simulating these processes, minimize time and labor for development of engine technology, are the goals of our KIVA development program.

  7. Entropic lattice Boltzmann method for multiphase flows: Fluid-solid interfaces.

    Science.gov (United States)

    Mazloomi M, Ali; Chikatamarla, Shyam S; Karlin, Iliya V

    2015-08-01

    The recently introduced entropic lattice Boltzmann model (ELBM) for multiphase flows [A. Mazloomi M., S. S. Chikatamarla, and I. V. Karlin, Phys. Rev. Lett. 114, 174502 (2015)] is extended to the simulation of dynamic fluid-solid interface problems. The thermodynamically consistent, nonlinearly stable ELBM together with a polynomial representation of the equation of state enables us to investigate the dynamics of the contact line in a wide range of applications, from capillary filling to liquid drop impact onto a flat surfaces with different wettability. The static interface behavior is tested by means of the liquid column in a channel to verify the Young-Laplace law. The numerical results of a capillary filling problem in a channel with wettability gradient show an excellent match with the existing analytical solution. Simulations of drop impact onto both wettable and nonwettable surfaces show that the ELBM reproduces the experimentally observed drop behavior in a quantitative manner. Results reported herein demonstrate that the present model is a promising alternative for studying the vapor-liquid-solid interface dynamics.

  8. Subsurface Transport Over Reactive Multiphases (STORM): A general, coupled, nonisothermal multiphase flow, reactive transport, and porous medium alteration simulator, Version 2 user's guide

    Energy Technology Data Exchange (ETDEWEB)

    DH Bacon; MD White; BP McGrail

    2000-03-07

    The Hanford Site, in southeastern Washington State, has been used extensively to produce nuclear materials for the US strategic defense arsenal by the Department of Energy (DOE) and its predecessors, the US Atomic Energy Commission and the US Energy Research and Development Administration. A large inventory of radioactive and mixed waste has accumulated in 177 buried single- and double shell tanks. Liquid waste recovered from the tanks will be pretreated to separate the low-activity fraction from the high-level and transuranic wastes. Vitrification is the leading option for immobilization of these wastes, expected to produce approximately 550,000 metric tons of Low Activity Waste (LAW) glass. This total tonnage, based on nominal Na{sub 2}O oxide loading of 20% by weight, is destined for disposal in a near-surface facility. Before disposal of the immobilized waste can proceed, the DOE must approve a performance assessment, a document that described the impacts, if any, of the disposal facility on public health and environmental resources. Studies have shown that release rates of radionuclides from the glass waste form by reaction with water determine the impacts of the disposal action more than any other independent parameter. This report describes the latest accomplishments in the development of a computational tool, Subsurface Transport Over Reactive Multiphases (STORM), Version 2, a general, coupled non-isothermal multiphase flow and reactive transport simulator. The underlying mathematics in STORM describe the rate of change of the solute concentrations of pore water in a variably saturated, non-isothermal porous medium, and the alteration of waste forms, packaging materials, backfill, and host rocks.

  9. Subsurface Transport Over Reactive Multiphases (STORM): A general, coupled, nonisothermal multiphase flow, reactive transport, and porous medium alteration simulator, Version 2 user's guide

    International Nuclear Information System (INIS)

    Bacon, D.H.; White, M.D.; McGrail, B.P.

    2000-01-01

    The Hanford Site, in southeastern Washington State, has been used extensively to produce nuclear materials for the US strategic defense arsenal by the Department of Energy (DOE) and its predecessors, the US Atomic Energy Commission and the US Energy Research and Development Administration. A large inventory of radioactive and mixed waste has accumulated in 177 buried single- and double shell tanks. Liquid waste recovered from the tanks will be pretreated to separate the low-activity fraction from the high-level and transuranic wastes. Vitrification is the leading option for immobilization of these wastes, expected to produce approximately 550,000 metric tons of Low Activity Waste (LAW) glass. This total tonnage, based on nominal Na 2 O oxide loading of 20% by weight, is destined for disposal in a near-surface facility. Before disposal of the immobilized waste can proceed, the DOE must approve a performance assessment, a document that described the impacts, if any, of the disposal facility on public health and environmental resources. Studies have shown that release rates of radionuclides from the glass waste form by reaction with water determine the impacts of the disposal action more than any other independent parameter. This report describes the latest accomplishments in the development of a computational tool, Subsurface Transport Over Reactive Multiphases (STORM), Version 2, a general, coupled non-isothermal multiphase flow and reactive transport simulator. The underlying mathematics in STORM describe the rate of change of the solute concentrations of pore water in a variably saturated, non-isothermal porous medium, and the alteration of waste forms, packaging materials, backfill, and host rocks

  10. Flow mapping of multiphase flows using a novel single stem endoscopic particle image velocimetry instrument

    International Nuclear Information System (INIS)

    Lad, N; Adebayo, D; Aroussi, A

    2011-01-01

    Particle image velocimetry (PIV) is a successful flow mapping technique which can optically quantify large portions of a flow regime. This enables the method to be completely non-intrusive. The ability to be non-intrusive to any flow has allowed PIV to be used in a large range of industrial sectors for many applications. However, a fundamental disadvantage of the conventional PIV technique is that it cannot easily be used with flows which have no or limited optical access. Flows which have limited optical access for PIV measurement have been addressed using endoscopic PIV techniques. This system uses two separate probes which relay a light sheet and imaging optics to a planar position within the desired flow regime. This system is effective in medical and engineering applications. The present study has been involved in the development of a new endoscopic PIV system which integrates the illumination and imaging optics into one rigid probe. This paper focuses on the validation of the images taken from the novel single stem endoscopic PIV system. The probe is used within atomized spray flow and is compared with conventional PIV measurement and also pitot-static data. The endoscopic PIV system provides images which create localized velocity maps that are comparable with the global measurement of the conventional PIV system. The velocity information for both systems clearly show similar results for the spray characterization and are also validated using the pitot-static data

  11. Computation of three-dimensional multiphase flow dynamics by Fully-Coupled Immersed Flow (FCIF) solver

    Science.gov (United States)

    Miao, Sha; Hendrickson, Kelli; Liu, Yuming

    2017-12-01

    This work presents a Fully-Coupled Immersed Flow (FCIF) solver for the three-dimensional simulation of fluid-fluid interaction by coupling two distinct flow solvers using an Immersed Boundary (IB) method. The FCIF solver captures dynamic interactions between two fluids with disparate flow properties, while retaining the desirable simplicity of non-boundary-conforming grids. For illustration, we couple an IB-based unsteady Reynolds Averaged Navier Stokes (uRANS) simulator with a depth-integrated (long-wave) solver for the application of slug development with turbulent gas and laminar liquid. We perform a series of validations including turbulent/laminar flows over prescribed wavy boundaries and freely-evolving viscous fluids. These confirm the effectiveness and accuracy of both one-way and two-way coupling in the FCIF solver. Finally, we present a simulation example of the evolution from a stratified turbulent/laminar flow through the initiation of a slug that nearly bridges the channel. The results show both the interfacial wave dynamics excited by the turbulent gas forcing and the influence of the liquid on the gas turbulence. These results demonstrate that the FCIF solver effectively captures the essential physics of gas-liquid interaction and can serve as a useful tool for the mechanistic study of slug generation in two-phase gas/liquid flows in channels and pipes.

  12. CFD of mixing of multi-phase flow in a bioreactor using population balance model.

    Science.gov (United States)

    Sarkar, Jayati; Shekhawat, Lalita Kanwar; Loomba, Varun; Rathore, Anurag S

    2016-05-01

    Mixing in bioreactors is known to be crucial for achieving efficient mass and heat transfer, both of which thereby impact not only growth of cells but also product quality. In a typical bioreactor, the rate of transport of oxygen from air is the limiting factor. While higher impeller speeds can enhance mixing, they can also cause severe cell damage. Hence, it is crucial to understand the hydrodynamics in a bioreactor to achieve optimal performance. This article presents a novel approach involving use of computational fluid dynamics (CFD) to model the hydrodynamics of an aerated stirred bioreactor for production of a monoclonal antibody therapeutic via mammalian cell culture. This is achieved by estimating the volume averaged mass transfer coefficient (kL a) under varying conditions of the process parameters. The process parameters that have been examined include the impeller rotational speed and the flow rate of the incoming gas through the sparger inlet. To undermine the two-phase flow and turbulence, an Eulerian-Eulerian multiphase model and k-ε turbulence model have been used, respectively. These have further been coupled with population balance model to incorporate the various interphase interactions that lead to coalescence and breakage of bubbles. We have successfully demonstrated the utility of CFD as a tool to predict size distribution of bubbles as a function of process parameters and an efficient approach for obtaining optimized mixing conditions in the reactor. The proposed approach is significantly time and resource efficient when compared to the hit and trial, all experimental approach that is presently used. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:613-628, 2016. © 2016 American Institute of Chemical Engineers.

  13. Robust second-order scheme for multi-phase flow computations

    Science.gov (United States)

    Shahbazi, Khosro

    2017-06-01

    A robust high-order scheme for the multi-phase flow computations featuring jumps and discontinuities due to shock waves and phase interfaces is presented. The scheme is based on high-order weighted-essentially non-oscillatory (WENO) finite volume schemes and high-order limiters to ensure the maximum principle or positivity of the various field variables including the density, pressure, and order parameters identifying each phase. The two-phase flow model considered besides the Euler equations of gas dynamics consists of advection of two parameters of the stiffened-gas equation of states, characterizing each phase. The design of the high-order limiter is guided by the findings of Zhang and Shu (2011) [36], and is based on limiting the quadrature values of the density, pressure and order parameters reconstructed using a high-order WENO scheme. The proof of positivity-preserving and accuracy is given, and the convergence and the robustness of the scheme are illustrated using the smooth isentropic vortex problem with very small density and pressure. The effectiveness and robustness of the scheme in computing the challenging problem of shock wave interaction with a cluster of tightly packed air or helium bubbles placed in a body of liquid water is also demonstrated. The superior performance of the high-order schemes over the first-order Lax-Friedrichs scheme for computations of shock-bubble interaction is also shown. The scheme is implemented in two-dimensional space on parallel computers using message passing interface (MPI). The proposed scheme with limiter features approximately 50% higher number of inter-processor message communications compared to the corresponding scheme without limiter, but with only 10% higher total CPU time. The scheme is provably second-order accurate in regions requiring positivity enforcement and higher order in the rest of domain.

  14. Pore-scale studies of multiphase flow and reaction involving CO2 sequestration in geologic formations

    Science.gov (United States)

    Kang, Q.; Wang, M.; Lichtner, P. C.

    2008-12-01

    In geologic CO2 sequestration, pore-scale interfacial phenomena ultimately govern the key processes of fluid mobility, chemical transport, adsorption, and reaction. However, spatial heterogeneity at the pore scale cannot be resolved at the continuum scale, where averaging occurs over length scales much larger than typical pore sizes. Natural porous media, such as sedimentary rocks and other geological media encountered in subsurface formations, are inherently heterogeneous. This pore-scale heterogeneity can produce variabilities in flow, transport, and reaction processes that take place within a porous medium, and can result in spatial variations in fluid velocity, aqueous concentrations, and reaction rates. Consequently, the unresolved spatial heterogeneity at the pore scale may be important for reactive transport modeling at the larger scale. In addition, current continuum models of surface complexation reactions ignore a fundamental property of physical systems, namely conservation of charge. Therefore, to better understand multiphase flow and reaction involving CO2 sequestration in geologic formations, it is necessary to quantitatively investigate the influence of the pore-scale heterogeneity on the emergent behavior at the field scale. We have applied the lattice Boltzmann method to simulating the injection of CO2 saturated brine or supercritical CO2 into geological formations at the pore scale. Multiple pore-scale processes, including advection, diffusion, homogeneous reactions among multiple aqueous species, heterogeneous reactions between the aqueous solution and minerals, ion exchange and surface complexation, as well as changes in solid and pore geometry are all taken into account. The rich pore scale information will provide a basis for upscaling to the continuum scale.

  15. Effect of wettability on scale-up of multiphase flow from core-scale to reservoir fine-grid-scale

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Y.C.; Mani, V.; Mohanty, K.K. [Univ. of Houston, TX (United States)

    1997-08-01

    Typical field simulation grid-blocks are internally heterogeneous. The objective of this work is to study how the wettability of the rock affects its scale-up of multiphase flow properties from core-scale to fine-grid reservoir simulation scale ({approximately} 10{prime} x 10{prime} x 5{prime}). Reservoir models need another level of upscaling to coarse-grid simulation scale, which is not addressed here. Heterogeneity is modeled here as a correlated random field parameterized in terms of its variance and two-point variogram. Variogram models of both finite (spherical) and infinite (fractal) correlation length are included as special cases. Local core-scale porosity, permeability, capillary pressure function, relative permeability functions, and initial water saturation are assumed to be correlated. Water injection is simulated and effective flow properties and flow equations are calculated. For strongly water-wet media, capillarity has a stabilizing/homogenizing effect on multiphase flow. For small variance in permeability, and for small correlation length, effective relative permeability can be described by capillary equilibrium models. At higher variance and moderate correlation length, the average flow can be described by a dynamic relative permeability. As the oil wettability increases, the capillary stabilizing effect decreases and the deviation from this average flow increases. For fractal fields with large variance in permeability, effective relative permeability is not adequate in describing the flow.

  16. Dynamic relaxation processes in compressible multiphase flows. Application to evaporation phenomena

    Directory of Open Access Journals (Sweden)

    Le Métayer O.

    2013-07-01

    Full Text Available Phase changes and heat exchanges are examples of physical processes appearing in many industrial applications involving multiphase compressible flows. Their knowledge is of fundamental importance to reproduce correctly the resulting effects in simulation tools. A fine description of the flow topology is thus required to obtain the interfacial area between phases. This one is responsible for the dynamics and the kinetics of heat and mass transfer when evaporation or condensation occurs. Unfortunately this exchange area cannot be obtained easily and accurately especially when complex mixtures (drops, bubbles, pockets of very different sizes appear inside the transient medium. The natural way to solve this specific trouble consists in using a thin grid to capture interfaces at all spatial scales. But this possibility needs huge computing resources and can be hardly used when considering physical systems of large dimensions. A realistic method is to consider instantaneous exchanges between phases by the way of additional source terms in a full non-equilibrium multiphase flow model [2,15,17]. In this one each phase obeys its own equation of state and has its own set of equations and variables (pressure, temperature, velocity, energy, entropy,.... When enabling the relaxation source terms the multiphase mixture instantaneously tends towards a mechanical or thermodynamic equilibrium state at each point of the flow. This strategy allows to mark the boundaries of the real flow behavior and to magnify the dominant physical effects (heat exchanges, evaporation, drag,... inside the medium. A description of the various relaxation processes is given in the paper. Les changements de phase et les transferts de chaleur sont des exemples de phénomènes physiques présents dans de nombreuses applications industrielles faisant intervenir des écoulements compressibles multiphasiques. La connaissance des mécanismes associés est primordiale afin de reproduire

  17. Instantaneous equations for multiphase flow in porous media without length-scale restrictions using a non-local averaging volume

    International Nuclear Information System (INIS)

    Espinosa-Paredes, Gilberto

    2010-01-01

    The aim of this paper is to propose a framework to obtain a new formulation for multiphase flow conservation equations without length-scale restrictions, based on the non-local form of the averaged volume conservation equations. The simplification of the local averaging volume of the conservation equations to obtain practical equations is subject to the following length-scale restrictions: d << l << L, where d is the characteristic length of the dispersed phases, l is the characteristic length of the averaging volume, and L is the characteristic length of the physical system. If the foregoing inequality does not hold, or if the scale of the problem of interest is of the order of l, the averaging technique and therefore, the macroscopic theories of multiphase flow should be modified in order to include appropriate considerations and terms in the corresponding equations. In these cases the local form of the averaged volume conservation equations are not appropriate to describe the multiphase system. As an example of the conservation equations without length-scale restrictions, the natural circulation boiling water reactor was consider to study the non-local effects on the thermal-hydraulic core performance during steady-state and transient behaviors, and the results were compared with the classic local averaging volume conservation equations.

  18. TOUGHREACT User's Guide: A Simulation Program for Non-isothermal Multiphase Reactive geochemical Transport in Variable Saturated Geologic Media

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Tianfu; Sonnenthal, Eric; Spycher, Nicolas; Pruess, Karsten

    2004-05-24

    Coupled modeling of subsurface multiphase fluid and heat flow, solute transport and chemical reactions can be used for the assessment of mineral alteration in hydrothermal systems, waste disposal sites, acid mine drainage remediation, contaminant transport, and groundwater quality. A comprehensive non-isothermal multi-component reactive fluid flow and geochemical transport simulator, TOUGHREACT, has been developed. A wide range of subsurface thermo-physical-chemical processes is considered under various thermohydrological and geochemical conditions of pressure, temperature, water saturation, and ionic strength. The program can be applied to one-, two- or three-dimensional porous and fractured media with physical and chemical heterogeneity. The model can accommodate any number of chemical species present in liquid, gas and solid phases. A variety of equilibrium chemical reactions are considered, such as aqueous complexation, gas dissolution/exsolution, and cation exchange. Mineral dissolution/precipitation can proceed either subject to local equilibrium or kinetic conditions. Changes in porosity and permeability due to mineral dissolution and precipitation can be considered. Linear adsorption and decay can be included. For the purpose of future extensions, surface complexation by double layer model is coded in the program. Xu and Pruess (1998) developed a first version of a non-isothermal reactive geochemical transport model, TOUGHREACT, by introducing reactive geochemistry into the framework of the existing multi-phase fluid and heat flow code TOUGH2 (Pruess, 1991). Xu, Pruess, and their colleagues have applied the program to a variety of problems such as: (1) supergene copper enrichment (Xu et al, 2001), (2) caprock mineral alteration in a hydrothermal system (Xu and Pruess, 2001a), and (3) mineral trapping for CO{sub 2} disposal in deep saline aquifers (Xu et al, 2003b and 2004a). For modeling the coupled thermal, hydrological, and chemical processes during

  19. Micro-Ct Imaging of Multi-Phase Flow in Carbonates and Sandstones

    Science.gov (United States)

    Andrew, M. G.; Bijeljic, B.; Blunt, M. J.

    2013-12-01

    One of the most important mechanisms that limits the escape of CO2 when injected into the subsurface for the purposes of carbon storage is capillary trapping, where CO2 is stranded as pore-scale droplets (ganglia). Prospective storage sites are aquifers or reservoirs that tend to be at conditions where CO2 will reside as a super-critical phase. In order to fully describe physical mechanisms characterising multi-phase flow during and post CO2 injection, experiments need to be conducted at these elevated aquifer/reservoir conditions - this poses a considerable experimental challenge. A novel experimental apparatus has been developed which uses μCT scanning for the non-invasive imaging of the distribution of CO2 in the pore space of rock with resolutions of 7μm at temperatures and pressures representative of the conditions present in prospective saline aquifer CO2 storage sites. The fluids are kept in chemical equilibrium with one-another and with the rock into which they are injected. This is done to prevent the dissolution of the CO2 in the brine to form carbonic acid, which can then react with the rock, particularly carbonates. By eliminating reaction we study the fundamental mechanisms of capillary trapping for an unchanging pore structure. In this study we present a suite of results from three carbonate and two sandstone rock types, showing that, for both cases the CO2 acts as the non-wetting phase and significant quantities of CO2 is trapped. The carbonate examined represent a wide variety of pore topologies with one rock with a very well connected, high porosity pore space (Mt Gambier), one with a lower porosity, poorly connected pore space (Estaillades) and one with a cemented bead pack type pore space (Ketton). Both sandstones (Doddington and Bentheimer) were high permeability granular quartzites. CO2 was injected into each rock, followed by brine injection. After brine injection the entire length of the rock core was scanned, processed and segmented into

  20. A novel heterogeneous algorithm to simulate multiphase flow in porous media on multicore CPU-GPU systems

    Science.gov (United States)

    McClure, J. E.; Prins, J. F.; Miller, C. T.

    2014-07-01

    Multiphase flow implementations of the lattice Boltzmann method (LBM) are widely applied to the study of porous medium systems. In this work, we construct a new variant of the popular "color" LBM for two-phase flow in which a three-dimensional, 19-velocity (D3Q19) lattice is used to compute the momentum transport solution while a three-dimensional, seven velocity (D3Q7) lattice is used to compute the mass transport solution. Based on this formulation, we implement a novel heterogeneous GPU-accelerated algorithm in which the mass transport solution is computed by multiple shared memory CPU cores programmed using OpenMP while a concurrent solution of the momentum transport is performed using a GPU. The heterogeneous solution is demonstrated to provide speedup of 2.6 × as compared to multi-core CPU solution and 1.8 × compared to GPU solution due to concurrent utilization of both CPU and GPU bandwidths. Furthermore, we verify that the proposed formulation provides an accurate physical representation of multiphase flow processes and demonstrate that the approach can be applied to perform heterogeneous simulations of two-phase flow in porous media using a typical GPU-accelerated workstation.

  1. Modification of TOUGH2 to Include the Dusty Gas Model for Gas Diffusion; TOPICAL

    International Nuclear Information System (INIS)

    WEBB, STEPHEN W.

    2001-01-01

    The GEO-SEQ Project is investigating methods for geological sequestration of CO(sub 2). This project, which is directed by LBNL and includes a number of other industrial, university, and national laboratory partners, is evaluating computer simulation methods including TOUGH2 for this problem. The TOUGH2 code, which is a widely used code for flow and transport in porous and fractured media, includes simplified methods for gas diffusion based on a direct application of Fick's law. As shown by Webb (1998) and others, the Dusty Gas Model (DGM) is better than Fick's Law for modeling gas-phase diffusion in porous media. In order to improve gas-phase diffusion modeling for the GEO-SEQ Project, the EOS7R module in the TOUGH2 code has been modified to include the Dusty Gas Model as documented in this report. In addition, the liquid diffusion model has been changed from a mass-based formulation to a mole-based model. Modifications for separate and coupled diffusion in the gas and liquid phases have also been completed. The results from the DGM are compared to the Fick's law behavior for TCE and PCE diffusion across a capillary fringe. The differences are small due to the relatively high permeability (k= 10(sup -11) m(sup 2)) of the problem and the small mole fraction of the gases. Additional comparisons for lower permeabilities and higher mole fractions may be useful

  2. Modeling GPR data to interpret porosity and DNAPL saturations for calibration of a 3-D multiphase flow simulation

    Science.gov (United States)

    Sneddon, Kristen W.; Powers, Michael H.; Johnson, Raymond H.; Poeter, Eileen P.

    2002-01-01

    Dense nonaqueous phase liquids (DNAPLs) are a pervasive and persistent category of groundwater contamination. In an effort to better understand their unique subsurface behavior, a controlled and carefully monitored injection of PCE (perchloroethylene), a typical DNAPL, was performed in conjunction with the University of Waterloo at Canadian Forces Base Borden in 1991. Of the various geophysical methods used to monitor the migration of injected PCE, the U.S. Geological Survey collected 500-MHz ground penetrating radar (GPR) data. These data are used in determining calibration parameters for a multiphase flow simulation. GPR data were acquired over time on a fixed two-dimensional surficial grid as the DNAPL was injected into the subsurface. Emphasis is on the method of determining DNAPL saturation values from this time-lapse GPR data set. Interactive full-waveform GPR modeling of regularized field traces resolves relative dielectric permittivity versus depth profiles for pre-injection and later-time data. Modeled values are end members in recursive calculations of the Bruggeman-Hanai-Sen (BHS) mixing formula, yielding interpreted pre-injection porosity and post-injection DNAPL saturation values. The resulting interpreted physical properties of porosity and DNAPL saturation of the Borden test cell, defined on a grid spacing of 50 cm with 1-cm depth resolution, are used as observations for calibration of a 3-D multiphase flow simulation. Calculated values of DNAPL saturation in the subsurface at 14 and 22 hours after the start of injection, from both the GPR and the multiphase flow modeling, are interpolated volumetrically and presented for visual comparison.

  3. Insights into the use of time-lapse GPR data as observations for inverse multiphase flow simulations of DNAPL migration

    Science.gov (United States)

    Johnson, R.H.; Poeter, E.P.

    2007-01-01

    Perchloroethylene (PCE) saturations determined from GPR surveys were used as observations for inversion of multiphase flow simulations of a PCE injection experiment (Borden 9??m cell), allowing for the estimation of optimal bulk intrinsic permeability values. The resulting fit statistics and analysis of residuals (observed minus simulated PCE saturations) were used to improve the conceptual model. These improvements included adjustment of the elevation of a permeability contrast, use of the van Genuchten versus Brooks-Corey capillary pressure-saturation curve, and a weighting scheme to account for greater measurement error with larger saturation values. A limitation in determining PCE saturations through one-dimensional GPR modeling is non-uniqueness when multiple GPR parameters are unknown (i.e., permittivity, depth, and gain function). Site knowledge, fixing the gain function, and multiphase flow simulations assisted in evaluating non-unique conceptual models of PCE saturation, where depth and layering were reinterpreted to provide alternate conceptual models. Remaining bias in the residuals is attributed to the violation of assumptions in the one-dimensional GPR interpretation (which assumes flat, infinite, horizontal layering) resulting from multidimensional influences that were not included in the conceptual model. While the limitations and errors in using GPR data as observations for inverse multiphase flow simulations are frustrating and difficult to quantify, simulation results indicate that the error and bias in the PCE saturation values are small enough to still provide reasonable optimal permeability values. The effort to improve model fit and reduce residual bias decreases simulation error even for an inversion based on biased observations and provides insight into alternate GPR data interpretations. Thus, this effort is warranted and provides information on bias in the observation data when this bias is otherwise difficult to assess. ?? 2006 Elsevier B

  4. The multiphase flow system used in exploiting depleted reservoirs: water-based Micro-bubble drilling fluid

    Science.gov (United States)

    Li-hui, Zheng; Xiao-qing, He; Li-xia, Fu; Xiang-chun, Wang

    2009-02-01

    Water-based micro-bubble drilling fluid, which is used to exploit depleted reservoirs, is a complicated multiphase flow system that is composed of gas, water, oil, polymer, surfactants and solids. The gas phase is separate from bulk water by two layers and three membranes. They are "surface tension reducing membrane", "high viscosity layer", "high viscosity fixing membrane", "compatibility enhancing membrane" and "concentration transition layer of liner high polymer (LHP) & surfactants" from every gas phase centre to the bulk water. "Surface tension reducing membrane", "high viscosity layer" and "high viscosity fixing membrane" bond closely to pack air forming "air-bag", "compatibility enhancing membrane" and "concentration transition layer of LHP & surfactants" absorb outside "air-bag" to form "incompact zone". From another point of view, "air-bag" and "incompact zone" compose micro-bubble. Dynamic changes of "incompact zone" enable micro-bubble to exist lonely or aggregate together, and lead the whole fluid, which can wet both hydrophilic and hydrophobic surface, to possess very high viscosity at an extremely low shear rate but to possess good fluidity at a higher shear rate. When the water-based micro-bubble drilling fluid encounters leakage zones, it will automatically regulate the sizes and shapes of the bubbles according to the slot width of fracture, the height of cavern as well as the aperture of openings, or seal them by making use of high viscosity of the system at a very low shear rate. Measurements of the rheological parameters indicate that water-based micro-bubble drilling fluid has very high plastic viscosity, yield point, initial gel, final gel and high ratio of yield point and plastic viscosity. All of these properties make the multiphase flow system meet the requirements of petroleum drilling industry. Research on interface between gas and bulk water of this multiphase flow system can provide us with information of synthesizing effective agents to

  5. Three-dimensional multiphase flow computational fluid dynamics models for proton exchange membrane fuel cell: A theoretical development

    Directory of Open Access Journals (Sweden)

    Jean-Paul Kone

    2017-03-01

    Full Text Available A review of published three-dimensional, computational fluid dynamics models for proton exchange membrane fuel cells that accounts for multiphase flow is presented. The models can be categorized as models for transport phenomena, geometry or operating condition effects, and thermal effects. The influences of heat and water management on the fuel cell performance have been repeatedly addressed, and these still remain two central issues in proton exchange membrane fuel cell technology. The strengths and weaknesses of the models, the modelling assumptions, and the model validation are discussed. The salient numerical features of the models are examined, and an overview of the most commonly used computational fluid dynamic codes for the numerical modelling of proton exchange membrane fuel cells is given. Comprehensive three-dimensional multiphase flow computational fluid dynamic models accounting for the major transport phenomena inside a complete cell have been developed. However, it has been noted that more research is required to develop models that include among other things, the detailed composition and structure of the catalyst layers, the effects of water droplets movement in the gas flow channels, the consideration of phase change in both the anode and the cathode sides of the fuel cell, and dissolved water transport.

  6. On the inclusion of the interfacial area between phases in the physical and mathematical description of subsurface multiphase flow. 1998 annual progress report

    International Nuclear Information System (INIS)

    Gray, W.G.; Soll, W.E.; Tompson, A.

    1998-01-01

    'Improved capabilities for modeling multiphase flow in the subsurface requires that several aspects of the system which impact the flow and transport processes be more properly accounted for. A distinguishing feature of multiphase flow in comparison to single phase flow is the existence of interfaces between fluids. At the microscopic (pore) scale, these interfaces are known to influence system behavior by supporting non-zero stresses such that the pressures in adjacent phases are not equal. In problems of interphase transport at the macroscopic (core) scale, knowledge of the total amount of interfacial area in the system provides a clue to the effectiveness of the communication between phases. Although interfacial processes are central to multiphase flow physics, their treatment in traditional porous-media theories has been implicit rather than explicit; and no attempts have been made to systematically account for the evolution of the interfacial area in dynamic systems or to include the dependence of constitutive functions, such as capillary pressure, on the interfacial area. This project implements a three-pronged approach to assessing the importance of various features of multiphase flow to its description. The research contributes to the improved understanding and precise physical description of multiphase subsurface flow by combining: (1) theoretical derivation of equations, (2) lattice Boltzmann modeling of hydrodynamics to identify characteristics and parameters, and (3) solution of the field-scale equations using a discrete numerical method to assess the advantages and disadvantages of the complete theory. This approach includes both fundamental scientific inquiry and a path for inclusion of the scientific results obtained in a technical tool that will improve assessment capabilities for multiphase flow situations that have arisen due to the introduction of organic materials in the natural environment. This report summarizes work after 1.5 years of a 3

  7. A turbulent transport network model in MULTIFLUX coupled with TOUGH2

    International Nuclear Information System (INIS)

    Danko, G.; Bahrami, D.; Birkholzer, J.T.

    2011-01-01

    A new numerical method is described for the fully iterated, conjugate solution of two discrete submodels, involving (a) a transport network model for heat, moisture, and airflows in a high-permeability, air-filled cavity; and (b) a variably saturated fractured porous medium. The transport network submodel is an integrated-parameter, computational fluid dynamics solver, describing the thermal-hydrologic transport processes in the flow channel system of the cavity with laminar or turbulent flow and convective heat and mass transport, using MULTIFLUX. The porous medium submodel, using TOUGH2, is a solver for the heat and mass transport in the fractured rock mass. The new model solution extends the application fields of TOUGH2 by integrating it with turbulent flow and transport in a discrete flow network system. We present demonstrational results for a nuclear waste repository application at Yucca Mountain with the most realistic model assumptions and input parameters including the geometrical layout of the nuclear spent fuel and waste with variable heat load for the individual containers. The MULTIFLUX and TOUGH2 model elements are fully iterated, applying a programmed reprocessing of the Numerical Transport Code Functionalization model-element in an automated Outside Balance Iteration loop. The natural, convective airflow field and the heat and mass transport in a representative emplacement drift during postclosure are explicitly solved in the new model. The results demonstrate that the direction and magnitude of the air circulation patterns and all transport modes are strongly affected by the heat and moisture transport processes in the surrounding rock, justifying the need for a coupled, fully iterated model solution such as the one presented in the paper.

  8. A study of multi-phase flow through the cathode side of an interdigitated flow field using a multi-fluid model

    DEFF Research Database (Denmark)

    Berning, Torsten; Odgaard, Madeleine; Kær, Søren Knudsen

    2010-01-01

    This work presents a study of multi-phase flow through the cathode side of a polymer electrolyte membrane fuel cell employing an interdigitated flow field plate. A previously published model has been extended in order to account for phase change kinetics, and a comparison between the interdigitated....... The additional compressor work due to the increased pressure loss will only slightly increase, and this may be offset by operating at lower stoichiometries as the interdigitated design is less mass transfer controlled, which means that the overall efficiency of the interdigitated arrangement will be higher...

  9. Numerical Tools for Multicomponent, Multiphase, Reactive Processes: Flow of CO{sub 2} in Porous Medium

    Energy Technology Data Exchange (ETDEWEB)

    Khattri, Sanjay Kumar

    2006-07-01

    The thesis is concerned with numerically simulating multicomponent, multiphase, reactive transport in heterogeneous porous medium. Such processes are ubiquitous, for example, deposition of green house gases, flow of hydrocarbons and groundwater remediation. Understanding such processes is important from social and economic point of view. For the success of geological sequestration, an accurate estimation of migration patterns of green-house gases is essential. Due to an ever increasing computer power, computational mathematics has become an important tool for predicting dynamics of porous media fluids. Numerical and mathematical modelling of processes in a domain requires grid generation in the domain, discretization of the continuum equations on the generated grid, solution of the formed linear or nonlinear system of discrete equations and finally visualization of the results. The thesis is composed of three chapters and eight papers. Chapter 2 presents two techniques for generating structured quadrilateral and hexahedral meshes. These techniques are called algebraic and elliptic methods. Algebraic techniques are by far the most simple and computationally efficient method for grid generation. Transfinite interpolation operators are a kind of algebraic grid generation technique. In this chapter, many transfinite interpolation operators for grid generation are derived from 1D projection operators. In this chapter, some important properties of hexahedral elements are also mentioned. These properties are useful in discretization of partial differential equations on hexahedral mesh, improving quality of the hexahedral mesh, mesh generation and visualization. Chapter 3 is about CO{sub 2} flow in porous media. In this chapter, we present the mathematical models and their discretization for capturing major physical processes associated with CO{sub 2} deposition in geological formations. Some important simulations of practical applications in 2D and 3D are presented

  10. Multiphase Venturi Dual Energy Gamma Ray combination performance in NUEX flow loop; Desempenho no flowloop do NUEX da medicao multifasica Venturi Dual Energy Gamma Ray

    Energy Technology Data Exchange (ETDEWEB)

    Barreiros, Claudio; Taranto, Cleber; Costa, Alcemir [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil); Pinguet, Bruno; Heluey, Vitor; Bessa, Fabiano; Loicq, Olivier [Schlumberger Servicos de Petroleo Ltda., Rio de Janeiro, RJ (Brazil)

    2008-07-01

    The Multiphase Venturi Dual Energy Gamma Ray Combination, Vx* technology, arrived in Brazil in 2000. PETROBRAS, Brazilian Oil Company, has been putting big efforts in its production business and also has demonstrated a large interest in having a multiphase meter approved by ANP for back allocation purposes. The oil industry was looking for ways to improve the back allocation process using an approved on line multiphase flow measurement device, thus replacing punctual test done today by a permanent monitoring device. Considering this scenario, a partnership project between PETROBRAS and Schlumberger was created in Brazil. The main objective of this project, which was held in NUEX flow loop, was to demonstrate to INMETRO (Brazilian Metrology Institute) that the Multiphase Venturi Dual Energy Gamma Ray Combination meter is able to be used for back allocation purpose. PETROBRAS and Schlumberger elaborated a complete methodology in the NUEX flow loop to demonstrate the results and benefits of the Multiphase Venturi Dual Energy Gamma Ray Combination meter. The test was witnessed by INMETRO and had a very good performance at the end. The results were within what was expected by Schlumberger, PETROBRAS and INMETRO. These results has been very useful to PETROBRAS in order to start using the Venturi Dual Energy Gamma Ray technology for well allocation purposes. (author)

  11. Design and Calibration of a Full-Scale Active Magnetic Bearing-Based Test Facility for Investigating Rotordynamic Properties of Turbomachinery Seals in Multiphase Flow

    DEFF Research Database (Denmark)

    Voigt, Andreas Jauernik; Mandrup-Poulsen, Christian; Nielsen, Kenny

    2017-01-01

    of the subsea installed rotating machinery. It is well known that careful design of turbomachinery seals, such as interstage and balance piston seals, is pivotal for the performance of pumps and compressors. Consequently, the ability to predict the complex interaction between fluid dynamics and rotordynamics...... leads to technical challenges for the subsea installed pumps and compressors that are now required to handle multiphase flow of varying gas to liquid ratios. This highlights the necessity for a strong research focus on multiphase flow impact on rotordynamic properties and thereby operational stability...

  12. Design and Calibration of a Full Scale Active Magnetic Bearing Based Test Facility for Investigating Rotordynamic Properties of Turbomachinery Seals in Multiphase Flow

    DEFF Research Database (Denmark)

    Voigt, Andreas Jauernik; Mandrup-Poulsen, Christian; Nielsen, Kenny Krogh

    2016-01-01

    of the subsea installed rotating machinery. It is well known that careful design of turbomachinery seals, such as interstage and balance piston seals, is pivotal for the performance of pumps and compressors. Consequently, the ability to predict the complex interaction between fluid dynamics and rotordynamics...... leads to technical challenges for the subsea installed pumps and compressors that are now required to handle multiphase flow of varying gas to liquid ratios. This highlights the necessity for a strong research focus on multiphase flow impact on rotordynamic properties and thereby operational stability...

  13. Numerical Simulation of Multiphase Magnetohydrodynamic Flow and Deformation of Electrolyte-Metal Interface in Aluminum Electrolysis Cells

    Science.gov (United States)

    Hua, Jinsong; Rudshaug, Magne; Droste, Christian; Jorgensen, Robert; Giskeodegard, Nils-Haavard

    2018-02-01

    A computational fluid dynamics based multiphase magnetohydrodynamic (MHD) flow model for simulating the melt flow and bath-metal interface deformation in realistic aluminum reduction cells is presented. The model accounts for the complex physics of the MHD problem in aluminum reduction cells by coupling two immiscible fluids, electromagnetic field, Lorentz force, flow turbulence, and complex cell geometry with large length scale. Especially, the deformation of bath-metal interface is tracked directly in the simulation, and the condition of constant anode-cathode distance (ACD) is maintained by moving anode bottom dynamically with the deforming bath-metal interface. The metal pad deformation and melt flow predicted by the current model are compared to the predictions using a simplified model where the bath-metal interface is assumed flat. The effects of the induced electric current due to fluid flow and the magnetic field due to the interior cell current on the metal pad deformation and melt flow are investigated. The presented model extends the conventional simplified box model by including detailed cell geometry such as the ledge profile and all channels (side, central, and cross-channels). The simulations show the model sensitivity to different side ledge profiles and the cross-channel width by comparing the predicted melt flow and metal pad heaving. In addition, the model dependencies upon the reduction cell operation conditions such as ACD, current distribution on cathode surface and open/closed channel top, are discussed.

