Extension of Generalized Fluid System Simulation Program's Fluid Property Database
Patel, Kishan
2011-01-01
This internship focused on the development of additional capabilities for the General Fluid Systems Simulation Program (GFSSP). GFSSP is a thermo-fluid code used to evaluate system performance by a finite volume-based network analysis method. The program was developed primarily to analyze the complex internal flow of propulsion systems and is capable of solving many problems related to thermodynamics and fluid mechanics. GFSSP is integrated with thermodynamic programs that provide fluid properties for sub-cooled, superheated, and saturation states. For fluids that are not included in the thermodynamic property program, look-up property tables can be provided. The look-up property tables of the current release version can only handle sub-cooled and superheated states. The primary purpose of the internship was to extend the look-up tables to handle saturated states. This involves a) generation of a property table using REFPROP, a thermodynamic property program that is widely used, and b) modifications of the Fortran source code to read in an additional property table containing saturation data for both saturated liquid and saturated vapor states. Also, a method was implemented to calculate the thermodynamic properties of user-fluids within the saturation region, given values of pressure and enthalpy. These additions required new code to be written, and older code had to be adjusted to accommodate the new capabilities. Ultimately, the changes will lead to the incorporation of this new capability in future versions of GFSSP. This paper describes the development and validation of the new capability.
Majumdar, Alok; Leclair, Andre; Moore, Ric; Schallhorn, Paul
2011-01-01
GFSSP stands for Generalized Fluid System Simulation Program. It is a general-purpose computer program to compute pressure, temperature and flow distribution in a flow network. GFSSP calculates pressure, temperature, and concentrations at nodes and calculates flow rates through branches. It was primarily developed to analyze Internal Flow Analysis of a Turbopump Transient Flow Analysis of a Propulsion System. GFSSP development started in 1994 with an objective to provide a generalized and easy to use flow analysis tool for thermo-fluid systems.
Generalized Fluid System Simulation Program (GFSSP) - Version 6
Majumdar, Alok; LeClair, Andre; Moore, Ric; Schallhorn, Paul
2015-01-01
The Generalized Fluid System Simulation Program (GFSSP) is a finite-volume based general-purpose computer program for analyzing steady state and time-dependent flow rates, pressures, temperatures, and concentrations in a complex flow network. The program is capable of modeling real fluids with phase changes, compressibility, mixture thermodynamics, conjugate heat transfer between solid and fluid, fluid transients, pumps, compressors, flow control valves and external body forces such as gravity and centrifugal. The thermo-fluid system to be analyzed is discretized into nodes, branches, and conductors. The scalar properties such as pressure, temperature, and concentrations are calculated at nodes. Mass flow rates and heat transfer rates are computed in branches and conductors. The graphical user interface allows users to build their models using the 'point, drag, and click' method; the users can also run their models and post-process the results in the same environment. The integrated fluid library supplies thermodynamic and thermo-physical properties of 36 fluids, and 24 different resistance/source options are provided for modeling momentum sources or sinks in the branches. Users can introduce new physics, non-linear and time-dependent boundary conditions through user-subroutine.
Generalized Fluid System Simulation Program, Version 5.0-Educational
Majumdar, A. K.
2011-01-01
The Generalized Fluid System Simulation Program (GFSSP) is a finite-volume based general-purpose computer program for analyzing steady state and time-dependent flow rates, pressures, temperatures, and concentrations in a complex flow network. The program is capable of modeling real fluids with phase changes, compressibility, mixture thermodynamics, conjugate heat transfer between solid and fluid, fluid transients, pumps, compressors and external body forces such as gravity and centrifugal. The thermofluid system to be analyzed is discretized into nodes, branches, and conductors. The scalar properties such as pressure, temperature, and concentrations are calculated at nodes. Mass flow rates and heat transfer rates are computed in branches and conductors. The graphical user interface allows users to build their models using the point, drag and click method; the users can also run their models and post-process the results in the same environment. The integrated fluid library supplies thermodynamic and thermo-physical properties of 36 fluids and 21 different resistance/source options are provided for modeling momentum sources or sinks in the branches. This Technical Memorandum illustrates the application and verification of the code through 12 demonstrated example problems.
Generalized Fluid System Simulation Program, Version 6.0
Majumdar, A. K.; LeClair, A. C.; Moore, R.; Schallhorn, P. A.
2016-01-01
The Generalized Fluid System Simulation Program (GFSSP) is a general purpose computer program for analyzing steady state and time-dependent flow rates, pressures, temperatures, and concentrations in a complex flow network. The program is capable of modeling real fluids with phase changes, compressibility, mixture thermodynamics, conjugate heat transfer between solid and fluid, fluid transients, pumps, compressors, and external body forces such as gravity and centrifugal. The thermofluid system to be analyzed is discretized into nodes, branches, and conductors. The scalar properties such as pressure, temperature, and concentrations are calculated at nodes. Mass flow rates and heat transfer rates are computed in branches and conductors. The graphical user interface allows users to build their models using the 'point, drag, and click' method; the users can also run their models and post-process the results in the same environment. Two thermodynamic property programs (GASP/WASP and GASPAK) provide required thermodynamic and thermophysical properties for 36 fluids: helium, methane, neon, nitrogen, carbon monoxide, oxygen, argon, carbon dioxide, fluorine, hydrogen, parahydrogen, water, kerosene (RP-1), isobutene, butane, deuterium, ethane, ethylene, hydrogen sulfide, krypton, propane, xenon, R-11, R-12, R-22, R-32, R-123, R-124, R-125, R-134A, R-152A, nitrogen trifluoride, ammonia, hydrogen peroxide, and air. The program also provides the options of using any incompressible fluid with constant density and viscosity or ideal gas. The users can also supply property tables for fluids that are not in the library. Twenty-four different resistance/source options are provided for modeling momentum sources or sinks in the branches. These options include pipe flow, flow through a restriction, noncircular duct, pipe flow with entrance and/or exit losses, thin sharp orifice, thick orifice, square edge reduction, square edge expansion, rotating annular duct, rotating radial duct
Energy Technology Data Exchange (ETDEWEB)
Thirukkanesh, S. [Eastern University, Department of Mathematics, Chenkalady (Sri Lanka); Ragel, F.C. [Eastern University, Department of Physics, Chenkalady (Sri Lanka); Sharma, Ranjan; Das, Shyam [P.D. Women' s College, Department of Physics, Jalpaiguri (India)
2018-01-15
We present an algorithm to generalize a plethora of well-known solutions to Einstein field equations describing spherically symmetric relativistic fluid spheres by relaxing the pressure isotropy condition on the system. By suitably fixing the model parameters in our formulation, we generate closed-form solutions which may be treated as an anisotropic generalization of a large class of solutions describing isotropic fluid spheres. From the resultant solutions, a particular solution is taken up to show its physical acceptability. Making use of the current estimate of mass and radius of a known pulsar, the effects of anisotropic stress on the gross physical behaviour of a relativistic compact star is also highlighted. (orig.)
Modeling Two-Phase Flow and Vapor Cycles Using the Generalized Fluid System Simulation Program
Smith, Amanda D.; Majumdar, Alok K.
2017-01-01
This work presents three new applications for the general purpose fluid network solver code GFSSP developed at NASA's Marshall Space Flight Center: (1) cooling tower, (2) vapor-compression refrigeration system, and (3) vapor-expansion power generation system. These systems are widely used across engineering disciplines in a variety of energy systems, and these models expand the capabilities and the use of GFSSP to include fluids and features that are not part of its present set of provided examples. GFSSP provides pressure, temperature, and species concentrations at designated locations, or nodes, within a fluid network based on a finite volume formulation of thermodynamics and conservation laws. This paper describes the theoretical basis for the construction of the models, their implementation in the current GFSSP modeling system, and a brief evaluation of the usefulness of the model results, as well as their applicability toward a broader spectrum of analytical problems in both university teaching and engineering research.
Appplication of a general fluid mechanics program to NTP system modeling
International Nuclear Information System (INIS)
Lee, S.K.
1993-01-01
An effort is currently underway at NASA and the Department of Energy (DOE) to develop an accurate model for predicting nuclear thermal propulsion (NTP) system performance. The objective of the effort is to develop several levels of computer programs which vary in detail and complexity according to user's needs. The current focus is on the Level 1 steady-state, parametric system model. This system model will combine a general fluid mechanics program, SAFSIM, with the ability to analyze turbines, pumps, nozzles, and reactor physics. SAFSIM (System Analysis Flow SIMulator) is a FORTRAN computer program that simulates integrated performance of systems involving fluid mechanics, heat transfer, and reactor dynamics. SAFSIM has the versatility to allow simulation of almost any system, including a nuclear reactor system. The focus of this paper is the validation of SAFSIM's capabilities as a base computational engine for a nuclear thermal propulsion system model. Validation is being accomplished by modeling of a nuclear engine test using SAFSIM and comparing the results to known experimental data
A Novel Approach for Modeling Chemical Reaction in Generalized Fluid System Simulation Program
Sozen, Mehmet; Majumdar, Alok
2002-01-01
The Generalized Fluid System Simulation Program (GFSSP) is a computer code developed at NASA Marshall Space Flight Center for analyzing steady state and transient flow rates, pressures, temperatures, and concentrations in a complex flow network. The code, which performs system level simulation, can handle compressible and incompressible flows as well as phase change and mixture thermodynamics. Thermodynamic and thermophysical property programs, GASP, WASP and GASPAK provide the necessary data for fluids such as helium, methane, neon, nitrogen, carbon monoxide, oxygen, argon, carbon dioxide, fluorine, hydrogen, water, a hydrogen, isobutane, butane, deuterium, ethane, ethylene, hydrogen sulfide, krypton, propane, xenon, several refrigerants, nitrogen trifluoride and ammonia. The program which was developed out of need for an easy to use system level simulation tool for complex flow networks, has been used for the following purposes to name a few: Space Shuttle Main Engine (SSME) High Pressure Oxidizer Turbopump Secondary Flow Circuits, Axial Thrust Balance of the Fastrac Engine Turbopump, Pressurized Propellant Feed System for the Propulsion Test Article at Stennis Space Center, X-34 Main Propulsion System, X-33 Reaction Control System and Thermal Protection System, and International Space Station Environmental Control and Life Support System design. There has been an increasing demand for implementing a combustion simulation capability into GFSSP in order to increase its system level simulation capability of a liquid rocket propulsion system starting from the propellant tanks up to the thruster nozzle for spacecraft as well as launch vehicles. The present work was undertaken for addressing this need. The chemical equilibrium equations derived from the second law of thermodynamics and the energy conservation equation derived from the first law of thermodynamics are solved simultaneously by a Newton-Raphson method. The numerical scheme was implemented as a User
Compressible generalized Newtonian fluids
Czech Academy of Sciences Publication Activity Database
Málek, Josef; Rajagopal, K.R.
2010-01-01
Roč. 61, č. 6 (2010), s. 1097-1110 ISSN 0044-2275 Institutional research plan: CEZ:AV0Z20760514 Keywords : power law fluid * uniform temperature * compressible fluid Subject RIV: BJ - Thermodynamics Impact factor: 1.290, year: 2010
Spinning fluids in general relativity
Ray, J. R.; Smalley, L. L.
1982-01-01
General relativity field equations are employed to examine a continuous medium with internal spin. A variational principle formerly applied in the special relativity case is extended to the general relativity case, using a tetrad to express the spin density and the four-velocity of the fluid. An energy-momentum tensor is subsequently defined for a spinning fluid. The equations of motion of the fluid are suggested to be useful in analytical studies of galaxies, for anisotropic Bianchi universes, and for turbulent eddies.
Majumdar, A. K.; Hedayat, A.
2015-01-01
This paper describes the experience of the authors in using the Generalized Fluid System Simulation Program (GFSSP) in teaching Design of Thermal Systems class at University of Alabama in Huntsville. GFSSP is a finite volume based thermo-fluid system network analysis code, developed at NASA/Marshall Space Flight Center, and is extensively used in NASA, Department of Defense, and aerospace industries for propulsion system design, analysis, and performance evaluation. The educational version of GFSSP is freely available to all US higher education institutions. The main purpose of the paper is to illustrate the utilization of this user-friendly code for the thermal systems design and fluid engineering courses and to encourage the instructors to utilize the code for the class assignments as well as senior design projects.
Majumdar, A. K.
2011-01-01
The Generalized Fluid System Simulation Program (GFSSP) is a finite-volume based general-purpose computer program for analyzing steady state and time-dependent flow rates, pressures, temperatures, and concentrations in a complex flow network. The program is capable of modeling real fluids with phase changes, compressibility, mixture thermodynamics, conjugate heat transfer between solid and fluid, fluid transients, pumps, compressors and external body forces such as gravity and centrifugal. The thermofluid system to be analyzed is discretized into nodes, branches, and conductors. The scalar properties such as pressure, temperature, and concentrations are calculated at nodes. Mass flow rates and heat transfer rates are computed in branches and conductors. The graphical user interface allows users to build their models using the point, drag and click method; the users can also run their models and post-process the results in the same environment. The integrated fluid library supplies thermodynamic and thermo-physical properties of 36 fluids and 21 different resistance/source options are provided for modeling momentum sources or sinks in the branches. This Technical Memorandum illustrates the application and verification of the code through 12 demonstrated example problems. This supplement gives the input and output data files for the examples.
Majumdar, A. K.; Hedayat, A.
2015-01-01
This paper describes the experience of the authors in using the Generalized Fluid System Simulation Program (GFSSP) in teaching Design of Thermal Systems class at University of Alabama in Huntsville. GFSSP is a finite volume based thermo-fluid system network analysis code, developed at NASA/Marshall Space Flight Center, and is extensively used in NASA, Department of Defense, and aerospace industries for propulsion system design, analysis, and performance evaluation. The educational version of GFSSP is freely available to all US higher education institutions. The main purpose of the paper is to illustrate the utilization of this user-friendly code for the thermal systems design and fluid engineering courses and to encourage the instructors to utilize the code for the class assignments as well as senior design projects. The need for a generalized computer program for thermofluid analysis in a flow network has been felt for a long time in aerospace industries. Designers of thermofluid systems often need to know pressures, temperatures, flow rates, concentrations, and heat transfer rates at different parts of a flow circuit for steady state or transient conditions. Such applications occur in propulsion systems for tank pressurization, internal flow analysis of rocket engine turbopumps, chilldown of cryogenic tanks and transfer lines, and many other applications of gas-liquid systems involving fluid transients and conjugate heat and mass transfer. Computer resource requirements to perform time-dependent, three-dimensional Navier-Stokes computational fluid dynamic (CFD) analysis of such systems are prohibitive and therefore are not practical. Available commercial codes are generally suitable for steady state, single-phase incompressible flow. Because of the proprietary nature of such codes, it is not possible to extend their capability to satisfy the above-mentioned needs. Therefore, the Generalized Fluid System Simulation Program (GFSSP1) has been developed at NASA
International Nuclear Information System (INIS)
Farquhar, N.G.; Schwab, J.A.
1977-01-01
A system of heat exchangers is disclosed for cooling process fluids. The system is particularly applicable to cooling steam generator blowdown fluid in a nuclear plant prior to chemical purification of the fluid in which it minimizes the potential of boiling of the plant cooling water which cools the blowdown fluid
Generating perfect fluid spheres in general relativity
Boonserm, Petarpa; Visser, Matt; Weinfurtner, Silke
2005-06-01
Ever since Karl Schwarzschild’s 1916 discovery of the spacetime geometry describing the interior of a particular idealized general relativistic star—a static spherically symmetric blob of fluid with position-independent density—the general relativity community has continued to devote considerable time and energy to understanding the general-relativistic static perfect fluid sphere. Over the last 90 years a tangle of specific perfect fluid spheres has been discovered, with most of these specific examples seemingly independent from each other. To bring some order to this collection, in this article we develop several new transformation theorems that map perfect fluid spheres into perfect fluid spheres. These transformation theorems sometimes lead to unexpected connections between previously known perfect fluid spheres, sometimes lead to new previously unknown perfect fluid spheres, and in general can be used to develop a systematic way of classifying the set of all perfect fluid spheres.