  14. Coupling Analysis of Low-Speed Multiphase Flow and High-Frequency Electromagnetic Field in a Complex Pipeline Structure

    Directory of Open Access Journals (Sweden)

    Xiaokai Huo

    2014-01-01

    Full Text Available Accurate estimation of water content in an oil-water mixture is a key technology in oil exploration and production. Based on the principles of the microwave transmission line (MTL, the logging probe is an important water content measuring apparatus. However, the effects of mixed fluid flow on the measurement of electromagnetic field parameters are rarely considered. This study presents the coupling model for low-speed multiphase flow and high-frequency electromagnetic field in a complex pipeline structure. We derived the S-parameter equations for the stratified oil/water flow model. The corresponding relationship between the S-parameters and water holdup is established. Evident coupling effects of the fluid flow and the electromagnetic field are confirmed by comparing the calculated S-parameters for both stratified and homogeneous flow patterns. In addition, a multiple-solution problem is analyzed for the inversion of dielectric constant from the S-parameters. The most sensitive phase angle range is determined to improve the detection of variation in the dielectric constant. Suggestions are proposed based on the influence of the oil/water layer on measurement sensitivity to optimize the geometric parameters of a device structure. The method proposed elucidates how accuracy and sensitivity can be improved in water holdup measurements under high water content conditions.

  15. TOUGH2 simulations of the TEVES Project including the behavior of a single-component NAPL

    Energy Technology Data Exchange (ETDEWEB)

    Webb, S.W. [Sandia National Labs., Albuquerque, NM (United States). Geohydrology Dept.

    1996-05-01

    The TEVES (Thermal Enhanced Vapor Extraction System) Project is a demonstration of a process designed to extract solvents and chemicals contained in the Chemical Waste Landfill at Sandia National Laboratories. In this process, the ground is electrically heated, and borehole(s) within the heated zone are maintained at a vacuum to draw air and evaporated contaminants into the borehole and a subsequent treatment facility. TOUGH2 simulations have been performed to evaluate the fluid flow and heat transfer behavior of the system. The TOUGH2 version used in this study includes air, water, and a single-component non-aqueous phase liquid (NAPL). In the present simulations, an initial o-xylene inventory is assumed in the heated zone for illustration purposes. Variation in borehole (vapor extraction) vacuum, borehole location, and soil permeability were investigated. Simulations indicate that the temperatures in the soil are relatively insensitive to the magnitude of the borehole vacuum or the borehole locations. In contrast, however, the NAPL and liquid water saturation distributions are sensitive to these borehole parameters. As the borehole vacuum and air flow rate through the soil decrease, the possibility of contaminant (NAPL) migration from the heated zone into the surrounding unheated soil increases. The borehole location can also affect the likelihood of contaminant movement into the unheated soil.

  16. EOSN: A TOUGH2 module for noble gases

    International Nuclear Information System (INIS)

    Shan, Chao; Pruess, Karsten

    2003-01-01

    We developed a new fluid property module for TOUGH2, called EOSN, to simulate transport of noble gases in the subsurface. Currently, users may select any of five different noble gases as well as CO2, two at a time. For the three gas components (air and two user-specified noble gases) in EOSN, the Henry's coefficients and the diffusivities in the gas phase are no longer assumed constants, but are temperature dependent. We used the Crovetto et al. (1982) model to estimate Henry's coefficients, and the Reid et al. (1987) correlations to calculate gas phase diffusivities. The new module requires users to provide names of the selected noble gases, which properties are provided internally. There are options for users to specify any (non-zero) molecular weights and half-lives for the gas components. We provide two examples to show applications of TOUGH2IEOSN. While temperature effects are relatively insignificant for one example problem where advection is dominant, they cause almost an order of magnitude difference for the other case where diffusion becomes a dominant process and temperature variations are relatively large. It appears that thermodynamic effects on gas diffusivities and Henry's coefficients can be important for low-permeability porous media and zones with large temperature variations

  17. Study of geometry to obtain the volume fraction of multiphase flows using the MCNP-X code

    International Nuclear Information System (INIS)

    Peixoto, Philippe N.B.; Salgado, Cesar M.

    2015-01-01

    The gamma ray attenuation technique is used in many works to obtaining volume fraction of multiphase flows in the oil industry, because it is a noninvasive technique with good precision. In these studies are simulated various geometries with different flow regime, compositions of materials, source-detector positions and types of collimation for sources. This work aim evaluate the interference in the results of the geometry changes and obtaining the best measuring geometry to provide the volume fractions accurately by evaluating different geometries simulations (ranging the source-detector position, flow schemes and homogeneity Makeup) in the MCNP-X code. The study was performed for two types of biphasic compositions of materials (oil-water and oil-air), two flow regimes (annular and smooth stratified) and was varied the position of each material in relative to source and detector positions. Another study to evaluate the interference of homogeneity of the compositions in the results was also conducted in order to verify the possibility of removing part of the composition and make a homogeneous blend using a mixer equipment. All these variations were simulated with two different types of beam, divergent beam and pencil beam. From the simulated geometries, it was possible to compare the differences between the areas of the spectra generated for each model. The results indicate that the flow regime and the differences in the material's densities interfere in the results being necessary to establish a specific simulation geometry for each flows regime. However, the simulations indicate that changing the type of collimation of sources do not affect the results, but improving the counts statistics, increasing the accurate. (author)

  18. Comprehensive Approaches to Multiphase Flows in Geophysics - Application to nonisothermal, nonhomogenous, unsteady, large-scale, turbulent dusty clouds I. Hydrodynamic and Thermodynamic RANS and LES Models

    Energy Technology Data Exchange (ETDEWEB)

    S. Dartevelle

    2005-09-05

    The objective of this manuscript is to fully derive a geophysical multiphase model able to ''accommodate'' different multiphase turbulence approaches; viz., the Reynolds Averaged Navier-Stokes (RANS), the Large Eddy Simulation (LES), or hybrid RANSLES. This manuscript is the first part of a larger geophysical multiphase project--lead by LANL--that aims to develop comprehensive modeling tools for large-scale, atmospheric, transient-buoyancy dusty jets and plume (e.g., plinian clouds, nuclear ''mushrooms'', ''supercell'' forest fire plumes) and for boundary-dominated geophysical multiphase gravity currents (e.g., dusty surges, diluted pyroclastic flows, dusty gravity currents in street canyons). LES is a partially deterministic approach constructed on either a spatial- or a temporal-separation between the large and small scales of the flow, whereas RANS is an entirely probabilistic approach constructed on a statistical separation between an ensemble-averaged mean and higher-order statistical moments (the so-called ''fluctuating parts''). Within this specific multiphase context, both turbulence approaches are built up upon the same phasic binary-valued ''function of presence''. This function of presence formally describes the occurrence--or not--of any phase at a given position and time and, therefore, allows to derive the same basic multiphase Navier-Stokes model for either the RANS or the LES frameworks. The only differences between these turbulence frameworks are the closures for the various ''turbulence'' terms involving the unknown variables from the fluctuating (RANS) or from the subgrid (LES) parts. Even though the hydrodynamic and thermodynamic models for RANS and LES have the same set of Partial Differential Equations, the physical interpretations of these PDEs cannot be the same, i.e., RANS models an averaged field, while LES simulates a

  19. Investigation of Multiscale and Multiphase Flow, Transport and Reaction in Heavy Oil Recovery Processes

    Energy Technology Data Exchange (ETDEWEB)

    Yorstos, Yannis C.

    2003-03-19

    The report describes progress made in the various thrust areas of the project, which include internal drives for oil recovery, vapor-liquid flows, combustion and reaction processes and the flow of fluids with yield stress.

  20. Modelling compressible multiphase flows Quelques résultats concernant la modélisation des écoulements multiphasiques

    Directory of Open Access Journals (Sweden)

    Coquel Frédéric

    2013-07-01

    Full Text Available We give in this paper a short review of some recent achievements within the framework of multiphase flow modeling. We focus first on a class of compressible two-phase flow models, detailing closure laws and their main properties. Next we briefly summarize some attempts to model two-phase flows in a porous region, and also a class of compressible three-phase flow models. Some of the main difficulties arising in the numerical simulation of solutions of these complex and highly non-linear systems of PDEs are then discussed, and we eventually show some numerical results when tackling two-phase flows with mass transfer. Nous présentons dans cet article quelques résultats récents concernant la modélisation et la simulation numérique des écoulements multiphasiques. Nous nous concentrons tout d’abord sur une classe de modèles diphasiques compressibles, en détaillant les lois de fermeture et les principales propriétés du sytème. Nous résumons ensuite brièvement les propositions de modélisation d’écoulements diphasiques en milieu poreux et d’écoulements triphasiques. Quelques difficultés apparaissant dans la simulation numérique de ces modèles sont présentées, et des résultats récents comportant un transfert de masse entre phases sont finalement décrits.

  1. FT-IR spectroscopic imaging of reactions in multiphase flow in microfluidic channels.

    Science.gov (United States)

    Chan, K L Andrew; Kazarian, Sergei G

    2012-05-01

    Rapid, in situ, and label-free chemical analysis in microfluidic devices is highly desirable. FT-IR spectroscopic imaging has previously been shown to be a powerful tool to visualize the distribution of different chemicals in flows in a microfluidic device at near video rate imaging speed without tracers or dyes. This paper demonstrates the possibility of using this imaging technology to capture the chemical information of all reactants and products at different points in time and space in a two-phase system. Differences in the rates of chemical reactions in laminar flow and segmented flow systems are also compared. Neutralization of benzoic acid in decanol with disodium phosphate in water has been used as the model reaction. Quantitative information, such as concentration profiles of reactant and products, can be extracted from the imaging data. The same feed flow rate was used in both the laminar flow and segmented flow systems. The laminar flow pattern was achieved using a plain wide T-junction, whereas the segmented flow was achieved by introducing a narrowed section and a nozzle at the T-junction. The results show that the reaction rate is limited by diffusion and is much slower with the laminar flow pattern, whereas the reaction is completed more quickly in the segmented flow due to better mixing.

  2. Advanced high speed X-ray CT scanner for measurement and visualization of multi-phase flow

    International Nuclear Information System (INIS)

    Hori, Keiichi; Fujimoto, Tetsuro; Kawanishi, Kohei; Nishikawa, Hideo

    1998-01-01

    The development of an ultra-fast X-ray computed tomography (CT) scanner has been performed. The object of interest is in a transient or unsettled state, which makes the conventional CT scanner inappropriate. A concept of electrical switching of electron beam of X-ray generation unit is adopted to reduce the scanning time instead of a mechanical motion adopted by a conventional CT scanner. The mechanical motion is a major obstacle to improve the scanning speed. A prototype system with a scanning time of 3.6 milliseconds was developed at first. And, the feasibility was confirmed to measure the dynamic events of two-phase flow. However, faster scanning speed is generally required for the practical use in the thermalhydraulics research field. Therefore, the development of advanced type has been performed. This advanced type can operate under the scanning time of 0.5 milliseconds and is applicable for the measurement of the multi-phase flow with velocity up to 4-5 m/s. (author)

  3. Modelling of multiphase flow in concrete cells of the radioactive waste storage facility at El Cabril (Spain)

    International Nuclear Information System (INIS)

    Chaparro, M.C.; Saaltink, M.W.

    2015-01-01

    El Cabril is the low and intermediate level radioactive waste disposal facility for Spain. After sealing the cells that stored the radioactive waste, water was collected from a drainpipe, indicating the flow of water within the cell. A hypothesis had been proposed to explain this phenomenon which consists of capillary rise from groundwater and evaporation and condensation within the cell produced by temperature gradients caused by seasonal temperature fluctuations outside. To corroborate this hypothesis a 2D numerical model was made taking into account all relevant processes such as multiphase flow and heat transport. Data were used measured by sensors in the cells and data from laboratory test. There is a good agreement between the temperature measured by the sensors and the ones calculated by the model. The model shows a drying of the concrete at the hot side (that is the wall during summer and the container during winter). The concrete is saturated with water at the cold side (that is the container during summer and the wall in winter), leading to runoff of water to the drainpipe. The flux at this drainpipe occurred in the two yearly periods, being higher in winter than in summer. (authors)

  4. Microtomographic imaging of multiphase flow in porous media: Validation of image analysis algorithms, and assessment of data representativeness and quality

    Science.gov (United States)

    Wildenschild, D.; Porter, M. L.

    2009-04-01

    Significant strides have been made in recent years in imaging fluid flow in porous media using x-ray computerized microtomography (CMT) with 1-20 micron resolution; however, difficulties remain in combining representative sample sizes with optimal image resolution and data quality; and in precise quantification of the variables of interest. Tomographic imaging was for many years focused on volume rendering and the more qualitative analyses necessary for rapid assessment of the state of a patient's health. In recent years, many highly quantitative CMT-based studies of fluid flow processes in porous media have been reported; however, many of these analyses are made difficult by the complexities in processing the resulting grey-scale data into reliable applicable information such as pore network structures, phase saturations, interfacial areas, and curvatures. Yet, relatively few rigorous tests of these analysis tools have been reported so far. The work presented here was designed to evaluate the effect of image resolution and quality, as well as the validity of segmentation and surface generation algorithms as they were applied to CMT images of (1) a high-precision glass bead pack and (2) gas-fluid configurations in a number of glass capillary tubes. Interfacial areas calculated with various algorithms were compared to actual interfacial geometries and we found very good agreement between actual and measured surface and interfacial areas. (The test images used are available for download at the website listed below). http://cbee.oregonstate.edu/research/multiphase_data/index.html

  5. Investigation of Multiscale and Multiphase Flow, Transport and Reaction in Heavy Oil Recovery Processes

    Energy Technology Data Exchange (ETDEWEB)

    Yortsos, Yanis C.

    2002-10-08

    In this report, the thrust areas include the following: Internal drives, vapor-liquid flows, combustion and reaction processes, fluid displacements and the effect of instabilities and heterogeneities and the flow of fluids with yield stress. These find respective applications in foamy oils, the evolution of dissolved gas, internal steam drives, the mechanics of concurrent and countercurrent vapor-liquid flows, associated with thermal methods and steam injection, such as SAGD, the in-situ combustion, the upscaling of displacements in heterogeneous media and the flow of foams, Bingham plastics and heavy oils in porous media and the development of wormholes during cold production.

  6. Multiphase imaging of gas flow in a nanoporous material using remote-detection NMR.

    Science.gov (United States)

    Harel, Elad; Granwehr, Josef; Seeley, Juliette A; Pines, Alex

    2006-04-01

    Pore structure and connectivity determine how microstructured materials perform in applications such as catalysis, fluid storage and transport, filtering or as reactors. We report a model study on silica aerogel using a time-of-flight magnetic resonance imaging technique to characterize the flow field and explain the effects of heterogeneities in the pore structure on gas flow and dispersion with 129Xe as the gas-phase sensor. The observed chemical shift allows the separate visualization of unrestricted xenon and xenon confined in the pores of the aerogel. The asymmetrical nature of the dispersion pattern alludes to the existence of a stationary and a flow regime in the aerogel. An exchange time constant is determined to characterize the gas transfer between them. As a general methodology, this technique provides insights into the dynamics of flow in porous media where several phases or chemical species may be present.

  7. Thermofluidynamics of the multiphase flow inside cylindroconical fermenters with different scales

    Directory of Open Access Journals (Sweden)

    Meironke Heiko

    2014-01-01

    Full Text Available In this work the experimental investigations of the flow and the temperature field during the fermentation of beer in cylindroconical tanks are presented. The flow stability is affected of the height/diameter ratio. Increasing the ratio leads to an unsteady, three-dimensional flow with several smaller vortices. In the course of our research the experiments have been performed with real fermentation fluid (wort under various height/diameter ratio. In the study, two tanks have been used in the laboratory and on an industrial scale, which were equipped with special design features. The velocity fields during a real fermentation process are measured by means of Ultrasound Doppler Velocimetry. It permits measurements in opaque fluids. Furthermore temperature measurements are conducted to analyse the interrelationship between the heat transfer and flow structure.

  8. An adaptive mesh refinement-multiphase lattice Boltzmann flux solver for simulation of complex binary fluid flows

    Science.gov (United States)

    Yuan, H. Z.; Wang, Y.; Shu, C.

    2017-12-01

    This paper presents an adaptive mesh refinement-multiphase lattice Boltzmann flux solver (AMR-MLBFS) for effective simulation of complex binary fluid flows at large density ratios. In this method, an AMR algorithm is proposed by introducing a simple indicator on the root block for grid refinement and two possible statuses for each block. Unlike available block-structured AMR methods, which refine their mesh by spawning or removing four child blocks simultaneously, the present method is able to refine its mesh locally by spawning or removing one to four child blocks independently when the refinement indicator is triggered. As a result, the AMR mesh used in this work can be more focused on the flow region near the phase interface and its size is further reduced. In each block of mesh, the recently proposed MLBFS is applied for the solution of the flow field and the level-set method is used for capturing the fluid interface. As compared with existing AMR-lattice Boltzmann models, the present method avoids both spatial and temporal interpolations of density distribution functions so that converged solutions on different AMR meshes and uniform grids can be obtained. The proposed method has been successfully validated by simulating a static bubble immersed in another fluid, a falling droplet, instabilities of two-layered fluids, a bubble rising in a box, and a droplet splashing on a thin film with large density ratios and high Reynolds numbers. Good agreement with the theoretical solution, the uniform-grid result, and/or the published data has been achieved. Numerical results also show its effectiveness in saving computational time and virtual memory as compared with computations on uniform meshes.

  9. Multiphase flow simulation with gravity effect in anisotropic porous media using multipoint flux approximation

    KAUST Repository

    Negara, Ardiansyah

    2015-03-04

    Numerical investigations of two-phase flows in anisotropic porous media have been conducted. In the flow model, the permeability has been considered as a full tensor and is implemented in the numerical scheme using the multipoint flux approximation within the framework of finite difference method. In addition, the experimenting pressure field approach is used to obtain the solution of the pressure field, which makes the matrix of coefficient of the global system easily constructed. A number of numerical experiments on the flow of two-phase system in two-dimensional porous medium domain are presented. In this work, the gravity is included in the model to capture the possible buoyancy-driven effects due to density differences between the two phases. Different anisotropy scenarios have been considered. From the numerical results, interesting patterns of the flow, pressure, and saturation fields emerge, which are significantly influenced by the anisotropy of the absolute permeability field. It is found that the two-phase system moves along the principal direction of anisotropy. Furthermore, the effects of anisotropy orientation on the flow rates and the cross flow index are also discussed in the paper.

  10. The role of fault zones in affecting multiphase flow at Yucca Mountain

    International Nuclear Information System (INIS)

    Tsang, Y.W.; Pruess, K.; Wang, J.S.Y.

    1993-01-01

    Within Yucca Mountain, the potential High Level Nuclear-Waste Repository site, there are large scale fault zones, most notably the Ghost Dance Fault. The effect of such high-permeability, large scale discontinuities on the flow and transport is a question of concern in assessing the ability of the site to isolate radio-nuclides from the biosphere. In this paper, we present a numerical study to investigate the role of the fault in affecting both the liquid and gas phase flows in the natural state at Yucca Mountain prior to waste emplacement, as well as after the waste emplacement when the fluid flow is strongly heat-driven. Our study shows that if the characteristic curves of the Ghost Dance Fault obey the same relationship between saturated permeability and capillary scaling parameter, as is observed from the measured data of Yucca Mountain welded and nonwelded tuffs. Apache Leap tuffs, and Las Cruces soil, then a large saturated permeability of the Ghost Dance Fault will play little role in channeling water into the fault, or inenhancing the flow of water down the fault. However, the Fault may greatly enhance the upward gas flow after emplacement of waste. This may have implications on the transport of gaseous radio-nuclides such as C 14 . The results of this study also focus attention on the need for field measurements of fluid flow in the fault zones

  11. KIVA-hpFE: Predictive turublent reactive and multiphase flow in engines : Science Supporting Mission of the Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Carrington, David Bradley [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Waters, Jiajia [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-09-26

    Research and development of KIVA-hpFE for turbulent reactive and multiphase flow particularly as related to engine modeling program has relevance to National energy security and climate change. Climate change is a source problem, and energy national security is consumption of petroleum products problem. Accurately predicting engine processes leads to, lower greenhouse gas (GHG) emission, where engines in the transportation sector currently account for 26% of the U.S. GHG emissions. Less dependence on petroleum products leads to greater energy security. By Environmental Protection Agency standards, some vehicles are now reaching 42 to the 50 mpg mark. These are conventional gasoline engines. Continued investment and research into new technical innovations, the potential exists to save more than 4 million barrels of oil per day or approximately $200 to $400 million per day. This would be a significant decrease in emission and use of petroleum and a very large economic stimulus too! It is estimated with further advancements in combustion, the current emissions can be reduced up to 40%. Enabling better understanding of fuel injection and fuel-air mixing, thermodynamic combustion losses, and combustion/emission formation processes enhances our ability to help solve both problems. To provide adequate capability for accurately simulating these processes, minimize time and labor for development of engine technology, are the goals of our KIVA development program.

  12. Effect of Finite Particle Size on Convergence of Point Particle Models in Euler-Lagrange Multiphase Dispersed Flow

    Science.gov (United States)

    Nili, Samaun; Park, Chanyoung; Haftka, Raphael T.; Kim, Nam H.; Balachandar, S.

    2017-11-01

    Point particle methods are extensively used in simulating Euler-Lagrange multiphase dispersed flow. When particles are much smaller than the Eulerian grid the point particle model is on firm theoretical ground. However, this standard approach of evaluating the gas-particle coupling at the particle center fails to converge as the Eulerian grid is reduced below particle size. We present an approach to model the interaction between particles and fluid for finite size particles that permits convergence. We use the generalized Faxen form to compute the force on a particle and compare the results against traditional point particle method. We apportion the different force components on the particle to fluid cells based on the fraction of particle volume or surface in the cell. The application is to a one-dimensional model of shock propagation through a particle-laden field at moderate volume fraction, where the convergence is achieved for a well-formulated force model and back coupling for finite size particles. Comparison with 3D direct fully resolved numerical simulations will be used to check if the approach also improves accuracy compared to the point particle model. Work supported by the U.S. Department of Energy, National Nuclear Security Administration, Advanced Simulation and Computing Program, as a Cooperative Agreement under the Predictive Science Academic Alliance Program, under Contract No. DE-NA0002378.

  13. Simulation of Multiphase Flow of the Oil-Water Separation in a Rotating Packed Bed for Oil Purification

    Directory of Open Access Journals (Sweden)

    Xiaojun Zhang

    2013-01-01

    particle contaminant, moisture and gas simultaneously. As the major unit of HIGEE, the RPB uses centrifugal force to intensify mass transfer. Because of the special structure of RPB, the hydraulic characteristics of the RPB are very important. In this study, the multiphase flow model in porous media of the RPB is presented, and the dynamical oil-water separation in the RPB is simulated using a commercial computational fluid dynamics code. The operating conditions and configuration on the hydraulic performance of the RPB are investigated. The results have indicated that the separation efficiency of HIGEE rotating oil purifier is predominantly affected by operating conditions and the configurations. The best inlet pressure is 0.002 MPa. When the liquid inlet is placed in the outside of the lower surface of RPB; oil outlet is placed in the upper surface, where it is near the rotation axis; and water outlet is placed in the middle of the RPB, where it is far away from the oil outlet, the separating efficiency is the best.

  14. Towards multi-phase flow simulations in the PDE framework Peano

    KAUST Repository

    Bungartz, Hans-Joachim

    2011-07-27

    In this work, we present recent enhancements and new functionalities of our flow solver in the partial differential equation framework Peano. We start with an introduction including an overview of the Peano development and a short description of the basic concepts of Peano and the flow solver in Peano concerning the underlying structured but adaptive Cartesian grids, the data structure and data access optimisation, and spatial and time discretisation of the flow solver. The new features cover geometry interfaces and additional application functionalities. The two geometry interfaces, a triangulation-based description supported by the tool preCICE and a built-in geometry using geometry primitives such as cubes, spheres, or tetrahedra allow for the efficient treatment of complex and changing geometries, an essential ingredient for most application scenarios. The new application functionality concerns a coupled heat-flow problem and two-phase flows. We present numerical examples, performance and validation results for these new functionalities. © 2011 Springer-Verlag.

  15. Study of high viscous multiphase phase flow in a horizontal pipe

    Science.gov (United States)

    Baba, Yahaya D.; Aliyu, Aliyu M.; Archibong, Archibong-Eso; Almabrok, Almabrok A.; Igbafe, A. I.

    2018-03-01

    Heavy oil accounts for a major portion of the world's total oil reserves. Its production and transportation through pipelines is beset with great challenges due to its highly viscous nature. This paper studies the effects of high viscosity on heavy oil two-phase flow characteristics such as pressure gradient, liquid holdup, slug liquid holdup, slug frequency and slug liquid holdup using an advanced instrumentation (i.e. Electrical Capacitance Tomography). Experiments were conducted in a horizontal flow loop with a pipe internal diameter (ID) of 0.0762 m; larger than most reported in the open literature for heavy oil flow. Mineral oil of 1.0-5.0 Pa.s viscosity range and compressed air were used as the liquid and gas phases respectively. Pressure gradient (measured by means differential pressure transducers) and mean liquid holdup was observed to increase as viscosity of oil is increased. Obtained results also revealed that increase in liquid viscosity has significant effects on flow pattern and slug flow features.

  16. Notes on Well-Posed, Ensemble Averaged Conservation Equations for Multiphase, Multi-Component, and Multi-Material Flows

    International Nuclear Information System (INIS)

    Ray A. Berry

    2005-01-01

    At the INL researchers and engineers routinely encounter multiphase, multi-component, and/or multi-material flows. Some examples include: Reactor coolant flows Molten corium flows Dynamic compaction of metal powders Spray forming and thermal plasma spraying Plasma quench reactor Subsurface flows, particularly in the vadose zone Internal flows within fuel cells Black liquor atomization and combustion Wheat-chaff classification in combine harvesters Generation IV pebble bed, high temperature gas reactor The complexity of these flows dictates that they be examined in an averaged sense. Typically one would begin with known (or at least postulated) microscopic flow relations that hold on the ''small'' scale. These include continuum level conservation of mass, balance of species mass and momentum, conservation of energy, and a statement of the second law of thermodynamics often in the form of an entropy inequality (such as the Clausius-Duhem inequality). The averaged or macroscopic conservation equations and entropy inequalities are then obtained from the microscopic equations through suitable averaging procedures. At this stage a stronger form of the second law may also be postulated for the mixture of phases or materials. To render the evolutionary material flow balance system unique, constitutive equations and phase or material interaction relations are introduced from experimental observation, or by postulation, through strict enforcement of the constraints or restrictions resulting from the averaged entropy inequalities. These averaged equations form the governing equation system for the dynamic evolution of these mixture flows. Most commonly, the averaging technique utilized is either volume or time averaging or a combination of the two. The flow restrictions required for volume and time averaging to be valid can be severe, and violations of these restrictions are often found. A more general, less restrictive (and far less commonly used) type of averaging known as

  17. A method of modeling time-dependent rock damage surrounding underground excavations in multiphase groundwater flow

    International Nuclear Information System (INIS)

    Christian-Frear, T.; Freeze, G.

    1997-01-01

    Underground excavations produce damaged zones surrounding the excavations which have disturbed hydrologic and geomechanical properties. Prediction of fluid flow in these zones must consider both the mechanical and fluid flow processes. Presented here is a methodology which utilizes a mechanical model to predict damage and disturbed rock zone (DRZ) development around the excavation and then uses the predictions to develop time-dependent DRZ porosity relationships. These relationships are then used to adjust the porosity of the DRZ in the fluid flow model based upon the time and distance from the edge of the excavation. The application of this methodology is presented using a site-specific example from the Waste Isolation Pilot Plant, a US Department of Energy facility in bedded salts being evaluated for demonstration of the safe underground disposal of transuranic waste from US defense-related activities

  18. Flow Dynamic Analysis of Core Shooting Process through Experiment and Multiphase Modeling

    Directory of Open Access Journals (Sweden)

    Changjiang Ni

    2016-01-01

    Full Text Available Core shooting process is the most widely used technique to make sand cores and it plays an important role in the quality of sand cores as well as the manufacture of complicated castings in metal casting industry. In this paper, the flow behavior of sand particles in the core box was investigated synchronously with transparent core box, high-speed camera, and pressure measuring system. The flow pattern of sand particles in the shooting head of the core shooting machine was reproduced with various colored core sand layers. Taking both kinetic and frictional stress into account, a kinetic-frictional constitutive correlation was established to describe the internal momentum transfer in the solid phase. Two-fluid model (TFM simulations with turbulence model were then performed and good agreement was achieved between the experimental and simulation results on the flow behavior of sand particles in both the shooting head and the core box. Based on the experimental and simulation results, the flow behavior of sand particles in the core box, the formation of “dead zone” in the shooting head, and the effect of drag force were analyzed in terms of sand volume fraction (αs, sand velocity (Vs, and pressure variation (P.

  19. Visualization and measurement of pressurized multiphase flow using neutron radiography of JRR-3M system

    Energy Technology Data Exchange (ETDEWEB)

    Katoh, Yasuo [Yamaguchi Univ. (Japan); Matsubayasi, Masahito

    1998-01-01

    Concerning the transient phenomenon of solid-gas two-phase flow, an attempt was made to visualize and measure a flow phenomenon in which three-dimensional bubbles occurred, grew and collapsed in the vicinity of a gas injection nozzle while solid particles were circulating. Such a phenomenon could not or hardly be visualized and measured by conventional methods. Such two-phase flow was visualized using neutron radiography, its characteristics measured and the usefulness of the visualization by neutron radiography confirmed. For this purpose, three-dimensional fluidized bed vessels, rectangular or cylindrical-shaped, made of steel or aluminum sheet, were prepared. Polyethylene or glass beads were used as solid particles and activated carbon particles as the tracer. In the experiment, nitrogen gas was blown into the vessel from one nozzle and distributors provided at the bottom of the vessel and exhausted from the top via the exhaust valve, by which the pressure in the vessel was controlled. The imaging was done in the following way: A test chamber was provided beside the vessel to receive neutron beams from the JRR-3M system, the intensity of transmitted neutrons was converted to visible light by scintillator and the images were videotaped. The initial objectives of visualizing and measuring bubbles occurring, growing and collapsing and solid particles circulating in the solid-gas two-phase flow have been achieved by means of neutron radiography. (N.H.)

  20. Experimental Study of Stable Surfaces for Anti-Slug Control in Multi-phase Flow

    DEFF Research Database (Denmark)

    Pedersen, Simon; Løhndorf, Petar Durdevic; Yang, Zhenyu

    2014-01-01

    -phase flow dynamics, the slug can be avoided or eliminated by proper facility design and control of operational conditions. Based on a testing facility which can emulate a pipeline-riser or a gas-lifted production well in a scaled-down manner, this paper experimentally studies the correlations of key...

  1. An Experimental and Computational Study of Multiphase Flow Behaviour in Circulating Fluidized Beds

    Energy Technology Data Exchange (ETDEWEB)

    Mathiesen, Vidar

    1997-12-31

    Gas/solid flows have been studied extensively, mainly because they are important in nuclear, chemical and petroleum industries. This thesis describes an experiment done at two different circulating fluidized bed systems. Laser Doppler anemometry (LDA) and phase Doppler anemometry (PDA) were used to measure mean and fluctuating velocity, diameter and solids concentration. A typical core-annulus flow was obtained in both cases. The measurements show a relative mean velocity as well as a relative fluctuating velocity between different particle sizes. An axial segregation by size and its variation with the superficial gas velocity are demonstrated. Significant radial segregation is found in both risers. A three-dimensional Computational Fluid Dynamics model was developed based on Eulerian description of the phases where the kinetic theory of granular flow is the basis of the turbulence modelling in the solid phases. There are one gas phase and any number of solid phases. Simulations of flow behaviour in two- and three-dimensions agree well with experiments and the model is able to handle axial segregation by size for different superficial gas velocities and particle size distributions. 107 refs., 79 figs., 6 tabs.

  2. Complexity reduction of multi-phase flows in heterogeneous porous media

    KAUST Repository

    Ghommem, Mehdi

    2013-01-01

    In this paper, we apply mode decomposition and interpolatory projection methods to speed up simulations of two-phase flows in highly heterogeneous porous media. We propose intrusive and non-intrusive model reduction approaches that enable a significant reduction in the dimension of the flow problem size while capturing the behavior of the fully-resolved solutions. In one approach, we employ the dynamic mode decomposition (DMD) and the discrete empirical interpolation method (DEIM). This approach does not require any modification of the reservoir simulation code but rather postprocesses a set of global snapshots to identify the dynamically-relevant structures associated with the flow behavior. In a second approach, we project the governing equations of the velocity and the pressure fields on the subspace spanned by their proper orthogonal decomposition (POD) modes. Furthermore, we use DEIM to approximate the mobility related term in the global system assembly and then reduce the online computational cost and make it independent of the fine grid. To show the effectiveness and usefulness of the aforementioned approaches, we consider the SPE 10 benchmark permeability field and present a variety of numerical examples of two-phase flow and transport. The proposed model reduction methods can be efficiently used when performing uncertainty quantification or optimization studies and history matching.

  3. INVESTIGATION OF MULTISCALE AND MULTIPHASE FLOW, TRANSPORT AND REACTION IN HEAVY OIL RECOVERY PROCESSES

    Energy Technology Data Exchange (ETDEWEB)

    Yannis C. Yortsos

    2003-02-01

    This is final report for contract DE-AC26-99BC15211. The report describes progress made in the various thrust areas of the project, which include internal drives for oil recovery, vapor-liquid flows, combustion and reaction processes and the flow of fluids with yield stress. The report consists mainly of a compilation of various topical reports, technical papers and research reports published produced during the three-year project, which ended on May 6, 2002 and was no-cost extended to January 5, 2003. Advances in multiple processes and at various scales are described. In the area of internal drives, significant research accomplishments were made in the modeling of gas-phase growth driven by mass transfer, as in solution-gas drive, and by heat transfer, as in internal steam drives. In the area of vapor-liquid flows, we studied various aspects of concurrent and countercurrent flows, including stability analyses of vapor-liquid counterflow, and the development of novel methods for the pore-network modeling of the mobilization of trapped phases and liquid-vapor phase changes. In the area of combustion, we developed new methods for the modeling of these processes at the continuum and pore-network scales. These models allow us to understand a number of important aspects of in-situ combustion, including steady-state front propagation, multiple steady-states, effects of heterogeneity and modes of combustion (forward or reverse). Additional aspects of reactive transport in porous media were also studied. Finally, significant advances were made in the flow and displacement of non-Newtonian fluids with Bingham plastic rheology, which is characteristic of various heavy oil processes. Various accomplishments in generic displacements in porous media and corresponding effects of reservoir heterogeneity are also cited.

  4. Production polyphasique. Modélisation des écoulements à bouchons Multiphase Production Slug-Flow Modeling

    Directory of Open Access Journals (Sweden)

    Drouffe J. M.

    2006-11-01

    Full Text Available L'exploitation des hydrocarbures en mer reste une activité coûteuse et qui peut, même, se révéler, éventuellement dangereuse. Les concepts de production polyphasique tels que Poséidon permettent à la fois : - une réduction importante des coûts de production; - la suppression des risques humains liés à la présence permanente en mer d'équipes importantes. Les programmes de simulation des écoulements diphasiques actuellement disponibles pour la mise en oeuvre de ces concepts, sont tous basés sur une approche déterministeclassique. Cet article présente une nouvelle approche statistiquenon conventionnelle qui devrait nous permettre de mieux préciser les caractéristiques des écoulements à bouchons et donc de pouvoir mieux dimensionner et exploiter nos futures installations de production et transport polyphasique longue distance. Offshore hydrocarbon production remains a costly venture, and even one that might possibly be dangerous. Multiphase production concepts such as Poseidon make for both a considerable reduction in production costs and the elimination of human risks linked to the constant offshore presence of large crews. The two-phase flow simulation programs now available for implementing such concepts are all based on a standard deterministicapproach. This article describes a new and unconventional statisticalapproach that we feel more accurately describes the characteristics of slug flows and hence is more effecting for the sizing and operating of future production and long-distance pipelining installations.

  5. Stochastic Models of Macroscale Quantities for the Prediction of the REV Scale for Multiphase Flow through Porous Media

    Science.gov (United States)

    Talbot, C.; McClure, J. E.; Armstrong, R. T.; Mostaghimi, P.; Hu, Y.; Miller, C. T.

    2017-12-01

    Microscale experimental and computational methods can be used to evaluate fundamental microscale mechanisms and deduce macroscale constitutive relationships and parameter values. The link between the microscale and the macroscale is especially demanding, because technical issues arise regarding the necessary scale of the system needed for a meaningful set of macroscale measures to be insensitive to the size of the system, which is known as a representative elementary volume (REV). While the REV scale is routinely determined for single-phase flow in porous media, no systematic study of the scale of a REV for the comprehensive set of macroscale measures considered here has been reported in the literature. A comprehensive set of measures of the macroscale state is developed. We further develop and apply methods to predict the REV scale and quantify the uncertainty of the estimate for this set of macroscale quantities. We model the system state in terms of standard errors of macroscale quantities as a multivariate Gaussian process dependent on the size of the domain simulated. We determine predictive distributions of function values and a posterior distributions of weights using standard kernels, as well as a kernel constructed using relationships between physical quantities. For each kernel, we discuss the decay of the mean and covariance with increasing domain size, and use cross-validation to facilitate model selection. The procedure yields a model of the domain size needed to achieve a REV with quantifiable uncertainty. We present results in the context of multiphase fluid flow through a highly resolved realization of sandstone imaged using micro-CT. A 1440x1440x4320 section of the full 2520x2520x5280 imaged medium is simulated using the lattice-Boltzmann method. We compare the fidelity of the predictive model with results obtained by an analogous approach using polynomial regression.

  6. Numerical study of Tallinn storm-water system flooding conditions using CFD simulations of multi-phase flow in a large-scale inverted siphon

    Science.gov (United States)

    Kaur, K.; Laanearu, J.; Annus, I.

    2017-10-01

    The numerical experiments are carried out for qualitative and quantitative interpretation of a multi-phase flow processes associated with malfunctioning of the Tallinn storm-water system during rain storms. The investigations are focused on the single-line inverted siphon, which is used as under-road connection of pipes of the storm-water system under interest. A multi-phase flow solver of Computational Fluid Dynamics software OpenFOAM is used for simulating the three-phase flow dynamics in the hydraulic system. The CFD simulations are performed with different inflow rates under same initial conditions. The computational results are compared essentially in two cases 1) design flow rate and 2) larger flow rate, for emptying the initially filled inverted siphon from a slurry-fluid. The larger flow-rate situations are under particular interest to detected possible flooding. In this regard, it is anticipated that the CFD solutions provide an important insight to functioning of inverted siphon under a restricted water-flow conditions at simultaneous presence of air and slurry-fluid.