Generating perfect fluid spheres in general relativity
International Nuclear Information System (INIS)
Boonserm, Petarpa; Visser, Matt; Weinfurtner, Silke
2005-01-01
Ever since Karl Schwarzschild's 1916 discovery of the spacetime geometry describing the interior of a particular idealized general relativistic star--a static spherically symmetric blob of fluid with position-independent density--the general relativity community has continued to devote considerable time and energy to understanding the general-relativistic static perfect fluid sphere. Over the last 90 years a tangle of specific perfect fluid spheres has been discovered, with most of these specific examples seemingly independent from each other. To bring some order to this collection, in this article we develop several new transformation theorems that map perfect fluid spheres into perfect fluid spheres. These transformation theorems sometimes lead to unexpected connections between previously known perfect fluid spheres, sometimes lead to new previously unknown perfect fluid spheres, and in general can be used to develop a systematic way of classifying the set of all perfect fluid spheres
Bandyopadhyay, Alak; Majumdar, Alok
2007-01-01
The present paper describes the verification and validation of a quasi one-dimensional pressure based finite volume algorithm, implemented in Generalized Fluid System Simulation Program (GFSSP), for predicting compressible flow with friction, heat transfer and area change. The numerical predictions were compared with two classical solutions of compressible flow, i.e. Fanno and Rayleigh flow. Fanno flow provides an analytical solution of compressible flow in a long slender pipe where incoming subsonic flow can be choked due to friction. On the other hand, Raleigh flow provides analytical solution of frictionless compressible flow with heat transfer where incoming subsonic flow can be choked at the outlet boundary with heat addition to the control volume. Nonuniform grid distribution improves the accuracy of numerical prediction. A benchmark numerical solution of compressible flow in a converging-diverging nozzle with friction and heat transfer has been developed to verify GFSSP's numerical predictions. The numerical predictions compare favorably in all cases.
International Nuclear Information System (INIS)
Rion, Jacky.
1982-01-01
Fluid flow control system featuring a series of grids placed perpendicular to the fluid flow direction, characterized by the fact that it is formed of a stack of identical and continuous grids, each of which consists of identical meshes forming a flat lattice. The said meshes are offset from one grid to the next. This system applies in particular to flow control of the coolant flowing at the foot of an assembly of a liquid metal cooled nuclear reactor [fr
Zhang, Lucy T; Yang, Jubiao
2016-12-01
In this work we explore the aerodynamics flow characteristics of a coupled fluid-structure interaction system using a generalized Bernoulli equation derived directly from the Cauchy momentum equations. Unlike the conventional Bernoulli equation where incompressible, inviscid, and steady flow conditions are assumed, this generalized Bernoulli equation includes the contributions from compressibility, viscous, and unsteadiness, which could be essential in defining aerodynamic characteristics. The application of the derived Bernoulli's principle is on a fully-coupled fluid-structure interaction simulation of the vocal folds vibration. The coupled system is simulated using the immersed finite element method where compressible Navier-Stokes equations are used to describe the air and an elastic pliable structure to describe the vocal fold. The vibration of the vocal fold works to open and close the glottal flow. The aerodynamics flow characteristics are evaluated using the derived Bernoulli's principles for a vibration cycle in a carefully partitioned control volume based on the moving structure. The results agree very well to experimental observations, which validate the strategy and its use in other types of flow characteristics that involve coupled fluid-structure interactions.
Zhang, Lucy T.; Yang, Jubiao
2017-01-01
In this work we explore the aerodynamics flow characteristics of a coupled fluid-structure interaction system using a generalized Bernoulli equation derived directly from the Cauchy momentum equations. Unlike the conventional Bernoulli equation where incompressible, inviscid, and steady flow conditions are assumed, this generalized Bernoulli equation includes the contributions from compressibility, viscous, and unsteadiness, which could be essential in defining aerodynamic characteristics. The application of the derived Bernoulli’s principle is on a fully-coupled fluid-structure interaction simulation of the vocal folds vibration. The coupled system is simulated using the immersed finite element method where compressible Navier-Stokes equations are used to describe the air and an elastic pliable structure to describe the vocal fold. The vibration of the vocal fold works to open and close the glottal flow. The aerodynamics flow characteristics are evaluated using the derived Bernoulli’s principles for a vibration cycle in a carefully partitioned control volume based on the moving structure. The results agree very well to experimental observations, which validate the strategy and its use in other types of flow characteristics that involve coupled fluid-structure interactions. PMID:29527541
Energy Technology Data Exchange (ETDEWEB)
Koike, H [Fuji Research Institute Corporation, Tokyo (Japan)
1992-08-01
The [alpha]-FLOW is a three-dimensional fluid analyzing software developed from cooperations among research institutes of private business companies and universities in Japan under the assistance from the Ministry of International Trade and Industry. This paper describes its summary and features. The system is a discrete system utilizing a supercomputer and a work station. The analysis modules incorporated in the system include those for non-compressive fluid analysis, compressive fluid analysis, analysis of non-compressive fluid including free surface, analysis of flows including combustion and chemical reactions, substance migration analysis, and heat transfer analysis. It has a feature that even non-specialists can analyze fluids easily as a result of the development of an expert system to support the numerical analysis. Development of the input data preparing system enables to utilize the work station to process from shape modeling to grid generation, and from inputting analyzing condition data to calculating the flows and outputting the calculation result, all in dialogue modes. An open architecture was adopted. 27 refs., 7 figs., 10 tabs.
Energy Technology Data Exchange (ETDEWEB)
McConaghy, C. F. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Gascoyne, P. R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
2017-09-28
The purpose ofthis project was to develop a general-purpose analysis system based on a programmable fluid processor (PFP). The PFP is an array of electrodes surrounded by fluid reservoirs and injectors. Injected droplets of various reagents are manjpulated and combined on the array by Dielectrophoretic (DEP) forces. The goal was to create a small handheld device that could accomplish the tasks currently undertaken by much larger, time consuming, manual manipulation in the lab. The entire effo1t was funded by DARPA under the Bio-Flips program. MD Anderson Cancer Center was the PI for the DARPA effort. The Bio-Flips program was a 3- year program that ran from September 2000 to September 2003. The CRADA was somewhat behind the Bi-Flips program running from June 2001 to June 2004 with a no cost extension to September 2004.
A systems approach to theoretical fluid mechanics: Fundamentals
Anyiwo, J. C.
1978-01-01
A preliminary application of the underlying principles of the investigator's general system theory to the description and analyses of the fluid flow system is presented. An attempt is made to establish practical models, or elements of the general fluid flow system from the point of view of the general system theory fundamental principles. Results obtained are applied to a simple experimental fluid flow system, as test case, with particular emphasis on the understanding of fluid flow instability, transition and turbulence.
Hamiltonian formalism for perfect fluids in general relativity
International Nuclear Information System (INIS)
Demaret, J.; Moncrief, V.
1980-01-01
Schutz's Hamiltonian theory of a relativistic perfect fluid, based on the velocity-potential version of classical perfect fluid hydrodynamics as formulated by Seliger and Whitham, is used to derive, in the framework of the Arnowitt, Deser, and Misner (ADM) method, a general partially reduced Hamiltonian for relativistic systems filled with a perfect fluid. The time coordinate is chosen, as in Lund's treatment of collapsing balls of dust, as minus the only velocity potential different from zero in the case of an irrotational and isentropic fluid. A ''semi-Dirac'' method can be applied to quantize astrophysical and cosmological models in the framework of this partially reduced formalism. If one chooses Taub's adapted comoving coordinate system, it is possible to derive a fully reduced ADM Hamiltonian, which is equal to minus the total baryon number of the fluid, generalizing a result previously obtained by Moncrief in the more particular framework of Taub's variational principle, valid for self-gravitating barotropic relativistic perfect fluids. An unconstrained Hamiltonian density is then explicitly derived for a fluid obeying the equation of state p=(gamma-1)rho (1 < or = γ < or = 2), which can adequately describe the phases of very high density attained in a catastrophic collapse or during the early stages of the Universe. This Hamiltonian density, shown to be equivalent to Moncrief's in the particular case of an isentropic fluid, can be simplified for fluid-filled class-A diagonal Bianchi-type cosmological models and appears as a suitable starting point for the study of the canonical quantization of these models
Generalized Roe's numerical scheme for a two-fluid model
International Nuclear Information System (INIS)
Toumi, I.; Raymond, P.