  7. Two problems in multiphase biological flows: Blood flow and particulate transport in microvascular network, and pseudopod-driven motility of amoeboid cells

    Science.gov (United States)

    Bagchi, Prosenjit

    2016-11-01

    In this talk, two problems in multiphase biological flows will be discussed. The first is the direct numerical simulation of whole blood and drug particulates in microvascular networks. Blood in microcirculation behaves as a dense suspension of heterogeneous cells. The erythrocytes are extremely deformable, while inactivated platelets and leukocytes are nearly rigid. A significant progress has been made in recent years in modeling blood as a dense cellular suspension. However, many of these studies considered the blood flow in simple geometry, e.g., straight tubes of uniform cross-section. In contrast, the architecture of a microvascular network is very complex with bifurcating, merging and winding vessels, posing a further challenge to numerical modeling. We have developed an immersed-boundary-based method that can consider blood cell flow in physiologically realistic and complex microvascular network. In addition to addressing many physiological issues related to network hemodynamics, this tool can be used to optimize the transport properties of drug particulates for effective organ-specific delivery. Our second problem is pseudopod-driven motility as often observed in metastatic cancer cells and other amoeboid cells. We have developed a multiscale hydrodynamic model to simulate such motility. We study the effect of cell stiffness on motility as the former has been considered as a biomarker for metastatic potential. Funded by the National Science Foundation.

  8. Experimental Quantification of Pore-Scale Flow Phenomena in 2D Heterogeneous Porous Micromodels: Multiphase Flow Towards Coupled Solid-Liquid Interactions

    Science.gov (United States)

    Li, Y.; Kazemifar, F.; Blois, G.; Christensen, K. T.

    2017-12-01

    Geological sequestration of CO2 within saline aquifers is a viable technology for reducing CO2 emissions. Central to this goal is accurately predicting both the fidelity of candidate sites pre-injection of CO2 and its post-injection migration. Moreover, local fluid pressure buildup may cause activation of small pre-existing unidentified faults, leading to micro-seismic events, which could prove disastrous for societal acceptance of CCS, and possibly compromise seal integrity. Recent evidence shows that large-scale events are coupled with pore-scale phenomena, which necessitates the representation of pore-scale stress, strain, and multiphase flow processes in large-scale modeling. To this end, the pore-scale flow of water and liquid/supercritical CO2 is investigated under reservoir-relevant conditions, over a range of wettability conditions in 2D heterogeneous micromodels that reflect the complexity of a real sandstone. High-speed fluorescent microscopy, complemented by a fast differential pressure transmitter, allows for simultaneous measurement of the flow field within and the instantaneous pressure drop across the micromodels. A flexible micromodel is also designed and fabricated, to be used in conjunction with the micro-PIV technique, enabling the quantification of coupled solid-liquid interactions.

  9. S-bend erosion in particulated multiphase flow with air and sand

    Directory of Open Access Journals (Sweden)

    Quamrul H Mazumder

    2016-09-01

    Full Text Available Solid particle erosion is a micro-mechanical process that removes material from a surface by repeated impact of entrained particles in the flow. Erosion is a leading cause of failure in fluid handling equipment such as pumps, pipes, valves, and fittings. The S-bend geometry is used to redirect flows in automotive, chemical processing, oil, gas, and food handling industries. An investigation was conducted using both computational fluid dynamics analysis and experimental methods to identify the location of maximum erosion. Three S-bend geometries with 12.7 mm inside diameter, r/D ratio of 1.5, three different air velocities and six different particle sizes were used in the current study. The experimental test section was of 12.7 mm inside diameter, r/D ratio of 1.5, and used 150 and 300 µm particle sizes.

  10. V-ONSET: Introducing turbulent multiphase flow facility focusing on Lagrangian interfacial transfer dynamics

    Science.gov (United States)

    Salibindla, Ashwanth; Masuk, Ashik Ullah Mohammad; Ni, Rui

    2017-11-01

    We have designed and constructed a new vertical water tunnel, V-ONSET, to investigate interfacial mass, momentum and energy transfer between two phases in a Lagrangian frame. This system features an independent control of mean flow and turbulence level. The mean flow opposes the rising/falling velocity of the second phase, ``suspending'' the particles and increasing tracking time in the view area. Strong turbulence is generated by shooting 88 digitally-controlled water jets into the test section. The second phase, either bubbles or oil droplets, can be introduced into the test section through a capillary island. In addition to this flow control system, V-ONSET comes with a 3D two-phase visualization system, consisting of high-speed cameras, two-colored LED system, and in-house Lagrangian particle tracking algorithm. This enables us to acquire the Lagrangian evolution of both phases and the interfacial transfer dynamics in between, paving the way for new closure models for two-phase simulations. Financial support for this project was provided by National Science Foundation under Grant Number: 1653389 and 1705246.

  11. Study on performance of double helical capacitance probe for water fraction measurement in multiphase flow

    Science.gov (United States)

    Ye, J.; Guo, L. J.; Zhou, H. L.

    2012-03-01

    A type of capacitance probe performance with two brass electrodes intertwined on the outer wall of insulation pipe like a double helix is investigated numerically in this paper, which can measure water fraction in air-oil-water two or three-phase flow in oil industry. The motivation of this paper is to optimize this kind of probe to improve its electric response and spatial resolution and so a 3-D numerical simulation using finite element method is employed to evaluate the effect of electrodes configuration of this capacitance probe on measuring water fraction in horizontal pipes. The electrostatic field of the probe is preliminarily analyzed referred to stratified flow of air-water two-phase flow regime. Several parameters are considered as main variables which have an important effect on the precision of the probe, such as central angle, position angle and length of the two electrodes. From the electrostatic field analysis, lumped capacitance between the two electrodes is obtained in every different electrode geometry model and the results of each model are compared to each other in order to select a better arrangement of the electrodes that has a better response to water fraction. And by using circuit simulation method, the numerical calculated lumped capacitance is transferred to voltage output through the circuit used in the experiment. The relationship between voltage and water fraction of calculated and experimental result are compared in order to test the reasonableness of the simulation. The results show that at high water fraction, the difference between numerical and measured data agrees very well.

  12. The effect of stratigraphic dip on multiphase flow at the Waste Isolation Pilot Plant

    International Nuclear Information System (INIS)

    Webb, S.W.; Larson, K.W.

    1995-01-01

    The natural stratigraphic dip at the Waste Isolation Pilot Plant (WIPP), although regionally only about 1 degree, has the potential to affect brine inflow and gas migration distances due to buoyancy forces. Brine inflow may increase due to countercurrent flow, and gas may preferentially migrate updip. Analytical and numerical modeling was used to evaluate the impact of the dip on brine inflow and gas migration distances at the WIPP in one, two, and three dimensions. Results show that the effect of dip on brine inflow and gas migration distance may be significant

  13. New Approaches in Modeling Multiphase Flows and Dispersion in Turbulence, Fractal Methods and Synthetic Turbulence

    CERN Document Server

    Nicolleau, FCGA; Redondo, J-M

    2012-01-01

    This book contains a collection of the main contributions from the first five workshops held by Ercoftac Special Interest Group on Synthetic Turbulence Models (SIG42. It is intended as an illustration of the sig's activities and of the latest developments in the field. This volume investigates the use of Kinematic Simulation (KS) and other synthetic turbulence models for the particular application to environmental flows. This volume offers the best syntheses on the research status in KS, which is widely used in various domains, including Lagrangian aspects in turbulence mixing/stirring, partic

  14. Dissipative Particle Dynamics and Other Particle Methods for Multiphase Fluid Flow in Fractured and Porous Media

    Energy Technology Data Exchange (ETDEWEB)

    Paul Meakin; Zhijie Xu

    2008-06-01

    Particle methods are much less computationally efficient than grid based numerical solution of the Navier Stokes equation, and they have been used much less extensively, particularly for engineering applications. However, they have important advantages for some applications. These advantages include rigorous mast conservation, momentum conservation and isotropy. In addition, there is no need for explicit interface tracking/capturing. Code development effort is relatively low, and it is relatively simple to simulate flows with moving boundaries. In addition, it is often quite easy to include coupling of fluid flow with other physical phenomena such a phase separation. Here we describe the application of three particle methods: molecular dynamics, dissipative particle dynamics and smoothed particle hydrodynamics. While these methods were developed to simulate fluids and other materials on three quite different scales – the molecular, meso and continuum scales, they are very closely related from a computational point of view. The mesoscale (between the molecular and continuum scales) dissipative particle dynamics method can be used to simulate systems that are too large to simulate using molecular dynamics but small enough for thermal fluctuations to play an important role. Important examples include polymer solutions, gels, small particle suspensions and membranes. In these applications inter particle and intra molecular hydrodynamic interactions are automatically included

  15. The role of pore space morphology in multi-phase flow in porous media

    Science.gov (United States)

    Wildenschild, D.; Prodanovic, M.; Jansik, D. P.

    2008-12-01

    Porous medium morphology can play an important role when we use numerical models to predict subsurface flow and transport behavior at larger scales. Yet, understanding the role that pore structure plays at smaller scales is a necessary first step. Fluid-fluid configuration in particular is highly influenced by the surface characteristics of the porous medium. Fluid configurations vary significantly between drainage and imbibiton (due to spontaneous, irreversible changes of the interface between fluids). We specifically measure large differences in wetting-nonwetting interfacial area as a function of different pore space morphology: as observed for a crushed volcanic tuff with high surface area and affinity for fluid films, and for smooth glass beads. The observed imbibition process for the glass beads resembles a piston-flow situation, whereas imbibition into the tuff appears dominated by fluid film connectivity with growth from pendular rings in spatially distant locations of the imaged system. The latter process leads to a very different distribution of fluids and overall lower saturations and interfacial areas than in the glass bead system. Characteristics such as pore- scale Pc-S curves and related interfacial area per volume have been quantified using computed microtomography. In addition, we present pore network characterization (pore connectivity, pore throats to pore body aspect ratio, pore body volumes and throat areas) of the two porous media.

  16. Multiphase Fluid Flow in Deformable Variable-Aperture Fractures - Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Detwiler, Russell

    2014-04-30

    Fractures provide flow paths that can potentially lead to fast migration of fluids or contaminants. A number of energy-­related applications involve fluid injections that significantly perturb both the pressures and chemical composition of subsurface fluids. These perturbations can cause both mechanical deformation and chemical alteration of host rocks with potential for significant changes in permeability. In fractured rock subjected to coupled chemical and mechanical stresses, it can be difficult to predict the sign of permeability changes, let alone the magnitude. This project integrated experimental and computational studies to improve mechanistic understanding of these coupled processes and develop and test predictive models and monitoring techniques. The project involved three major components: (1) study of two-­phase flow processes involving mass transfer between phases and dissolution of minerals along fracture surfaces (Detwiler et al., 2009; Detwiler, 2010); (2) study of fracture dissolution in fractures subjected to normal stresses using experimental techniques (Ameli, et al., 2013; Elkhoury et al., 2013; Elkhoury et al., 2014) and newly developed computational models (Ameli, et al., 2014); (3) evaluation of electrical resistivity tomography (ERT) as a method to detect and quantify gas leakage through a fractured caprock (Breen et al., 2012; Lochbuhler et al., 2014). The project provided support for one PhD student (Dr. Pasha Ameli; 2009-­2013) and partially supported a post-­doctoral scholar (Dr. Jean Elkhoury; 2010-­2013). In addition, the project provided supplemental funding to support collaboration with Dr. Charles Carrigan at Lawrence Livermore National Laboratory in connection with (3) and supported one MS student (Stephen Breen; 2011-­2013). Major results from each component of the project include the following: (1) Mineral dissolution in fractures occupied by two fluid phases (e.g., oil-­water or water-­CO{sub 2}) causes changes in local

  17. Modeling of Potential Distribution of Electrical Capacitance Tomography Sensor for Multiphase Flow Image

    Directory of Open Access Journals (Sweden)

    S. Sathiyamoorthy

    2007-09-01

    Full Text Available Electrical Capacitance Tomography (ECT was used to develop image of various multi phase flow of gas-liquid-solid in a closed pipe. The principal difficulties to obtained real time image from ECT sensor are permittivity distribution across the plate and capacitance is nonlinear; the electric field is distorted by the material present and is also sensitive to measurement errors and noise. This work present a detailed description is given on method employed for image reconstruction from the capacitance measurements. The discretization and iterative algorithm is developed for improving the predictions with minimum error. The author analyzed eight electrodes square sensor ECT system with two-phase water-gas and solid-gas.

  18. A phase-field lattice Boltzmann model for simulating multiphase flows in porous media: Application and comparison to experiments of CO2 sequestration at pore scale

    Science.gov (United States)

    Fakhari, Abbas; Li, Yaofa; Bolster, Diogo; Christensen, Kenneth T.

    2018-04-01

    We implement a phase-field based lattice-Boltzmann (LB) method for numerical simulation of multiphase flows in heterogeneous porous media at pore scales with wettability effects. The present method can handle large density and viscosity ratios, pertinent to many practical problems. As a practical application, we study multiphase flow in a micromodel representative of CO2 invading a water-saturated porous medium at reservoir conditions, both numerically and experimentally. We focus on two flow cases with (i) a crossover from capillary fingering to viscous fingering at a relatively small capillary number, and (ii) viscous fingering at a relatively moderate capillary number. Qualitative and quantitative comparisons are made between numerical results and experimental data for temporal and spatial CO2 saturation profiles, and good agreement is found. In particular, a correlation analysis shows that any differences between simulations and results are comparable to intra-experimental differences from replicate experiments. A key conclusion of this work is that system behavior is highly sensitive to boundary conditions, particularly inlet and outlet ones. We finish with a discussion on small-scale flow features, such as the emergence of strong recirculation zones as well as flow in which the residual phase is trapped, including a close look at the detailed formation of a water cone. Overall, the proposed model yields useful information, such as the spatiotemporal evolution of the CO2 front and instantaneous velocity fields, which are valuable for understanding the mechanisms of CO2 infiltration at the pore scale.

  19. Hydrodynamic and thermal modeling of solid particles in a multi-phase, multi-component flow

    International Nuclear Information System (INIS)

    Tentner, A.M.; Wider, H.U.

    1983-01-01

    This paper presents the new thermal hydraulic models describing the hydrodynamics of the solid fuel/steel chunks during an LMFBR hypothetical core-disruptive accident. These models, which account for two-way coupling between the solid and fluid phases, describe the mass, momentum, and energy exchanges which occur when the chunks are present at any axial location. They have been incorporated in LEVITATE, a code for the analysis of fuel and cladding dynamics under Loss-of-Flow (LOF) conditions. Their influence on fuel motion is presented in the context of the L6 TREAT experiment analysis. It is shown that the overall hydrodynamic behavior of the molten fuel and solid-fuel chunks is dependent on both the size of the chunks and the power level. At low and intermediate power levels the fuel motion is more dispersive when small chunks, rather than large ones, are present. At high power levels the situation is reversed. These effects are explained in detail

  20. Towards an integrated petrophysical tool for multiphase flow properties of core samples

    Energy Technology Data Exchange (ETDEWEB)

    Lenormand, R. [Institut Francais du Petrole, Rueil Malmaison (France)

    1997-08-01

    This paper describes the first use of an Integrated Petrophysical Tool (IPT) on reservoir rock samples. The IPT simultaneously measures the following petrophysical properties: (1) Complete capillary pressure cycle: primary drainage, spontaneous and forced imbibitions, secondary drainage (the cycle leads to the wettability of the core by using the USBM index); End-points and parts of the relative permeability curves; Formation factor and resistivity index. The IPT is based on the steady-state injection of one fluid through the sample placed in a Hassler cell. The experiment leading to the whole Pc cycle on two reservoir sandstones consists of about 30 steps at various oil or water flow rates. It takes about four weeks and is operated at room conditions. Relative permeabilities are in line with standard steady-state measurements. Capillary pressures are in accordance with standard centrifuge measurements. There is no comparison for the resistivity index, but the results are in agreement with literature data. However, the accurate determination of saturation remains the main difficulty and some improvements are proposed. In conclusion, the Integrated Petrophysical Tool is as accurate as standard methods and has the advantage of providing the various parameters on the same sample and during a single experiment. The FIT is easy to use and can be automated. In addition, it can be operated in reservoir conditions.

  1. Shock tube Multiphase Experiments

    Science.gov (United States)

    Middlebrooks, John; Allen, Roy; Paudel, Manoj; Young, Calvin; Musick, Ben; McFarland, Jacob

    2017-11-01

    Shock driven multiphase instabilities (SDMI) are unique physical phenomena that have far-reaching practical applications in engineering and science. The instability is present in high energy explosions, scramjet combustors, and supernovae events. The SDMI arises when a multiphase interface is impulsively accelerated by the passage of a shockwave. It is similar in development to the Richtmyer-Meshkov (RM) instability however, particle-to-gas coupling is the driving mechanism of the SDMI. As particle effects such as lag and phase change become more prominent, the SDMI's development begins to significantly deviate from the RM instability. We have developed an experiment for studying the SDMI in our shock tube facility. In our experiments, a multiphase interface is created using a laminar jet and flowed into the shock tube where it is accelerated by the passage of a planar shockwave. The interface development is captured using CCD cameras synchronized with planar laser illumination. This talk will give an overview of new experiments conducted to examine the development of a shocked cylindrical multiphase interface. The effects of Atwood number, particle size, and a second acceleration (reshock) of the interface will be discussed.

  2. Numerical Modeling of Reactive Multiphase Flow for FCC and Hot Gas Desulfurization Circulating Fluidized Beds

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Aubrey L. [WSU Research Corporation, Morgantown, WV (USA)

    2005-07-01

    This work was carried out to understand the behavior of the solid and gas phases in a CFB riser. Only the riser is modeled as a straight pipe. A model with linear algebraic approximation to solids viscosity of the form, {musubs} = 5.34{epsisubs}, ({espisubs} is the solids volume fraction) with an appropriate boundary condition at the wall obtained by approximate momentum balance solution at the wall to acount for the solids recirculation is tested against experimental results. The work done was to predict the flow patterns in the CFB risers from available experimental data, including data from a 7.5-cm-ID CFB riser at the Illinois Institute of Technology and data from a 20.0-cm-ID CFB riser at the Particulate Solid Research, Inc., facility. This research aims at modeling the removal of hydrogen sulfide from hot coal gas using zinc oxide as the sorbent in a circulating fluidized bed and in the process indentifying the parameters that affect the performance of the sulfidation reactor. Two different gas-solid reaction models, the unreacted shrinking core (USC) and the grain model were applied to take into account chemical reaction resistances. Also two different approaches were used to affect the hydrodynamics of the process streams. The first model takes into account the effect of micro-scale particle clustering by adjusting the gas-particle drag law and the second one assumes a turbulent core with pseudo-steady state boundary condition at the wall. A comparison is made with experimental results.

  3. Electrical capacitance tomography (ECT) and gamma radiation meter for comparison with and validation and tuning of computational fluid dynamics (CFD) modeling of multiphase flow

    International Nuclear Information System (INIS)

    Pradeep, Chaminda; Yan, Ru; Mylvaganam, Saba; Vestøl, Sondre; Melaaen, Morten C

    2014-01-01

    The electrical capacitance tomographic (ECT) approach is increasingly seen as attractive for measurement and control applications in the process industries. Recently, there is increased interest in using the tomographic details from ECT for comparing with and validating and tuning CFD models of multiphase flow. Collaboration with researchers working in the field of computational fluid dynamics (CFD) modeling of multiphase flows gives valuable information for both groups of researchers in the field of ECT and CFD. By studying the ECT tomograms of multiphase flows under carefully monitored inflow conditions of the different media and by obtaining the capacitance values, C(i, j, t) with i = 1…N, j = 1, 2,…N and i ≠ j obtained from ECT modules with N electrodes, it is shown how the interface heights in a pipe with stratified flow of oil and air can be fruitfully compared to the values of those obtained from ECT and gamma radiation meter (GRM) for improving CFD modeling. Monitored inflow conditions in this study are flow rates of air, water and oil into a pipe which can be positioned at varying inclinations to the horizontal, thus emulating the pipelines laid in subsea installations. It is found that ECT-based tomograms show most of the features seen in the GRM-based visualizations with nearly one-to-one correspondence to interface heights obtained from these two methods, albeit some anomalies at the pipe wall. However, there are some interesting features the ECT manages to capture: features which the GRM or the CFD modeling apparently do not show, possibly due to parameters not defined in the inputs to the CFD model or much slower response of the GRM. Results presented in this paper indicate that a combination of ECT and GRM and preferably with other modalities with enhanced data fusion and analysis combined with CFD modeling can help to improve the modeling, measurement and control of multiphase flow in the oil and gas industries and in the process industries

  4. Electrical capacitance tomography (ECT) and gamma radiation meter for comparison with and validation and tuning of computational fluid dynamics (CFD) modeling of multiphase flow

    Science.gov (United States)

    Pradeep, Chaminda; Yan, Ru; Vestøl, Sondre; Melaaen, Morten C.; Mylvaganam, Saba

    2014-07-01

    The electrical capacitance tomographic (ECT) approach is increasingly seen as attractive for measurement and control applications in the process industries. Recently, there is increased interest in using the tomographic details from ECT for comparing with and validating and tuning CFD models of multiphase flow. Collaboration with researchers working in the field of computational fluid dynamics (CFD) modeling of multiphase flows gives valuable information for both groups of researchers in the field of ECT and CFD. By studying the ECT tomograms of multiphase flows under carefully monitored inflow conditions of the different media and by obtaining the capacitance values, C(i, j, t) with i = 1…N, j = 1, 2,…N and i ≠ j obtained from ECT modules with N electrodes, it is shown how the interface heights in a pipe with stratified flow of oil and air can be fruitfully compared to the values of those obtained from ECT and gamma radiation meter (GRM) for improving CFD modeling. Monitored inflow conditions in this study are flow rates of air, water and oil into a pipe which can be positioned at varying inclinations to the horizontal, thus emulating the pipelines laid in subsea installations. It is found that ECT-based tomograms show most of the features seen in the GRM-based visualizations with nearly one-to-one correspondence to interface heights obtained from these two methods, albeit some anomalies at the pipe wall. However, there are some interesting features the ECT manages to capture: features which the GRM or the CFD modeling apparently do not show, possibly due to parameters not defined in the inputs to the CFD model or much slower response of the GRM. Results presented in this paper indicate that a combination of ECT and GRM and preferably with other modalities with enhanced data fusion and analysis combined with CFD modeling can help to improve the modeling, measurement and control of multiphase flow in the oil and gas industries and in the process industries

  5. Coupling of Multiphase Flow and Geomechanics in Fractured Porous Media: Application to CO2 Leakages from Natural and Stimulated Fractures

    Science.gov (United States)

    Ezzedine, S. M.

    2015-12-01

    Leakage to the atmosphere of a significant fraction of injected CO2 would constitute a failure of a geological CO2 storage project from a greenhouse gas mitigation perspective. We present a numerical model that simulates flow and transport of CO2 into heterogeneous subsurface systems. The model, StoTran, is a flexible numerical environment that uses state-of-the-art finite element and finite volume methods and unstructured adaptive mesh refinement scheme implemented using MPI and OpenMP protocols. Multiphase flow equations and the geomechanical equations are implicitly solved and either fully or sequentially coupled. StoTran can address inverse and forward problems under deterministic or stochastic conditions. For the current study, StoTran has been used to simulate several scenarios spanning from a homogeneous single layered reservoir to heterogeneous multi-layered systems, which including cap-rock with embedded fractures, have been simulated under different operations of CO2 injection and CO2 leakages conditions. Results show the impact of the injection and leakage rates on the time evolution of the spread of the CO2 plume, its interception of the fractured cap-rock and the risk associated with the contamination of the overlaying aquifer. Spatial and temporal moments have been calculated for different, deterministic of stochastic, subsurface physical and chemical properties. Spatial moments enable assessing the extent of the region of investigation under conditions of uncertainty. Furthermore, several leakage scenarios show the intermittence behavior and development of the CO2 plume in the subsurface; its first interception with the fractures located further far from the injection well then, at a second stage, its interception with the fracture within the immediate vicinity of the injection well. We will present a remedy to CO2 leakages from the reservoir in order to enhance a long term containment of the injected CO2. This work performed under the auspices of

  6. DEVELOPMENT OF A COMPUTATIONAL MULTIPHASE FLOW MODEL FOR FISCHER TROPSCH SYNTHESIS IN A SLURRY BUBBLE COLUMN REACTOR

    Energy Technology Data Exchange (ETDEWEB)

    Donna Post Guillen; Tami Grimmett; Anastasia M. Gribik; Steven P. Antal

    2010-09-01

    The Hybrid Energy Systems Testing (HYTEST) Laboratory is being established at the Idaho National Laboratory to develop and test hybrid energy systems with the principal objective to safeguard U.S. Energy Security by reducing dependence on foreign petroleum. A central component of the HYTEST is the slurry bubble column reactor (SBCR) in which the gas-to-liquid reactions will be performed to synthesize transportation fuels using the Fischer Tropsch (FT) process. SBCRs are cylindrical vessels in which gaseous reactants (for example, synthesis gas or syngas) is sparged into a slurry of liquid reaction products and finely dispersed catalyst particles. The catalyst particles are suspended in the slurry by the rising gas bubbles and serve to promote the chemical reaction that converts syngas to a spectrum of longer chain hydrocarbon products, which can be upgraded to gasoline, diesel or jet fuel. These SBCRs operate in the churn-turbulent flow regime which is characterized by complex hydrodynamics, coupled with reacting flow chemistry and heat transfer, that effect reactor performance. The purpose of this work is to develop a computational multiphase fluid dynamic (CMFD) model to aid in understanding the physico-chemical processes occurring in the SBCR. Our team is developing a robust methodology to couple reaction kinetics and mass transfer into a four-field model (consisting of the bulk liquid, small bubbles, large bubbles and solid catalyst particles) that includes twelve species: (1) CO reactant, (2) H2 reactant, (3) hydrocarbon product, and (4) H2O product in small bubbles, large bubbles, and the bulk fluid. Properties of the hydrocarbon product were specified by vapor liquid equilibrium calculations. The absorption and kinetic models, specifically changes in species concentrations, have been incorporated into the mass continuity equation. The reaction rate is determined based on the macrokinetic model for a cobalt catalyst developed by Yates and Satterfield [1]. The

  7. Uncertainty quantification tools for multiphase gas-solid flow simulations using MFIX

    Energy Technology Data Exchange (ETDEWEB)

    Fox, Rodney O. [Iowa State Univ., Ames, IA (United States); Passalacqua, Alberto [Iowa State Univ., Ames, IA (United States)

    2016-02-01

    Computational fluid dynamics (CFD) has been widely studied and used in the scientific community and in the industry. Various models were proposed to solve problems in different areas. However, all models deviate from reality. Uncertainty quantification (UQ) process evaluates the overall uncertainties associated with the prediction of quantities of interest. In particular it studies the propagation of input uncertainties to the outputs of the models so that confidence intervals can be provided for the simulation results. In the present work, a non-intrusive quadrature-based uncertainty quantification (QBUQ) approach is proposed. The probability distribution function (PDF) of the system response can be then reconstructed using extended quadrature method of moments (EQMOM) and extended conditional quadrature method of moments (ECQMOM). The report first explains the theory of QBUQ approach, including methods to generate samples for problems with single or multiple uncertain input parameters, low order statistics, and required number of samples. Then methods for univariate PDF reconstruction (EQMOM) and multivariate PDF reconstruction (ECQMOM) are explained. The implementation of QBUQ approach into the open-source CFD code MFIX is discussed next. At last, QBUQ approach is demonstrated in several applications. The method is first applied to two examples: a developing flow in a channel with uncertain viscosity, and an oblique shock problem with uncertain upstream Mach number. The error in the prediction of the moment response is studied as a function of the number of samples, and the accuracy of the moments required to reconstruct the PDF of the system response is discussed. The QBUQ approach is then demonstrated by considering a bubbling fluidized bed as example application. The mean particle size is assumed to be the uncertain input parameter. The system is simulated with a standard two-fluid model with kinetic theory closures for the particulate phase implemented into

  8. Petrological Geodynamics of Mantle Melting I. AlphaMELTS + Multiphase Flow: Dynamic Equilibrium Melting, Method and Results

    Directory of Open Access Journals (Sweden)

    Massimiliano Tirone

    2017-10-01

    Full Text Available The complex process of melting in the Earth's interior is studied by combining a multiphase numerical flow model with the program AlphaMELTS which provides a petrological description based on thermodynamic principles. The objective is to address the fundamental question of the effect of the mantle and melt dynamics on the composition and abundance of the melt and the residual solid. The conceptual idea is based on a 1-D description of the melting process that develops along an ideal vertical column where local chemical equilibrium is assumed to apply at some level in space and time. By coupling together the transport model and the chemical thermodynamic model, the evolution of the melting process can be described in terms of melt distribution, temperature, pressure and solid and melt velocities but also variation of melt and residual solid composition and mineralogical abundance at any depth over time. In this first installment of a series of three contributions, a two-phase flow model (melt and solid assemblage is developed under the assumption of complete local equilibrium between melt and a peridotitic mantle (dynamic equilibrium melting, DEM. The solid mantle is also assumed to be completely dry. The present study addresses some but not all the potential factors affecting the melting process. The influence of permeability and viscosity of the solid matrix are considered in some detail. The essential features of the dynamic model and how it is interfaced with AlphaMELTS are clearly outlined. A detailed and explicit description of the numerical procedure should make this type of numerical models less obscure. The general observation that can be made from the outcome of several simulations carried out for this work is that the melt composition varies with depth, however the melt abundance not necessarily always increases moving upwards. When a quasi-steady state condition is achieved, that is when melt abundance does not varies significantly

  9. DEVELOPMENT OF MULTI-PHASE AND MULTI-COMPONENT FLOW MODEL WITH REACTION IN POROUS MEDIA FOR RISK ASSESSMENT ON SOIL CONTAMINATION DUE TO MINERAL OIL

    Science.gov (United States)

    Sakamoto, Yasuhide; Nishiwaki, Junko; Hara, Junko; Kawabe, Yoshishige; Sugai, Yuichi; Komai, Takeshi

    In late years, soil contamination due to mineral oil in vacant lots of oil factory and oil field has become obvious. Measure for soil contamina tion and risk assessment are neces sary for sustainable development of industrial activity. Especially, in addition to contaminated sites, various exposure paths for human body such as well water, soil and farm crop are supposed. So it is very important to comprehend the transport phenomena of contaminated material under the environments of soil and ground water. In this study, mineral oil as c ontaminated material consisting of mu lti-component such as aliphatic and aromatic series was modeled. Then numerical mode l for transport phenomena in surface soil and aquifer was constructed. On the basis of modeling for mineral oil, our numerical model consists of three-phase (oil, water and gas) forty three-component. This numerical model becomes base program for risk assessment system on soil contamination due to mineral oil. Using this numerical model, we carried out some numerical simulation for a laboratory-scale experiment on oil-water multi-phase flow. Relative permeability that dominate flow behavior in multi-phase condition was formulated and the validity of the numerical model developed in this study was considered.

  10. Modeling of Liquid Steel/Slag/Argon Gas Multiphase Flow During Tundish Open Eye Formation in a Two-Strand Tundish

    Science.gov (United States)

    Chatterjee, Saikat; Li, Donghui; Chattopadhyay, Kinnor

    2018-04-01

    Multiphase flows are frequently encountered in metallurgical operations. One of the most effective ways to understand these processes is by flow modeling. The process of tundish open eye (TOE) formation involves three-phase interaction between liquid steel, slag, and argon gas. The two-phase interaction involving argon gas bubbles and liquid steel can be modeled relatively easily using the discrete phase modeling technique. However, the effect of an upper slag layer cannot be captured using this approach. The presence of an upper buoyant phase can have a major effect on the behavior of TOEs. Hence, a multiphase model, including three phases, viz. liquid steel, slag, and argon gas, in a two-strand slab caster tundish, was developed to study the formation and evolution of TOEs. The volume of fluid model was used to track the interphase between liquid steel and slag phases, while the discrete phase model was used to trace the movement of the argon gas bubbles in liquid steel. The variation in the TOE areas with different amounts of aspirated argon gas was examined in the presence of an overlying slag phase. The mathematical model predictions were compared against steel plant measurements.

  11. Abnormal intraluminal signal within the pulmonary arteries on MR imaging: Differentiation between slow blood flow and thrombus using an ECG-gated; multiphasic: Spin-echo technique

    International Nuclear Information System (INIS)

    White, R.D.; Higgins, C.B.

    1986-01-01

    The authors evaluated abnormal MR imaging signal patterns in the pulmonary arteries of 22 patients with pulmonary hypertension (n = 13), pulmonary embolus (n = 4), or both (n = 5). Using multiphasic (five or six phases; 19 patients) or standard (three patients with pulmonary embolus) ECG-gated, double spin-echo techniques, they were able to differentiate between causes of such abnormal signal patterns. The pattern of slow blood flow (abnormal signal in systole with fluctuating distribution during cardiac cycle, and intensity increasing visually from first to second echo) was noted in 89% of patients with pulmonary hypertension alone or in combination with pulmonary embolism, and was characteristic of high systolic pulmonary pressures (12 of 12 patients with pressure > 80 mm Hg, vs. 3 of 5 patients with pressure 55 mm Hg vs. 5 of 7 patients with pressures <55 mm Hg). This pattern was differentiated from that of thrombus (persistent signal with fixed distribution during cardiac cycle, and little to no visible intensity change from first to second echo), which was noted in six of seven proved embolus cases. Thus, gated multiphase MR imaging shows potential for the noninvasive visualization of pulmonary embolus and the differentiation of this entity from the slow blood flow of pulmonary hypertension

  12. Advancement of compressible multiphase flows and sodium-water reaction analysis program SERAPHIM. Validation of a numerical method for the simulation of highly underexpanded jets

    International Nuclear Information System (INIS)

    Uchibori, Akihiro; Ohshima, Hiroyuki; Watanabe, Akira

    2010-01-01

    SERAPHIM is a computer program for the simulation of the compressible multiphase flow involving the sodium-water chemical reaction under a tube failure accident in a steam generator of sodium cooled fast reactors. In this study, the numerical analysis of the highly underexpanded air jets into the air or into the water was performed as a part of validation of the SERAPHIM program. The multi-fluid model, the second-order TVD scheme and the HSMAC method considering a compressibility were used in this analysis. Combining these numerical methods makes it possible to calculate the multiphase flow including supersonic gaseous jets. In the case of the air jet into the air, the calculated pressure, the shape of the jet and the location of a Mach disk agreed with the existing experimental results. The effect of the difference scheme and the mesh resolution on the prediction accuracy was clarified through these analyses. The behavior of the air jet into the water was also reproduced successfully by the proposed numerical method. (author)

  13. Beyond the Black Box: Coupling x-ray tomographic imaging of multi-phase flow processes to numerical models and traditional laboratory measurements

    DEFF Research Database (Denmark)

    Wildenschild, Dorthe; Porter, M.L.; Schaap, M.G.

    Quantitative non-invasive imaging has evolved rapidly in the last decade, and is now being used to assess a variety of problems in vadose zone research, including unsaturated flow and transport of water and contaminants, macropore-dominated processes, soil-water-root interactions, more recent work...... on colloidal processes, and significant work on NAPL-water interactions . We are now able to use non-invasive imaging to probe processes that could not previously be quantified because of lack of opacity, resolution, or accurate techniques for quantitative measurement. This work presents an overview of recent...... advances in x-ray microtomography techniques that can generate high-resolution image-based data for (1) validation of pore-scale multi-phase flow models such as the lattice-Boltzmann technique and pore network models (with respect to fluid saturations, fluid distribution, and relationships among capillary...

  14. Towards Identification of Rotordynamic Properties for Seals in Multiphase Flow Using Active Magnetic Bearings. Design and Commissioning of a Novel Test Facility

    DEFF Research Database (Denmark)

    Voigt, Andreas Jauernik

    important contact free force measurement capabilities. The third module houses the smooth annular test seals and the fourth module adds a single phase air flow supply to the test facility infrastructure. For experimental identification purposes the ability to acquire precise information of the forces...... and compressors for which reason the ability to predict the complex interaction between fluid dynamics and rotordynamics within these seals is a key aspect in the design of rotating equipment. Numerical tools offering predictive capabilities for seals subjected to multiphase flow conditions are currently being...... developed and refined, however a pronounced lack of experimental data renders benchmarking and validation impossible. This thesis focusses on documenting the design and commissioning of a test facility enabling the much needed experimental identification of rotordynamic properties for turbomachinery seals...

  15. TOURGHREACT: A Simulation Program for Non-isothermal MultiphaseReactive Geochemical Transport in Variably Saturated GeologicMedia

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Tianfu; Sonnenthal, Eric; Spycher, Nicolas; Pruess, Karsten

    2004-12-07

    TOUGHREACT is a numerical simulation program for chemically reactive non-isothermal flows of multiphase fluids in porous and fractured media. The program was written in Fortran 77 and developed by introducing reactive geochemistry into the multiphase fluid and heat flow simulator TOUGH2. A variety of subsurface thermo-physical-chemical processes are considered under a wide range of conditions of pressure, temperature, water saturation, ionic strength, and pH and Eh. Interactions between mineral assemblages and fluids can occur under local equilibrium or kinetic rates. The gas phase can be chemically active. Precipitation and dissolution reactions can change formation porosity and permeability. The program can be applied to many geologic systems and environmental problems, including geothermal systems, diagenetic and weathering processes, subsurface waste disposal, acid mine drainage remediation, contaminant transport, and groundwater quality. Here we present two examples to illustrate applicability of the program: (1) injectivity effects of mineral scaling in a fractured geothermal reservoir and (2) CO2 disposal in a deep saline aquifer.

  16. On the extension of multi-phase models to sub-residual saturations

    International Nuclear Information System (INIS)

    Lingineni, S.; Chen, Y.T.; Boehm, R.F.