1993-01-01
This paper is devoted to a mathematical and numerical study of a six equation two-fluid model. We will prove that the model is strictly hyperbolic due to the inclusion of the virtual mass force term in the phasic momentum equations. The two-fluid model is naturally written under a nonconservative form. To solve the nonlinear Riemann problem for this nonconservative hyperbolic system, a generalized Roe's approximate Riemann solver, is used, based on a linearization of the nonconservative terms. A Godunov type numerical scheme is built, using this approximate Riemann solver. 10 refs., 5 figs,
Generalized dark energy interactions with multiple fluids
Energy Technology Data Exchange (ETDEWEB)
De Bruck, Carsten van; Mifsud, Jurgen [Consortium for Fundamental Physics, School of Mathematics and Statistics, University of Sheffield, Hounsfield Road, Sheffield S3 7RH (United Kingdom); Mimoso, José P.; Nunes, Nelson J., E-mail: c.vandebruck@sheffield.ac.uk, E-mail: jmifsud1@sheffield.ac.uk, E-mail: jpmimoso@fc.ul.pt, E-mail: njnunes@fc.ul.pt [Instituto de Astrofísica e Ciências do Espaço, Faculdade de Ciências da Universidade de Lisboa, Campo Grande, PT1749-016 Lisboa (Portugal)
2016-11-01
In the search for an explanation for the current acceleration of the Universe, scalar fields are the most simple and useful tools to build models of dark energy. This field, however, must in principle couple with the rest of the world and not necessarily in the same way to different particles or fluids. We provide the most complete dynamical system analysis to date, consisting of a canonical scalar field conformally and disformally coupled to both dust and radiation. We perform a detailed study of the existence and stability conditions of the systems and comment on constraints imposed on the disformal coupling from Big-Bang Nucleosynthesis and given current limits on the variation of the fine-structure constant.
Supercritical fluids technology. Pt. 1 General topics
International Nuclear Information System (INIS)
Marongiu, B.; De Giorgi, M. R.; Porcedda, S.; Cadoni, E.
1998-01-01
Supercritical fluids technology is among the emerging 'clean' technologies, that allows the minimization in the use of chemical and thermic treatments and products irradiation, diminishing the quantity of liquid wastes to be treated. In this first article phase equilibria thermodynamics and fluid mechanics of transport phenomena are reviewed [it
Green's function for a generalized two-dimensional fluid.
Iwayama, Takahiro; Watanabe, Takeshi
2010-09-01
A Green's function for a generalized two-dimensional (2D) fluid in an unbounded domain (the so-called α turbulence system) is discussed. The generalized 2D fluid is characterized by a relationship between an advected quantity q and the stream function ψ : namely, q=-(-Δ){α/2}ψ . Here, α is a real number and q is referred to as the vorticity. In this study, the Green's function refers to the stream function produced by a delta-functional distribution of q , i.e., a point vortex with unit strength. The Green's function has the form G{(α)}(r)∝r{α-2} , except when α is an even number, where r is the distance from the point vortex. This functional form is known as the Riesz potential. When α is a positive even number, the logarithmic correction to the Riesz potential has the form G(r){(α)}∝r{α-2} ln r . In contrast, when α is a negative even number, G{(α)} is given by the higher-order Laplacian of the delta function. The transition of the small-scale behavior of q at α=2 , a well-known property of forced and dissipative α turbulence, is explained in terms of the Green's function. Moreover, the azimuthal velocity around the point vortex is derived from the Green's function. The functional form of the azimuthal velocity indicates that physically realizable systems for the generalized 2D fluid exist only when α≤3 . The Green's function and physically realizable systems for an anisotropic generalized 2D fluid are presented as an application of the present study.
Acoustic geometry for general relativistic barotropic irrotational fluid flow
International Nuclear Information System (INIS)
Visser, Matt; Molina-ParIs, Carmen
2010-01-01
'Acoustic spacetimes', in which techniques of differential geometry are used to investigate sound propagation in moving fluids, have attracted considerable attention over the last few decades. Most of the models currently considered in the literature are based on non-relativistic barotropic irrotational fluids, defined in a flat Newtonian background. The extension, first to special relativistic barotropic fluid flow and then to general relativistic barotropic fluid flow in an arbitrary background, is less straightforward than it might at first appear. In this paper, we provide a pedagogical and simple derivation of the general relativistic 'acoustic spacetime' in an arbitrary (d+1)-dimensional curved-space background.
Selection of fluids for tritium pumping systems
International Nuclear Information System (INIS)
Chastagner, P.
1984-02-01
The degradation characteristics of three types of vacuum pump fluids, polyphenyl ethers, perfluoropolyethers and hydrocarbon oils were reviewed. Fluid selection proved to be a critical factor in the long-term performance of tritium pumping systems and subsequent tritium recovery operations. Thermal degradation and tritium radiolysis of pump fluids produce contaminants which can damage equipment and interfere with tritium recovery operations. General characteristics of these fluids are as follows: polyphenyl ether has outstanding radiation resistance, is very stable under normal diffusion pump conditions, but breaks down in the presence of oxygen at anticipated operating temperatures. Perfluoropolyether fluids are very stable and do not react chemically with most gases. Thermal and mechanical degradation products are inert, but the radiolysis products are very corrosive. Most of the degradation products of hydrogen oils are volatile and the principal radiolysis product is methane. Our studies show that polyphenyl ethers and hydrocarbon oils are the preferred fluids for use in tritium pumping systems. No corrosive materials are formed and most of the degradation products can be removed with suitable filter systems
Spinning fluids in general relativity: a variational formulation
International Nuclear Information System (INIS)
Oliveira, H.P. de; Salim, J.M.
1990-01-01
In this paper we present a variational formulation for spinning fluids in General Relativity. In our model each volume element of the fluid has rigid microstructure. We deduce a symmetrical energy-moment tensor where there is an explicit contribution of kinetic spin energy to the total energy. (author)
Fluid Temperature of Aero Hydraulic Systems
Directory of Open Access Journals (Sweden)
I. S. Shumilov
2016-01-01
Full Text Available In modern supersonic aircrafts due to aerodynamic skin heating a temperature of hydraulics environment significantly exceeds that of permissible for fluids used. The same problem exists for subsonic passenger aircrafts, especially for Airbuses, which have hydraulics of high power where convective heat transfer with the environment is insufficient and there is no required temperature control of fluid. The most significant in terms of heat flow is the flow caused by the loss of power to the pump and when designing the hydraulic system (HS it is necessary to pay very serious attention to it. To use a constant capacity pump is absolutely unacceptable, since HS efficiency in this case is extremely low, and the most appropriate are variable-capacity pumps, cut-off pumps, dual-mode pumps. The HS fluid cooling system should provide high reliability, lightweight, simple design, and a specified heat transfer in all flight modes.A system cooling the fluid by the fuel of feeding lines of the aircraft engines is the most effective, and it is widely used in supersonic aircrafts, where power of cooling system is essential. Subsonic aircrafts widely use convective heat exchangers. In thermal design of the aircraft hydraulics, the focus is generally given to the maximum and minimum temperatures of the HS fluid, the choice of the type of heat exchanger (convective or flow-through, the place of its installation. In calculating the operating temperature of a hydraulic system and its cooling systems it is necessary to determine an increase of the working fluid temperature when throttling it. There are three possible formulas to calculate the fluid temperature in throttling, with the error of a calculated temperature drop from 30% to 4%.The article considers the HS stationary and noon-stationary operating conditions and their calculation, defines temperatures of fluid and methods to control its specified temperature. It also discusses various heat exchanger schemes
Intraoperative Fluids and Fluid Management for Ambulatory Dental Sedation and General Anesthesia.