    1995-01-01

    This paper focuses on the limitations of applying multi-phase flow and transport models to simulate the hydrothermal processes occurring when the liquid saturation falls below residual levels. A typical scenario of a heat-generating high-level waste package emplaced in a backfilled drift of a waste repository is presented. The hydrothermal conditions in the vicinity of the waste package as well as in the far-field are determined using multi-phase, non-isothermal codes such as TOUGH2 and FEHM. As the waste package temperature increases, heat-pipe effects are created and water is driven away from the package into colder regions where it condenses. The variations in the liquid saturations close to the waste package are determined using these models with extended capillary pressure-saturations relationships to sub-residual regime. The predictions indicate even at elevated temperatures, waste package surroundings are not completely dry. However, if transport based modeling is used to represent liquid saturation variations in the sub-residual regime, then complete dry conditions are predicted within the backfill for extended periods of time. The relative humidity conditions near the waste package are also found to be sensitive to the representation of capillary pressure-saturation relationship used for sub-residual regime. An experimental investigation is carried out to study the variations in liquid saturations and relative humidity conditions in sub-residual regimes. Experimental results indicated that extended multi-phase models without interphase transport can not predict dry-out conditions and the simulations underpredict the humidity conditions near the waste package

  17. TOUGHREACT User's Guide: A Simulation Program for Non-isothermal Multiphase Reactive Geochemical Transport in Variably Saturated Geologic Media, V1.2.1

    International Nuclear Information System (INIS)

    Xu, Tianfu; Sonnenthal, Eric; Spycher, Nicolas; Pruess, Karsten

    2008-01-01

    Coupled modeling of subsurface multiphase fluid and heat flow, solute transport, and chemical reactions can be applied to many geologic systems and environmental problems, including geothermal systems, diagenetic and weathering processes, subsurface waste disposal, acid mine drainage remediation, contaminant transport, and groundwater quality. TOUGHREACT has been developed as a comprehensive non-isothermal multi-component reactive fluid flow and geochemical transport simulator to investigate these and other problems. A number of subsurface thermo-physical-chemical processes are considered under various thermohydrological and geochemical conditions of pressure, temperature, water saturation, and ionic strength. TOUGHREACT can be applied to one-, two- or three-dimensional porous and fractured media with physical and chemical heterogeneity. The code can accommodate any number of chemical species present in liquid, gas and solid phases. A variety of equilibrium chemical reactions are considered, such as aqueous complexation, gas dissolution/exsolution, and cation exchange. Mineral dissolution/precipitation can take place subject to either local equilibrium or kinetic controls, with coupling to changes in porosity and permeability and capillary pressure in unsaturated systems. Chemical components can also be treated by linear adsorption and radioactive decay. The first version of the non-isothermal reactive geochemical transport code TOUGHREACT was developed (Xu and Pruess, 1998) by introducing reactive geochemistry into the framework of the existing multi-phase fluid and heat flow code TOUGH2 (Pruess, 1991). TOUGHREACT was further enhanced with the addition of (1) treatment of mineral-water-gas reactive-transport under boiling conditions, (2) an improved HKF activity model for aqueous species, (3) gas species diffusion coefficients calculated as a function of pressure, temperature, and molecular properties, (4) mineral reactive surface area formulations for fractured

  18. TOUGHREACT User's Guide: A Simulation Program for Non-isothermal Multiphase Reactive Geochemical Transport in Variably Saturated Geologic Media, V1.2.1

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Tianfu; Sonnenthal, Eric; Spycher, Nicolas; Pruess, Karsten

    2008-09-29

    Coupled modeling of subsurface multiphase fluid and heat flow, solute transport, and chemical reactions can be applied to many geologic systems and environmental problems, including geothermal systems, diagenetic and weathering processes, subsurface waste disposal, acid mine drainage remediation, contaminant transport, and groundwater quality. TOUGHREACT has been developed as a comprehensive non-isothermal multi-component reactive fluid flow and geochemical transport simulator to investigate these and other problems. A number of subsurface thermo-physical-chemical processes are considered under various thermohydrological and geochemical conditions of pressure, temperature, water saturation, and ionic strength. TOUGHREACT can be applied to one-, two- or three-dimensional porous and fractured media with physical and chemical heterogeneity. The code can accommodate any number of chemical species present in liquid, gas and solid phases. A variety of equilibrium chemical reactions are considered, such as aqueous complexation, gas dissolution/exsolution, and cation exchange. Mineral dissolution/precipitation can take place subject to either local equilibrium or kinetic controls, with coupling to changes in porosity and permeability and capillary pressure in unsaturated systems. Chemical components can also be treated by linear adsorption and radioactive decay. The first version of the non-isothermal reactive geochemical transport code TOUGHREACT was developed (Xu and Pruess, 1998) by introducing reactive geochemistry into the framework of the existing multi-phase fluid and heat flow code TOUGH2 (Pruess, 1991). TOUGHREACT was further enhanced with the addition of (1) treatment of mineral-water-gas reactive-transport under boiling conditions, (2) an improved HKF activity model for aqueous species, (3) gas species diffusion coefficients calculated as a function of pressure, temperature, and molecular properties, (4) mineral reactive surface area formulations for fractured

  19. Coupled multiphase reactive flow and mineral dissolution-precipitation kinetics: Examples of long-term CO2 sequestration in Utsira Sand, Norway and Mt. Simon Formation, Midwest USA

    Science.gov (United States)

    Zhang, Y.; Zhang, G.; Lu, P.; Hu, B.; Zhu, C.

    2017-12-01

    The extent of CO2 mineralization after CO2 injection into deep saline aquifers is a result of the complex coupling of multiphase fluid flow, mass transport, and brine-mineral reactions. The effects of dissolution rate laws and groundwater flow on the long-term fate of CO2 have been seriously overlooked. To investigate these effects, we conducted multiphase (CO2 and brine) coupled reactive transport modeling of CO2 storage in two sandy formations (Utsira Sand, Norway1,2 and Mt. Simon formation, USA 3) using ToughReact and simulated a series of scenarios. The results indicated that: (1) Different dissolution rate laws for feldspars can significantly affect the amount of CO2 mineralization. Increased feldspar dissolution will promote CO2 mineral trapping through the coupling between feldspar dissolution and carbonate mineral precipitation at raised pH. The predicted amount of CO2 mineral trapping when using the principle of detailed balancing-based rate law for feldspar dissolution is about twice as much as that when using sigmoidal rate laws in the literature. (2) Mineral trapping is twice as much when regional groundwater flow is taken into consideration in long-term simulations (e.g., 10,000 years) whereas most modeling studies neglected the regional groundwater flow back and effectively simulated a batch reactor process. Under the influence of regional groundwater flow, the fresh brine from upstream continuously dissolves CO2 at the tail of CO2 plume, generating a large acidified area where large amount of CO2 mineralization takes place. The upstream replenishment of groundwater results in ˜22% mineral trapping at year 10,000, compared to ˜4% when this effect is ignored. Refs: 1Zhang, G., Lu, P., Wei, X., Zhu, C. (2016). Impacts of Mineral Reaction Kinetics and Regional Groundwater Flow on Long-Term CO2 Fate at Sleipner. Energy & Fuels, 30(5), 4159-4180. 2Zhu, C., Zhang, G., Lu, P., Meng, L., Ji, X. (2015). Benchmark modeling of the Sleipner CO2 plume

  20. Multiphase-flow numerical modeling of the 18 May 1980 lateral blast at Mount St. Helens, USA

    Science.gov (United States)

    Ongaro, T.E.; Widiwijayanti, C.; Clarke, A.B.; Voight, B.; Neri, A.

    2011-01-01

    Volcanic lateral blasts are among the most spectacular and devastating of natural phenomena, but their dynamics are still poorly understood. Here we investigate the best documented and most controversial blast at Mount St. Helens (Washington State, United States), on 18 May 1980. By means of three-dimensional multiphase numerical simulations we demonstrate that the blast front propagation, fi nal runout, and damage can be explained by the emplacement of an unsteady, stratifi ed pyroclastic density current, controlled by gravity and terrain morphology. Such an interpretation is quantitatively supported by large-scale observations at Mount St. Helens and will infl uence the defi nition and predictive mapping of hazards on blast-dangerous volcanoes worldwide. ?? 2011 Geological Society of America.

  1. Multiphase flow towards coupled solid-liquid interactions in 2D heterogeneous porous micromodels: a fluorescent microscopy and micro-PIV measurement at pore scale

    Science.gov (United States)

    Li, Yaofa; Kazemifar, Farzan; Blois, Gianluca; Christensen, Kenneth; Kenneth Christensen, Notre Dame Team

    2017-11-01

    Multiphase flow in porous media is relevant to a range of applications in the energy and environmental sectors. Recently, the interest has been renewed by geological storage of CO2 within saline aquifers. Central to this goal is predicting the fidelity of candidate sites pre-injection of CO2 and its post-injection migration. Moreover, local pressure buildup may cause micro-seismic events, which could prove disastrous, and possibly compromise seal integrity. Evidence shows that the large-scale events are coupled with pore-scale phenomena, necessitating the understanding of pore-scale stress, strain, and flow processes and their representation in large-scale modeling. To this end, the pore-scale flow of water and supercritical CO2 is investigated under reservoir-relevant conditions over a range of wettability conditions in 2D heterogeneous micromodels that reflect the complexity of real sandstone. High-speed fluorescent microscopy, complemented by a fast differential pressure transmitter, allows for simultaneous measurement of the flow field within and the instantaneous pressure drop across the micromodels. A flexible micromodel is also designed, to be used in conjunction with the micro-PIV technique, enabling the quantification of coupled solid-liquid interactions. This work was supported as part of the GSCO2, an EFRC funded by the US DOE, Office of Science, and partially supported by WPI-I2CNER.

  2. Simulation of Water Percolation in a FEBEX Bentonite Block using TOUGH2 Program

    International Nuclear Information System (INIS)

    Bru, A.

    2001-01-01

    We use Tough2 program to simulate the water percolation in a Febex bentonite Block. From obtained results, we conclude that mean field approximation does not describe this process because the heterogeneity of the medium it is not include in mathematical formalism. (Author) 17 refs

  3. Ultrasonic Doppler measurement technique for the diagnosis of non-steady state multi-phase flow processes; Ultraschall-Doppler-Messtechnik zur Diagnose instationaerer Mehrphasen-Stroemungsvorgaenge

    Energy Technology Data Exchange (ETDEWEB)

    Specht, O.; Fiedler, O. [Rostock Univ. (Germany). Fachbereich Elektrotechnik; Skerl, O.

    1997-12-01

    In many areas of technology and in industry, there is an increasing requirement for a flexible, non-invasive measurement technique for flow speeds and through flows. The ultrasonic clamp-on measurement technique can fulfil these requirements and is being used to an increasing extent. The application of this technique only presupposes the acoustic transparency of the pipe wall, which is the case for most materials, such as metals, plastics and glass. The ultrasonic running time process is preferred to the Doppler process for mainly one-phase fluids. Due to its working principle, the ultrasonic Doppler process depends on multi-phase fluids, because it uses the frequency displacement of the sound waves backscattered at the phase boundaries as the measurement parameter for the speed of flow. [Deutsch] In vielen Bereichen der Technik und in der Industrie besteht zunehmend die Forderung nach einer flexiblen, nichtinvasiven Messtechnik fuer Stroemungsgeschwindigkeiten und Durchfluesse. Die Ultraschall-Clamp-On-Messtechnik kann diese Anforderungen erfuellen und wird in wachsendem Umfang eingesetzt. Die Anwendung dieser Technik setzt nur die akustische Transparenz der Rohrwand voraus, was fuer die meisten Materialien wie Metalle, Kunststoffe und Glas der Fall ist. Bei ueberwiegend einphasigen Fluiden wird das Ultraschall-Laufzeit-Verfahren gegenueber dem Doppler-Verfahren bevorzugt. Das Ultraschall-Doppler-Verfahren ist nach seinem Wirkprinzip auf mehrphasige Fluide angewiesen, denn es nutzt die Frequenzverschiebung der an den Phasengrenzen rueckgestreuten Schallwellen als Messgroesse fuer die Stroemungsgeschwindigkeit. (orig.)

  4. A fast and robust TOUGH2 module to simulate geological CO2 storage in saline aquifers

    Science.gov (United States)

    Shabani, Babak; Vilcáez, Javier

    2018-02-01

    A new TOUGH2 module to simulate geological CO2 storage (GCS) in saline aquifers is developed based on the widely employed ECO2N module of TOUGH2. The newly developed TOUGH2 module uses a new non-iterative fugacity-activity thermodynamic model to obtain the partitioning of CO2 and H2O between the aqueous and gas phases. Simple but robust thermophysical correlations are used to obtain density, viscosity, and enthalpy of the gas phase. The implementation and accuracy of the employed thermophysical correlations are verified by comparisons against the national institute of standards and technology (NIST) online thermophysical database. To assess the computation accuracy and efficiency, simulation results obtained with the new TOUGH2 module for a one-dimensional non-isothermal radial and a three-dimensional isothermal system are compared against the simulation results obtained with the ECO2N module. Treating salt mass fraction in the aqueous phase as a constant, along with the inclusion of a non-iterative fugacity-activity thermodynamic model, and simple thermophysical correlations, resulted in simulations much faster than simulations with ECO2N module, without losing numerical accuracy. Both modules yield virtually identical results. Additional field-scale simulations of CO2 injection into an actual non-isothermal and heterogeneous geological formation confirmed that the new module is much faster than the ECO2N module in simulating complex field-scale conditions. Owing to its capability to handle CO2-CH4-H2S-N2 gas mixtures and its compatibility with TOUGHREACT, this new TOUGH2 module offers the possibility of developing a fast and robust TOUGHREACT module to predict the fate of CO2 in GCS sites under biotic conditions where CO2, CH4, H2S, and N2 gases can be formed.

  5. Development of Conductivity Sensors for Multi-Phase Flow Local Measurements at the Polytechnic University of Valencia (UPV) and University Jaume I of Castellon (UJI).

    Science.gov (United States)

    Muñoz-Cobo, José Luis; Chiva, Sergio; Méndez, Santos; Monrós, Guillem; Escrivá, Alberto; Cuadros, José Luis

    2017-05-10

    This paper describes all the procedures and methods currently used at UPV (Universitat Politécnica de Valencia) and UJI (University Jaume I) for the development and use of sensors for multi-phase flow analysis in vertical pipes. This paper also describes the methods that we use to obtain the values of the two-phase flow magnitudes from the sensor signals and the validation and cross-verification methods developed to check the consistency of the results obtained for these magnitudes with the sensors. First, we provide information about the procedures used to build the multi-sensor conductivity probes and some of the tests performed with different materials to avoid sensor degradation issues. In addition, we provide information about the characteristics of the electric circuits that feed the sensors. Then the data acquisition of the conductivity probe, the signal conditioning and the data processing including the device that have been designed to automatize all the measurement process of moving the sensors inside the channels by means of stepper electric motors controlled by computer are shown in operation. Then, we explain the methods used for bubble identification and categorization. Finally, we describe the methodology used to obtain the two-phase flow information from the sensor signals. This includes the following items: void fraction, gas velocity, Sauter mean diameter and interfacial area concentration. The last part of this paper is devoted to the conductance probes developed for the annular flow analysis, which includes the analysis of the interfacial waves produced in annular flow and that requires a different type of sensor.

  6. Formation mechanism of channel segregation in carbon steels by inclusion flotation: X-ray microtomography characterization and multi-phase flow modeling

    International Nuclear Information System (INIS)

    Cao, Yan Fei; Chen, Yun; Li, Dian Zhong

    2016-01-01

    Recent experimental dissections of steel ingots and multi-scale simulations have led to the discovery of a potential driving force for channel segregation: the flotation of oxide-based inclusion (D. Li et al., Nat. Commun. 5:5572 (2014)). Further experimental analysis and numerical modeling are necessary to clarify this mechanism in detail. In this work, the inclusions in a carbon steel ingot that exhibits severe channel segregations were characterized by the 3D X-ray microtomography, which revealed a significant enrichment and growth of inclusions in the channels. Based on above microtomography characterization, a 2D macrosegregation model encompassing the inclusion flotation was established. In the model, the motions of solid inclusions and liquid were described using the multi-phase flow scheme within the Euler-Lagrange framework. The benchmark simulations showed that sufficient inclusion populations with appropriate sizes are capable of altering the local flow patterns and destabilize the mushy zone, initiating the subsequent channel segregation. The continuous interplay between melt convection, inclusion flotation and solidification eventually causes the formation of macroscale channel. The predicted sizes and volume fraction of inclusions that are able to trigger the channel segregation effectively are consistent with the data obtained via microtomography characterization. The macrosegregation model was then applied to predict the channel segregations in an industrial carbon steel ingot. A rather good agreement of A-segregates was achieved between the simulation and the dissected ingot.

  7. Implementation of leak detection techniques in ducts with critical regimen multiphase flow; Implementacao de tecnicas de deteccao de vazamentos em dutos em regime de escoamento multifasico critico

    Energy Technology Data Exchange (ETDEWEB)

    Martins, Rodrigo S.; Maitelli, Andr L.; Doria Neto, Adriao D.; Salazar, Andres O. [Rio Grande do Norte Univ., Natal, RN (Brazil)

    2005-07-01

    This paper presents signals processing techniques and artificial neural networks to identify leaks in multiphase flow pipeline. The greatest difficulty on traditional methods of leak detection (volume balance, pressure point analysis, etc) is that they are insufficient to design an adequate profile for the real conditions of oil pipeline transport. These difficult conditions goes since unevenly soil, that cause columns or vacuum throughout pipelines, until the presence of multi phases like water, gas and oil; plus other components as sand, which use to produce discontinuous flow off and diverse variations. To attenuate these difficulties, the transform wavelet was used to map the signal pressure in different resolution plan allowing the extraction of descriptors that identify leaks patterns and with then to provide training for the neural network multilayer perceptron (MLP) to learning of how to classify this pattern and report whenever this characterize leaks. During the tests were used transient and regime signals and pipelines with punctures with size variations from 1/2'' to 1'' of diameter to simulate leaks and, this way, it was possible to detect leaks with a time window of two minutes. The result show that the proposed descriptors considered, based in statistical methods applied in domain transform, are sufficient to identify leaks patterns and make it possible to train the neural classifier to indicate the occurrence of pipeline leaks. (author)

  8. Fundamentals and recent advances in X-ray micro computed tomography (microCT) applied on thermal-fluid dynamics and multiphase flows

    International Nuclear Information System (INIS)

    Santini, Maurizio

    2015-01-01

    X-ray computed tomography (CT) is a well-known technique nowadays, since its first practical application by Sir. G. Hounsfield (Nobel price for medicine 1979) has continually benefited from optimising improvements, especially in medical applications. Indeed, also application of CT in various engineering research fields provides fundamental informations on a wide range of applications, considering that the technique is not destructive, allowing 3D visualization without perturbation of the analysed material. Nowadays, it is technologically possible to design and realize an equipment that achieve a micrometric resolution and even improve the sensibility in revealing differences in materials having very radiotransparency, allowing i.e. to distinguish between different fluids (with different density) or states of matter (like with two-phase flows). At the University of Bergamo, a prototype of an X-ray microCT system was developed since 2008, so being fully operative from 2012, with specific customizations for investigations in thermal-fluid dynamics and multiphase flow researches. A technical session held at the UIT International Conference in L'Aquila (Italy), at which this paper is referring, has presented some microCT fundamentals, to allow the audience to gain basics to follow the “fil-rouge” that links all the instrumentation developments, till the recent applications. Hereinafter are reported some applications currently developed at Bergamo University at the X-ray computed micro-tomography laboratory. (paper)

  9. Beyond the Black Box: Coupling x-ray tomographic imaging of multi-phase flow processes to numerical models and traditional laboratory measurements (Invited)

    Science.gov (United States)

    Wildenschild, D.; Porter, M. L.; Schaap, M. G.; Joekar-Niasar, V.; Schjonning, P.; Wollesen de Jonge, L.; Moldrup, P.

    2010-12-01

    Quantitative non-invasive imaging has evolved rapidly in the last decade, and is now being used to assess a variety of problems in vadose zone research, including unsaturated flow and transport of water and contaminants, macropore-dominated processes, soil-water-root interactions, more recent work on colloidal processes, and significant work on NAPL-water interactions . We are now able to use non-invasive imaging to probe processes that could not previously be quantified because of lack of opacity, resolution, or accurate techniques for quantitative measurement. This work presents an overview of recent advances in x-ray microtomography techniques that can generate high-resolution image-based data for (1) validation of pore-scale multi-phase flow models such as the lattice-Boltzmann technique and pore network models (with respect to fluid saturations, fluid distribution, and relationships among capillary pressure, saturation, fluid-fluid interfacial area, etc.), and (2) making the link between tomographic data and more traditional laboratory-based soil/vadose zone characterization such as hydraulic conductivity, air permeability, and pycnometer-based porosity measurements). Finally, limitations and advantages of these various approaches, as well as tomography specific issues such as resolution vs. REV requirement, access to the different types of equipment, etc. will be discussed.

  10. Single-step reinitialization and extending algorithms for level-set based multi-phase flow simulations

    Science.gov (United States)

    Fu, Lin; Hu, Xiangyu Y.; Adams, Nikolaus A.

    2017-12-01

    We propose efficient single-step formulations for reinitialization and extending algorithms, which are critical components of level-set based interface-tracking methods. The level-set field is reinitialized with a single-step (non iterative) "forward tracing" algorithm. A minimum set of cells is defined that describes the interface, and reinitialization employs only data from these cells. Fluid states are extrapolated or extended across the interface by a single-step "backward tracing" algorithm. Both algorithms, which are motivated by analogy to ray-tracing, avoid multiple block-boundary data exchanges that are inevitable for iterative reinitialization and extending approaches within a parallel-computing environment. The single-step algorithms are combined with a multi-resolution conservative sharp-interface method and validated by a wide range of benchmark test cases. We demonstrate that the proposed reinitialization method achieves second-order accuracy in conserving the volume of each phase. The interface location is invariant to reapplication of the single-step reinitialization. Generally, we observe smaller absolute errors than for standard iterative reinitialization on the same grid. The computational efficiency is higher than for the standard and typical high-order iterative reinitialization methods. We observe a 2- to 6-times efficiency improvement over the standard method for serial execution. The proposed single-step extending algorithm, which is commonly employed for assigning data to ghost cells with ghost-fluid or conservative interface interaction methods, shows about 10-times efficiency improvement over the standard method while maintaining same accuracy. Despite their simplicity, the proposed algorithms offer an efficient and robust alternative to iterative reinitialization and extending methods for level-set based multi-phase simulations.

  11. X-ray Microtomography of Intermittency in Multiphase Flow at Steady State Using a Differential Imaging Method

    Science.gov (United States)

    Gao, Ying; Lin, Qingyang; Bijeljic, Branko; Blunt, Martin J.

    2017-12-01

    We imaged the steady state flow of brine and decane in Bentheimer sandstone. We devised an experimental method based on differential imaging to examine how flow rate impacts impact the pore-scale distribution of fluids during coinjection. This allows us to elucidate flow regimes (connected, or breakup of the nonwetting phase pathways) for a range of fractional flows at two capillary numbers, Ca, namely 3.0 × 10-7 and 7.5 × 10-6. At the lower Ca, for a fixed fractional flow, the two phases appear to flow in connected unchanging subnetworks of the pore space, consistent with conventional theory. At the higher Ca, we observed that a significant fraction of the pore space contained sometimes oil and sometimes brine during the 1 h scan: this intermittent occupancy, which was interpreted as regions of the pore space that contained both fluid phases for some time, is necessary to explain the flow and dynamic connectivity of the oil phase; pathways of always oil-filled portions of the void space did not span the core. This phase was segmented from the differential image between the 30 wt % KI brine image and the scans taken at each fractional flow. Using the grey scale histogram distribution of the raw images, the oil proportion in the intermittent phase was calculated. The pressure drops at each fractional flow at low and high flow rates were measured by high-precision differential pressure sensors. The relative permeabilities and fractional flow obtained by our experiment at the mm-scale compare well with data from the literature on cm-scale samples.

  12. Using pore-scale imaging and modeling to provide new insights in multi-phase flow, transport and reaction phenomena in porous media (Invited)

    Science.gov (United States)

    Bijeljic, B.; Andrew, M. G.; Menke, H. P.; Blunt, M. J.

    2013-12-01

    Advances in X ray imaging techniques made it possible not only to accurately describe solid and fluid(s) distributions in the pore space but also to study dynamics of multi-phase flow and reactive transport in-situ. This has opened up a range of new opportunities to better understand fundamental physics at the pore scale by experiment, and test and validate theoretical models in order to develop predictive tools at the pore scale and use it for upscaling. Firstly, we illustrate this concept by describing a new methodology for predicting non-Fickian transport in millimeter-sized three-dimensional micro-CT images of a beadpack, a sandstone, and a carbonate, representing porous media with an increasing degree of pore-scale complexity. The key strategy is to retain the full information on flow and transport signature of a porous medium by using probability distribution functions (PDFs) of voxel velocities for flow, and both PDFs of particle displacements and PDFs of particle transit times between voxels for transport. For this purpose, direct-simulation flow and transport model is used to analyse the relationship between pore structure, velocity, and the dynamics of the evolving plume. The model predictions for PDFs of particle displacements obtained by the model are in excellent agreement with those measured on similar cores in nuclear magnetic resonance experiments. A key determinant for non-Fickian transport is the spread in velocity distribution in the pore space. Further, we present micro-CT imaging of capillary trapping of scCO2 at reservoir conditions in a range of carbonates and sandstones having different pore structure and demonstrate that substantial quantities of scCO2 can be trapped in the pore space. Higher residual scCO2 saturations are found in sandstones compared to carbonates. The trapped ganglia exhibit different distribution of size, related to the inherent structure of pore space. Pore structures with large, open pores that are well connected lead

  13. Comparison of long-term numerical simulations at the Ketzin pilot site using the Schlumberger ECLIPSE and LBNL TOUGH2 simulators

    Science.gov (United States)

    Kempka, T.; Norden, B.; Tillner, E.; Nakaten, B.; Kühn, M.

    2012-04-01

    Geological modelling and dynamic flow simulations were conducted at the Ketzin pilot site showing a good agreement of history matched geological models with CO2 arrival times in both observation wells and timely development of reservoir pressure determined in the injection well. Recently, a re-evaluation of the seismic 3D data enabled a refinement of the structural site model and the implementation of the fault system present at the top of the Ketzin anticline. The updated geological model (model size: 5 km x 5 km) shows a horizontal discretization of 5 x 5 m and consists of three vertical zones, with the finest discretization at the top (0.5 m). According to the revised seismic analysis, the facies modelling to simulate the channel and floodplain facies distribution at Ketzin was updated. Using a sequential Gaussian simulator for the distribution of total and effective porosities and an empiric porosity-permeability relationship based on site and literature data available, the structural model was parameterized. Based on this revised reservoir model of the Stuttgart formation, numerical simulations using the TOUGH2-MP/ECO2N and Schlumberger Information Services (SIS) ECLIPSE 100 black-oil simulators were undertaken in order to evaluate the long-term (up to 10,000 years) migration of the injected CO2 (about 57,000 t at the end of 2011) and the development of reservoir pressure over time. The simulation results enabled us to quantitatively compare both reservoir simulators based on current operational data considering the long-term effects of CO2 storage including CO2 dissolution in the formation fluid. While the integration of the static geological model developed in the SIS Petrel modelling package into the ECLIPSE simulator is relatively flawless, a work-flow allowing for the export of Petrel models into the TOUGH2-MP input file format had to be implemented within the scope of this study. The challenge in this task was mainly determined by the presence of a

  14. Techniques de débitmétrie polyphasique non intrusive. Revue bibliographique Non Intrusive Multiphase Flow Measurement Techniques. Bibliographic Review

    Directory of Open Access Journals (Sweden)

    Lynch J.

    2006-11-01

    Full Text Available Cet article présente les différentes techniques de débitmétrie polyphasique non intrusive décrites dans la littérature du domaine public. Ces techniques sont considérées du point de vue de leur application dans le cadre de la production pétrolière sous-marine (mélange eau/huile/gaz. A partir d'une analyse des différentes méthodes physiques qui peuvent être utilisées, des perspectives d'avenir sont proposées. Several operations in the oil reservoir exploitation industry call for flowmeters capable of delivering information on the quantity and rate of flow of the different phases (gas, oil, water, solids . . . present in a pipeline. Amongst these are the estimation of remaining reserves and of well performance, control of production units such as multiphase pumping systems and fiscal monitoring in the case of pipeline networking. Existing methods, based on phase separation, require separate test lines and thus tend to be cumbersome, give only intermittent values of flow parameters and need to be calibrated due to the intrusive nature of the measurements. These drawbacks are seen to be all the more critical in subsea production where the ideal flowmeter would be compact, require little maintenance and supply precise real time data for network and multiphase pump control. In recent years flow measurement in two or more phase systems has received increasing attention both in laboratory studies and for applications in a variety of industries (for example : nuclear power production and food processing as well as of course oil production. We review here the many methods considered for non-intrusive flow metering with two or more components from the point of view of an industrial (in particular subsea oil production application. The situation is rendered delicate, in particular for density measurement, by the uncontrolled nature of the flow which may occur in any of several regimes with differing spatial distributions of the components

  15. Influence of core sand properties on flow dynamics of core shooting process based on experiment and multiphase simulation

    Directory of Open Access Journals (Sweden)

    Chang-jiang Ni

    2017-03-01

    Full Text Available The influence of core sand properties on flow dynamics was investigated synchronously with various core sands, transparent core-box and high-speed camera. To confirm whether the core shooting process has significant turbulence, the flow pattern of sand particles in the shooting head and core box was reproduced with colored core sands. By incorporating the kinetic theory of granular flow (KTGF, kinetic-frictional constitutive correlation and turbulence model, a two-fluid model (TFM was established to study the flow dynamics of the core shooting process. Two-fluid model (TFM simulations were then performed and a areasonable agreement was achieved between the simulation and experimental results. Based on the experimental and simulation results, the effects of turbulence, sand density, sand diameter and binder ratio were analyzed in terms of filling process, sand volume fraction (αs and sand velocity (Vs.

  16. A three-field model of transient 3D multiphase, three-component flow for the computer code IV A3. Pt. 1

    International Nuclear Information System (INIS)

    Kolev, N.I.

    1991-12-01

    This work contains description of the physical and mathematical basis on which the IVA3 computer code relies. After describing the state of the art of the 3D modeling for transient multiphase flows, the model assumptions and the modeling technique used in IVA3 are described. Starting with the principles of conservation of mass, momentum, and energy, the non averaged conservation equations are derived for each of the velocity fields which consist of different isothermal components. Thereafter averaging is applied and the working form of the system of 21 partial differential equations is derived. Special attention is paid to the strict consistence of the modeling technique used in IVA3 with the second principle of thermodynamics. The entropy concept used is derived starting with the unaveraged conservation equations and subsequent averaging. The source terms of the entropy production are carefully defined and the final form of the averaged entropy equation is given ready for direct practical applications. The idea of strong analytical thermodynamic coupling between pressure field and changes of the other thermodynamic properties, which is used for the first time in 3D multi fluid modeling, is presented in detail. After obtaining the working form of the conservation equations, the discretization procedure and the reduction to algebraic problems is presented. The mathematical solution method together with some information about the architecture of IVA3 including the local momentum decoupling and accuracy control is presented too. (orig./GL) [de

  17. Efficient C1-continuous phase-potential upwind (C1-PPU) schemes for coupled multiphase flow and transport with gravity

    Science.gov (United States)

    Jiang, Jiamin; Younis, Rami M.

    2017-10-01

    In the presence of counter-current flow, nonlinear convergence problems may arise in implicit time-stepping when the popular phase-potential upwinding (PPU) scheme is used. The PPU numerical flux is non-differentiable across the co-current/counter-current flow regimes. This may lead to cycles or divergence in the Newton iterations. Recently proposed methods address improved smoothness of the numerical flux. The objective of this work is to devise and analyze an alternative numerical flux scheme called C1-PPU that, in addition to improving smoothness with respect to saturations and phase potentials, also improves the level of scalar nonlinearity and accuracy. C1-PPU involves a novel use of the flux limiter concept from the context of high-resolution methods, and allows a smooth variation between the co-current/counter-current flow regimes. The scheme is general and applies to fully coupled flow and transport formulations with an arbitrary number of phases. We analyze the consistency property of the C1-PPU scheme, and derive saturation and pressure estimates, which are used to prove the solution existence. Several numerical examples for two- and three-phase flows in heterogeneous and multi-dimensional reservoirs are presented. The proposed scheme is compared to the conventional PPU and the recently proposed Hybrid Upwinding schemes. We investigate three properties of these numerical fluxes: smoothness, nonlinearity, and accuracy. The results indicate that in addition to smoothness, nonlinearity may also be critical for convergence behavior and thus needs to be considered in the design of an efficient numerical flux scheme. Moreover, the numerical examples show that the C1-PPU scheme exhibits superior convergence properties for large time steps compared to the other alternatives.

  18. Online slug detection in multi-phase transportation pipelines using electrical tomography

    DEFF Research Database (Denmark)

    Pedersen, Simon; Mai, Christian; Hansen, Leif

    2015-01-01

    Slugging flow in offshore oil & gas multi-phase transportation pipelines cause big challenges as the flow regime induces flow and pressure oscillations in the multi-phase pipelines. The negative impacts of the most severe slugs are significant and thus the elimination of slugging flow in the pipe......Slugging flow in offshore oil & gas multi-phase transportation pipelines cause big challenges as the flow regime induces flow and pressure oscillations in the multi-phase pipelines. The negative impacts of the most severe slugs are significant and thus the elimination of slugging flow...

  19. National laboratories` capabilities summaries for the DOE Virtual Center for Multiphase Dynamics (VCMD)

    Energy Technology Data Exchange (ETDEWEB)

    Joyce, E.L.

    1997-03-01

    The Virtual Center For Multiphase Dynamics (VCMD) integrates and develops the resources of industry, government, academia, and professional societies to enable reliable analysis in multiphase computational fluid dynamics. The primary means of the VCMD focus will be by the creation, support, and validation of a computerized simulation capability for multiphase flow and multiphase flow applications. This paper briefly describes the capabilities of the National Laboratories in this effort.

  20. Study of Multi-phase Flow in Porous Media : Comparison of SPH Simulations with Micro-model Experiments

    OpenAIRE

    Kunz, P.; Zarikos, I. M.; Karadimitriou, N. K.; Huber, M.; Nieken, U.; Hassanizadeh, S. M.

    2016-01-01

    We present simulations and experiments of drainage processes in a micro-model. A direct numerical simulation is introduced which is capable of describing wetting phenomena on the pore scale. A numerical smoothed particle hydrodynamics model was developed and used to simulate the two-phase flow of immiscible fluids. The experiments were performed in a micro-model which allows the visualization of interface propagation in detail. We compare the experiments and simulations of a quasistatic drain...

  1. The Merluza gas pipeline : a complete multiphase flow analysis, coupling pig launching with pressure constrained survival analysis

    Energy Technology Data Exchange (ETDEWEB)

    Baptista, R.M.; Maricato, A.L.G. [Petrobras Research and Development Center, Rio de Janeiro (Brazil)

    2004-07-01

    The 214 km, 16-inch diameter Merluza wet gas pipeline transports gas from the offshore Merluza gas field to an onshore treatment facility at Presidente Barnardes Refinery in Sao Paulo, Brazil. It is unique in that it carries a considerable amount of condensate, requiring frequent pigging. In addition, the capacity requirements at the pipeline tail are variable. The cycling nature has necessitated a survival analysis for both packing and drafting operations, accounting for up to 4 pigs operating simultaneously within the line. Operational limits of the slug catcher also present pressure constraints downstream of the pipeline. This paper presented the results of a set of pipeline flow numerical simulations for the pipeline. The objective was to estimate the imbalances caused by the presence of more than one pig within the line. Pig motion was evaluated by tracking and the pressure was explained by the accumulated volume downstream of the pig. The work was conceived under the two-phase flow domain, using OlgaS, a well known commercial two-phase flow numerical simulator. The results of the simulation were in good agreement with measured operational data, and allowed the operational programmer to optimize pig launching. The simulation also made it possible to take full advantage of the maximum pipeline capacity. 1 tab., 10 figs.

  2. A review of solid-fluid selection options for optical-based measurements in single-phase liquid, two-phase liquid-liquid and multiphase solid-liquid flows

    Science.gov (United States)

    Wright, Stuart F.; Zadrazil, Ivan; Markides, Christos N.

    2017-09-01

    Experimental techniques based on optical measurement principles have experienced significant growth in recent decades. They are able to provide detailed information with high-spatiotemporal resolution on important scalar (e.g., temperature, concentration, and phase) and vector (e.g., velocity) fields in single-phase or multiphase flows, as well as interfacial characteristics in the latter, which has been instrumental to step-changes in our fundamental understanding of these flows, and the development and validation of advanced models with ever-improving predictive accuracy and reliability. Relevant techniques rely upon well-established optical methods such as direct photography, laser-induced fluorescence, laser Doppler velocimetry/phase Doppler anemometry, particle image/tracking velocimetry, and variants thereof. The accuracy of the resulting data depends on numerous factors including, importantly, the refractive indices of the solids and liquids used. The best results are obtained when the observational materials have closely matched refractive indices, including test-section walls, liquid phases, and any suspended particles. This paper reviews solid-liquid and solid-liquid-liquid refractive-index-matched systems employed in different fields, e.g., multiphase flows, turbomachinery, bio-fluid flows, with an emphasis on liquid-liquid systems. The refractive indices of various aqueous and organic phases found in the literature span the range 1.330-1.620 and 1.251-1.637, respectively, allowing the identification of appropriate combinations to match selected transparent or translucent plastics/polymers, glasses, or custom materials in single-phase liquid or multiphase liquid-liquid flow systems. In addition, the refractive indices of fluids can be further tuned with the use of additives, which also allows for the matching of important flow similarity parameters such as density and viscosity.

  3. Multiphase flow and transport caused by spontaneous gas phase growth in the presence of dense non-aqueous phase liquid.

    Science.gov (United States)

    Roy, James W; Smith, James E

    2007-01-30

    Disconnected bubbles or ganglia of trapped gas may occur below the top of the capillary fringe through a number of mechanisms. In the presence of dense non-aqueous phase liquid (DNAPL), the disconnected gas phase experiences mass transfer of dissolved gases, including volatile components from the DNAPL. The properties of the gas phase interface can also change. This work shows for the first time that when seed gas bubbles exist spontaneous gas phase growth can be expected to occur and can significantly affect water-gas-DNAPL distributions, fluid flow, and mass transfer. Source zone behaviour was observed in three different experiments performed in a 2-dimensional flow cell. In each case, a DNAPL pool was created in a zone of larger glass beads over smaller glass beads, which served as a capillary barrier. In one experiment effluent water samples were analyzed to determine the vertical concentration profile of the plume above the pool. The experiments effectively demonstrated a) a cycle of spontaneous gas phase expansion and vertical advective mobilization of gas bubbles and ganglia above the DNAPL source zone, b) DNAPL redistribution caused by gas phase growth and mobilization, and c) that these processes can significantly affect mass transport from a NAPL source zone.

  4. A review of cell-scale multiphase flow modeling, including water management, in polymer electrolyte fuel cells

    International Nuclear Information System (INIS)

    Andersson, M.; Beale, S.B.; Espinoza, M.; Wu, Z.; Lehnert, W.

    2016-01-01

    Highlights: • The transport expressions inside PEFC GDLs are developed to describe significantly different systems. • Insight into the fundamental processes of liquid water evolution and transport in the GDL and GC is still lacking. • One important feature is the possibility to track the front between the liquid and the gas phases. • The two phase micro channels pressure drop correlations may not be applicable for GCs since one wall being porous. - Abstract: The PEFC has emerged as the most viable fuel cell type for automotive and some portable applications, and also has potential back-up power unit applications due to its low operating temperature, comparative simplicity of construction, high power density, and ease of operation. In spite of tremendous scientific advances, as well as engineering progress over the last few decades, the commercialization of PEFCs remains unrealized, owing primarily to economic viability associated with the high prices of materials and components and technical problems relating primarily to water management. The difficulty in addressing the water management issues lies mostly in the two-phase multi-component flow involving phase-change in porous media, coupled heat and mass transfer, interactions between the porous layers and gas channel (GC) and the complex relationship between water content and cell performance. Due to the low temperature of operation, water generated by the electrochemical reactions often condenses into liquid form, potentially flooding the gas diffusion layer (GDL), GC or other components. Insight into the fundamental processes of liquid water evolution and transport is still lacking, preventing further enhanced PEFC development. The aim of this paper is to give a comprehensive introduction to PEFC modeling inside GCs and GDLs, with a focus on two-phase flow and related phase-change and transport processes. Relevant momentum, mass and heat transport processes are introduced and the microstructural effects

  5. Micro-PIV measurements of multiphase flow of water and liquid CO2 in 2-D heterogeneous porous micromodels

    Science.gov (United States)

    Li, Yaofa; Kazemifar, Farzan; Blois, Gianluca; Christensen, Kenneth T.

    2017-07-01

    We present an experimental study of pore-scale flow dynamics of liquid CO2 and water in a two-dimensional heterogeneous porous micromodel, inspired by the structure of a reservoir rock, at reservoir-relevant conditions (80 bar, 21°C). The entire process of CO2 infiltration into a water-saturated micromodel was captured using fluorescence microscopy and the micro-PIV method, which together reveal complex fluid displacement patterns and abrupt changes in velocity. The CO2 front migrated through the resident water in an intermittent manner, forming dendritic structures, termed fingers, in directions along, normal to, and even opposing the bulk pressure gradient. Such characteristics indicate the dominance of capillary fingering through the micromodel. Velocity burst events, termed Haines jumps, were also captured in the heterogeneous micromodel, during which the local Reynolds number was estimated to be ˜21 in the CO2 phase, exceeding the range of validity of Darcy's law. Furthermore, these drainage events were observed to be cooperative (i.e., across multiple pores simultaneously), with the zone of influence of such events extending beyond tens of pores, confirming, in a quantitative manner, that Haines jumps are nonlocal phenomena. After CO2 completely breaks through the porous section, shear-induced circulations caused by flowing CO2 were also observed, in agreement with previous studies using a homogeneous porous micromodel. To our knowledge, this study is the first quantitative measurement that incorporates both reservoir-relevant conditions and rock-inspired heterogeneity, and thus will be useful for pore-scale model development and validation.

  6. Three-Dimensional Electrical Resistivity Tomography of the Solfatara Crater (Italy): Implication for the Multiphase Flow Structure of the Shallow Hydrothermal System

    Science.gov (United States)

    Gresse, Marceau; Vandemeulebrouck, Jean; Byrdina, Svetlana; Chiodini, Giovanni; Revil, André; Johnson, Timothy C.; Ricci, Tullio; Vilardo, Giuseppe; Mangiacapra, Annarita; Lebourg, Thomas; Grangeon, Jacques; Bascou, Pascale; Metral, Laurent

    2017-11-01

    The Solfatara volcano is the main degassing area of the Campi Flegrei caldera, characterized by 60 years of unrest. Assessing such renewal activity is a challenging task because hydrothermal interactions with magmatic gases remain poorly understood. In this study, we decipher the complex structure of the shallow Solfatara hydrothermal system by performing the first 3-D, high-resolution, electrical resistivity tomography of the volcano. The 3-D resistivity model was obtained from the inversion of 43,432 resistance measurements performed on an area of 0.68 km2. The proposed interpretation of the multiphase hydrothermal structures is based on the resistivity model, a high-resolution infrared surface temperature image, and 1,136 soil CO2 flux measurements. In addition, we realized 27 soil cation exchange capacity and pH measurements demonstrating a negligible contribution of surface conductivity to the shallow bulk electrical conductivity. Hence, we show that the resistivity changes are mainly controlled by fluid content and temperature. The high-resolution tomograms identify for the first time the structure of the gas-dominated reservoir at 60 m depth that feeds the Bocca Grande fumarole through a 10 m thick channel. In addition, the resistivity model reveals a channel-like conductive structure where the liquid produced by steam condensation around the main fumaroles flows down to the Fangaia area within a buried fault. The model delineates the emplacement of the main geological structures: Mount Olibano, Solfatara cryptodome, and tephra deposits. It also reveals the anatomy of the hydrothermal system, especially two liquid-dominated plumes, the Fangaia mud pool and the Pisciarelli fumarole, respectively.

  7. Successful well test application of portable multi-phase flow meter for high gas-volume and high water-cut wells in east Kalimantan, Indonesia

    Energy Technology Data Exchange (ETDEWEB)

    Kaura, Jiten D.; Finley, D.B. [PT Halliburton Indonesia, Jakarta (Indonesia); Sudradjat, Wangsa; Riyanto, Latief [Tota E and P Indonesie, Jakarta (Indonesia); Halverson, Martin [FlowSys AS, Bergen (Norway)

    2004-07-01

    Recently, testing was needed on production wells in East Kalimantan. The wells were in a mature field, and productivity from the wells field featured high water cut (WC) and extremely high gas-volume fractions (GVF). The WC and GVF ranged from 80 to 100% and 90 to 100%, respectively. Moreover, most of the wells are low productivity so they are very sensitive to back-pressure. The high WC, high GVF and low-productivity from these wells in this area present an extreme challenge for accurate production measurement. Barges are commonly used to perform well services in the swamp area of this marginal field, and production allocations from wells in this difficult area were previously monitored and measured with conventional well-test equipment on-board a well testing barge. The well test equipment traditionally used requires a large footprint, and the associated flaring presents an environmental situation in this sensitive swamp area. Hence, the MPFM solution was chosen. To better meet the challenges presented by the testing conditions, a portable multiphase flow meter (MPFM) was chosen to perform the testing from the well-testing barge. For comparative purposes, the MPFM was installed on the barge immediately upstream of the well testing equipment. Initial measurements with the MPFM yielded results that were {+-} 30% of the test separator reading. A slight modification was introduced to the MPFM system in the form of a gas knock-out (GKO) vessel. Subsequent measurements with the modified MPFM system yielded readings that were {+-}10% of the test separator reading. (author)

  8. An Experimenting Field Approach for the Numerical Solution of Multiphase Flow in Porous Media

    KAUST Repository

    Salama, Amgad

    2015-07-14

    In this work, we apply the experimenting pressure field technique to the problem of the flow of two or more immiscible phases in porous media. In this technique, a set of predefined pressure fields are introduced to the governing partial differential equations. This implies that the velocity vector field and the divergence at each cell of the solution mesh can be determined. However, since none of these fields is the true pressure field entailed by the boundary conditions and/or the source terms, the divergence at each cell will not be the correct one. Rather the residue which is the difference between the true divergence and the calculated one is obtained. These fields are designed such that these residuals are used to construct the matrix of coefficients of the pressure equation and the right-hand side. The experimenting pressure fields are generated in the solver routine and are fed to the different routines, which may be called physics routines, which return to the solver the elements of the matrix of coefficients. Therefore, this methodology separates the solver routines from the physics routines and therefore results in simpler, easy to construct, maintain, and update algorithms.

  9. Multiphase, multicomponent flow and transport models for Nuclear Test-Ban Treaty monitoring and nuclear waste disposal applications

    Science.gov (United States)

    Jordan, Amy

    Open challenges remain in using numerical models of subsurface flow and transport systems to make useful predictions related to nuclear waste storage and nonproliferation. The work presented here addresses the sensitivity of model results to unknown parameters, states, and processes, particularly uncertainties related to incorporating previously unrepresented processes (e.g., explosion-induced fracturing, hydrous mineral dehydration) into a subsurface flow and transport numerical simulator. The Finite Element Heat and Mass (FEHM) transfer code is used for all numerical models in this research. An experimental campaign intended to validate the predictive capability of numerical models that include the strongly coupled thermal, hydrological, and chemical processes in bedded salt is also presented. Underground nuclear explosions (UNEs) produce radionuclide gases that may seep to the surface over weeks to months. The estimated timing of gas arrival at the surface may be used to deploy personnel and equipment to the site of a suspected UNE, if allowed under the terms of the Comprehensive Nuclear Test-Ban Treaty. A model was developed using FEHM that considers barometrically pumped gas transport through a simplified fractured medium and was used to quantify the impact of uncertainties in hydrologic parameters (fracture aperture, matrix permeability, porosity, and saturation) and season of detonation on the timing of gas breakthrough. Numerical sensitivity analyses were performed for the case of a 1 kt UNE at a 400 m burial depth. Gas arrival time was found to be most affected by matrix permeability and fracture aperture. Gases having higher diffusivity were more sensitive to uncertainty in the rock properties. The effect of seasonality in the barometric pressure forcing was found to be important, with detonations in March the least likely to be detectable based on barometric data for Rainier Mesa, Nevada. Monte Carlo modeling was also used to predict the window of

  10. Online slug detection in multi-phase transportation pipelines using electrical tomography

    DEFF Research Database (Denmark)

    Pedersen, Simon; Mai, Christian; Hansen, Leif

    2015-01-01

    Slugging flow in offshore oil & gas multi-phase transportation pipelines cause big challenges as the flow regime induces flow and pressure oscillations in the multi-phase pipelines. The negative impacts of the most severe slugs are significant and thus the elimination of slugging flow in the pipe...

  11. Tube Radial Distribution Flow Separation in a Microchannel Using an Ionic Liquid Aqueous Two-Phase System Based on Phase Separation Multi-Phase Flow.

    Science.gov (United States)

    Nagatani, Kosuke; Shihata, Yoshinori; Matsushita, Takahiro; Tsukagoshi, Kazuhiko

    2016-01-01

    Ionic liquid aqueous two-phase systems were delivered into a capillary tube to achieve tube radial distribution flow (TRDF) or annular flow in a microspace. The phase diagram, viscosity of the phases, and TRDF image of the 1-butyl-3-methylimidazolium chloride and NaOH system were examined. The TRDF was formed with inner ionic liquid-rich and outer ionic liquid-poor phases in the capillary tube. The phase configuration was explained using the viscous dissipation principle. We also examined the distribution of rhodamine B in a three-branched microchannel on a microchip with ionic liquid aqueous two-phase systems for the first time.

  12. Numerical modelling of 2D solid/fluid interactions in explosive volcanic regimes using finite volumes: magma and multiphase flow dynamics induced by seismic elastic waves.

    Science.gov (United States)

    Martin, R.

    2001-12-01

    In many volcanoes like the Popocatepetl, it is not well known if seismicity induces explosive eruptions, or inversely if the dynamics induces seismicity, or how both mechanisms trigger each other. In order to understand this mechanisms we numerically simulate, at greater scales than in laboratory, the behaviour of highly viscous magmas submitted to an incoming PSV wave involving high stresses. For that purpose we use a finite volume scheme of second order with a semi implicit algorithm in time for the fluid and a classical velocity/stress formulation at the second order to describe the elastic waves. The magma is considered as compressible and consists in a high viscous fluid and volatile gases. The gas fractions are computed following a power state law of the pressure. The disturbance of the fluid by the wave causes the pressure to increase and the gas to exsolve. The magma is then submitted to a convection behaviour and can arise through the conduit till reaching a certain depth which defines the location of fragmentation of the mixture. These simulations allow us to conclude that, depending on the magnitude of the wave, a viscous compressible fluid like a magma can be highly disturbed and differ strongly then from the quasistatic and acoustic behaviour classically taken into account in classical modelling of waves travelling through acoustic fluid/elastic solid structures. Depending on the Reynolds number, from laminar to turbulent, the fluid can not any longer be assumed incompressible, irrotational and non viscous. Inversely, when the magma has reached the fragmentation depth in the conduit, the fluid becomes multiphasic with specific exit velocities, pressures, temperatures, particle fractions. It is modelled with one particle phase and one gas phase interacting with drag forces and heat exchange terms. With a similar algorithm as described before, we show that the flow can be expelled at shock speeds and produce travelling elastic waves in the ground through

  13. The use of TOUGH2 for the LBL/USGS 3-dimensional site-scale model of Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Bodvarsson, G.; Chen, G.; Haukwa, C.; Kwicklis, E.

    1995-01-01

    The three-dimensional site-scale numerical model o the unsaturated zone at Yucca Mountain is under continuous development and calibration through a collaborative effort between Lawrence Berkeley Laboratory (LBL) and the United States Geological Survey (USGS). The site-scale model covers an area of about 30 km 2 and is bounded by major fault zones to the west (Solitario Canyon Fault), east (Bow Ridge Fault) and perhaps to the north by an unconfirmed fault (Yucca Wash Fault). The model consists of about 5,000 grid blocks (elements) with nearly 20,000 connections between them; the grid was designed to represent the most prevalent geological and hydro-geological features of the site including major faults, and layering and bedding of the hydro-geological units. Submodels are used to investigate specific hypotheses and their importance before incorporation into the three-dimensional site-scale model. The primary objectives of the three-dimensional site-scale model are to: (1) quantify moisture, gas and heat flows in the ambient conditions at Yucca Mountain, (2) help in guiding the site-characterization effort (primarily by USGS) in terms of additional data needs and to identify regions of the mountain where sufficient data have been collected, and (3) provide a reliable model of Yucca Mountain that is validated by repeated predictions of conditions in new boreboles and the ESF and has therefore the confidence of the public and scientific community. The computer code TOUGH2 developed by K. Pruess at LBL was used along with the three-dimensional site-scale model to generate these results. In this paper, we also describe the three-dimensional site-scale model emphasizing the numerical grid development, and then show some results in terms of moisture, gas and heat flow

  14. Transport phenomena in multiphase flows

    CERN Document Server

    Mauri, Roberto

    2015-01-01

    This textbook provides a thorough presentation of the phenomena related to the transport of mass, momentum and energy.  It lays all the basic physical principles, then for the more advanced readers, it offers an in-depth treatment with advanced mathematical derivations and ends with some useful applications of the models and equations in specific settings. The important idea behind the book is to unify all types of transport phenomena, describing them within a common framework in terms of cause and effect, respectively represented by the driving force and the flux of the transported quantity. The approach and presentation are original in that the book starts with a general description of transport processes, providing the macroscopic balance relations of fluid dynamics and heat and mass transfer, before diving into the mathematical realm of continuum mechanics to derive the microscopic governing equations at the microscopic level. The book is a modular teaching tool and can be used either for an introductory...

  15. Imaging cross fault multiphase flow using time resolved high pressure-temperature synchrotron fluid tomography: implications for the geological storage of carbon dioxide within sandstone saline aquifers

    Science.gov (United States)

    Seers, Thomas; Andrew, Matthew; Bijeljic, Branko; Blunt, Martin; Dobson, Kate; Hodgetts, David; Lee, Peter; Menke, Hannah; Singh, Kamaljit; Parsons, Aaron

    2015-04-01

    Applied shear stresses within high porosity granular rocks result in characteristic deformation responses (rigid grain reorganisation, dilation, isovolumetric strain, grain fracturing and/or crushing) emanating from elevated stress concentrations at grain contacts. The strain localisation features produced by these processes are generically termed as microfaults (also shear bands), which occur as narrow tabular regions of disaggregated, rotated and/or crushed grains. Because the textural priors that favour microfault formation make their host rocks (esp. porous sandstones) conducive to the storage of geo-fluids, such structures are often abundant features within hydrocarbon reservoirs, aquifers and potential sites of CO2 storage (i.e. sandstone saline aquifers). The porosity collapse which accompanies microfault formation typically results in localised permeability reduction, often encompassing several orders of magnitude. Given that permeability is the key physical parameter that governs fluid circulation in the upper crust, this petrophysical degradation implicates microfaults as being flow impeding structures which may act as major baffles and/or barriers to fluid flow within the subsurface. Such features therefore have the potential to negatively impact upon hydrocarbon production or CO2 injection, making their petrophysical characterisation of considerable interest. Despite their significance, little is known about the pore-scale processes involved in fluid trapping and transfer within microfaults, particularly in the presence of multiphase flow analogous to oil accumulation, production and CO2 injection. With respect to the geological storage of CO2 within sandstone saline aquifers it has been proposed that even fault rocks with relatively low phyllosilicate content or minimal quartz cementation may act as major baffles or barriers to migrating CO2 plume. Alternatively, as ubiquitous intra-reservoir heterogeneities, micro-faults also have the potential to

  16. Recovery Act: An Integrated Experimental and Numerical Study: Developing a Reaction Transport Model that Couples Chemical Reactions of Mineral Dissolution/Precipitation with Spatial and Temporal Flow Variations.

    Energy Technology Data Exchange (ETDEWEB)

    Saar, Martin O. [ETH Zurich (Switzerland); Univ. of Minnesota, Minneapolis, MN (United States); Seyfried, Jr., William E. [Univ. of Minnesota, Minneapolis, MN (United States); Longmire, Ellen K. [Univ. of Minnesota, Minneapolis, MN (United States)

    2016-06-24

    A total of 12 publications and 23 abstracts were produced as a result of this study. In particular, the compilation of a thermodynamic database utilizing consistent, current thermodynamic data is a major step toward accurately modeling multi-phase fluid interactions with solids. Existing databases designed for aqueous fluids did not mesh well with existing solid phase databases. Addition of a second liquid phase (CO2) magnifies the inconsistencies between aqueous and solid thermodynamic databases. Overall, the combination of high temperature and pressure lab studies (task 1), using a purpose built apparatus, and solid characterization (task 2), using XRCT and more developed technologies, allowed observation of dissolution and precipitation processes under CO2 reservoir conditions. These observations were combined with results from PIV experiments on multi-phase fluids (task 3) in typical flow path geometries. The results of the tasks 1, 2, and 3 were compiled and integrated into numerical models utilizing Lattice-Boltzmann simulations (task 4) to realistically model the physical processes and were ultimately folded into TOUGH2 code for reservoir scale modeling (task 5). Compilation of the thermodynamic database assisted comparisons to PIV experiments (Task 3) and greatly improved Lattice Boltzmann (Task 4) and TOUGH2 simulations (Task 5). PIV (Task 3) and experimental apparatus (Task 1) have identified problem areas in TOUGHREACT code. Additional lab experiments and coding work has been integrated into an improved numerical modeling code.

  17. Simulation of Water Percolation in a FEBEX Bentonite Block Using TOUGH2 Program; Simulacion de la Percolacion de Agua en un Bloque de Bentonite Febex Utilizando el Programa TOUGH2

    Energy Technology Data Exchange (ETDEWEB)

    Bru, A.

    2001-07-01

    We use Tough2 program to simulate the water percolation in a Febex bentonite Block. From obtained results, we conclude that mean field approximation does not describe this process because the heterogeneity of the medium it is not include in mathematical formalism. (Author) 17 refs.

  18. Turbulence modification and multiphase turbulence transport modeling

    International Nuclear Information System (INIS)

    Besnard, D.C.; Kataoka, I.; Serizawa, A.

    1991-01-01

    It is shown here that in the derivation of turbulence transport models for multiphase flows, terms naturally appear that can be interpreted as related to turbulence modification of one field by the other. We obtain two such terms, one suggesting turbulence enhancement due to instabilities in two-phase flow, the second one showing turbulence damping due to the presence of the other field, both in gas-particle and gas-liquid cases

  19. Global Sensitivity and Data-Worth Analyses in iTOUGH2: User's Guide

    Energy Technology Data Exchange (ETDEWEB)

    Wainwright, Haruko Murakami [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Earth Sciences Division; Univ. of California, Berkeley, CA (United States); Finsterle, Stefan [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Earth Sciences Division; Univ. of California, Berkeley, CA (United States)

    2016-07-15

    This manual explains the use of local sensitivity analysis, the global Morris OAT and Sobol’ methods, and a related data-worth analysis as implemented in iTOUGH2. In addition to input specification and output formats, it includes some examples to show how to interpret results.

  20. Numerical simulation of complex multi-phase fluid of casting process and its applications

    Directory of Open Access Journals (Sweden)

    CHEN Li-liang

    2006-05-01

    Full Text Available The fluid of casting process is a typical kind of multi-phase flow. Actually, many casting phenomena have close relationship with the multi-phase flow, such as molten metal filling process, air entrapment, slag movement, venting process of die casting, gas escaping of lost foam casting and so on. Obviously, in order to analyze these phenomena accurately, numerical simulation of the multi-phase fluid is necessary. Unfortunately, so far, most of the commercial casting simulation systems do not have the ability of multi-phase flow modeling due to the difficulty in the multi-phase flow calculation. In the paper, Finite Different Method (FDM technique was adopt to solve the multi-phase fluid model. And a simple object of the muiti-phase fluid was analyzed to obtain the fluid rates of the liquid phase and the entrapped air phase.

  1. User's Guide for Hysteretic Capillary Pressure and Relative Permeability Functions in iTOUGH2

    Energy Technology Data Exchange (ETDEWEB)

    Doughty, C.A.

    2009-08-01

    The precursor of TOUGH2, TOUGH, was originally developed with non-hysteretic characteristic curves. Hysteretic capillary pressure functions were implemented in TOUGH in the late 1980s by Niemi and Bodvarsson (1988), and hysteretic capillary pressure and relative permeability functions were added to iTOUGH2 about ten years later by Finsterle et al. (1998). Recently, modifications were made to the iTOUGH2 hysteretic formulation to make it more robust and efficient (Doughty, 2007). Code development is still underway, with the ultimate goal being a hysteretic module that fits into the standard TOUGH2 (Pruess et al., 1991) framework. This document provides a user's guide for the most recent version of the hysteretic code, which runs within iTOUGH2 (Finsterle, 1999a,b,c). The current code differs only slightly from what was presented in Doughty (2007), hence that document provides the basic information on the processes being modeled and how they are conceptualized. This document focuses on a description of the user-specified parameters required to run hysteretic iTOUGH2. In the few instances where the conceptualization differs from that of Doughty (2007), the features described here are the current ones. Sample problems presented in this user's guide use the equation-of-state module ECO2N (Pruess, 2005). The components present in ECO2N are H{sub 2}O, NaCl, and CO{sub 2}. Two fluid phases and one solid phase are considered: an aqueous phase, which primarily consists of liquid H2O and may contain dissolved NaCl and CO{sub 2}; a supercritical phase which primarily consists of CO{sub 2}, but also includes a small amount of gaseous H{sub 2}O; and a solid phase consisting of precipitated NaCl. Details of the ECO2N formulation may be found in Pruess (2005). The aqueous phase is the wetting phase and is denoted ''liquid'', whereas the supercritical phase is the non-wetting phase and is denoted ''gas''. The hysteretic formalism

  2. Multiphasic growth curve analysis.

    NARCIS (Netherlands)

    Koops, W.J.

    1986-01-01

    Application of a multiphasic growth curve is demonstrated with 4 data sets, adopted from literature. The growth curve used is a summation of n logistic growth functions. Human height growth curves of this type are known as "double logistic" (n = 2) and "triple logistic" (n = 3) growth curves (Bock

  3. Utilization of computational simulator for comparison of correlations in multiphase flow in ESP (Electrical Submersible Pumping) systems; Utilizacao de simulador computacional para a comparacao das correlacoes de escoamento multifasico em sistemas BCS

    Energy Technology Data Exchange (ETDEWEB)

    Anjos, Roselaine M. dos; Maitelli, Carla Wilza S.P.; Maitelli, Andre L. [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil); Costa, Rutacio O. [Petroleo Brasileiro S.A. (PETROBRAS), Rio de Janeiro, RJ (Brazil)

    2012-07-01

    Electrical Submersible Pumping (ESP) is an artificial lifting method which can be used both onshore and offshore for the production of high flow rates of liquid. By using the computational simulator for systems ESP developed by the AUTOPOC/LAUT - UFRN, this work aimed to evaluate empirical correlations for calculation of multiphase flow in tubing typical of artificial lifting systems operating by ESP. The parameters used for evaluating the correlations are some of the dynamic variables of the system such as head that indicates the lifting capacity of the system, the flow rate of fluid in the pump and the discharge pressure at the pump. Five (5) correlations were evaluated, from which only one considered slipping between phases, but does not take into account flow patterns and, four others considering slipping between the phases as well the flow patterns. The simulation results obtained for all these correlations were compared to results from a commercial computational simulator, extensively used in the oil industry. For both simulators, input values and simulation time, were virtually the same. The results showed that the simulator used in this work showed satisfactory performance, since no significant differences from those obtained with the commercial simulator. (author)

  4. Fundamentals of Turbulent and Multi-Phase Combustion

    CERN Document Server

    Kuo, Kenneth Kuan-yun

    2012-01-01

    Detailed coverage of advanced combustion topics from the author of Principles of Combustion, Second Edition Turbulence, turbulent combustion, and multiphase reacting flows have become major research topics in recent decades due to their application across diverse fields, including energy, environment, propulsion, transportation, industrial safety, and nanotechnology. Most of the knowledge accumulated from this research has never been published in book form-until now. Fundamentals of Turbulent and Multiphase Combustion presents up-to-date, integrated coverage of the fundamentals of turbulence

  5. Multiphase blast interaction between heterogeneous explosives

    Science.gov (United States)

    Ripley, Robert; Ryan, Sydney; Jenkins, Charles M.

    2017-06-01

    Spherical charges loaded with micrometric metal powders feature explosively dispersed particle fields. The interaction phenomena of opposing multiphase flow fields from multiple charges depend on the charge spacing, loading configuration and particle morphology. For identical heterogeneous charges with a separation distance in the near field, the multiphase blast interaction includes particle-particle collision in the shocked air and impinging detonation products between the charges. Experiments recorded using high-speed framing cameras show the blast interaction process and resolve details of the multiphase structures. Hydrocode simulations are conducted using inelastic Lagrangian particle groups with a Direct Simulation Monte Carlo particle collision model. The numerical results distinguish the multiphase interaction layer and gas dynamic boundaries, with an emphasis on the particle laden Mach stem. The experimental results provide data for comparison to the interacting front velocities and Mach stem velocity. Modeling results for twin charges are shown to be different from a single heterogeneous blast reflection due to the stochastic and dissipative particle collisions. Remaining differences between the experimental and numerical results are discussed. The numerical results are further analyzed to assess particle fragmentation and potential for enhanced reaction in the interaction region between heterogeneous charges. DISTRIBUTION A. Approved for public release; distribution is unlimited. 96TW-2017-0079.

  6. Multiphase Instabilities in Explosive Dispersal of Particles

    Science.gov (United States)

    Rollin, Bertrand; Ouellet, Frederick; Annamalai, Subramanian; Balachandar, S. ``Bala''

    2015-11-01

    Explosive dispersal of particles is a complex multiphase phenomenon that can be observed in volcanic eruptions or in engineering applications such as multiphase explosives. As the layer of particles moves outward at high speed, it undergoes complex interactions with the blast-wave structure following the reaction of the energetic material. Particularly in this work, we are interested in the multiphase flow instabilities related to Richmyer-Meshkov (RM) and Rayleigh-Taylor (RM) instabilities (in the gas phase and particulate phase), which take place as the particle layer disperses. These types of instabilities are known to depend on initial conditions for a relatively long time of their evolution. Using a Eulerian-Lagrangian approach, we study the growth of these instabilities and their dependence on initial conditions related to the particulate phase - namely, (i) particle size, (ii) initial distribution, and (iii) mass ratio (particles to explosive). Additional complexities associated with compaction of the layer of particles are avoided here by limiting the simulations to modest initial volume fraction of particles. A detailed analysis of the initial conditions and its effects on multiphase RM/RT-like instabilities in the context of an explosive dispersal of particles is presented. This work was supported by the U.S. Department of Energy, National Nuclear Security Administration, Advanced Simulation and Computing Program, as a Cooperative Agreement under the Predictive Science Academic Alliance Program, Contract No. DE-NA0002378.

  7. Modified Invasion Percolation Models for Multiphase Processes

    Energy Technology Data Exchange (ETDEWEB)

    Karpyn, Zuleima [Pennsylvania State Univ., State College, PA (United States)

    2015-01-31

    This project extends current understanding and modeling capabilities of pore-scale multiphase flow physics in porous media. High-resolution X-ray computed tomography imaging experiments are used to investigate structural and surface properties of the medium that influence immiscible displacement. Using experimental and computational tools, we investigate the impact of wetting characteristics, as well as radial and axial loading conditions, on the development of percolation pathways, residual phase trapping and fluid-fluid interfacial areas.

  8. A workflow for handling heterogeneous 3D models with the TOUGH2 family of codes: Applications to numerical modeling of CO 2 geological storage

    Science.gov (United States)

    Audigane, Pascal; Chiaberge, Christophe; Mathurin, Frédéric; Lions, Julie; Picot-Colbeaux, Géraldine

    2011-04-01

    This paper is addressed to the TOUGH2 user community. It presents a new tool for handling simulations run with the TOUGH2 code with specific application to CO 2 geological storage. This tool is composed of separate FORTRAN subroutines (or modules) that can be run independently, using input and output files in ASCII format for TOUGH2. These modules have been developed specifically for modeling of carbon dioxide geological storage and their use with TOUGH2 and the Equation of State module ECO2N, dedicated to CO 2-water-salt mixture systems, with TOUGHREACT, which is an adaptation of TOUGH2 with ECO2N and geochemical fluid-rock interactions, and with TOUGH2 and the EOS7C module dedicated to CO 2-CH 4 gas mixture is described. The objective is to save time for the pre-processing, execution and visualization of complex geometry for geological system representation. The workflow is rapid and user-friendly and future implementation to other TOUGH2 EOS modules for other contexts (e.g. nuclear waste disposal, geothermal production) is straightforward. Three examples are shown for validation: (i) leakage of CO 2 up through an abandoned well; (ii) 3D reactive transport modeling of CO 2 in a sandy aquifer formation in the Sleipner gas Field, (North Sea, Norway); and (iii) an estimation of enhanced gas recovery technology using CO 2 as the injected and stored gas to produce methane in the K12B Gas Field (North Sea, Denmark).

  9. Hysteresis in multiphase microfluidics at a T-junction.

    Science.gov (United States)

    Zagnoni, Michele; Anderson, Jamie; Cooper, Jonathan M

    2010-06-15

    Multiphase microfluidics offer a wide range of functionalities in the fields of fluid dynamics, biology, particle synthesis, and, more recently, also in logical computation. In this article, we describe the hysteresis of immiscible, multiphase flow obtained in hydrophilic, microfluidic systems at a T-junction. Stable and unstable state behaviors, in the form of segmented and parallel flow patterns of oil and water, were reliably produced, depending upon the history of the flow rates applied to the phases. The transition mechanisms between the two states were analyzed both experimentally and using numerical simulations, describing how the physical and fluid dynamic parameters influenced the hysteretic behavior of the flow. The characteristics of these multiphase systems render them suitable to be used as pressure comparators and also for the implementation of microfluidic logic operations.

  10. Numerical simulation of compressible multiphase flows with or without phase transition. Application to laser plasma interaction; Modelisation et simulation d'ecoulements multiphasiques compressibles avec ou sans changement de phase. Application a l'interaction laser-plasma

    Energy Technology Data Exchange (ETDEWEB)

    Perrier, V

    2007-07-15

    This work deals with the modelling and simulation of compressible flows. A seven equations model is obtained by homogenizing the Euler system. Fluctuation terms are modeled as relaxation terms. When the relaxation terms tend to infinity, which means that the phases are well mixed, a five equations model is obtained via an asymptotic expansion. This five equations model is strictly hyperbolic, but nonconservative. The discretization of this model is obtained by an asymptotic expansion of a scheme for the seven equations model. The numerical method is implemented, validated on analytic cases, and compared with experiments in the case of multiphase shocks. We are then interested in the modelling of phase transition with two equations of state. Optimization of the mixture entropy leads to the fact that three zones can be separated: one in which the pure liquid is the most stable, one in which the pure gas is the most stable, and one in which a mixture with equality of temperature, pressure and chemical potentials is the most stable. Conditions are given on the coupling of the two equations of state for ensuring that the mixture equation of state is convex, and that the system is strictly hyperbolic. In order to take into account phase transition, a vaporization wave is introduced in the solution of the Riemann problem, that is modeled as a deflagration wave. It is then proved that the usual closure, the Chapman-Jouguet closure, is wrong in general, and a correct closure in the case when both fluids have a perfect gas equation of state. Last, the solution of the Riemann problem is implemented in a multiphase code, and validated on analytic cases. In the same code, models of laser release and thermal conduction are implemented to simulate laser ablation. The results are comparable to the ones obtained with scale laws. The last chapter, fully independent, is concerned with correctors in stochastic homogenization in the case of heavy tails process. (author)

  11. Cyclonic Capacitive Sensor for Multiphase Composition Measurement

    Directory of Open Access Journals (Sweden)

    Javier ORTIZ

    2015-08-01

    Full Text Available A Cyclonic Capacitive Sensor is proposed for real time multiphase composition measurement with a characteristic suitable for offshore installations. The sensor makes a novel use of an electrostatic technique that takes advantage of a non-linear distribution of phase-interfaces in a cyclonic multiphase flow stratifier. The novel sensor consists of a stack of ring electrodes confined into a cyclone-type phase stratifier. The capacitance detected at each ring electrode pair is a function of the phase volumetric fraction, the temperature and chemical composition dependent phase permittivities and the physical dimensions of the ring electrodes. If the number of electrodes is made proportional to the number of unknown parameters, a complete set of linearly independent equations can be established to resolve the desired parameters, mainly the composition. The robustness of such sensor can be improved by adding a redundant electrode pair. Analytical, numerical and experimental analyses are presented.

  12. Geophysical Multiphase Flow With Interphase Exchanges - Hydrodynamic and Thermodynamic Models, and Numerical Techniques, Version GMFIX-1.61, Design Document Attachment 1

    International Nuclear Information System (INIS)

    Dartevelle, S.

    2006-01-01

    Since the multiphase system is made up of a large number of particles, it is impractical to solve the motion of each individual particle; hence GMFIX v1.61 is based upon the Implicit Multi-Field formalism (IMF) which treats all phases in the system as interpenetrating continua. Each instantaneous local point variable (mass, velocity, temperature, pressure, so forth) must be treated to acknowledge the fact that any given arbitrary volume can be shared by different phases at the same time. This treatment may involve, for instance, an averaging or a smoothing process. GMFIX is the geophysical version of MFIX codes developed by NETL and ORNL. MFIX comes after 30 years of continuous developments and improvements from K-FIX codes from LANL. At the time this manuscript was ready for publication (March 2005), some differences exist between the current versions of GMFIX (v. 1.61) and MFIX (v: 1.60) regarding the exact formulation of the energy and momentum equations, the interfacial closures, and the turbulence formulation. Yet both GMFIX and MFIX are being improved, and developed tightly sides by sides

  13. Three-dimensional multi-phase flow computational fluid dynamics model for analysis of transport phenomena and thermal stresses in PEM fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Maher, A.R.; Al-Baghdadi, S. [International Technological Univ., London (United Kingdom). Dept. of Mechanical Engineering; Haroun, A.K.; Al-Janabi, S. [Babylon Univ., Babylon (Iraq). Dept. of Mechanical Engineering

    2007-07-01

    Fuel cell technology is expected to play an important role in meeting the growing demand for distributed generation because it can convert the chemical energy of a clean fuel directly into electrical energy. An operating fuel cell has varying local conditions of temperature, humidity, and power generation across the active area of the fuel cell in 3D. This paper presented a model that was developed to improve the basic understanding of the transport phenomena and thermal stresses in PEM fuel cells, and to investigate the behaviour of polymer membrane under hygro and thermal stresses during the cell operation. This comprehensive 3D, multiphase, non-isothermal model accounts for the major transport phenomena in a PEM fuel cell, notably convective and diffusive heat and mass transfer; electrode kinetics; transport and phase change mechanism of water; and potential fields. The model accounts for the liquid water flux inside the gas diffusion layers by viscous and capillary forces and can therefore predict the amount of liquid water inside the gas diffusion layers. This study also investigated the key parameters affecting fuel cell performance including geometry, materials and operating conditions. The model considers the many interacting, complex electrochemical, transport phenomena, thermal stresses and deformation that cannot be studied experimentally. It was concluded that the model can provide a computer-aided tool for the design and optimization of future fuel cells with much higher power density and lower cost. 21 refs., 2 tabs., 14 figs.

  14. Estimating the gas hydrate recovery prospects in the western Black Sea basin based on the 3D multiphase flow of fluid and gas components within highly permeable paleo-channel-levee systems

    Science.gov (United States)

    Burwicz, Ewa; Zander, Timo; Rottke, Wolf; Bialas, Joerg; Hensen, Christian; Atgin, Orhan; Haeckel, Matthias

    2017-04-01

    Gas hydrate deposits are abundant in the Black Sea region and confirmed by direct observations as well as geophysical evidence, such as continuous bottom simulating reflectors (BSRs). Although those gas hydrate accumulations have been well-studied for almost two decades, the migration pathways of methane that charge the gas hydrate stability zone (GHSZ) in the region are unknown. The aim of this study is to explore the most probable gas migration scenarios within a three-dimensional finite element grid based on seismic surveys and available basin cross-sections. We have used the commercial software PetroMod(TM) (Schlumberger) to perform a set of sensitivity studies that narrow the gap between the wide range of sediment properties affecting the multi-phase flow in porous media. The high-resolution model domain focuses on the Danube deep-sea fan and associated buried sandy channel-levee systems whereas the total extension of the model domain covers a larger area of the western Black Sea basin. Such a large model domain allows for investigating biogenic as well as thermogenic methane generation and a permeability driven migration of the free phase of methane on a basin scale to confirm the hypothesis of efficient methane migration into the gas hydrate reservoir layers by horizontal flow along the carrier beds.

  15. ECO2M: A TOUGH2 Fluid Property Module for Mixtures of Water, NaCl, and CO2, Including Super- and Sub-Critical Conditions, and Phase Change Between Liquid and Gaseous CO2

    Energy Technology Data Exchange (ETDEWEB)

    Pruess, K.

    2011-04-01

    ECO2M is a fluid property module for the TOUGH2 simulator (Version 2.0) that was designed for applications to geologic storage of CO{sub 2} in saline aquifers. It includes a comprehensive description of the thermodynamics and thermophysical properties of H{sub 2}O - NaCl - CO{sub 2} mixtures, that reproduces fluid properties largely within experimental error for temperature, pressure and salinity conditions in the range of 10 C {le} T {le} 110 C, P {le} 600 bar, and salinity from zero up to full halite saturation. The fluid property correlations used in ECO2M are identical to the earlier ECO2N fluid property package, but whereas ECO2N could represent only a single CO{sub 2}-rich phase, ECO2M can describe all possible phase conditions for brine-CO{sub 2} mixtures, including transitions between super- and sub-critical conditions, and phase change between liquid and gaseous CO{sub 2}. This allows for seamless modeling of CO{sub 2} storage and leakage. Flow processes can be modeled isothermally or non-isothermally, and phase conditions represented may include a single (aqueous or CO{sub 2}-rich) phase, as well as two-and three-phase mixtures of aqueous, liquid CO{sub 2} and gaseous CO{sub 2} phases. Fluid phases may appear or disappear in the course of a simulation, and solid salt may precipitate or dissolve. TOUGH2/ECO2M is upwardly compatible with ECO2N and accepts ECO2N-style inputs. This report gives technical specifications of ECO2M and includes instructions for preparing input data. Code applications are illustrated by means of several sample problems, including problems that had been previously solved with TOUGH2/ECO2N.