Saraghi, Mana
2015-01-01
Intravenous fluids are administered in virtually every parenteral sedation and general anesthetic. The purpose of this article is to review the physiology of body-water distribution and fluid dynamics at the vascular endothelium, evaluation of fluid status, calculation of fluid requirements, and the clinical rationale for the use of various crystalloid and colloid solutions. In the setting of elective dental outpatient procedures with minor blood loss, isotonic balanced crystalloid solutions are the fluids of choice. Colloids, on the other hand, have no use in outpatient sedation or general anesthesia for dental or minor oral surgery procedures but may have several desirable properties in long and invasive maxillofacial surgical procedures where advanced hemodynamic monitoring may assess the adequacy of intravascular volume.
The Hamiltonian structure of general relativistic perfect fluids
International Nuclear Information System (INIS)
Bao, D.; Houston Univ., TX; Marsden, J.; Walton, R.
1985-01-01
We show that the evolution equations for a perfect fluid coupled to general relativity in a general lapse and shift, are Hamiltonian relative to a certain Poisson structure. For the fluid variables, a Lie-Poisson structure associated to the dual of a semi-direct product Lie algebra is used, while the bracket for the gravitational variables has the usual canonical symplectic structure. The evolution is governed by a Hamiltonian which is equivalent to that obtained from a canonical analysis. The relationship of our Hamiltonian structure with other approaches in the literature, such as Clebsch potentials, Lagrangian to Eulerian transformations, and its use in clarifying linearization stability, are discussed. (orig.)
Hamiltonian models for the Madelung fluid and generalized Langevin equations
International Nuclear Information System (INIS)
Nonnenmacher, T.F.
1985-01-01
We present a Hamiltonian formulation of some type of an 'electromagnetic' Madelung fluid leading to a fluid mechanics interpretation of the Aharonov-Bohm effect and to a subsidary condition to be required in order to make the correspondence between Schroedinger's quantum mechanics and Madelung's fluid mechanics unique. Then we discuss some problems related with the Brownian oscillator. Our aim is to start out with a Hamiltonian for the composite system with surrounding heat bath) and to finally arrive at a stochastic differential equation with completely determined statistical properties. (orig./HSI)
On generalized Volterra systems
Charalambides, S. A.; Damianou, P. A.; Evripidou, C. A.
2015-01-01
We construct a large family of evidently integrable Hamiltonian systems which are generalizations of the KM system. The algorithm uses the root system of a complex simple Lie algebra. The Hamiltonian vector field is homogeneous cubic but in a number of cases a simple change of variables transforms such a system to a quadratic Lotka-Volterra system. We present in detail all such systems in the cases of A3, A4 and we also give some examples from higher dimensions. We classify all possible Lotka-Volterra systems that arise via this algorithm in the An case.
Generalized Asynchronous Systems
Directory of Open Access Journals (Sweden)
E. S. Kudryashova
2012-01-01
Full Text Available The paper consider a mathematical model of a concurrent system, the special case of which is an asynchronous system. Distributed asynchronous automata are introduced here. It is proved that Petri nets and transition systems with independence can be considered as distributed asynchronous automata. Time distributed asynchronous automata are defined in a standard way by correspondence which relates events with time intervals. It is proved that the time distributed asynchronous automata generalize time Petri nets and asynchronous systems.
Introduction to thermo-fluids systems design
Garcia McDonald, André
2012-01-01
A fully comprehensive guide to thermal systems design covering fluid dynamics, thermodynamics, heat transfer and thermodynamic power cycles Bridging the gap between the fundamental concepts of fluid mechanics, heat transfer and thermodynamics, and the practical design of thermo-fluids components and systems, this textbook focuses on the design of internal fluid flow systems, coiled heat exchangers and performance analysis of power plant systems. The topics are arranged so that each builds upon the previous chapter to convey to the reader that topics are not stand-alone i
Fluids in volcanic and geothermal systems
Sigvaldason, Gudmundur E.
Mineral buffers control the composition of most volatile components of magmas and dissolved species in geothermal fluids. The only element which occurs in significant quantities in volcanic and geothermal fluids and is not controlled by mineral buffers is chlorine. It is argued that in absence of marine influence, geothermal fluids reflect the chlorine content of associated magmatic fluids. The chlorine content of oceanic volcanic rocks has a positive correlation with elements, which are believed to indicate a heterogenous source region. Since the source is generally believed to be the Earth's mantle, the implication is that the mantle is heterogenous with regard to chlorine and other volatiles. Such heterogeneities would have important consequences for genesis and distribution of ore. All major magma types of the oceanic environment occur in Iceland. Their spatial distribution is closely related to a volcanotectonic pattern, suggesting crustal control. A geophysical model of crustal accretion in a rift zone is used in conjunction with classical petrology to predict geochemical processes in a rift zone crust. The model has two kinematic parameters-drift rate and subsidence rate-which combined describe trajectories of mass particles deposited on the surface. When considering in conjunction with thermal gradients of the rift zone a series of metamorphic reactions and chemical fractionation processes are bound to occur, eventually resulting in a layering of the oceanic crust. The physical parameters result in a derived variable, rift zone residence time, which depends on the width of a rift zone. Long residence times in a wide rift zone lead to multistage recycling of material. Other properties of the model, based on geometric arrangement of productive fissure swarms within a rift zone, explain off-rift volcanism as directly related to rift zone processes, either as plate trapped magmatic domains or a transgressive thermal anomaly into an older crust. Off
Capacitive system detects and locates fluid leaks
1966-01-01
Electronic monitoring system automatically detects and locates minute leaks in seams of large fluid storage tanks and pipelines covered with thermal insulation. The system uses a capacitive tape-sensing element that is adhesively bonded over seams where fluid leaks are likely to occur.
Burkhardt, Z.; Ramachandran, N.; Majumdar, A.
2017-01-01
Fluid Transient analysis is important for the design of spacecraft propulsion system to ensure structural stability of the system in the event of sudden closing or opening of the valve. Generalized Fluid System Simulation Program (GFSSP), a general purpose flow network code developed at NASA/MSFC is capable of simulating pressure surge due to sudden opening or closing of valve when thermodynamic properties of real fluid are available for the entire range of simulation. Specifically GFSSP needs an accurate representation of pressure-density relationship in order to predict pressure surge during a fluid transient. Unfortunately, the available thermodynamic property programs such as REFPROP, GASP or GASPAK does not provide the thermodynamic properties of Monomethylhydrazine (MMH). This paper will illustrate the process used for building a customized table of properties of state variables from available properties and speed of sound that is required by GFSSP for simulation. Good agreement was found between the simulations and measured data. This method can be adopted for modeling flow networks and systems with other fluids whose properties are not known in detail in order to obtain general technical insight. Rigorous code validation of this approach will be done and reported at a future date.
Interfacing a General Purpose Fluid Network Flow Program with the SINDA/G Thermal Analysis Program
Schallhorn, Paul; Popok, Daniel
1999-01-01
A general purpose, one dimensional fluid flow code is currently being interfaced with the thermal analysis program Systems Improved Numerical Differencing Analyzer/Gaski (SINDA/G). The flow code, Generalized Fluid System Simulation Program (GFSSP), is capable of analyzing steady state and transient flow in a complex network. The flow code is capable of modeling several physical phenomena including compressibility effects, phase changes, body forces (such as gravity and centrifugal) and mixture thermodynamics for multiple species. The addition of GFSSP to SINDA/G provides a significant improvement in convective heat transfer modeling for SINDA/G. The interface development is conducted in multiple phases. This paper describes the first phase of the interface which allows for steady and quasi-steady (unsteady solid, steady fluid) conjugate heat transfer modeling.