  16. "Student Lab"-on-a-Chip: Integrating Low-Cost Microfluidics into Undergraduate Teaching Labs to Study Multiphase Flow Phenomena in Small Vessels

    Science.gov (United States)

    Young, Edmond W. K.; Simmons, Craig A.

    2009-01-01

    We describe a simple, low-cost laboratory session to demonstrate the Fahraeus-Lindqvist effect, a microphase flow phenomenon that occurs in small blood vessels and alters the effective rheological properties of blood. The experiments are performed by flowing cells through microchannels fabricated by soft lithography and characterization of cell…

  17. A three-field model of transient 3D multiphase, three-component flow for the computer code IV A3. Pt. 2

    International Nuclear Information System (INIS)

    Kolev, N.I.

    1991-12-01

    The second part of the IVA3 code description contains the constitutive models used for the interfacial transport phenomena and the code validation results. First 20 flow patterns are defined and the transition criteria are discussed. The dynamic fragmentation and coalescence models used in IVA3 are documented. After the description of the models for predicting the flow patterns and flow structure sizes the models for the interfacial mechanical interaction are described. Finally the models for interfacial heat and mass transfer are given with emphasis on the time averaging of the heat and mass source terms. The code validation passes several stages from simple tests on well known benchmarks trough simulation of one-, two-, and three-phase flows in simple and complicated geometries. The gradually increase of the complexity and the successful comparison of the predictions with experimental data is the main characteristic of the verification procedure. It is demonstrated by several examples that IVA3 is a powerful tool for three-fluid modelling of complicated three-phase flows in complex geometry with strong thermal and mechanical interaction between the velocity fields. (orig.) [de

  18. An evaluation of interface capturing methods in a VOF based model for multiphase flow of a non-Newtonian ceramic in tape casting

    DEFF Research Database (Denmark)

    Jabbari, Masoud; Bulatova, Regina; Hattel, Jesper Henri

    2014-01-01

    The aim of the present study is to evaluate the different interface capturing methods as well as to find the best approach for flow modeling of the ceramic slurry in the tape casting process. The conventional volume of fluid (VOF) method with three different interpolation methods for interface ca...... it is used to investigate the flow of a La0.85Sr0.15MnO3 (LSM) ceramic slurry modeled with the Ostwald de Waele power law. Results of the modeling are compared with corresponding experimental data and good agreement is found. © 2013 Elsevier Inc. All rights reserved....

  19. Multiphase Thermodynamic Tables for Efficient Numerical Simulation of Cavitating Flows: A Novel Look-Up Approach Toward Efficient and Accurate Tables

    NARCIS (Netherlands)

    Khatami, F.; van der Weide, Edwin Theodorus Antonius; Hoeijmakers, Hendrik Willem Marie

    2015-01-01

    In this paper a numerical simulation of unsteady sheet cavitation is presented as it occurs on an NACA-0015 hydrofoil. The computational approach is based on the Euler equations for unsteady compressible flow, using an equilibrium cavitation model of Schnerr, Schmidt, and Saurel. It was found that

  20. Evaluation of a coupled model for numerical simulation of a multiphase flow system in a porous medium and a surface fluid.

    Science.gov (United States)

    Hibi, Yoshihiko; Tomigashi, Akira

    2015-09-01

    Numerical simulations that couple flow in a surface fluid with that in a porous medium are useful for examining problems of pollution that involve interactions among atmosphere, water, and groundwater, including saltwater intrusion along coasts. Coupled numerical simulations of such problems must consider both vertical flow between the surface fluid and the porous medium and complicated boundary conditions at their interface. In this study, a numerical simulation method coupling Navier-Stokes equations for surface fluid flow and Darcy equations for flow in a porous medium was developed. Then, the basic ability of the coupled model to reproduce (1) the drawdown of a surface fluid observed in square-pillar experiments, using pillars filled with only fluid or with fluid and a porous medium and (2) the migration of saltwater (salt concentration 0.5%) in the porous medium using the pillar filled with fluid and a porous medium was evaluated. Simulations that assumed slippery walls reproduced well the results with drawdowns of 10-30 cm when the pillars were filled with packed sand, gas, and water. Moreover, in the simulation of saltwater infiltration by the method developed in this study, velocity was precisely reproduced because the experimental salt concentration in the porous medium after saltwater infiltration was similar to that obtained in the simulation. Furthermore, conditions across the boundary between the porous medium and the surface fluid were satisfied in these numerical simulations of square-pillar experiments in which vertical flow predominated. Similarly, the velocity obtained by the simulation for a system coupling flow in surface fluid with that in a porous medium when horizontal flow predominated satisfied the conditions across the boundary. Finally, it was confirmed that the present simulation method was able to simulate a practical-scale surface fluid and porous medium system. All of these numerical simulations, however, required a great deal of

  1. A variational method for multiphase volume-preserving interface motions

    Czech Academy of Sciences Publication Activity Database

    Švadlenka, Karel; Ginder, E.; Omata, S.

    2014-01-01

    Roč. 257, Feb (2014), s. 157-179 ISSN 0377-0427 Institutional support: RVO:67985840 Keywords : mean curvature flow * volume preservation * multiphase Subject RIV: BA - General Mathematics Impact factor: 1.266, year: 2014 http://www.sciencedirect.com/science/article/pii/S0377042713004391

  2. Multiphase fluid structure interaction in bends and T-joints

    NARCIS (Netherlands)

    Cargnelutti, M.F.; Belfroid, S.P.C.; Schiferli, W.; Osch, M.M.E. van

    2010-01-01

    Air-water experiments were carried out in a horizontal 1" pipe system to measure the magnitude of the forces induced by the multiphase flow. Forces and accelerations were measured on a number of bends and T-joint configurations for a wide range of operating conditions. Five different configurations

  3. Quantitative analyses of pore-scale multi-phase flow processes: An application of synchrotron-based micro-imaging in the environmental sciences

    Science.gov (United States)

    Wildenschild, D.; Christensen, B. S.; Culligan, K. A.; Rivers, M. L.; Hopmans, J. W.; Kent, A. J.; Gray, W. G.

    2002-12-01

    Our current understanding of groundwater flow and contaminant transport in the subsurface is, to a large degree, limited by existing measurement techniques. To correctly describe transport of contaminant species, it is essential to understand the interplay of advection, mechanical dispersion, and diffusion and their dependency on soil water distribution, degree of saturation, as well as gas-liquid phase contact characteristics. However, these pore-scale mechanisms cannot be measured with traditional experimental techniques. X-ray computerized microtomography provides non-invasive pore-scale observation of variables such as changing fluid phase content and distribution, as well as interfacial area and curvatures. We present results obtained at the microtomography facility at GSECARS (sector 13) at the Advanced Photon Source, Argonne National Laboratory. Samples of 6-7 mm diameter sand or glass bead packs were scanned at different stages of drainage and imbibition and with varying boundary conditions. We observed significant differences in fluid saturation and phase distribution for different boundary conditions, clearly showing preferential flow and a dependence on the applied flow rate. Individual pores, water/air interfaces and their curvatures as a function of pore-water pressure were resolved and the interfacial areas quantified using image analysis techniques. We plan to use this detailed information to verify existing pore-scale numerical models and to aid development of new modeling approaches dealing with contaminant flow and transport in the subsurface. Use of the Advanced Photon Source was supported by the U.S. Department of Energy, Basic Energy Sciences, Office of Science, under Contract No. W-31-109-Eng-38.

  4. CFD Modeling of a Multiphase Gravity Separator Vessel

    KAUST Repository

    Narayan, Gautham

    2017-05-23

    The poster highlights a CFD study that incorporates a combined Eulerian multi-fluid multiphase and a Population Balance Model (PBM) to study the flow inside a typical multiphase gravity separator vessel (GSV) found in oil and gas industry. The simulations were performed using Ansys Fluent CFD package running on KAUST supercomputer, Shaheen. Also, a highlight of a scalability study is presented. The effect of I/O bottlenecks and using Hierarchical Data Format (HDF5) for collective and independent parallel reading of case file is presented. This work is an outcome of a research collaboration on an Aramco project on Shaheen.

  5. A Cell-Centered Multiphase ALE Scheme With Structural Coupling

    Energy Technology Data Exchange (ETDEWEB)

    Dunn, Timothy Alan [Univ. of California, Davis, CA (United States)

    2012-04-16

    A novel computational scheme has been developed for simulating compressible multiphase flows interacting with solid structures. The multiphase fluid is computed using a Godunov-type finite-volume method. This has been extended to allow computations on moving meshes using a direct arbitrary-Eulerian- Lagrangian (ALE) scheme. The method has been implemented within a Lagrangian hydrocode, which allows modeling the interaction with Lagrangian structural regions. Although the above scheme is general enough for use on many applications, the ultimate goal of the research is the simulation of heterogeneous energetic material, such as explosives or propellants. The method is powerful enough for application to all stages of the problem, including the initial burning of the material, the propagation of blast waves, and interaction with surrounding structures. The method has been tested on a number of canonical multiphase tests as well as fluid-structure interaction problems.

  6. Evaluation of the Synergistic Effect of Erosion-Corrosion on AISI 4330 Steel in Saline-Sand Multiphase Flow by Electrochemical and Gravimetric Techniques

    Directory of Open Access Journals (Sweden)

    Dario Yesid Peña Ballesteros

    2016-01-01

    Full Text Available The synergistic effects of fluid flow, sand particles, and solution pH on erosion-corrosion of AISI 4330 steel alloy in saline-sand medium were studied through a rotating cylinder electrode (RCE system by weight-loss and electrochemical measurements. The worn surface was analyzed by X-ray diffraction (XRD and scanning electron microscopy (SEM. Results show that, under all the test conditions assessed, the passivity of the steel alloy could not be maintained; as a result, an activation mechanism dominates the corrosion process of steel alloy. Furthermore, the potentiodynamic curves show that, with the increasing of the electrode flow rate and particle size, the anodic current density increased, which is due to deterioration of the electrode by the impacting slurry. Although the increase of particle size affects the anodic current density, the effect of particle size does not cause a significant change in the polarization behavior of the steel electrode. The electrochemical impedance and potentiodynamic curves suggest that erosion-corrosion phenomenon of the ASISI 4330 steel is under mixed control of mass transport and charge transfer. The inductive loops formed in the impedance plots are representative of an increase in roughness of the electrode caused by the particles impacting at the surface. The change in the passivity of the steel alloy as the pH is altered plays an important role in the corrosion rate.

  7. Cyclonic multiphase flow measurement system GLCC{copyright}1 for oil well capacity evaluation; Sistema de medicion de flujo multifasico mediante tecnologia ciclonica GLCC{copyright}1 para aforo de pozos petroleros

    Energy Technology Data Exchange (ETDEWEB)

    Godoy-Alcantar, J. M; Cervantes-Martinez, G; Cruz-Maya, J. A; Hernandez-Buenfil, M. A; Ramirez-Antonio, I [Instituto Mexicano del Petroleo, Mexico, D.F, (Mexico)]. E-mail: mgodoy@imp.mx

    2008-10-15

    This paper shows the development of a portable multiphase flow measurement system based in cyclonic separation technology GLCC{copyright}1. This system is aimed for oil well measurement and was developed in three phases; the first devoted to the geometric design of a cyclonic separator by means of designs sofware GLCCV7.8 and the selection of measurement instrumentation and flux control valves. In the second phase, the automatic control system was designed for the implementation of four control strategies each one related with a possible scenario of the well behavior. The third constitutes the integration of the measurement and control devices through a user interface aimed for visualization, information processing and system's operation and control. Experimental results in oil well measurements show the efficiency and workability of the integrated system. [Spanish] En el presente trabajo se muestra el desarrollo de un sistema portatil para la medicion de flujo multifasico, basado en la tecnologia de separacion ciclonica GLCC{copyright}1 y su utilizacion el aforo de pozos petroleros. El desarrollo del sistema se compone de tres fases, la primera se orienta hacia el diseno geometrico de un separador tipo ciclonico por medio del simulador GLCCV 7.8, asi como el dimensionamiento y la seleccion de los instrumentos de medicion y valvulas de control de flujo. En la segunda fase, se lleva a cabo la etapa de diseno del control automatico del sistema, el cual se fundamenta en el desarrollo e implantacion de cuatro estrategias de control basadas en el comportamiento dinamico de las variables de produccion del pozo; la tercera fase, la constituye el desarrollo de una interfaz para la integracion y operacion conjunta de los componentes de medicion y control del sistema, asi como de visualizacion, procesamiento y almacenamiento de la informacion. Se muestran los resultados experimentales de una prueba de medicion realizada en campo, las mediciones obtenidas muestran la

  8. Investigating Multiphase Flow Phenomena in Fine-Grained Reservoir Rocks: Insights from Using Ethane Permeability Measurements over a Range of Pore Pressures

    Directory of Open Access Journals (Sweden)

    Eric Aidan Letham

    2018-01-01

    Full Text Available The ability to quantify effective permeability at the various fluid saturations and stress states experienced during production from shale oil and shale gas reservoirs is required for efficient exploitation of the resources, but to date experimental challenges prevent measurement of the effective permeability of these materials over a range of fluid saturations. To work towards overcoming these challenges, we measured effective permeability of a suite of gas shales to gaseous ethane over a range of pore pressures up to the saturated vapour pressure. Liquid/semiliquid ethane saturation increases due to adsorption and capillary condensation with increasing pore pressure resulting in decreasing effective permeability to ethane gas. By how much effective permeability to ethane gas decreases with adsorption and capillary condensation depends on the pore size distribution of each sample and the stress state that effective permeability is measured at. Effective permeability decreases more at higher stress states because the pores are smaller at higher stress states. The largest effective permeability drops occur in samples with dominant pore sizes in the mesopore range. These pores are completely blocked due to capillary condensation at pore pressures near the saturated vapour pressure of ethane. Blockage of these pores cuts off the main fluid flow pathways in the rock, thereby drastically decreasing effective permeability to ethane gas.

  9. Advanced Imaging Techniques for Multiphase Flows Analysis

    Science.gov (United States)

    Amoresano, A.; Langella, G.; Di Santo, M.; Iodice, P.

    2017-08-01

    Advanced numerical techniques, such as fuzzy logic and neural networks have been applied in this work to digital images acquired on two applications, a centrifugal pump and a stationary spray in order to define, in a stochastic way, the gas-liquid interface evolution. Starting from the numeric matrix representing the image it is possible to characterize geometrical parameters and the time evolution of the jet. The algorithm used works with the fuzzy logic concept to binarize the chromatist of the pixels, depending them, by using the difference of the light scattering for the gas and the liquid phase.. Starting from a primary fixed threshold, the applied technique, can select the ‘gas’ pixel from the ‘liquid’ pixel and so it is possible define the first most probably boundary lines of the spray. Acquiring continuously the images, fixing a frame rate, a most fine threshold can be select and, at the limit, the most probably geometrical parameters of the jet can be detected.

  10. Constitutive relations for multiphase flow modeling

    Energy Technology Data Exchange (ETDEWEB)

    Jacobs, H.; Vaeth, L.; Thurnay, K. [Forschungszentrum Karlsruhe GmbH Technik und Umwelt (Germany). Inst. fuer Neutronenphysik und Reaktortechnik

    1998-01-01

    The constitutive relations that are used in the three-field fluid dynamics code IVA-KA for determining the drag in three-phase mixtures and the heat transferred by radiation are described together with some comparisons of calculational results with experiments. In these experiments (QUEOS), large quantities of solid particles are injected into water. Potential deficiencies of the present drag model are discussed. (author)

  11. Smart RTD for Multiphase Flow Systems

    Czech Academy of Sciences Publication Activity Database

    Šimčík, Miroslav; Růžička, Marek; Mota, A.; Teixeira, J. A.

    2012-01-01

    Roč. 90, č. 11 (2012), s. 1739-1749 ISSN 0263-8762 R&D Projects: GA ČR GA104/07/1110; GA MŠk(CZ) LG11014 Grant - others:FCT(PT) SFRH/BD/37082/2007 Institutional support: RVO:67985858 Keywords : residence time * fluid particle age * RTD Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 1.927, year: 2012

  12. Chemical reactor modeling multiphase reactive flows

    CERN Document Server

    Jakobsen, Hugo A

    2014-01-01

    Chemical Reactor Modeling closes the gap between Chemical Reaction Engineering and Fluid Mechanics.  The second edition consists of two volumes: Volume 1: Fundamentals. Volume 2: Chemical Engineering Applications In volume 1 most of the fundamental theory is presented. A few numerical model simulation application examples are given to elucidate the link between theory and applications. In volume 2 the chemical reactor equipment to be modeled are described. Several engineering models are introduced and discussed. A survey of the frequently used numerical methods, algorithms and schemes is provided. A few practical engineering applications of the modeling tools are presented and discussed. The working principles of several experimental techniques employed in order to get data for model validation are outlined. The monograph is based on lectures regularly taught in the fourth and fifth years graduate courses in transport phenomena and chemical reactor modeling, and in a post graduate course in modern reactor m...

  13. Heterogeneous scalable framework for multiphase flows

    Energy Technology Data Exchange (ETDEWEB)

    Morris, Karla Vanessa [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2013-09-01

    Two categories of challenges confront the developer of computational spray models: those related to the computation and those related to the physics. Regarding the computation, the trend towards heterogeneous, multi- and many-core platforms will require considerable re-engineering of codes written for the current supercomputing platforms. Regarding the physics, accurate methods for transferring mass, momentum and energy from the dispersed phase onto the carrier fluid grid have so far eluded modelers. Significant challenges also lie at the intersection between these two categories. To be competitive, any physics model must be expressible in a parallel algorithm that performs well on evolving computer platforms. This work created an application based on a software architecture where the physics and software concerns are separated in a way that adds flexibility to both. The develop spray-tracking package includes an application programming interface (API) that abstracts away the platform-dependent parallelization concerns, enabling the scientific programmer to write serial code that the API resolves into parallel processes and threads of execution. The project also developed the infrastructure required to provide similar APIs to other application. The API allow object-oriented Fortran applications direct interaction with Trilinos to support memory management of distributed objects in central processing units (CPU) and graphic processing units (GPU) nodes for applications using C++.

  14. The TOUGH codes - a family of simulation tools for multiphase flowand transport processes in permeable media

    Energy Technology Data Exchange (ETDEWEB)

    Pruess, Karsten

    2003-08-08

    Numerical simulation has become a widely practiced andaccepted technique for studying flow and transport processes in thevadose zone and other subsurface flow systems. This article discusses asuite of codes, developed primarily at Lawrence Berkeley NationalLaboratory (LBNL), with the capability to model multiphase flows withphase change. We summarize history and goals in the development of theTOUGH codes, and present the governing equations for multiphase,multicomponent flow. Special emphasis is given to space discretization bymeans of integral finite differences (IFD). Issues of code implementationand architecture are addressed, as well as code applications,maintenance, and future developments.

  15. Annihilation Radiation Gauge for Relative Density and Multiphase Fluid Monitoring

    Directory of Open Access Journals (Sweden)

    Vidal A.

    2014-03-01

    Full Text Available The knowledge of the multi-phase flow parameters are important for the petroleum industry, specifically during the transport in pipelines and network related to exploitation’s wells. Crude oil flow is studied by Monte Carlo simulation and experimentally to determine transient liquid phase in a laboratory system. Relative density and fluid phase time variation is monitored employing a fast nuclear data acquisition setup that includes two large volume BaF2 scintillator detectors coupled to an electronic chain and data display in a LabView® environment. Fluid parameters are determined by the difference in count rate of coincidence pulses. The operational characteristics of the equipment indicate that 2 % deviation in the CCR corresponds to a variation, on average, of 20 % in the fraction of liquid of the multiphase fluid.

  16. Multi-Phase Modeling of Rainbird Water Injection

    Science.gov (United States)

    Vu, Bruce T.; Moss, Nicholas; Sampson, Zoe

    2014-01-01

    This paper describes the use of a Volume of Fluid (VOF) multiphase model to simulate the water injected from a rainbird nozzle used in the sound suppression system during launch. The simulations help determine the projectile motion for different water flow rates employed at the pad, as it is critical to know if water will splash on the first-stage rocket engine during liftoff.

  17. ECO2N V. 2.0: A New TOUGH2 Fluid Property Module for Mixtures of Water, NaCl, and CO2

    Energy Technology Data Exchange (ETDEWEB)

    Pan, L. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Spycher, N. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Doughty, C. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Pruess, K. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2014-12-01

    ECO2N V2.0 is a fluid property module for the TOUGH2 simulator (Version 2.1) that was designed for applications to geologic sequestration of CO2 in saline aquifers and enhanced geothermal reservoirs. ECO2N V2.0 is an enhanced version of the previous ECO2N V1.0 module (Pruess, 2005). It expands the temperature range up to about 300°C whereas V1.0 can only be used for temperatures below about 110°C. V2.0 includes a comprehensive description of the thermodynamics and thermophysical properties of H2O - NaCl -CO2 mixtures, that reproduces fluid properties largely within experimental error for the temperature, pressure and salinity conditions of interest (10 °C < T < 300 °C; P < 600 bar; salinity up to halite saturation). This includes density, viscosity, and specific enthalpy of fluid phases as functions of temperature, pressure, and composition, as well as partitioning of mass components H2O, NaCl and CO2 among the different phases. In particular, V2.0 accounts for the effects of water on the thermophysical properties of the CO2-rich phase, which was ignored in V1.0, using a model consistent with the solubility models developed by Spycher and Pruess (2005, 2010). In terms of solubility models, V2.0 uses the same model for partitioning of mass components among the different phases (Spycher and Pruess, 2005) as V1.0 for the low temperature range (<99°C) but uses a new model (Spycher and Pruess, 2010) for the high temperature range (>109°C). In the transition range (99-109°C), a smooth interpolation is applied to estimate the partitioning as a function of the temperature. Flow processes can be modeled isothermally or non-isothermally, and phase conditions represented may include a single (aqueous or CO2-rich) phase, as well as two-phase mixtures. Fluid phases may appear or disappear in the course of a simulation, and solid salt may precipitate or dissolve. This report gives technical

  18. Problems of multiphase fluid filtration

    CERN Document Server

    Konovalov, AN

    1994-01-01

    This book deals with a spectrum of problems related to the mathematical modeling of multiphase filtration. Emphasis is placed on an inseparable triad: model - algorithm - computer code. An analysis of new and traditional filtration problems from the point of view of both their numerical implementation and the reproduction of one or another technological characteristics of the processes under consideration is given. The basic principles which underlie the construction of efficient numerical methods taking into account the filtration problems are discussed: non-evolutionary nature, degeneration,

  19. Multiphase, Multicomponent Fluid Flow in Homogeneous and Heterogeneous Porous Media Écoulement de fluides multiconstituants polyphasiques dans des milieux poreux homogènes et hétérogènes

    Directory of Open Access Journals (Sweden)

    Chella R.

    2006-12-01

    Full Text Available The flow of several components and several phases through a porous medium is generally described by introducing macroscopic mass-balance equations under the form of generalized dispersion equations. This model raises several questions that are discussed in this paper on the basis of results obtained from the volume averaging method, coupled with pore-scale simulations of the multiphase flow. The study is limited to a binary, two-phase system, and we assume that the momentum equations can be solved independently from the diffusion/advection equations. The assumption of local-equilibrium is discussed and several length-scale and time-scale constraints are provided. A key issue concerns the impact on the dispersion tensors of the pore-scale equilibrium condition at the interface between the different phases. Our results show that this phenomenon may lead to significant variations of the dispersion coefficients with respect to passive dispersion, i. e. , dispersion without interfacial mass fluxes. Macroscopic equations are then obtained in the general case, and several local closure problems are provided that allow one to calculate the dispersion tensors and others properties, from the pore-scale geometry, velocities, and fluid characteristics. Examples of solutions of these closure problems are given in the case of two-dimensional representative unit cells. The two-phase flow equations are solved in two different ways : a boundary element technique, or a modified lattice Boltzmann approach. Solutions of the closure problems associated with the dispersion equations are then given using a finite volume element formulation of the partial differential equations. The results show the influence of velocity and saturation on the effective parameters. They emphasize the importance of geometry on the behavior of the dispersion tensor. Extension of these results to a larger-scale including the effect of heterogeneities is proposed in a limited case

  20. Multiphase pumping: indoor performance test and oilfield application

    Science.gov (United States)

    Kong, Xiangling; Zhu, Hongwu; Zhang, Shousen; Li, Jifeng

    2010-03-01

    Multiphase pumping is essentially a means of adding energy to the unprocessed effluent which enables the liquid and gas mixture to be transported over a long distances without prior separation. A reduction, consolidation, or elimination of the production infrastructure, such as separation equipments and offshore platforms can be developed more economically. Also it successfully lowed the backpressure of wells, revived dead wells and improved the production and efficiency of oilfield. This paper reviews the issues related to indoor performance test and an oilfield application of the helico-axial multiphase pump designed by China University of Petroleum (Beijing). Pump specification and its hydraulic design are given. Results of performance testing under different condition, such as operational speed and gas volume fraction (GVF) etc are presented. Experimental studies on combination of theoretical analysis showed the multiphase pump satisfies the similitude rule, which can be used in the development of new MPP design and performance prediction. Test results showed that rising the rotation speed and suction pressure could better its performance, pressure boost improved, high efficiency zone expanding and the flow rate related to the optimum working condition increased. The pump worked unstable as GVF increased to a certain extent and slip occurred between two phases in the pump, creating surging and gas lock at a high GVF. A case of application in Nanyang oilfield is also studied.

  1. A QCQP Approach for OPF in Multiphase Radial Networks with Wye and Delta Connections: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Zamzam, Ahmed, S.; Zhaoy, Changhong; Dall' Anesey, Emiliano; Sidiropoulos, Nicholas D.

    2017-06-27

    This paper examines the AC Optimal Power Flow (OPF) problem for multiphase distribution networks featuring renewable energy resources (RESs). We start by outlining a power flow model for radial multiphase systems that accommodates wye-connected and delta-connected RESs and non-controllable energy assets. We then formalize an AC OPF problem that accounts for both types of connections. Similar to various AC OPF renditions, the resultant problem is a non convex quadratically-constrained quadratic program. However, the so-called Feasible Point Pursuit-Successive Convex Approximation algorithm is leveraged to obtain a feasible and yet locally-optimal solution. The merits of the proposed solution approach are demonstrated using two unbalanced multiphase distribution feeders with both wye and delta connections.

  2. Discrete modeling considerations in multiphase fluid dynamics

    International Nuclear Information System (INIS)

    Ransom, V.H.; Ramshaw, J.D.

    1988-01-01

    The modeling of multiphase flows play a fundamental role in light water reactor safety. The main ingredients in our discrete modeling Weltanschauung are the following considerations: (1) Any physical model must be cast into discrete form for a digital computer. (2) The usual approach of formulating models in differential form and then discretizing them is potentially hazardous. It may be preferable to formulate the model in discrete terms from the outset. (3) Computer time and storage constraints limit the resolution that can be employed in practical calculations. These limits effectively define the physical phenomena, length scales, and time scales which cannot be directly represented in the calculation and therefore must be modeled. This information should be injected into the model formulation process at an early stage. (4) Practical resolution limits are generally so coarse that traditional convergence and truncation-error analyses become irrelevant. (5) A discrete model constitutes a reduced description of a physical system, from which fine-scale details are eliminated. This elimination creates a statistical closure problem. Methods from statistical physics may therefore be useful in the formulation of discrete models. In the present paper we elaborate on these themes and illustrate them with simple examples. 48 refs

  3. PACKAGE (Plasma Analysis, Chemical Kinetics and Generator Efficiency): a computer program for the calculation of partial chemical equilibrium/partial chemical rate controlled composition of multiphased mixtures under one dimensional steady flow

    Energy Technology Data Exchange (ETDEWEB)

    Yousefian, V.; Weinberg, M.H.; Haimes, R.

    1980-02-01

    The NASA CEC Code was the starting point for PACKAGE, whose function is to evaluate the composition of a multiphase combustion product mixture under the following chemical conditions: (1) total equilibrium with pure condensed species; (2) total equilibrium with ideal liquid solution; (3) partial equilibrium/partial finite rate chemistry; and (4) fully finite rate chemistry. The last three conditions were developed to treat the evolution of complex mixtures such as coal combustion products. The thermodynamic variable pairs considered are either pressure (P) and enthalpy, P and entropy, at P and temperature. Minimization of Gibbs free energy is used. This report gives detailed discussions of formulation and input/output information used in the code. Sample problems are given. The code development, description, and current programming constraints are discussed. (DLC)

  4. Development of a multiphase shock tube for energetic materials characterization.

    Energy Technology Data Exchange (ETDEWEB)

    Castaneda, Jaime N.; Cooper, Marcia A.; Beresh, Steven Jay; Trott, Wayne Merle; Wagner, Justin L.; Kearney, Sean Patrick; Baer, Melvin R.; Pruett, Brian O. M.

    2010-06-01

    A novel multiphase shock tube to study particle dynamics in gas-solid flows has been constructed and tested. Currently, there is a gap in data for flows having particle volume fractions between the dusty and granular regimes. The primary purpose of this new facility is to fill that gap by providing high quality data of shock-particle interactions in flows having dense gas particle volume fractions. Towards this end, the facility aims to drive a shock into a spatially isotropic field, or curtain, of particles. Through bench-top experimentation, a method emerged for achieving this challenging task that involves the use of a gravity-fed contoured particle seeder. The seeding method is capable of producing fields of spatially isotropic particles having volume fractions of about 1 to 35%. The use of the seeder in combination with the shock tube allows for the testing of the impingement of a planar shock on a dense field of particles. The first experiments in the multiphase shock tube have been conducted and the facility is now operational.

  5. Application of GPU to computational multiphase fluid dynamics

    International Nuclear Information System (INIS)

    Nagatake, T; Kunugi, T

    2010-01-01

    The MARS (Multi-interfaces Advection and Reconstruction Solver) [1] is one of the surface volume tracking methods for multi-phase flows. Nowadays, the performance of GPU (Graphics Processing Unit) is much higher than the CPU (Central Processing Unit). In this study, the GPU was applied to the MARS in order to accelerate the computation of multi-phase flows (GPU-MARS), and the performance of the GPU-MARS was discussed. From the performance of the interface tracking method for the analyses of one-directional advection problem, it is found that the computing time of GPU(single GTX280) was around 4 times faster than that of the CPU (Xeon 5040, 4 threads parallelized). From the performance of Poisson Solver by using the algorithm developed in this study, it is found that the performance of the GPU showed around 30 times faster than that of the CPU. Finally, it is confirmed that the GPU showed the large acceleration of the fluid flow computation (GPU-MARS) compared to the CPU. However, it is also found that the double-precision computation of the GPU must perform with very high precision.

  6. Multiphase volume-preserving interface motions via localized signed distance vector scheme

    Czech Academy of Sciences Publication Activity Database

    Muhammad, R. Z.; Švadlenka, Karel

    2015-01-01

    Roč. 8, č. 5 (2015), s. 969-988 ISSN 1937-1632 Institutional support: RVO:67985840 Keywords : multiphase mean curvature flow * vector-valued signed distance * volume preservation Subject RIV: BA - General Mathematics Impact factor: 0.737, year: 2015 http://www.aimsciences.org/journals/displayArticlesnew.jsp?paperID=11386

  7. Simulating Anomalous Dispersion and Multiphase Segregation in Porous Media with the Lattice Boltzmann Method

    Science.gov (United States)

    Matin, Rastin; Misztal, Marek K.; Hernandez-Garcia, Anier; Mathiesen, Joachim

    2015-11-01

    Many hydrodynamic phenomena such as flows at micron scale in porous media, large Reynolds numbers flows, non-Newtonian and multiphase flows have been simulated numerically using the lattice Boltzmann method. By solving the Lattice Boltzmann Equation on three-dimensional unstructured meshes, we efficiently model single-phase fluid flow in real rock samples. We use the flow field to estimate the permeability and further investigate the anomalous dispersion of passive tracers in porous media. By extending our single-phase model with a free-energy based method, we are able to simulate binary systems with moderate density ratios in a thermodynamically consistent way. In this presentation we will present our recent results on both anomalous transport and multiphase segregation.

  8. Multiphase modeling of geologic carbon sequestration in saline aquifers.

    Science.gov (United States)

    Bandilla, Karl W; Celia, Michael A; Birkholzer, Jens T; Cihan, Abdullah; Leister, Evan C

    2015-01-01

    Geologic carbon sequestration (GCS) is being considered as a climate change mitigation option in many future energy scenarios. Mathematical modeling is routinely used to predict subsurface CO2 and resident brine migration for the design of injection operations, to demonstrate the permanence of CO2 storage, and to show that other subsurface resources will not be degraded. Many processes impact the migration of CO2 and brine, including multiphase flow dynamics, geochemistry, and geomechanics, along with the spatial distribution of parameters such as porosity and permeability. In this article, we review a set of multiphase modeling approaches with different levels of conceptual complexity that have been used to model GCS. Model complexity ranges from coupled multiprocess models to simplified vertical equilibrium (VE) models and macroscopic invasion percolation models. The goal of this article is to give a framework of conceptual model complexity, and to show the types of modeling approaches that have been used to address specific GCS questions. Application of the modeling approaches is shown using five ongoing or proposed CO2 injection sites. For the selected sites, the majority of GCS models follow a simplified multiphase approach, especially for questions related to injection and local-scale heterogeneity. Coupled multiprocess models are only applied in one case where geomechanics have a strong impact on the flow. Owing to their computational efficiency, VE models tend to be applied at large scales. A macroscopic invasion percolation approach was used to predict the CO2 migration at one site to examine details of CO2 migration under the caprock. © 2015, National Ground Water Association.

  9. CO{sub 2} interfacial properties: application to multiphase flow at reservoir conditions; Proprietes interfaciales du CO{sub 2}: application aux ecoulements en milieu poreux en pression et temperature

    Energy Technology Data Exchange (ETDEWEB)

    Chalbaud, C

    2007-07-15

    In this work we deal with the interfacial properties of CO{sub 2} at reservoir conditions with a special interest on deep saline aquifers. Each chapter of this dissertation represents a different physical scale studied with different experimental devices and simulation tools. The results obtained in the first part of this study represent a complete data set of brine-CO{sub 2} interfacial tension at reservoir conditions. A semi-analytical equation is proposed in order to facilitate the work of reservoir engineers. The second deals with the interfacial properties at the pore scale using glass micro-models at different wettability conditions. This part shows the wetting behavior of CO{sub 2} on hydrophobic or oil-wet solid surfaces. A pore network model was used for the interpretation and exploitation of these results. The third part corresponds to two different experimental approaches at the core scale at different wettability conditions associated to a modelling at flue Darcy scale. This part is a significant contribution to the validation of COORES compositional reservoir simulator developed by IFP. It has also allow us to estimate multiphase properties, Pc and kr, for brine-CO{sub 2} systems at reservoir conditions. This study presents the necessary scales to model CO{sub 2} storage in deep saline aquifers. (author)

  10. Black hole feedback in a multiphase interstellar medium

    Science.gov (United States)

    Bourne, Martin A.; Nayakshin, Sergei; Hobbs, Alexander

    2014-07-01

    Ultrafast outflows (UFOs) from supermassive black holes (SMBHs) are thought to regulate the growth of SMBHs and host galaxies, resulting in a number of observational correlations. We present high-resolution numerical simulations of the impact of a thermalized UFO on the ambient gas in the inner part of the host galaxy. Our results depend strongly on whether the gas is homogeneous or clumpy. In the former case all of the ambient gas is driven outward rapidly as expected based on commonly used energy budget arguments, while in the latter the flows of mass and energy de-couple. Carrying most of the energy, the shocked UFO escapes from the bulge via paths of least resistance, taking with it only the low-density phase of the host. Most of the mass is however in the high-density phase, and is affected by the UFO much less strongly, and may even continue to flow inwards. We suggest that the UFO energy leakage through the pores in the multiphase interstellar medium (ISM) may explain why observed SMBHs are so massive despite their overwhelmingly large energy production rates. The multiphase ISM effects reported here are probably under-resolved in cosmological simulations but may be included in prescriptions for active galactic nuclei feedback in future simulations and in semi-analytical models.

  11. MSTS - Multiphase Subsurface Transport Simulator theory manual

    International Nuclear Information System (INIS)

    White, M.D.; Nichols, W.E.

    1993-05-01

    The US Department of Energy, through the Yucca Mountain Site Characterization Project Office, has designated the Yucca Mountain site in Nevada for detailed study as the candidate US geologic repository for spent nuclear fuel and high-level radioactive waste. Site characterization will determine the suitability of the Yucca Mountain site for the potential waste repository. If the site is determined suitable, subsequent studies and characterization will be conducted to obtain authorization from the Nuclear Regulatory Commission to construct the potential waste repository. A principal component of the characterization and licensing processes involves numerically predicting the thermal and hydrologic response of the subsurface environment of the Yucca Mountain site to the potential repository over a 10,000-year period. The thermal and hydrologic response of the subsurface environment to the repository is anticipated to include complex processes of countercurrent vapor and liquid migration, multiple-phase heat transfer, multiple-phase transport, and geochemical reactions. Numerical simulators based on mathematical descriptions of these subsurface phenomena are required to make numerical predictions of the thermal and hydrologic response of the Yucca Mountain subsurface environment The engineering simulator called the Multiphase Subsurface Transport Simulator (MSTS) was developed at the request of the Yucca Mountain Site Characterization Project Office to produce numerical predictions of subsurface flow and transport phenomena at the potential Yucca Mountain site. This document delineates the design architecture and describes the specific computational algorithms that compose MSTS. Details for using MSTS and sample problems are given in the open-quotes User's Guide and Referenceclose quotes companion document

  12. Multiphase modelling of mud volcanoes

    Science.gov (United States)

    Colucci, Simone; de'Michieli Vitturi, Mattia; Clarke, Amanda B.