Expanding perfect fluid generalizations of the C metric
International Nuclear Information System (INIS)
Wylleman, Lode; Beke, David
2010-01-01
Petrov type D gravitational fields, generated by a perfect fluid with spatially homogeneous energy density and with flow lines which form a nonshearing and nonrotating timelike congruence, are reexamined. It turns out that the anisotropic such spacetimes, which comprise the vacuum C metric as a limit case, can have nonzero expansion, contrary to the conclusion in the original investigation by Barnes [A. Barnes, Gen. Relativ. Gravit. 4, 105 (1973).]. Apart from the static members, this class consists of cosmological models with precisely one symmetry. The general line element is constructed and some important properties are discussed. It is also shown that purely electric Petrov type D vacuum spacetimes admit shear-free normal timelike congruences everywhere, even in the nonstatic regions. This result incited to deduce intrinsic, easily testable criteria regarding shear-free normality and staticity of Petrov type D spacetimes in general, which are added in an appendix.
Asymmetric bubble collapse and jetting in generalized Newtonian fluids
Shukla, Ratnesh K.; Freund, Jonathan B.
2017-11-01
The jetting dynamics of a gas bubble near a rigid wall in a non-Newtonian fluid are investigated using an axisymmetric simulation model. The bubble gas is assumed to be homogeneous, with density and pressure related through a polytropic equation of state. An Eulerian numerical description, based on a sharp interface capturing method for the shear-free bubble-liquid interface and an incompressible Navier-Stokes flow solver for generalized fluids, is developed specifically for this problem. Detailed simulations for a range of rheological parameters in the Carreau model show both the stabilizing and destabilizing non-Newtonian effects on the jet formation and impact. In general, for fixed driving pressure ratio, stand-off distance and reference zero-shear-rate viscosity, shear-thinning and shear-thickening promote and suppress jet formation and impact, respectively. For a sufficiently large high-shear-rate limit viscosity, the jet impact is completely suppressed. Thresholds are also determined for the Carreau power-index and material time constant. The dependence of these threshold rheological parameters on the non-dimensional driving pressure ratio and wall stand-off distance is similarly established. Implications for tissue injury in therapeutic ultrasound will be discussed.
M. C. Sagis, Leonard
2001-03-01
In this paper, we develop a theory for the calculation of the surface diffusion coefficient for an arbitrarily curved fluid-fluid interface. The theory is valid for systems in hydrodynamic equilibrium, with zero mass-averaged velocities in the bulk and interfacial regions. We restrict our attention to systems with isotropic bulk phases, and an interfacial region that is isotropic in the plane parallel to the dividing surface. The dividing surface is assumed to be a simple interface, without memory effects or yield stresses. We derive an expression for the surface diffusion coefficient in terms of two parameters of the interfacial region: the coefficient for plane-parallel diffusion D (AB)aa(ξ) , and the driving force d(B)I||(ξ) . This driving force is the parallel component of the driving force for diffusion in the interfacial region. We derive an expression for this driving force using the entropy balance.
General proof of the entropy principle for self-gravitating fluid in f(R) gravity
Energy Technology Data Exchange (ETDEWEB)
Fang, Xiongjun [Department of Physics and Key Laboratory of Low Dimensional Quantum Structures andQuantum Control of Ministry of Education, Hunan Normal University,Changsha, Hunan 410081 (China); Guo, Minyong [Department of Physics, Beijing Normal University,Beijing 100875 (China); Jing, Jiliang [Department of Physics and Key Laboratory of Low Dimensional Quantum Structures andQuantum Control of Ministry of Education, Hunan Normal University,Changsha, Hunan 410081 (China)
2016-08-29
The discussions on the connection between gravity and thermodynamics attract much attention recently. We consider a static self-gravitating perfect fluid system in f(R) gravity, which is an important theory could explain the accelerated expansion of the universe. We first show that the Tolman-Oppenheimer-Volkoff equation of f(R) theories can be obtained by thermodynamical method in spherical symmetric spacetime. Then we prove that the maximum entropy principle is also valid for f(R) gravity in general static spacetimes beyond spherical symmetry. The result shows that if the constraint equation is satisfied and the temperature of fluid obeys Tolmans law, the extrema of total entropy implies other components of gravitational equations. Conversely, if f(R) gravitational equation hold, the total entropy of the fluid should be extremum. Our work suggests a general and solid connection between f(R) gravity and thermodynamics.
Heat transfer fluids for solar DHW systems
Energy Technology Data Exchange (ETDEWEB)
Wedel, S.; Bezzel, E.
2000-07-01
The aim of this work was to investigate the sudden clogging of the pipes in collectors as a consequence of liquid deterioration after repeated boiling during stagnation. A method to perform simple screening as accelerated tests of a large number liquid of samples subjected to various chemical- and physical environments have been designed. The acceleration factor of experiments relative to real systems is quite substantial primarily due to the extensive stress cycles in tests. Possible degradation mechanisms have been investigated and generally, there are two different paths to degradation of glycol: Thermal degradation and oxidative degradation primarily yielding propylene derivatives and carboxylic acids respectively. Polymerisation is an obvious possibility in a system containing various organic compounds such as acids and alcohols. Consequently, the reaction patterns alter making room for alternative interconnected mechanisms thus generating a broad spectrum of possible degradation products. Reserve alkalinity and pH are somewhat unreliable means of solely estimating the state of a liquid in relation to degradation and precipitation, as curvature of the RA-pH relations are different from liquid to liquid. For the majority of liquids, precipitation is not correlated with pH and RA. Coloration and precipitation in the liquid phase during stagnation separated liquids in two sub-categories. Fluids with inhibitor have sparing to moderate sedimentation and are brownish-black due to deterioration. Glycols without additives were either pale or colourless and did not precipitate. During normal operation, all fluids are clear and transparent and the majority has the same initial colour. The same distinction in liquids was observed on examination on the inside surface of the tubes concerning extent and the quantity of deposit. Liquids with additives tend to have significantly more deposit covering a larger surface than liquids without. Visual evaluation has proved that
Numerical solution of pipe flow problems for generalized Newtonian fluids
International Nuclear Information System (INIS)
Samuelsson, K.
1993-01-01
In this work we study the stationary laminar flow of incompressible generalized Newtonian fluids in a pipe with constant arbitrary cross-section. The resulting nonlinear boundary value problems can be written in a variational formulation and solved using finite elements and the augmented Lagrangian method. The solution of the boundary value problem is obtained by finding a saddle point of the augmented Lagrangian. In the algorithm the nonlinear part of the equations is treated locally and the solution is obtained by iteration between this nonlinear problem and a global linear problem. For the solution of the linear problem we use the SSOR preconditioned conjugate gradient method. The approximating problem is solved on a sequence of adaptively refined grids. A scheme for adjusting the value of the crucial penalization parameter of the augmented Lagrangian is proposed. Applications to pipe flow and a problem from the theory of capacities are given. (author) (34 refs.)
Control system for fluid heated steam generator
Boland, J.F.; Koenig, J.F.
1984-05-29
A control system for controlling the location of the nucleate-boiling region in a fluid heated steam generator comprises means for measuring the temperature gradient (change in temperature per unit length) of the heating fluid along the steam generator; means for determining a control variable in accordance with a predetermined function of temperature gradients and for generating a control signal in response thereto; and means for adjusting the feedwater flow rate in accordance with the control signal.
What Does Dynamical Systems Theory Teach Us about Fluids?
International Nuclear Information System (INIS)
Bosetti, Hadrien; Posch, Harald A.
2014-01-01
We use molecular dynamics simulations to compute the Lyapunov spectra of many-particle systems resembling simple fluids in thermal equilibrium and in non-equilibrium stationary states. Here we review some of the most interesting results and point to open questions. (general)
Orbital Express fluid transfer demonstration system
Rotenberger, Scott; SooHoo, David; Abraham, Gabriel
2008-04-01
Propellant resupply of orbiting spacecraft is no longer in the realm of high risk development. The recently concluded Orbital Express (OE) mission included a fluid transfer demonstration that operated the hardware and control logic in space, bringing the Technology Readiness Level to a solid TRL 7 (demonstration of a system prototype in an operational environment). Orbital Express (funded by the Defense Advanced Research Projects Agency, DARPA) was launched aboard an Atlas-V rocket on March 9th, 2007. The mission had the objective of demonstrating technologies needed for routine servicing of spacecraft, namely autonomous rendezvous and docking, propellant resupply, and orbital replacement unit transfer. The demonstration system used two spacecraft. A servicing vehicle (ASTRO) performed multiple dockings with the client (NextSat) spacecraft, and performed a variety of propellant transfers in addition to exchanges of a battery and computer. The fluid transfer and propulsion system onboard ASTRO, in addition to providing the six degree-of-freedom (6 DOF) thruster system for rendezvous and docking, demonstrated autonomous transfer of monopropellant hydrazine to or from the NextSat spacecraft 15 times while on orbit. The fluid transfer system aboard the NextSat vehicle was designed to simulate a variety of client systems, including both blowdown pressurization and pressure regulated propulsion systems. The fluid transfer demonstrations started with a low level of autonomy, where ground controllers were allowed to review the status of the demonstration at numerous points before authorizing the next steps to be performed. The final transfers were performed at a full autonomy level where the ground authorized the start of a transfer sequence and then monitored data as the transfer proceeded. The major steps of a fluid transfer included the following: mate of the coupling, leak check of the coupling, venting of the coupling, priming of the coupling, fluid transfer, gauging
Dynamic analysis of multibody system immersed in a fluid medium
International Nuclear Information System (INIS)
Wu, R.W.; Liu, L.K.; Levy, S.
1977-01-01
This paper is concerned primarily with the development and evaluation of an analysis method for the reponse prediction of immersed systems to seismic and other dynamic excitations. For immersed multibody systems, the hydrodynamic interaction causes coupled motion among the solid bodies. Also, under intense external excitations, impact between bodies may occur. The complex character of such systems inhibit the use of conventional analytical solutions in closed form. Therefore, approximate numerical schemes have been devised. For an incompressible, inviscid fluid, the hydrodynamic forces exerted by the fluid on solid bodies are determined to be linearly proportional to the acceleration of the vibrating solid bodies; i.e., the presence of the fluid only affects the inertia of the solid body system. A finite element computer program has been developed for computing this hydrodynamic (or added) mass effect. This program can be used to determine the hydrodynamic mass of a two-dimensional fluid field with solid bodies of arbitrary geometry. Triangular elements and linear pressure interpolation function are used to discretize the fluid region. The component element method is used to determine the dynamic response of the multibody system to externally applied mechanical loading or support excitation. The present analysis method for predicting the dynamic response of submerged multibody system is quite general and pertains to any number of solid bodies. However in this paper, its application is demonstrated only for 4 and 25 body systems. (Auth.)
GVS - GENERAL VISUALIZATION SYSTEM
Keith, S. R.
1994-01-01
The primary purpose of GVS (General Visualization System) is to support scientific visualization of data output by the panel method PMARC_12 (inventory number ARC-13362) on the Silicon Graphics Iris computer. GVS allows the user to view PMARC geometries and wakes as wire frames or as light shaded objects. Additionally, geometries can be color shaded according to phenomena such as pressure coefficient or velocity. Screen objects can be interactively translated and/or rotated to permit easy viewing. Keyframe animation is also available for studying unsteady cases. The purpose of scientific visualization is to allow the investigator to gain insight into the phenomena they are examining, therefore GVS emphasizes analysis, not artistic quality. GVS uses existing IRIX 4.0 image processing tools to allow for conversion of SGI RGB files to other formats. GVS is a self-contained program which contains all the necessary interfaces to control interaction with PMARC data. This includes 1) the GVS Tool Box, which supports color histogram analysis, lighting control, rendering control, animation, and positioning, 2) GVS on-line help, which allows the user to access control elements and get information about each control simultaneously, and 3) a limited set of basic GVS data conversion filters, which allows for the display of data requiring simpler data formats. Specialized controls for handling PMARC data include animation and wakes, and visualization of off-body scan volumes. GVS is written in C-language for use on SGI Iris series computers running IRIX. It requires 28Mb of RAM for execution. Two separate hardcopy documents are available for GVS. The basic document price for ARC-13361 includes only the GVS User's Manual, which outlines major features of the program and provides a tutorial on using GVS with PMARC_12 data. Programmers interested in modifying GVS for use with data in formats other than PMARC_12 format may purchase a copy of the draft GVS 3.1 Software Maintenance
Directory of Open Access Journals (Sweden)
Waqar Azeem Khan
Full Text Available The present paper deals with the analysis of melting heat and mass transfer characteristics in the stagnation point flow of an incompressible generalized Burgers fluid over a stretching sheet in the presence of non-linear radiative heat flux. A uniform magnetic field is applied normal to the flow direction. The governing equations in dimensional form are reduced to a system of dimensionless expressions by implementation of suitable similarity transformations. The resulting dimensionless problem governing the generalized Burgers is solved analytically by using the homotopy analysis method (HAM. The effects of different flow parameters like the ratio parameter, magnetic parameter, Prandtl number, melting parameter, radiation parameter, temperature ratio parameter and Schmidt number on the velocity, heat and mass transfer characteristics are computed and presented graphically. Moreover, useful discussions in detail are carried out with the help of plotted graphs and tables. Keywords: Generalized Burgers fluid, Non-linear radiative flow, Magnetic field, Melting heat transfer
Reliable Fluid Power Pitch Systems
DEFF Research Database (Denmark)
Liniger, Jesper; Pedersen, Henrik Clemmensen; Soltani, Mohsen
2015-01-01
The key objectives of wind turbine manufactures and buyers are to reduce the Total Cost of Ownership and Total Cost of Energy. Among others, low downtime of a wind turbine is important to increase the amount of energy produced during its lifetime. Historical data indicate that pitch systems accou...
Fluid structure interaction in piping systems
Energy Technology Data Exchange (ETDEWEB)
Svingen, Bjoernar
1996-12-31
The Dr. ing. thesis relates to an analysis of fluid structure interaction in piping systems in the frequency domain. The governing equations are the water hammer equations for the liquid, and the beam-equations for the structure. The fluid and structural equations are coupled through axial stresses and fluid continuity relations controlled by the contraction factor (Poisson coupling), and continuity and force relations at the boundaries (junction coupling). A computer program has been developed using the finite element method as a discretization technique both for the fluid and for the structure. This is made for permitting analyses of large systems including branches and loops, as well as including hydraulic piping components, and experiments are executed. Excitations are made in a frequency range from zero Hz and up to at least one thousand Hz. Frequency dependent friction is modelled as stiffness proportional Rayleigh damping both for the fluid and for the structure. With respect to the water hammer equations, stiffness proportional damping is seen as an artificial (bulk) viscosity term. A physical interpretation of this term in relation to transient/oscillating hydraulic pipe-friction is given. 77 refs., 72 figs., 4 tabs.
Generalized reduced fluid model with finite ion-gyroradius effects
International Nuclear Information System (INIS)
Hsu, C.T.; Hazeltine, R.D.; Morrison, P.J.
1985-04-01
Reduced fluid models have become important tools for studying the nonlinear dynamics of plasma in a large aspect-ratio tokamak. A self-consistent nonlinear reduced fluid model, with finite ion-gyroradius effects is presented. The model is distinctive in allowing for arbitrary beta and in satisfying an exact, relatively simple energy conservation law
Fluid biomarkers in multiple system atrophy
DEFF Research Database (Denmark)
Laurens, Brice; Constantinescu, Radu; Freeman, Roy
2015-01-01
Despite growing research efforts, no reliable biomarker currently exists for the diagnosis and prognosis of multiple system atrophy (MSA). Such biomarkers are urgently needed to improve diagnostic accuracy, prognostic guidance and also to serve as efficacy measures or surrogates of target...... engagement for future clinical trials. We here review candidate fluid biomarkers for MSA and provide considerations for further developments and harmonization of standard operating procedures. A PubMed search was performed until April 24, 2015 to review the literature with regard to candidate blood...... and cerebrospinal fluid (CSF) biomarkers for MSA. Abstracts of 1760 studies were retrieved and screened for eligibility. The final list included 60 studies assessing fluid biomarkers in patients with MSA. Most studies have focused on alpha-synuclein, markers of axonal degeneration or catecholamines. Their results...