    2015-04-01

    Mud volcanism is a worldwide phenomenon, classically considered as the surface expression of piercement structures rooted in deep-seated over-pressured sediments in compressional tectonic settings. The release of fluids at mud volcanoes during repeated explosive episodes has been documented at numerous sites and the outflows resemble the eruption of basaltic magma. As magma, the material erupted from a mud volcano becomes more fluid and degasses while rising and decompressing. The release of those gases from mud volcanism is estimated to be a significant contributor both to fluid flux from the lithosphere to the hydrosphere, and to the atmospheric budget of some greenhouse gases, particularly methane. For these reasons, we simulated the fluid dynamics of mud volcanoes using a newly-developed compressible multiphase and multidimensional transient solver in the OpenFOAM framework, taking into account the multicomponent nature (CH4, CO2, H2O) of the fluid mixture, the gas exsolution during the ascent and the associated changes in the constitutive properties of the phases. The numerical model has been tested with conditions representative of the LUSI, a mud volcano that has been erupting since May 2006 in the densely populated Sidoarjo regency (East Java, Indonesia), forcing the evacuation of 40,000 people and destroying industry, farmland, and over 10,000 homes. The activity of LUSI mud volcano has been well documented (Vanderkluysen et al., 2014) and here we present a comparison of observed gas fluxes and mud extrusion rates with the outcomes of numerical simulations. Vanderkluysen, L.; Burton, M. R.; Clarke, A. B.; Hartnett, H. E. & Smekens, J.-F. Composition and flux of explosive gas release at LUSI mud volcano (East Java, Indonesia) Geochem. Geophys. Geosyst., Wiley-Blackwell, 2014, 15, 2932-2946

  13. Effect of forward looking sites on a multi-phase lattice hydrodynamic model

    Science.gov (United States)

    Redhu, Poonam; Gupta, Arvind Kumar

    2016-03-01

    A new multi-phase lattice hydrodynamic traffic flow model is proposed by considering the effect of multi-forward looking sites on a unidirectional highway. We examined the qualitative properties of proposed model through linear as well as nonlinear stability analysis. It is shown that the multi-anticipation effect can significantly enlarge the stability region on the phase diagram and exhibit three-phase traffic flow. It is also observed that the multi-forward looking sites have prominent influence on traffic flow when driver senses the relative flux of leading vehicles. Theoretical findings are verified using numerical simulation which confirms that the traffic jam is suppressed efficiently by considering the information of leading vehicles in unidirectional multi-phase traffic flow.

  14. Simulating anomalous transport and multiphase segregation in porous media with the Lattice Boltzmann Method

    Science.gov (United States)

    Matin, Rastin; Hernandez, Anier; Misztal, Marek; Mathiesen, Joachim

    2015-04-01

    Many hydrodynamic phenomena ranging from flows at micron scale in porous media, large Reynolds numbers flows, non-Newtonian and multiphase flows have been simulated on computers using the lattice Boltzmann (LB) method. By solving the Lattice Boltzmann Equation on unstructured meshes in three dimensions, we have developed methods to efficiently model the fluid flow in real rock samples. We use this model to study the spatio-temporal statistics of the velocity field inside three-dimensional real geometries and investigate its relation to the, in general, anomalous transport of passive tracers for a wide range of Peclet and Reynolds numbers. We extend this model by free-energy based method, which allows us to simulate binary systems with large-density ratios in a thermodynamically consistent way and track the interface explicitly. In this presentation we will present our recent results on both anomalous transport and multiphase segregation.

  15. ITOUGH2 software qualification

    Energy Technology Data Exchange (ETDEWEB)

    Finsterle, S.; Pruess, K.; Fraser, P.

    1996-10-01

    The purpose of this report is to provide all software baseline documents necessary for the software qualification of ITOUGH2. ITOUGH2 is a computer program providing inverse modeling capabilities for TOUGH2. TOUGH2 is a numerical simulation code for multi-dimensional coupled fluid and heat flow of multiphase, multicomponent fluid mixtures in porous and fractured media.

  16. Twin screw subsurface and surface multiphase pumps

    Energy Technology Data Exchange (ETDEWEB)

    Dass, P. [CAN-K GROUP OF COMPANIES, Edmonton, Alberta (Canada)

    2011-07-01

    A new subsurface twin screw multiphase pump has been developed to replace ESP and other artificial lift technologies. This technology has been under development for a few years, has been field tested and is now going for commercial applications. The subsurface twin screw technology consists of a pair of screws that do not touch and can be run with a top drive or submersible motor; and it carries a lot of benefits. This technology is easy to install and its low slippage makes it highly efficient with heavy oil. In addition twin screw multiphase pumps are capable of handling high viscosity fluids and thus their utilization can save water when used in thermal applications. It also induces savings of chemicals because asphaltenes do not break down easily as well as a reduction in SOR. The subsurface twin screw multiphase pump presented herein is an advanced technology which could be used in thermal applications.

  17. Multiphase CFD simulation of a solid bowl centrifuge

    Energy Technology Data Exchange (ETDEWEB)

    Romani Fernandez, X.; Nirschl, H. [Universitaet Karlsruhe, Institut fuer MVM, Karlsruhe (Germany)

    2009-05-15

    This study presents some results from the numerical simulation of the flow in an industrial solid bowl centrifuge used for particle separation in industrial fluid processing. The computational fluid dynamics (CFD) software Fluent was used to simulate this multiphase flow. Simplified two-dimensional and three-dimensional geometries were built and meshed from the real centrifuge geometry. The CFD results show a boundary layer of axially fast moving fluid at the gas-liquid interface. Below this layer there is a thin recirculation. The obtained tangential velocity values are lower than the ones for the rigid-body motion. Also, the trajectories of the solid particles are evaluated. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  18. Reactive and multiphase modelling for the identification of monitoring parameters to detect CO2 intrusion into freshwater aquifers

    Science.gov (United States)

    Fahrner, S.; Schaefer, D.; Wiegers, C.; Köber, R.; Dahmke, A.

    2011-12-01

    A monitoring at geological CO2 storage sites has to meet environmental, regulative, financial and public demands and thus has to enable the detection of CO2 leakages. Current monitoring concepts for the detection of CO2 intrusion into freshwater aquifers located above saline storage formations in course of leakage events lack the identification of monitoring parameters. Their response to CO2 intrusion still has to be enlightened. Scenario simulations of CO2 intrusion in virtual synthetic aquifers are performed using the simulators PhreeqC and TOUGH2 to reveal relevant CO2-water-mineral interactions and multiphase behaviour on potential monitoring parameters. The focus is set on pH, total dissolved inorganic carbon (TIC) and the hydroelectric conductivity (EC). The study aims at identifying at which conditions the parameters react rapidly, durable and in a measurable degree. The depth of the aquifer, the mineralogy, the intrusion rates, the sorption specification and capacities, and groundwater flow velocities are varied in the course of the scenario modelling. All three parameters have been found suited in most scenarios. However, in case of a lack of calcite combined with low saturation of the water with respect to CO2 and shallow conditions, changes are close to the measurement resolution. Predicted changes in EC result from the interplay between carbonic acid production and its dissociation, and pH buffering by mineral dissolution. The formation of a discrete gas phase in cases of full saturation of the groundwater in confined aquifers illustrates the potential bipartite resistivity response: An increased hydroelectric conductivity at locations with dissolved CO2, and a high resistivity where the gas phase dominates the pore volume occupation. Increased hydrostatic pressure with depth and enhanced groundwater flow velocities enforce gas dissolution and diminish the formation of a discrete gas phase. Based on the results, a monitoring strategy is proposed which

  19. Digital image analysis of stress-dependent granular compaction and its impact on multiphase fluid distributions

    Science.gov (United States)

    Yoon, H.; Klise, K. A.; Torrealba, V.; Karpyn, Z.

    2014-12-01

    Pore-scale investigation of multiphase fluid behavior in porous media is useful for obtaining quantitative information about relationships between micro-pore structures and multiphase flow and their impact on fluid distribution under different conditions. Recent advances in imaging techniques such as X-ray computed microtomography (microCT) allows us to examine three-dimensional (3D) micro-pore structures and multiphase distribution. However, many previous experiments with microCT imaging have been largely limited to static conditions. In this work, we focus on stress-dependent granular compaction under flowing conditions and its impact on displacement mechanisms and multiphase distribution under multiple drainage and imbibition cycles. A stack of 3D images were obtained with microCT to examine pore structures and fluid distribution under each cycle. Advanced imaging processing techniques were employed to improve the quality of multiphase segmentations. Key characteristics of pore structures and fluid distribution include porosity, permeability, specific surface area, interfacial area, Euler characteristic, and phase saturation. Additional lattice-Boltzmann simulations are used to investigate how inter-granular compaction mechanisms may affect fluid displacement and residual trapping at the pore-scale. This will improve our understanding of the dynamic interaction of slow compaction and fluid flow relevant to subsurface applications such as geologic CO2 storage and enhanced oil recovery. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  20. Biphilicity and Superbiphilicity for Wettability Control of Multiphase Heat Transfer

    Science.gov (United States)

    Attinger, Daniel; Betz, Amy Rachel; Schutzius, T. M.; Jenkins, J.; Kim, C.-J.; Megaridis, C. M.

    2012-11-01

    Multiphase energy transport, such as in boiling, suggests contradictory requirements on the wettability of the solid surfaces coming into contact with the working fluid. On the one hand, a hydrophobic wall promotes nucleation. On the other hand, a hydrophilic wall promotes water contact and enhances the critical heat flux. An analogous situation appears in the opposite thermodynamic process, i.e. condensation. These apparently contradictory requirements can be accommodated with biphilic surfaces, which juxtapose hydrophilic and hydrophobic regions. Biphilic surfaces were first manufactured in 1964 by Young and Hummel, who sprayed Teflon drops onto a smooth steel surface: they showed enhanced heat transfer coefficient during boiling of water. Our recent work has revisited the manufacturing of biphilic surfaces using micro- and nanofabrication processes (Betz et al. 2010, Schutzius et al. 2012); for instance, we fabricated the first superbiphilic surfaces, which juxtapose superhydrophobic and superhydrophilic areas. Using these surfaces, we measured significant enhancement during pool boiling of both the heat transfer coefficient and the critical heat flux. This enhanced performance can be explained by the inherent ability of the surfaces to control multiphase flow, decreasing nucleation energies and shaping drops, bubbles and jets, to maximize transport and prevent instabilities.

  1. Multiphase Nanocrystalline Ceramic Concept for Nuclear Fuel

    International Nuclear Information System (INIS)

    Mecartnery, Martha; Graeve, Olivia; Patel, Maulik

    2017-01-01

    The goal of this research is to help develop new fuels for higher efficiency, longer lifetimes (higher burn-up) and increased accident tolerance in future nuclear reactors. Multiphase nanocrystalline ceramics will be used in the design of simulated advanced inert matrix nuclear fuel to provide for enhanced plasticity, better radiation tolerance, and improved thermal conductivity

  2. Multiphase Nanocrystalline Ceramic Concept for Nuclear Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Mecartnery, Martha [Univ. of California, Irvine, CA (United States); Graeve, Olivia [Univ. of California, San Diego, CA (United States); Patel, Maulik [Univ. of Liverpool (United Kingdom)

    2017-05-25

    The goal of this research is to help develop new fuels for higher efficiency, longer lifetimes (higher burn-up) and increased accident tolerance in future nuclear reactors. Multiphase nanocrystalline ceramics will be used in the design of simulated advanced inert matrix nuclear fuel to provide for enhanced plasticity, better radiation tolerance, and improved thermal conductivity

  3. On multiphase negative flash for ideal solutions

    DEFF Research Database (Denmark)

    Yan, Wei; Stenby, Erling Halfdan

    2012-01-01

    There is a recent interest to solve multiphase negative flash problems where the phase amounts can be negative for normal positive feed composition. Solving such a negative flash problem using successive substitution needs an inner loop for phase distribution calculation at constant fugacity...

  4. Multiphase magnetic systems: Measurement and simulation

    Science.gov (United States)

    Cao, Yue; Ahmadzadeh, Mostafa; Xu, Ke; Dodrill, Brad; McCloy, John S.

    2018-01-01

    Multiphase magnetic systems are common in nature and are increasingly being recognized in technical applications. One characterization method which has shown great promise for determining separate and collective effects of multiphase magnetic systems is first order reversal curves (FORCs). Several examples are given of FORC patterns which provide distinguishing evidence of multiple phases. In parallel, a visualization method for understanding multiphase magnetic interaction is given, which allocates Preisach magnetic elements as an input "Preisach hysteron distribution pattern" to enable simulation of different "wasp-waisted" magnetic behaviors. These simulated systems allow reproduction of different major hysteresis loops and FORC patterns of real systems and parameterized theoretical systems. The experimental FORC measurements and FORC diagrams of four commercially obtained magnetic materials, particularly those sold as nanopowders, show that these materials are often not phase pure. They exhibit complex hysteresis behaviors that are not predictable based on relative phase fraction obtained by characterization methods such as diffraction. These multiphase materials, consisting of various fractions of BaFe12O19, ɛ-Fe2O3, and γ-Fe2O3, are discussed.

  5. Computed Tomography Scanning to Understand Micro-to-Macro Controls on Multiphase Flow during Geologic Carbon Storage; NETL-TRS-3-2017; NETL Technical Report Series; U.S. Department of Energy, National Energy Technology Laboratory: Morgantown, WV, 2017; p 24.

    Energy Technology Data Exchange (ETDEWEB)

    Crandall, Dustin M. [National Energy Technology Lab. (NETL), Morgantown, WV (United States); Moore, Johnathan E. [National Energy Technology Lab. (NETL) and AECOM, Morgantown, WV (United States); Tudek, John K. [National Energy Technology Lab. (NETL) and AECOM, Morgantown, WV (United States); Gill, Magdalena K [National Energy Technology Lab. (NETL) and ORISE, Morgantown, WV (United States)

    2017-03-01

    Evaluation of the fate and transport of carbon dioxide (CO2) in deep reservoirs is crucial to the development of long-term geologic carbon sequestration (GCS) technologies. In this report, various studies using computed tomography (CT) scanning are utilized in conjunction with traditional flow tests to observe the multi-scale phenomena associated with CO2 injection in geologic media. Pore scale analyses were performed to determine the infiltration characteristics of CO2 into a brine saturated reservoir rock. Multiphase floods were performed to evaluate the saturation of CO2 into a brine-saturated reservoir rock and determine how structural changes within the lithology affect such interactions. Additionally, CO2 induced swelling of unconventional reservoir rock was evaluated with respect to reductions in fracture transmissivity due to matrix swelling. These studies are just a few examples of the benefits of multi-scale CT imaging in conjunction with traditional laboratory methodology to gain a better understanding of the interactions between CO2 and the lithologies it interacts with during GCS.

  6. Multiphase transport in polymer electrolyte membrane fuel cells

    Science.gov (United States)

    Gauthier, Eric D.

    Polymer electrolyte membrane fuel cells (PEMFCs) enable efficient conversion of fuels to electricity. They have enormous potential due to the high energy density of the fuels they utilize (hydrogen or alcohols). Power density is a major limitation to wide-scale introduction of PEMFCs. Power density in hydrogen fuel cells is limited by accumulation of water in what is termed fuel cell `flooding.' Flooding may occur in either the gas diffusion layer (GDL) or within the flow channels of the bipolar plate. These components comprise the electrodes of the fuel cell and balance transport of reactants/products with electrical conductivity. This thesis explores the role of electrode materials in the fuel cell and examines the fundamental connection between material properties and multiphase transport processes. Water is generated at the cathode catalyst layer. As liquid water accumulates it will utilize the largest pores in the GDL to go from the catalyst layer to the flow channels. Water collects to large pores via lateral transport at the interface between the GDL and catalyst layer. We have shown that water may be collected in these large pores from several centimeters away, suggesting that we could engineer the GDL to control flooding with careful placement and distribution of large flow-directing pores. Once liquid water is in the flow channels it forms slugs that block gas flow. The slugs are pushed along the channel by a pressure gradient that is dependent on the material wettability. The permeable nature of the GDL also plays a major role in slug growth and allowing bypass of gas between adjacent channels. Direct methanol fuel cells (DMFCs) have analogous multiphase flow issues where carbon dioxide bubbles accumulate, `blinding' regions of the fuel cell. This problem is fundamentally similar to water management in hydrogen fuel cells but with a gas/liquid phase inversion. Gas bubbles move laterally through the porous GDL and emerge to form large bubbles within the

  7. Analysis of a bubble coalescence in the multiphase lattice Boltzmann method

    International Nuclear Information System (INIS)

    Ryu, Seung Yeob; Park, Cheon Tae; Lee, Chung Chan; Kim, Keung Koo

    2008-01-01

    Recently, the lattice Boltzmann method (LBM) has gained much attention for its ability to simulate fluid flows, and for its potential advantages over a conventional CFD method. The key advantages of LBM are, (1) suitability for parallel computations, (2) absence of the need to solve the time-consuming Poisson equation for a pressure, and (3) an ease with multiphase flows, complex geometries and interfacial dynamics may be treated. To study the effect of the mobility coefficient Γ and the width of the interface layer, two stationary bubbles without a collision are considered. The gap of the two bubbles is taken as 4, while the width of the interface (w) and the mobility coefficient Γ are varied. In the present work, the lattice Boltzmann model for multiphase flows proposed by Zheng et al. is used for simulating two stationary bubbles without a collision. By adopting a finite difference gradient operator of a sufficient isotropy, the spurious currents can be made smaller. The main objective of the present work is to establish the lattice Boltzmann method as a viable tool for the simulation of multiphase or multi-component flows

  8. Flow regimes

    International Nuclear Information System (INIS)

    Liles, D.R.

    1982-01-01

    Internal boundaries in multiphase flow greatly complicate fluid-dynamic and heat-transfer descriptions. Different flow regimes or topological configurations can have radically dissimilar interfacial and wall mass, momentum, and energy exchanges. To model the flow dynamics properly requires estimates of these rates. In this paper the common flow regimes for gas-liquid systems are defined and the techniques used to estimate the extent of a particular regime are described. Also, the current computer-code procedures are delineated and introduce a potentially better method is introduced

  9. Variational continuum multiphase poroelasticity theory and applications

    CERN Document Server

    Serpieri, Roberto

    2017-01-01

    This book collects the theoretical derivation of a recently presented general variational macroscopic continuum theory of multiphase poroelasticity (VMTPM), together with its applications to consolidation and stress partitioning problems of interest in several applicative engineering contexts, such as in geomechanics and biomechanics. The theory is derived based on a purely-variational deduction, rooted in the least-Action principle, by considering a minimal set of kinematic descriptors. The treatment herein considered keeps a specific focus on the derivation of most general medium-independent governing equations. It is shown that VMTPM recovers paradigms of consolidated use in multiphase poroelasticity such as Terzaghi's stress partitioning principle and Biot's equations for wave propagation. In particular, the variational treatment permits the derivation of a general medium-independent stress partitioning law, and the proposed variational theory predicts that the external stress, the fluid pressure, and the...

  10. Application and Perspectives of Multiphase Induction Motors

    Directory of Open Access Journals (Sweden)

    Benas Kundrotas

    2012-04-01

    Full Text Available The article considers the areas of applying multiphase induction motors. Their advantages against three phase motors have become the main reason for employing them in multiphase drives. The paper deals with the six-phase induction motor having two similar three phase windings in the stator shifted by 30 degrees in space and three phase windings in the rotor. Differential equations for this motor are presented and transformed to dq synchronous reference frame. The transformed equations are expressed in a matrix form and solved by MATLAB software using the Dormand-Prince (ode45 method. The transient characteristics of the torque, speed and current of the six-phase induction motor are calculated and discussed.Article in Lithuanian

  11. Multi-phase EMI noise separator

    OpenAIRE

    2011-01-01

    Common mode (CM) and differential mode (DM) components of multi-phase conducted electromagnetic interference (EMI) noise emanating from electronic circuits such as power converters/inverters are separated by respective coupled inductors connected to each phase of three or more phases and which are coupled to each other differently for CM and DM noise of the respective phases. The inductors of the DM separation unit are coupled such that a substantially ideal zero impedance is presented to DM ...

  12. A Gallium multiphase equation of state

    Energy Technology Data Exchange (ETDEWEB)

    Crockett, Scott D [Los Alamos National Laboratory; Greeff, Carl [Los Alamos National Laboratory

    2009-01-01

    A new SESAME multiphase Gallium equation of state (EOS) has been developed. The equation of state includes three of the solid phases (Ga I, Ga II, Ga III) and a fluid phase (liquid/gas). The EOS includes consistent latent heat between the phases. We compare the results to the liquid Hugoniol data. We also explore the possibility of re-freezing via dynamic means such as isentropic and shock compression.

  13. How winning changes motivation in multiphase competitions.

    Science.gov (United States)

    Huang, Szu-Chi; Etkin, Jordan; Jin, Liyin

    2017-06-01

    What drives motivation in multiphase competitions? Adopting a dynamic approach, this research examines how temporary standing-being ahead of (vs. behind) one's opponent-in a multiphase competition shapes subsequent motivation. Six competitions conducted in the lab and in the field demonstrate that the impact of being ahead on contestants' motivation depends on when (i.e., in which phase of the competition) contestants learn they are in the lead. In the early phase, contestants are concerned about whether they can win; being ahead increases motivation by making winning seem more attainable. In the later phase, however, contestants are instead driven by how much additional effort they believe they need to invest; being ahead decreases motivation by reducing contestants' estimate of the remaining effort needed to win. Temporary standing thus has divergent effects on motivation in multiphase competitions, driven by a shift in contestants' main concern from the early to the later phase and thus the meaning they derive from being ahead of their opponent. By leveraging insights gained from approaching individuals' self-regulation as a dynamic process, this research advances understanding of how motivation evolves in a unique interdependent self-regulatory context. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  14. Experimental characterization of energetic material dynamics for multiphase blast simulation.

    Energy Technology Data Exchange (ETDEWEB)

    Beresh, Steven Jay; Wagner, Justin L.; Kearney, Sean Patrick; Wright, Elton K.; Baer, Melvin R.; Pruett, Brian Owen Matthew

    2011-09-01

    Currently there is a substantial lack of data for interactions of shock waves with particle fields having volume fractions residing between the dilute and granular regimes, which creates one of the largest sources of uncertainty in the simulation of energetic material detonation. To close this gap, a novel Multiphase Shock Tube has been constructed to drive a planar shock wave into a dense gas-solid field of particles. A nearly spatially isotropic field of particles is generated in the test section by a gravity-fed method that results in a spanwise curtain of spherical 100-micron particles having a volume fraction of about 19%. Interactions with incident shock Mach numbers of 1.66, 1.92, and 2.02 were achieved. High-speed schlieren imaging simultaneous with high-frequency wall pressure measurements are used to reveal the complex wave structure associated with the interaction. Following incident shock impingement, transmitted and reflected shocks are observed, which lead to differences in particle drag across the streamwise dimension of the curtain. Shortly thereafter, the particle field begins to propagate downstream and spread. For all three Mach numbers tested, the energy and momentum fluxes in the induced flow far downstream are reduced about 30-40% by the presence of the particle field. X-Ray diagnostics have been developed to penetrate the opacity of the flow, revealing the concentrations throughout the particle field as it expands and spreads downstream with time. Furthermore, an X-Ray particle tracking velocimetry diagnostic has been demonstrated to be feasible for this flow, which can be used to follow the trajectory of tracer particles seeded into the curtain. Additional experiments on single spherical particles accelerated behind an incident shock wave have shown that elevated particle drag coefficients can be attributed to increased compressibility rather than flow unsteadiness, clarifying confusing results from the historical database of shock tube

  15. Multiphase flow in the geosphere around a repository for spent nuclear fuels. Inventory of the present knowledge; Flerfasfloede i geosfaeren kring ett foervar foer utbraent kaernbraensle. Inventering av kunskapslaeget

    Energy Technology Data Exchange (ETDEWEB)

    Aalen, Bengt [Bergab, Goeteborg (Sweden)

    2004-10-01

    Important quantities of gas can form in an underground repository for nuclear wastes. Gas can be formed through: corroding metals; water and certain organic substances that undergo radiolysis; organic material degrading through microbial activity. The last point is of concern mainly for intermediate-level wastes, which can hold large amounts of organic materials. The first point is the main process for high-level wastes. The gas could transport radioactive substances through the buffer and the geosphere into the biosphere, or affect the performance of the repository in a negative way. The present report gives a review of the knowledge about two-phase flow in connection with deep geologic repositories for spent nuclear fuel.

  16. Multiphase boudinage: a case study of amphibolites in marble in the Naxos migmatite core

    Directory of Open Access Journals (Sweden)

    S. Virgo

    2018-02-01

    Full Text Available In multiply deformed terrains multiphase boudinage is common, but identification and analysis of these is difficult. Here we present an analysis of multiphase boudinage and fold structures in deformed amphibolite layers in marble from the migmatitic centre of the Naxos metamorphic core complex. Overprinting between multiple boudinage generations is shown in exceptional 3-D outcrop. We identify five generations of boudinage, reflecting the transition from high-strain high-temperature ductile deformation to medium- to low-strain brittle boudins formed during cooling and exhumation. All boudin generations indicate E–W horizontal shortening and variable direction of bedding parallel extension, evolving from subvertical extension in the earliest boudins to subhorizontal N–S extension during exhumation. Two phases of E–W shortening can be inferred, the first associated with lower crustal synmigmatic convergent flow and the second associated with exhumation and N–S extension, possibly related to movement of the North Anatolian Fault.

  17. Industrial applications of multi-functional, multi-phase reactors

    NARCIS (Netherlands)

    Harmsen, G.J.; Chewter, L.A.

    1999-01-01

    To reveal trends in the design and operation of multi-functional, multi-phase reactors, this paper describes, in historical sequence, three industrial applications of multi-functional, multi-phase reactors developed and operated by Shell Chemicals during the last five decades. For each case, we

  18. A Senior Project-Based Multiphase Motor Drive System Development

    Science.gov (United States)

    Abdel-Khalik, Ayman S.; Massoud, Ahmed M.; Ahmed, Shehab

    2016-01-01

    Adjustable-speed drives based on multiphase motors are of significant interest for safety-critical applications that necessitate wide fault-tolerant capabilities and high system reliability. Although multiphase machines are based on the same conceptual theory as three-phase machines, most undergraduate electrical machines and electric drives…

  19. Transfers in multiphase environment; Transferts en milieu multiphasique

    Energy Technology Data Exchange (ETDEWEB)

    Marinhas, S.; Delahaye, A.; Fournaison, L. [Cemagref - GPAN, 92 - Antony (France); Dalmazzone, D.; Furst, W. [Ecole Nationale Superieure de Techniques Avancees (ENSTA), 75 - Paris (France); Petitet, J.P. [Laboratoire d' Ingenierie des Materiaux et des Hautes Pressions (LIMHP), CNRS, 93 - Villetaneuse (France); Trinquet, F.; Royon, L.; Kayossi, H.; Guiffant, G. [Laboratoire Matiere Systeme Complexe, CNRS UMR 7057, 75 - Paris (France); El Omari, L.; Baonga, J.B.; Louahlia-Gualous, H.; Panday, P.K. [Institut FEMTO, Dept. C.R.E.S.T.-UTBM-UFC, UMR CNRS 6174, 90 - Belfort (France); Asbik, M.; Ansari, O. [UFR de Modelisation, Optimisation et Ingenierie des Systemes Energetiques, Faculte des Sciences et Techniques, Errachidia (Morocco); Zeghmati, B. [Perpignan Univ., Laboratoire de Mathematiques et Physique des Systemes, Groupe de Mecanique Energetique (M.E.P.S.-G.M.E.), EA 3086, 66 (France); Jamil, A.; Zeraouli, Y.; Dumas, J.P. [Pau Univ. et des Pays de l' Adour, Lab. de Thermique, Energetique et Procedes (LaTEP), 64 (France); Roux, P.; Fichot, F. [CEA Cadarache, Institut de Radioprotection et de Surete Nucleaire (IRSN), 13 - Saint-Paul-lez-Durance (France); Gobin, D.; Goyeau, B. [Laboratoire FAST, 91 - Orsay (France); Quintard, M. [Institut de Mecanique des Fluides, 31 - Toulouse (France); Barthes, M.; Reynard, Ch.; Santini, R.; Tadrist, L. [Laboratoire IUSTI CNRS UMR 6595, 13 - Marseille (France)

    2005-07-01

    This session about heat and mass transfers in multiphase flows gathers 17 papers dealing with: dynamic study of gas hydrate slurry applied to secondary refrigeration; ice melting inside an agitated reactor: experiment and phenomenological approach; experimental and numerical investigation of the local thickness change of a liquid film dripping around an horizontal tube; evaporation of a liquid film dripping around the external wall of an horizontal tube: laminar-turbulent transition phenomenon; coldness distribution by stabilized ice slurries, study of the behaviour under thermal cycling; study of phases disequilibria of two-phase refrigerating fluids; solidification of binary mixtures, influence of the local chemical non-equilibrium and of the effective transport properties; analysis of heat transfers during the growth of a vapor bubble; forecasting of micro-porosity inside Al-Si alloy smelting parts; estimation of a source term in a 2D transient problem: application to electron beam welding; mesoscopic approach of thermal flows; experimental and numerical study of the impact of a circular jet on a heated disc; inverse conduction method for a jet impacting a rotating cylinder: feasibility study; experimental follow up of a fusion-solidification front with and without transfer promoter; parametric study of a latent heat storage tank during horizontal drainage; stability between two layers of a same supercritical fluid; numerical modeling of the heat transfer inside a stainless steel slab. (J.S.)

  20. Multiphasic Scaffolds for Periodontal Tissue Engineering

    Science.gov (United States)

    Ivanovski, S.; Vaquette, C.; Gronthos, S.; Hutmacher, D.W.; Bartold, P.M.

    2014-01-01

    For a successful clinical outcome, periodontal regeneration requires the coordinated response of multiple soft and hard tissues (periodontal ligament, gingiva, cementum, and bone) during the wound-healing process. Tissue-engineered constructs for regeneration of the periodontium must be of a complex 3-dimensional shape and adequate size and demonstrate biomechanical stability over time. A critical requirement is the ability to promote the formation of functional periodontal attachment between regenerated alveolar bone, and newly formed cementum on the root surface. This review outlines the current advances in multiphasic scaffold fabrication and how these scaffolds can be combined with cell- and growth factor–based approaches to form tissue-engineered constructs capable of recapitulating the complex temporal and spatial wound-healing events that will lead to predictable periodontal regeneration. This can be achieved through a variety of approaches, with promising strategies characterized by the use of scaffolds that can deliver and stabilize cells capable of cementogenesis onto the root surface, provide biomechanical cues that encourage perpendicular alignment of periodontal fibers to the root surface, and provide osteogenic cues and appropriate space to facilitate bone regeneration. Progress on the development of multiphasic constructs for periodontal tissue engineering is in the early stages of development, and these constructs need to be tested in large animal models and, ultimately, human clinical trials. PMID:25139362

  1. Multiphase equation of state for iron

    Energy Technology Data Exchange (ETDEWEB)

    Kerley, G I

    1993-02-01

    The PANDA code is used to build a multiphase equation of state (EOS) table for iron. Separate EOS tables were first constructed for each of the individual phases. The phase diagram and multiphase EOS were then determined from the Helmholtz free energies. The model includes four solid phases ([alpha],[gamma], [delta], and [var epsilon]) and a fluid phase (including the liquid, vapor, and supercritical regions). The model gives good agreement with experimental thermophysical data, static compression data, phase boundaries, and shock-wave measurements. Contributions from thermal electronic excitation, computed from a quantum-statistical-mechanical model, were found to be very important. This EOS covers a wide range of densities (0--1000 g/cm[sup 3]) and temperatures (0--1.2[times]10[sup 7] K). It is also applicable to RHA steel. The new EOS is used in hydrocode simulations of plate impact experiments, a nylon ball impact on steel, and the shaped charge perforation of an RHA plate. The new EOS table can be accessed through the SNL-SESAME library as material number 2150.

  2. Critical pressure and multiphase flow in Blake Ridge gas hydrates

    Science.gov (United States)

    Flemings, P.B.; Liu, Xiuying; Winters, W.J.

    2003-01-01

    We use core porosity, consolidation experiments, pressure core sampler data, and capillary pressure measurements to predict water pressures that are 70% of the lithostatic stress, and gas pressures that equal the lithostatic stress beneath the methane hydrate layer at Ocean Drilling Program Site 997, Blake Ridge, offshore North Carolina. A 29-m-thick interconnected free-gas column is trapped beneath the low-permeability hydrate layer. We propose that lithostatic gas pressure is dilating fractures and gas is migrating through the methane hydrate layer. Overpressured gas and water within methane hydrate reservoirs limit the amount of free gas trapped and may rapidly export methane to the seafloor.

  3. Prediction of Multiphase Flow Properties from Network Models ...

    African Journals Online (AJOL)

    A uniform pore size structure resulted in more favorable two-phase relative permeability distribution, with the relative permeability depending greatly on the phase saturations. Capillary pressure, on the other hand, was found to increase with image resolution. Keywords: Network Model, Computer Tomography, Relative ...

  4. Transient multiphase flow modeling of gas well liquid loading

    NARCIS (Netherlands)

    Veeken, K.; Hu, B.; Schiferli, W.

    2009-01-01

    Gas well liquid loading occurs when gas production becomes insufficient to lift the associated liquids to surface. When that happens gas production first turns intermittent and eventually stops. Hence in depleting gas reservoirs the technical abandonment pressure and ultimate recovery are typically

  5. Artificial neural network and neutron application in a volume fraction calculation in annular and stratified multiphase system

    International Nuclear Information System (INIS)

    Ramos, Robson; Brandao, Luis E.B.; Pereira, Claudio M.N.A.; Schirru, Roberto; Silva, Ademir Xavier da

    2009-01-01

    Multiphase flows, type oil-water-gas are very common among different industrial activities, such as chemical industries and petroleum extraction, and its measurements show some difficulties to be taken. Precisely determining the volume fraction of each one of the elements that composes a multiphase flow is very important in chemical plants and petroleum industries. This work presents a methodology able to determine volume fraction on Annular and Stratified multiphase flow system with the use of neutrons and artificial intelligence, using the principles of transmission/scattering of fast neutrons from a 241 Am-Be source and measurements of point flow that are influenced by variations of volume fractions. The proposed geometries used on the mathematical model was used to obtain a data set where the thicknesses referred of each material had been changed in order to obtain volume fraction of each phase providing 119 compositions that were used in the simulation with MCNP-X -computer code based on Monte Carlo Method that simulates the radiation transport. An artificial neural network (ANN) was trained with data obtained using the MCNP-X, and used to correlate such measurements with the respective real fractions. The ANN was able to correlate the data obtained on the simulation with MCNP-X with the volume fractions of the multiphase flows (oil-water-gas), both in the pattern of annular flow as stratified, resulting in a average relative error (%) for each production set of: annular (air = 3.85; water = 4.31; oil=1.08); stratified (air = 3.10, water 2.01, oil = 1.45). The method demonstrated good efficiency in the determination of each material that composes the phases, thus demonstrating the feasibility of the technique. (author)

  6. Multiphasic On/Off Pheromone Signalling in Moths as Neural Correlates of a Search Strategy

    Science.gov (United States)

    Martinez, Dominique; Chaffiol, Antoine; Voges, Nicole; Gu, Yuqiao; Anton, Sylvia; Rospars, Jean-Pierre; Lucas, Philippe

    2013-01-01

    Insects and robots searching for odour sources in turbulent plumes face the same problem: the random nature of mixing causes fluctuations and intermittency in perception. Pheromone-tracking male moths appear to deal with discontinuous flows of information by surging upwind, upon sensing a pheromone patch, and casting crosswind, upon losing the plume. Using a combination of neurophysiological recordings, computational modelling and experiments with a cyborg, we propose a neuronal mechanism that promotes a behavioural switch between surge and casting. We show how multiphasic On/Off pheromone-sensitive neurons may guide action selection based on signalling presence or loss of the pheromone. A Hodgkin-Huxley-type neuron model with a small-conductance calcium-activated potassium (SK) channel reproduces physiological On/Off responses. Using this model as a command neuron and the antennae of tethered moths as pheromone sensors, we demonstrate the efficiency of multiphasic patterning in driving a robotic searcher toward the source. Taken together, our results suggest that multiphasic On/Off responses may mediate olfactory navigation and that SK channels may account for these responses. PMID:23613816

  7. Multiphasic on/off pheromone signalling in moths as neural correlates of a search strategy.

    Directory of Open Access Journals (Sweden)

    Dominique Martinez

    Full Text Available Insects and robots searching for odour sources in turbulent plumes face the same problem: the random nature of mixing causes fluctuations and intermittency in perception. Pheromone-tracking male moths appear to deal with discontinuous flows of information by surging upwind, upon sensing a pheromone patch, and casting crosswind, upon losing the plume. Using a combination of neurophysiological recordings, computational modelling and experiments with a cyborg, we propose a neuronal mechanism that promotes a behavioural switch between surge and casting. We show how multiphasic On/Off pheromone-sensitive neurons may guide action selection based on signalling presence or loss of the pheromone. A Hodgkin-Huxley-type neuron model with a small-conductance calcium-activated potassium (SK channel reproduces physiological On/Off responses. Using this model as a command neuron and the antennae of tethered moths as pheromone sensors, we demonstrate the efficiency of multiphasic patterning in driving a robotic searcher toward the source. Taken together, our results suggest that multiphasic On/Off responses may mediate olfactory navigation and that SK channels may account for these responses.

  8. Gasificaton Transport: A Multiphase CFD Approach & Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Dimitri Gidaspow; Veeraya Jiradilok; Mayank Kashyap; Benjapon Chalermsinsuwan

    2009-02-14

    The objective of this project was to develop predictive theories for the dispersion and mass transfer coefficients and to measure them in the turbulent fluidization regime, using existing facilities. A second objective was to use our multiphase CFD tools to suggest optimized gasifier designs consistent with aims of Future Gen. We have shown that the kinetic theory based CFD codes correctly compute: (1) Dispersion coefficients; and (2) Mass transfer coefficients. Hence, the kinetic theory based CFD codes can be used for fluidized bed reactor design without any such inputs. We have also suggested a new energy efficient method of gasifying coal and producing electricity using a molten carbonate fuel cell. The principal product of this new scheme is carbon dioxide which can be converted into useful products such as marble, as is done very slowly in nature. We believe this scheme is a lot better than the canceled FutureGen, since the carbon dioxide is safely sequestered.

  9. Local mean multiphase segmentation with HMMF models

    DEFF Research Database (Denmark)

    Hansen, Jacob Daniel Kirstejn; Lauze, Francois Bernard

    2017-01-01

    This paper presents two similar multiphase segmentation methods for recovery of segments in complex weakly structured images, with local and global bias fields, because they can occur in some X-ray CT imaging modalities. Derived from the Mumford-Shah functional, the proposed methods assume a fixed...... number of classes. They use local image average as discriminative features. Region labels are modelled by Hidden Markov Measure Field Models. The resulting problems are solved by straightforward alternate minimisation methods, particularly simple in the case of quadratic regularisation of the labels. We...... demonstrate the proposed methods’ capabilities on synthetic data using classical segmentation criteria as well as criteria specific to geoscience. We also present a few examples using real data....

  10. Solidification in Multicomponent Multiphase Systems (SIMMS)

    Science.gov (United States)

    Rex, S.; Hecht, U.

    2005-06-01

    The multiphase microstructures that evolve during the solidification of multicomponent alloys are attracting widespread interest for industrial applications and fundamental research.Thermodynamic databases are now well-established for many alloy systems. Thermodynamic calculations provide all the required information about phase equilibria, forming an integral part of both dedicated and comprehensive microstructure models. Among the latter, phase-field modelling has emerged as the method of choice. Solidification experiments are intended to trigger model development or to serve as benchmarks for model validation. For benchmarking, microgravity conditions offer a unique opportunity for avoiding buoyancy-induced convection and buoyancy forces in bulk samples. However, diffusion and the free-energy of interfaces and its anisotropy need to be determined.The measurement of chemical diffusivities in the liquid state can equally benefit from microgravity experiments.

  11. Intercomparison of Chemical Multiphase Box Models

    Science.gov (United States)

    Ervens, B.; Barth, M. C.; Herrmann, H.; McNeill, V. F.; Carlton, A. G.; Lance, S.; Morichetti, M.; Tilgner, A.

    2017-12-01

    It has been recognized for several decades that chemical processes in clouds and fogs can substantially alter atmospheric oxidant budgets and lead to aerosol mass formation. However, many current regional and global models do not include detailed aqueous-phase chemical mechanisms due to the lack of complete understanding of the underlying chemical processes, but also due to the computational burden of adding more constituents. The cloud chemistry community has begun an effort in connection with the Whiteface Mountain Observatory in New York to sample a suite of chemical compounds in cloud water and to evaluate and compare the state of knowledge of current gas-aqueous chemistry 0-dimensional models. Using the 17-18 September 2016 cloud event at Whiteface Mountain Observatory for input data, a cloud chemistry box model intercomparison was conducted. The focus of the intercomparison was on the predicted oxidant levels in both the gas and aqueous phases and on the formation of sulfate and secondary organic aerosol mass via aqueous-phase chemistry. We will present model results from the model intercomparison participants and discuss commonalities and reasons for differences in predicted concentrations of various chemical species in both phases. The conclusions of this workshop include a ranking of the importance of chemical (e.g., number of chemical species and processes), microphysical (e.g., cloud parameters) and meteorological (e.g., vertical mixing) parameters. An outlook will be given with recommendations on the most suitable multiphase chemical mechanism and essential parameters that should be derived from field measurements in order to improve the current state of chemical multiphase modules in models of various scales.

  12. Multiphasic MDCT in small bowel volvulus

    International Nuclear Information System (INIS)

    Feng Shiting; Chan Tao; Sun Canhui; Li Ziping; Guo Huanyi; Yang Guangqi; Peng Zhenpeng; Meng Quanfei

    2010-01-01

    Objective: Evaluate the use of MDCT with 3D CT angiography (CTA) and CT portal venography (CTPV) reconstruction for the diagnosis of small bowel volvulus (SBV). Methods: Multiphasic MDCT findings in nine patients (seven males and two females, age range 2-70) with surgically proven SBV were retrospectively reviewed. Non-contrast and double phase contrast enhanced MDCT including 3D CTA and CTPV reconstruction were performed in all the patients. Two experienced abdominal radiologists evaluated the images and defined the location, direction and degree of SBV. Results: On axial MDCT images, all cases show segmental or global dilatation of small intestine. Other findings include circumferential bowel wall thickening in eight cases, halo appearance and hyperemia in seven cases, whirl sign in six cases, beak-like appearance in six cases, closed loops in six cases and ascites in one case. CTA/CTPV showed abnormal courses involving main trunks of superior mesenteric artery (SMA) and superior mesenteric vein (SMV) in seven cases, with or without distortion of their tributaries. Normal course of SMA but abnormal course of SMV was seen in the other two cases. Of all the nine cases, whirl sign was seen in six cases and barber's pole sign in five cases. Dilated SMV was observed in eight cases and abrupt termination of SMA was found in one case. Compared with surgical findings, the location, direction and degree of SBV were correctly estimated in all cases based on CTA/CTPV. Conclusion: Multiphasic MDCT with CTA/CTPV reconstruction can play an important role in the diagnosis of SBV. The location, direction and degree of SBV can all be defined preoperatively using this method.

  13. Multiphasic MDCT in small bowel volvulus

    Energy Technology Data Exchange (ETDEWEB)

    Feng Shiting, E-mail: fst1977@163.com [Department of Radiology, The First Affiliated Hospital, Sun Yat-Sen University, 58th The Second Zhongshan Road, Guangzhou 510080 (China); Chan Tao, E-mail: taochan@hku.hk [Department of Diagnostic Radiology, University of Hong Kong, Room 406, Block K, Queen Mary Hospital (Hong Kong); Sun Canhui, E-mail: canhuisun@sina.com [Department of Radiology, The First Affiliated Hospital, Sun Yat-Sen University, 58th The Second Zhongshan Road, Guangzhou 510080 (China); Li Ziping, E-mail: liziping163@tom.com [Department of Radiology, The First Affiliated Hospital, Sun Yat-Sen University, 58th The Second Zhongshan Road, Guangzhou 510080 (China); Guo Huanyi, E-mail: guohuanyi@163.com [Department of Radiology, The First Affiliated Hospital, Sun Yat-Sen University, 58th The Second Zhongshan Road, Guangzhou 510080 (China); Yang Guangqi, E-mail: shwy03@126.com [Department of Radiology, The First Affiliated Hospital, Sun Yat-Sen University, 58th The Second Zhongshan Road, Guangzhou 510080 (China); Peng Zhenpeng, E-mail: ppzhen@21cn.com [Department of Radiology, The First Affiliated Hospital, Sun Yat-Sen University, 58th The Second Zhongshan Road, Guangzhou 510080 (China); Meng Quanfei, E-mail: mzycoco@gmail.com [Department of Radiology, The First Affiliated Hospital, Sun Yat-Sen University, 58th The Second Zhongshan Road, Guangzhou 510080 (China)

    2010-11-15

    Objective: Evaluate the use of MDCT with 3D CT angiography (CTA) and CT portal venography (CTPV) reconstruction for the diagnosis of small bowel volvulus (SBV). Methods: Multiphasic MDCT findings in nine patients (seven males and two females, age range 2-70) with surgically proven SBV were retrospectively reviewed. Non-contrast and double phase contrast enhanced MDCT including 3D CTA and CTPV reconstruction were performed in all the patients. Two experienced abdominal radiologists evaluated the images and defined the location, direction and degree of SBV. Results: On axial MDCT images, all cases show segmental or global dilatation of small intestine. Other findings include circumferential bowel wall thickening in eight cases, halo appearance and hyperemia in seven cases, whirl sign in six cases, beak-like appearance in six cases, closed loops in six cases and ascites in one case. CTA/CTPV showed abnormal courses involving main trunks of superior mesenteric artery (SMA) and superior mesenteric vein (SMV) in seven cases, with or without distortion of their tributaries. Normal course of SMA but abnormal course of SMV was seen in the other two cases. Of all the nine cases, whirl sign was seen in six cases and barber's pole sign in five cases. Dilated SMV was observed in eight cases and abrupt termination of SMA was found in one case. Compared with surgical findings, the location, direction and degree of SBV were correctly estimated in all cases based on CTA/CTPV. Conclusion: Multiphasic MDCT with CTA/CTPV reconstruction can play an important role in the diagnosis of SBV. The location, direction and degree of SBV can all be defined preoperatively using this method.

  14. Convex Relaxation of OPF in Multiphase Radial Networks with Wye and Delta Connections

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Changhong [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Dall-Anese, Emiliano [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Low, Steven [California Institute of Technology

    2017-08-01

    This panel presentation focuses on multiphase radial distribution networks with wye and delta connections, and proposes a semidefinite relaxation of the AC optimal power flow (OPF) problem. Two multiphase power flow models are developed to facilitate the integration of delta-connected loads or generation resources in the OPF problem. The first model is referred to as the extended branch flow model (EBFM). The second model leverages a linear relationship between phase-to-ground power injections and delta connections that holds under a balanced voltage approximation (BVA). Based on these models, pertinent OPF problems are formulated and relaxed to semidefinite programs (SDPs). Numerical studies on IEEE test feeders show that the proposed SDP relaxations can be solved efficiently by a generic optimization solver. Numerical evidence also indicates that solving the resultant SDP under BVA is faster than under EBFM. Moreover, both SDP solutions are numerically exact with respect to voltages and branch flows. It is further shown that the SDP solution under BVA has a small optimality gap, and the BVA model is accurate in the sense that it reproduces actual system voltages.

  15. Vega flow assurance system

    Energy Technology Data Exchange (ETDEWEB)

    Larsen, Marit; Munaweera, Sampath

    2010-07-01

    Vega is a gas condensate field located at the west coast of Norway and developed as a tie-in to the Gjoea platform. Operator is Statoil, production startup is estimated to the end of 2010. Flow assurance challenges are high reservoir pressure and temperature, hydrate and wax control, liquid accumulation and monitoring the well/template production rates. The Vega Flow Assurance System (FAS) is a software that supports monitoring and operation of the field. The FAS is based FlowManagerTM designed for real time systems. This is a flexible tool with its own steady state multiphase- and flow assurance models. Due to the long flowlines lines and the dynamic behavior, the multiphase flow simulator OLGA is also integrated in the system. Vega FAS will be used as: - An online monitoring tool - An offline what-if simulation and validation tool - An advisory control system for well production allocation. (Author)

  16. Multiphase Modeling of Secondary Atomization in a Shock Environment

    Science.gov (United States)

    St. Clair, Jeffrey; McGrath, Thomas; Balachandar, Sivaramakrishnan

    2017-06-01

    Understanding and developing accurate modeling strategies for shock-particulate interaction remains a challenging and important topic, with application to energetic materials development, volcanic eruptions, and safety/risk assessment. This work presents computational modeling of compressible multiphase flows with shock-induced droplet atomization. Droplet size has a strong influence on the interphase momentum and heat transfer. A test case is presented that is sensitive to this, requiring the dynamic modeling of the secondary atomization process occurring when the shock impacts the droplets. An Eulerian-Eulerian computational model that treats all phases as compressible, is hyperbolic and satisfies the 2nd Law of Thermodynamics is applied. Four different breakup models are applied to the test case in which a planar shock wave encounters a cloud of water droplets. The numerical results are compared with both experimental and previously-generated modeling results. The effect of the drag relation used is also investigated. The computed results indicate the necessity of using a droplet breakup model for this application, and the relative accuracy of results obtained with the different droplet breakup and drag models is discussed.

  17. Multiphase modeling of channelized pyroclastic density currents and the effect of confinement on mobility and entrainment

    Science.gov (United States)

    Kubo, A. I.; Dufek, J.

    2017-12-01

    Around explosive volcanic centers such as Mount Saint Helens, pyroclastic density currents (PDCs) pose a great risk to life and property. Understanding of the mobility and dynamics of PDCs and other gravity currents is vital to mitigating hazards of future eruptions. Evidence from pyroclastic deposits at Mount Saint Helens and one-dimensional modeling suggest that channelization of flows effectively increases run out distances. Dense flows are thought to scour and erode the bed leading to confinement for subsequent flows and could result in significant changes to predicted runout distance and mobility. Here, we present the results of three-dimensional multiphase models comparing confined and unconfined flows using simplified geometries. We focus on bed stress conditions as a proxy for conditions that could influence subsequent erosion and self-channelization. We also explore the controls on gas entrainment in all scenarios to determine how confinement impacts the particle concentration gradient, granular interactions, and mobility.

  18. Toward a General Theory for Multiphase Turbulence Part I: Development and Gauging of the Model Equations

    Energy Technology Data Exchange (ETDEWEB)

    B. A. Kashiwa; W. B. VanderHeyden

    2000-12-01

    A formalism for developing multiphase turbulence models is introduced by analogy to the phenomenological method used for single-phase turbulence. A sample model developed using the formalism is given in detail. The procedure begins with ensemble averaging of the exact conservation equations, with closure accomplished by using a combination of analytical and experimental results from the literature. The resulting model is applicable to a wide range of common multiphase flows including gas-solid, liquid-solid and gas-liquid (bubbly) flows. The model is positioned for ready extension to three-phase turbulence, or for use in two-phase turbulence in which one phase is accounted for in multiple size classes, representing polydispersivity. The formalism is expected to suggest directions toward a more fundamentally based theory, similar to the way that early work in single-phase turbulence has led to the spectral theory. The approach is unique in that a portion of the total energy decay rate is ascribed to each phase, as is dictated by the exact averaged equations, and results in a transport equation for energy decay rate associated with each phase. What follows is a straightforward definition of a turbulent viscosity for each phase, and accounts for the effect of exchange of fluctuational energy among phases on the turbulent shear viscosity. The model also accounts for the effect of slip momentum transfer among the phases on the production of turbulence kinetic energy and on the tensor character of the Reynolds stress. Collisional effects, when appropriate, are included by superposition. The model reduces to a standard form in limit of a single, pure material, and is expected to do a credible job of describing multiphase turbulent flows in a wide variety of regimes using a single set of coefficients.

  19. THE MULTIPHASE STRUCTURE AND POWER SOURCES OF GALACTIC WINDS IN MAJOR MERGERS

    International Nuclear Information System (INIS)

    Rupke, David S. N.; Veilleux, Sylvain

    2013-01-01

    Massive, galaxy-scale outflows are known to be ubiquitous in major mergers of disk galaxies in the local universe. In this paper, we explore the multiphase structure and power sources of galactic winds in six ultraluminous infrared galaxies (ULIRGs) at z –1 , and the highest velocities (2000-3000 km s –1 ) are seen only in ionized gas. The outflow energy and momentum in the QSOs are difficult to produce from a starburst alone, but are consistent with the QSO contributing significantly to the driving of the flow. Finally, when all gas phases are accounted for, the outflows are massive enough to provide negative feedback to star formation.

  20. DESIGN AND DEVELOPMENT OF INTEGRATED COMPACT MULTIPHASE SEPARATION SYSTEM (CMSS)

    Energy Technology Data Exchange (ETDEWEB)

    Ram S. Mohan; Ovadia Shoham

    2004-12-31

    The petroleum industry has relied in the past mainly on conventional vessel-type separators, which are bulky, heavy and expensive, to process wellhead production of oil-water-gas flow. Economic and operational pressures continue to force the petroleum industry to seek less expensive and more efficient separation alternatives in the form of compact separators. The compact dimensions, smaller footprint and lower weight of compact separators have a potential for cost savings to the industry, especially in offshore and subsea applications. Also, compact separators reduce the inventory of hydrocarbons significantly, which is critical for environmental and safety considerations. This report presents a brief overview of the activities and tasks accomplished during the part July 09, 2003--October 08, 2004, related to the Budget Period I (July 09, 2003--October 08, 2004) of the DOE project titled ''Design and Development of Integrated Compact Multiphase Separation System (CMSS{copyright})''. An executive summary is presented initially followed by the tasks of the current budget period. Then, detailed description of the experimental and modeling investigations are presented. Subsequently, the technical and scientific results of the activities of this project period are presented with discussions. The findings of this investigation are summarized in the ''Conclusions'' section followed by relevant references. The initial phase of the project (Budget Period I--07/09/2003 to 10/08/2004) focuses on the development of additional individual compact separation components, such as the horizontal pipe separator (HPS{copyright}), for obtaining clean oil stream from oil-water mixture, flow conditioning components, such as the helical pipe (HP) and slug damper (SD{copyright}), for dissipating slugs upstream of the compact separators. The project will also design and test an upstream slug generator (SG).

  1. Flow

    DEFF Research Database (Denmark)

    Knoop, Hans Henrik

    2006-01-01

    FLOW. Orden i hovedet på den fede måde Oplevelsesmæssigt er flow-tilstanden kendetegnet ved at man er fuldstændig involveret, fokuseret og koncentreret; at man oplever stor indre klarhed ved at vide hvad der skal gøres, og i hvilket omfang det lykkes; at man ved at det er muligt at løse opgaven...

  2. Multiphase turbulence mechanisms identification from consistent analysis of direct numerical simulation data

    Directory of Open Access Journals (Sweden)

    Ben Magolan

    2017-09-01

    Full Text Available Direct Numerical Simulation (DNS serves as an irreplaceable tool to probe the complexities of multiphase flow and identify turbulent mechanisms that elude conventional experimental measurement techniques. The insights unlocked via its careful analysis can be used to guide the formulation and development of turbulence models used in multiphase computational fluid dynamics simulations of nuclear reactor applications. Here, we perform statistical analyses of DNS bubbly flow data generated by Bolotnov (Reτ = 400 and Lu–Tryggvason (Reτ = 150, examining single-point statistics of mean and turbulent liquid properties, turbulent kinetic energy budgets, and two-point correlations in space and time. Deformability of the bubble interface is shown to have a dramatic impact on the liquid turbulent stresses and energy budgets. A reduction in temporal and spatial correlations for the streamwise turbulent stress (uu is also observed at wall-normal distances of y+ = 15, y/δ = 0.5, and y/δ = 1.0. These observations motivate the need for adaptation of length and time scales for bubble-induced turbulence models and serve as guidelines for future analyses of DNS bubbly flow data.

  3. Uncertainty Quantification of Multi-Phase Closures

    Energy Technology Data Exchange (ETDEWEB)

    Nadiga, Balasubramanya T. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Baglietto, Emilio [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

    2017-10-27

    In the ensemble-averaged dispersed phase formulation used for CFD of multiphase ows in nuclear reactor thermohydraulics, closures of interphase transfer of mass, momentum, and energy constitute, by far, the biggest source of error and uncertainty. Reliable estimators of this source of error and uncertainty are currently non-existent. Here, we report on how modern Validation and Uncertainty Quanti cation (VUQ) techniques can be leveraged to not only quantify such errors and uncertainties, but also to uncover (unintended) interactions between closures of di erent phenomena. As such this approach serves as a valuable aide in the research and development of multiphase closures. The joint modeling of lift, drag, wall lubrication, and turbulent dispersion|forces that lead to tranfer of momentum between the liquid and gas phases|is examined in the frame- work of validation of the adiabatic but turbulent experiments of Liu and Banko , 1993. An extensive calibration study is undertaken with a popular combination of closure relations and the popular k-ϵ turbulence model in a Bayesian framework. When a wide range of super cial liquid and gas velocities and void fractions is considered, it is found that this set of closures can be validated against the experimental data only by allowing large variations in the coe cients associated with the closures. We argue that such an extent of variation is a measure of uncertainty induced by the chosen set of closures. We also nd that while mean uid velocity and void fraction pro les are properly t, uctuating uid velocity may or may not be properly t. This aspect needs to be investigated further. The popular set of closures considered contains ad-hoc components and are undesirable from a predictive modeling point of view. Consequently, we next consider improvements that are being developed by the MIT group under CASL and which remove the ad-hoc elements. We use non-intrusive methodologies for sensitivity analysis and calibration (using

  4. Investigation on the Use of a Multiphase Eulerian CFD solver to simulate breaking waves

    DEFF Research Database (Denmark)

    Tomaselli, Pietro D.; Christensen, Erik Damgaard

    2015-01-01

    The main challenge in CFD multiphase simulations of breaking waves is the wide range of interfacial length scales occurring in the flow: from the free surface measurable in meters down to the entrapped air bubbles with size of a fraction of a millimeter. This paper presents a preliminary...... investigation on a CFD model capable of handling this problem. The model is based on a solver, available in the open-source CFD toolkit OpenFOAM, which combines the Eulerian multi-fluid approach for dispersed flows with a numerical interface sharpening method. The solver, enhanced with additional formulations...... for mass and momentum transfer among phases, was satisfactorily tested against an experimental bubble column flow. The model was then used to simulate the propagation of a laboratory solitary breaking wave. The motion of the free surface was successfully reproduced up to the breaking point. Further...

  5. Circulating fluidized bed hydrodynamics experiments for the multiphase fluid dynamics research consortium (MFDRC).

    Energy Technology Data Exchange (ETDEWEB)

    Oelfke, John Barry; Torczynski, John Robert; O' Hern, Timothy John; Tortora, Paul Richard; Bhusarapu, Satish (; ); Trujillo, Steven Mathew

    2006-08-01

    An experimental program was conducted to study the multiphase gas-solid flow in a pilot-scale circulating fluidized bed (CFB). This report describes the CFB experimental facility assembled for this program, the diagnostics developed and/or applied to make measurements in the riser section of the CFB, and the data acquired for several different flow conditions. Primary data acquired included pressures around the flow loop and solids loadings at selected locations in the riser. Tomographic techniques using gamma radiation and electrical capacitance were used to determine radial profiles of solids volume fraction in the riser, and axial profiles of the integrated solids volume fraction were produced. Computer Aided Radioactive Particle Tracking was used to measure solids velocities, fluxes, and residence time distributions. In addition, a series of computational fluid dynamics simulations was performed using the commercial code Arenaflow{trademark}.

  6. Numerical methods for multiphysics, multiphase, and multicomponent models for fuel cells

    Science.gov (United States)

    Xue, Guangri

    In this dissertation, we design and analyze efficient numerical methods for obtaining accurate solutions to model problems arising in fuel cells. A basic fuel cell model consists of five principles of conservation, namely, mass, momentum, species, charges (electrons and ions), and thermal energy. Overall, transport equations couple with electrochemical processes through source terms to describe reaction kinetics and electro-osmotic drag in the polymer electrolyte. To model multiphase species transport in the porous media and the gas channel of fuel cells, we consider a multiphase mixture model framework. The diffusivity of the two-phase mixture water conservation equation in this model is nonlinear, discontinuous, and degenerate. To handle this difficulty, we developed efficient and fast nonlinear iterative solvers based on the Kirchhoff transformation and nonlinear Dirichlet-Neumann domain decomposition methods. To model the coupling between the multiphase flow in the porous media and the viscous flow in the gas channel of fuel cells, we consider the Darcy-Stokes-Brinkman model, which treats both the Darcy equation and the Stokes equation in a single form of partial differential equation (PDE) but with strongly discontinuous viscosity and permeability coefficients. For this model, we develop robust finite element methods that are uniformly stable with respect to the highly discontinuous coefficients and their jumps. Finally, we develop new numerical methods for the full steady-state 3D multi-physics simulation of liquid-feed direct methanol fuel cells (DMFC), consisting of five fundamental conservation equations: mass, momentum, species, charges, and thermal energy. Fast convergence of nonlinear iteration is achieved in our method.

  7. Are cosmological gas accretion streams multiphase and turbulent?

    Science.gov (United States)

    Cornuault, Nicolas; Lehnert, Matthew D.; Boulanger, François; Guillard, Pierre

    2018-03-01

    Simulations of cosmological filamentary accretion reveal flows ("streams") of warm gas, T 104 K, which bring gas into galaxies efficiently. We present a phenomenological scenario in which gas in such flows, if it is shocked as it enters the halo as we assume and depending on the post-shock temperature, stream radius, its relative overdensity, and other factors, becomes biphasic and turbulent. We consider a collimated stream of warm gas that flows into a halo from an overdense filament of the cosmic web. The post-shock streaming gas expands because it has a higher pressure than the ambient halo gas and fragments as it cools. The fragmented stream forms a two phase medium: a warm cloudy phase embedded in hot post-shock gas. We argue that the hot phase sustains the accretion shock. During fragmentation, a fraction of the initial kinetic energy of the infalling gas is converted into turbulence among and within the warm clouds. The thermodynamic evolution of the post-shock gas is largely determined by the relative timescales of several processes. These competing timescales characterize the cooling, expansion of the post-shock gas, amount of turbulence in the clouds, and dynamical time of the halo. We expect the gas to become multiphase when the gas cooling and dynamical times are of the same order of magnitude. In this framework, we show that this mainly occurs in the mass range, Mhalo 1011 to 1013 M⊙, where the bulk of stars have formed in galaxies. Because of the expansion of the stream and turbulence, gas accreting along cosmic web filaments may eventually lose coherence and mix with the ambient halo gas. Through both the phase separation and "disruption" of the stream, the accretion efficiency onto a galaxy in a halo dynamical time is lowered. Decollimating flows make the direct interaction between galaxy feedback and accretion streams more likely, thereby further reducing the overall accretion efficiency. As we discuss in this work, moderating the gas accretion

  8. Grain transport mechanics in shallow flow

    Science.gov (United States)

    A physical model based on continuum multiphase flow is described to represent saltating transport of grains in shallow overland flows. The two-phase continuum flow of water and sediment considers coupled St.Venant type equations. The interactive cumulative effect of grains is incorporated by a dispe...

  9. Grain transport mechanics in shallow overland flow

    Science.gov (United States)

    A physical model based on continuum multiphase flow is described to represent saltating transport of grains in shallow overland flow. The two phase continuum flow of water and sediment considers coupled St.Venant type equations. The interactive cumulative effect of grains is incorporated by a disper...

  10. Multi-phase volcanic resurfacing at Loki Patera on Io.

    Science.gov (United States)

    de Kleer, K; Skrutskie, M; Leisenring, J; Davies, A G; Conrad, A; de Pater, I; Resnick, A; Bailey, V; Defrère, D; Hinz, P; Skemer, A; Spalding, E; Vaz, A; Veillet, C; Woodward, C E

    2017-05-10

    The Jovian moon Io hosts the most powerful persistently active volcano in the Solar System, Loki Patera. The interior of this volcanic, caldera-like feature is composed of a warm, dark floor covering 21,500 square kilometres surrounding a much cooler central 'island'. The temperature gradient seen across areas of the patera indicates a systematic resurfacing process, which has been seen to occur typically every one to three years since the 1980s. Analysis of past data has indicated that the resurfacing progressed around the patera in an anti-clockwise direction at a rate of one to two kilometres per day, and that it is caused either by episodic eruptions that emplace voluminous lava flows or by a cyclically overturning lava lake contained within the patera. However, spacecraft and telescope observations have been unable to map the emission from the entire patera floor at sufficient spatial resolution to establish the physical processes at play. Here we report temperature and lava cooling age maps of the entire patera floor at a spatial sampling of about two kilometres, derived from ground-based interferometric imaging of thermal emission from Loki Patera obtained on 8 March 2015 ut as the limb of Europa occulted Io. Our results indicate that Loki Patera is resurfaced by a multi-phase process in which two waves propagate and converge around the central island. The different velocities and start times of the waves indicate a non-uniformity in the lava gas content and/or crust bulk density across the patera.

  11. A mechanistic model of heat transfer for gas-liquid flow in vertical wellbore annuli.

    Science.gov (United States)

    Yin, Bang-Tang; Li, Xiang-Fang; Liu, Gang

    2018-01-01

    The most prominent aspect of multiphase flow is the variation in the physical distribution of the phases in the flow conduit known as the flow pattern. Several different flow patterns can exist under different flow conditions which have significant effects on liquid holdup, pressure gradient and heat transfer. Gas-liquid two-phase flow in an annulus can be found in a variety of practical situations. In high rate oil and gas production, it may be beneficial to flow fluids vertically through the annulus configuration between well tubing and casing. The flow patterns in annuli are different from pipe flow. There are both casing and tubing liquid films in slug flow and annular flow in the annulus. Multiphase heat transfer depends on the hydrodynamic behavior of the flow. There are very limited research results that can be found in the open literature for multiphase heat transfer in wellbore annuli. A mechanistic model of multiphase heat transfer is developed for different flow patterns of upward gas-liquid flow in vertical annuli. The required local flow parameters are predicted by use of the hydraulic model of steady-state multiphase flow in wellbore annuli recently developed by Yin et al. The modified heat-transfer model for single gas or liquid flow is verified by comparison with Manabe's experimental results. For different flow patterns, it is compared with modified unified Zhang et al. model based on representative diameters.

  12. Two-phase flow measurement based on oblique laser scattering

    Science.gov (United States)

    Vendruscolo, Tiago P.; Fischer, Robert; Martelli, Cícero; Rodrigues, Rômulo L. P.; Morales, Rigoberto E. M.; da Silva, Marco J.

    2015-07-01

    Multiphase flow measurements play a crucial role in monitoring productions processes in many industries. To guarantee the safety of processes involving multiphase flows, it is important to detect changes in the flow conditions before they can cause damage, often in fractions of seconds. Here we demonstrate how the scattering pattern of a laser beam passing a two-phase flow under an oblique angle to the flow direction can be used to detect derivations from the desired flow conditions in microseconds. Applying machine-learning techniques to signals obtained from three photo-detectors we achieve a compact, versatile, low-cost sensor design for safety applications.

  13. Neutron diffraction texture analysis of multi-phase systems

    International Nuclear Information System (INIS)

    Brokmeier, H.G.

    1989-01-01

    Neutron diffraction methods for texture analysis are closely parallel to well-known X-ray diffraction techniques. The chief advantage of neutron diffraction over X-ray diffraction, however, arises from the fact that the interaction of neutrons with matter is relatively weak, and consequently the penetration depth of neutrons is 10 2 -10 3 times larger than that of X-rays. Hence neutron diffraction is an efficient tool for measuring textures in multi-phase systems. Based on the high transmission of a neutron beam the effect of anisotropic absorption in multi-phase materials can be neglected in most cases. Moreover, the analysis of bulk textures becomes possible, such that textures in a wide variety of multi-phase systems can be studied which are of special interest in engineering and science (metals, alloys, composites, ceramics and geological specimens). (orig.)

  14. Attenuation of seismic waves in rocks saturated with multiphase fluids: theory and experiments

    Science.gov (United States)

    Tisato, N.; Quintal, B.; Chapman, S.; Podladchikov, Y.; Burg, J. P.

    2016-12-01

    Albeit seismic tomography could provide a detailed image of subsurface fluid distribution, the interpretation of the tomographic signals is often controversial and fails in providing a conclusive map of the subsurface saturation. However, tomographic information is important because the upward migration of multiphase fluids through the crust of the Earth can cause hazardous events such as eruptions, explosions, soil-pollution and earthquakes. In addition, multiphase fluids, such as hydrocarbons, represent important resources for economy. Seismic tomography can be improved considering complex elastic moduli and the attenuation of seismic waves (1/Q) that quantifies the energy lost by propagating elastic waves. In particular, a significant portion of the energy carried by the propagating wave is dissipated in saturated media by the wave-induced-fluid-flow (WIFF) and the wave-induced-gas-exsolution-dissolution (WIGED) mechanism. The latter describes how a propagating wave modifies the thermodynamic equilibrium between different fluid phases causing exsolution and dissolution of gas bubbles in the liquid, which in turn causes a significant frequency-dependent 1/Q and moduli dispersion. The WIGED theory was initially postulated for bubbly magmas but was only recently demonstrated and extended to bubbly water. We report the theory and laboratory experiments that have been performed to confirm the WIGED theory. In particular, we present i) attenuation measurements performed by means of the Broad Band Attenuation Vessel on porous media saturated with water and different gases, and ii) numerical experiments validating the laboratory observations. Then, we extend the theory to fluids and pressure-temperature conditions which are typical of phreatomagmatic and hydrocarbon domains and we compare the propagation of seismic waves in bubble-free and bubble-bearing subsurface domains. This work etends the knowledge of attenuation in rocks saturated with multiphase fluid and

  15. Multiphase Return Trajectory Optimization Based on Hybrid Algorithm

    Directory of Open Access Journals (Sweden)

    Yi Yang

    2016-01-01

    Full Text Available A hybrid trajectory optimization method consisting of Gauss pseudospectral method (GPM and natural computation algorithm has been developed and utilized to solve multiphase return trajectory optimization problem, where a phase is defined as a subinterval in which the right-hand side of the differential equation is continuous. GPM converts the optimal control problem to a nonlinear programming problem (NLP, which helps to improve calculation accuracy and speed of natural computation algorithm. Through numerical simulations, it is found that the multiphase optimal control problem could be solved perfectly.

  16. Catastrophic glacial multi-phase mass movements: a special type of glacial hazard

    Directory of Open Access Journals (Sweden)

    D. A. Petrakov

    2008-04-01

    Full Text Available Many glacier-related hazards are well typified and studied, but some events stand out from conventional classifications. The Kolka-Karmadon catastrophic event on 20 September 2002 in North Ossetia, North Caucasus, Russia is used as an example of a complex glacier failure exhibiting characteristics such as high mobility, long runout, ultrarapid movement and multiphase behaviour. We consider terminology protocol for glacier hazard classification and then, using the Kolka-Karmadon event and several other examples from around the world, we propose a new term for this family of events. Catastrophic glacier multi-phase mass movement (CGMM is described and further illustrated by eight major events from Russia, Georgia, Peru, Chile, and Canada. CGMM have a combination of specific features: extraordinary velocities and long-distance runout despite low path angle; progressive fluidisation along travel path; superelevation and run-up of the moving mass, air blast wave in the avalanche flow phase; entrainment of available materials in its path, and the repeated nature of the event. CGMM events may affect areas remote from glaciers which were previously considered as safe.

  17. Catastrophic glacial multi-phase mass movements: a special type of glacial hazard

    Science.gov (United States)

    Petrakov, D. A.; Chernomorets, S. S.; Evans, S. G.; Tutubalina, O. V.

    2008-04-01

    Many glacier-related hazards are well typified and studied, but some events stand out from conventional classifications. The Kolka-Karmadon catastrophic event on 20 September 2002 in North Ossetia, North Caucasus, Russia is used as an example of a complex glacier failure exhibiting characteristics such as high mobility, long runout, ultrarapid movement and multiphase behaviour. We consider terminology protocol for glacier hazard classification and then, using the Kolka-Karmadon event and several other examples from around the world, we propose a new term for this family of events. Catastrophic glacier multi-phase mass movement (CGMM) is described and further illustrated by eight major events from Russia, Georgia, Peru, Chile, and Canada. CGMM have a combination of specific features: extraordinary velocities and long-distance runout despite low path angle; progressive fluidisation along travel path; superelevation and run-up of the moving mass, air blast wave in the avalanche flow phase; entrainment of available materials in its path, and the repeated nature of the event. CGMM events may affect areas remote from glaciers which were previously considered as safe.

  18. Multiscale mechanics of TRIP-assisted multiphase steels: I. Characterization and mechanical testing

    International Nuclear Information System (INIS)

    Jacques, P.J.; Furnemont, Q.; Lani, F.; Pardoen, T.; Delannay, F.

    2007-01-01

    The mechanical behaviour of transformation-induced plasticity (TRIP)-assisted multiphase steels is addressed based on three different microstructures generated from the same steel grade. The mechanisms responsible for the work-hardening capacity and the resulting balance between strength and resistance to plastic localization are investigated at different length scales. The macroscopic mechanical response is determined by simple shear, uniaxial tension, Marciniak and equibiaxial tension supplemented by earlier tensile tests on notched and cracked specimens. It is shown that the transformation rate reaches a maximum for stress states intermediate between uniaxial tension and equibiaxial tension. At an intermediate length scale, the true in situ flow properties of the individual ferrite-bainite and retained austenite phases are determined by combining neutron diffraction and digital image correlation. This combined analysis elucidates the partitioning of stress and strain between the different constitutive phases. Based on these results, supplemented by transmission electron microscopy and electron backscattered diffraction observations, a general overview of the hardening behaviour of TRIP-assisted multiphase steels is depicted

  19. Plasmas in Multiphase Media: Bubble Enhanced Discharges in Liquids and Plasma/Liquid Phase Boundaries

    Energy Technology Data Exchange (ETDEWEB)

    Kushner, Mark Jay [University of Michigan

    2014-07-10

    In this research project, the interaction of atmospheric pressure plasmas with multi-phase media was computationally investigated. Multi-phase media includes liquids, particles, complex materials and porous surfaces. Although this investigation addressed fundamental plasma transport and chemical processes, the outcomes directly and beneficially affected applications including biotechnology, medicine and environmental remediation (e.g., water purification). During this project, we made advances in our understanding of the interaction of atmospheric pressure plasmas in the form of dielectric barrier discharges and plasma jets with organic materials and liquids. We also made advances in our ability to use computer modeling to represent these complex processes. We determined the method that atmospheric pressure plasmas flow along solid and liquid surfaces, and through endoscopic like tubes, deliver optical and high energy ion activation energy to organic and liquid surfaces, and produce reactivity in thin liquid layers, as might cover a wound. We determined the mechanisms whereby plasmas can deliver activation energy to the inside of liquids by sustaining plasmas in bubbles. These findings are important to the advancement of new technology areas such as plasma medicine

  20. Application of numerical grid generation for improved CFD analysis of multiphase screw machines

    Science.gov (United States)

    Rane, S.; Kovačević, A.

    2017-08-01

    Algebraic grid generation is widely used for discretization of the working domain of twin screw machines. Algebraic grid generation is fast and has good control over the placement of grid nodes. However, the desired qualities of grid which should be able to handle multiphase flows such as oil injection, may be difficult to achieve at times. In order to obtain fast solution of multiphase screw machines, it is important to further improve the quality and robustness of the computational grid. In this paper, a deforming grid of a twin screw machine is generated using algebraic transfinite interpolation to produce initial mesh upon which an elliptic partial differential equations (PDE) of the Poisson’s form is solved numerically to produce smooth final computational mesh. The quality of numerical cells and their distribution obtained by the differential method is greatly improved. In addition, a similar procedure was introduced to fully smoothen the transition of the partitioning rack curve between the rotors thus improving continuous movement of grid nodes and in turn improve robustness and speed of the Computational Fluid Dynamic (CFD) solver. Analysis of an oil injected twin screw compressor is presented to compare the improvements in grid quality factors in the regions of importance such as interlobe space, radial tip and the core of the rotor. The proposed method that combines algebraic and differential grid generation offer significant improvement in grid quality and robustness of numerical solution.

  1. Development and Research of Peristaltic Multiphase Piezoelectric Micro-Pump

    Science.gov (United States)

    Vinogradov, Alexander N.; Ivanikin, Igor A.; Lubchenco, Roman V.; Matveev, Yegor V.; Titov, Pavel A.

    2016-01-01

    The paper presents the results of a study of existing models and mathematical representations of a range of truly peristaltic multiphase micro-pumps with a piezoelectric actuator (piezo drive). Piezo drives with different types of substrates use vertical movements at deformation of individual piezoelectric elements, which define device…

  2. Multi-phase alternative current machine winding design | Khan ...

    African Journals Online (AJOL)

    ... single-phase to 18-phase excitation. Experimental results of a five-phase induction machine supplied from a static five-phase supply are provided to support the proposed design. Keywords: AC machine, Multi-phase machine, Stator winding, Five-phase. International Journal of Engineering, Science and Technology, Vol.

  3. Analysis of hygral induced crack growth in multiphase materials

    NARCIS (Netherlands)

    Sadouki, H.; Van Mier, J.G.M.

    1996-01-01

    In this paper a numerical model for simulating crack growth processes caused by moisture movement in a porous multiphase material like concrete is proposed. In the model, the material is schematized as a regular triangular network of beam elements. The meso-material structure of the material is

  4. Minnesota Multiphasic Personality Inventory Profiles Among Subgroups of Unwed Mothers