Conservation form of the equations of fluid dynamics in general nonsteady coordinates
Zhang, H.; Camarero, R.; Kahawita, R.
1985-11-01
Many of the differential equations arising in fluid dynamics may be stated in conservation-law form. A number of investigations have been conducted with the aim to derive the conservation-law form of the Navier-Stokes equations in general nonsteady coordinate systems. The present note has the objective to illustrate a mathematical methodology with which such forms of the equations may be derived in an easier and more general fashion. For numerical applications, the scalar form of the equations is eventually provided. Attention is given to the conservation form of equations in curvilinear coordinates and numerical considerations.
Conservation form of the equations of fluid dynamics in general nonsteady coordinates
International Nuclear Information System (INIS)
Zhang, H.; Camarero, R.; Kahawita, R.
1985-01-01
Many of the differential equations arising in fluid dynamics may be stated in conservation-law form. A number of investigations have been conducted with the aim to derive the conservation-law form of the Navier-Stokes equations in general nonsteady coordinate systems. The present note has the objective to illustrate a mathematical methodology with which such forms of the equations may be derived in an easier and more general fashion. For numerical applications, the scalar form of the equations is eventually provided. Attention is given to the conservation form of equations in curvilinear coordinates and numerical considerations. 6 references
Damping system immersed in a fluid
International Nuclear Information System (INIS)
1980-01-01
The invention relates to a damping system which is immersed in a fluid and allows slow motion, while opposing fast motion of a mobile or deformable system immersed in a fluid. Nuclear reactors utilize fabricated assemblies immmersed in the spent fuel storage pool to support the fuel elements placed in the pool, e.g., when refueling the reactor. These fabricated assemblies must be held in position, relative to the concrete walls of the pool, so as to allow slow deformation of the assemblies due to thermal expansion, while curbing fast motion, e.g., earthquake-induced motion. Such fast motion due to earthquakes might be the cause of resonance phenomena involving the fuel storage rack structure and the pool walls, should the rack structure and pool walls have the same resonant frequency. In the event of an earthquake, the damping system would provide for fast curbing of structure motion to prevent uncontrolled deformation which might result in breaks and destruction [fr
Exact solution for MHD flow of a generalized Oldroyd-B fluid with modified Darcy's law
International Nuclear Information System (INIS)
Khan, M.; Hayat, T.; Asghar, S.
2005-12-01
This paper deals with an exact solution for the magnetohydrodynamic (MHD) flow of a generalized Oldroyd-B fluid in a circular pipe. For the description of such a fluid, the fractional calculus approach has been used throughout the analysis. Based on modified Darcy's law for generalized Oldroyd-B fluid, the velocity field is calculated analytically. Several known solutions can be recovered as the limiting cases of our solution. (author)
Inhomogeneous generalizations of Bianchi type VIh models with perfect fluid
Roy, S. R.; Prasad, A.
1991-07-01
Inhomogeneous universes admitting an Abelian G2 of isometry and filled with perfect fluid have been derived. These contain as special cases exact homogeneous universes of Bianchi type VIh. Many of these universes asymptotically tend to homogeneous Bianchi VIh universes. The models have been discussed for their physical and kinematical behaviors.
Fluid flow dynamics in MAS systems
Wilhelm, Dirk; Purea, Armin; Engelke, Frank
2015-08-01
The turbine system and the radial bearing of a high performance magic angle spinning (MAS) probe with 1.3 mm-rotor diameter has been analyzed for spinning rates up to 67 kHz. We focused mainly on the fluid flow properties of the MAS system. Therefore, computational fluid dynamics (CFD) simulations and fluid measurements of the turbine and the radial bearings have been performed. CFD simulation and measurement results of the 1.3 mm-MAS rotor system show relatively low efficiency (about 25%) compared to standard turbo machines outside the realm of MAS. However, in particular, MAS turbines are mainly optimized for speed and stability instead of efficiency. We have compared MAS systems for rotor diameter of 1.3-7 mm converted to dimensionless values with classical turbomachinery systems showing that the operation parameters (rotor diameter, inlet mass flow, spinning rate) are in the favorable range. This dimensionless analysis also supports radial turbines for low speed MAS probes and diagonal turbines for high speed MAS probes. Consequently, a change from Pelton type MAS turbines to diagonal turbines might be worth considering for high speed applications. CFD simulations of the radial bearings have been compared with basic theoretical values proposing considerably smaller frictional loss values. The discrepancies might be due to the simple linear flow profile employed for the theoretical model. Frictional losses generated inside the radial bearings result in undesired heat-up of the rotor. The rotor surface temperature distribution computed by CFD simulations show a large temperature gradient over the rotor.
Heat transfer and fluid flow in nuclear systems
Fenech, Henri
1982-01-01
Heat Transfer and Fluid in Flow Nuclear Systems discusses topics that bridge the gap between the fundamental principles and the designed practices. The book is comprised of six chapters that cover analysis of the predicting thermal-hydraulics performance of large nuclear reactors and associated heat-exchangers or steam generators of various nuclear systems. Chapter 1 tackles the general considerations on thermal design and performance requirements of nuclear reactor cores. The second chapter deals with pressurized subcooled light water systems, and the third chapter covers boiling water reacto
General fluid theories, variational principles and self-organization
International Nuclear Information System (INIS)
Mahajan, S.M.
2002-01-01
This paper reports two distinct but related advances: (1) The development and application of fluid theories that transcend conventional magnetohydrodynamics (MHD), in particular, theories that are valid in the long-mean-free-path limit and in which pressure anisotropy, heat flow, and arbitrarily strong sheared flows are treated consistently. (2) The discovery of new pressure-confining plasma configurations that are self-organized relaxed states. (author)
Generalized added masses computation for fluid structure interaction
International Nuclear Information System (INIS)
Lazzeri, L.; Cecconi, S.; Scala, M.
1983-01-01
The aim of this paper a description of a method to simulate the dynamic effect of a fluid between two structures by means of an added mass and an added stiffness. The method is based on a potential theory which assumes the fluid is inviscid and incompressible (the case of compressibility is discussed); a solution of the corresponding field equation is given as a superposition of elementary conditions (i.e. applicable to elementary boundary conditions). Consequently the pressure and displacements of the fluid on the boundary are given as a function of the series coefficients; the ''work lost'' (i.e. the work done by the pressures on the difference between actual and estimated displacements) is minimized, in this way the expansion coefficients are related to the displacements on the boundaries. Virtual work procedures are then used to compute added masses. The particular case of a free surface (with gravity effects) is discussed, it is shown how the effect can be modelled by means of an added stiffness term. Some examples relative to vibrations in reservoirs are given and discussed. (orig.)
General Approach to Characterize Reservoir Fluids Using a Large PVT Database
DEFF Research Database (Denmark)
Varzandeh, Farhad; Yan, Wei; Stenby, Erling Halfdan
2016-01-01
methods. We proposed a general approach to develop correlations for model parameters and applied it to the characterization for the PC-SAFT EoS. The approach consists in first developing the correlations based on the DIPPR database, and then adjusting the correlations based on a large PVT database......, the approach gives better PVT calculation results for the tested systems. Comparison was also made between PC-SAFT with the proposed characterization method and other EoS models. The proposed approach can be applied to other EoS models for improving their fluid characterization. Besides, the challenges...
Complex Fluids in Energy Dissipating Systems
Directory of Open Access Journals (Sweden)
Francisco J. Galindo-Rosales
2016-07-01
Full Text Available The development of engineered systems for energy dissipation (or absorption during impacts or vibrations is an increasing need in our society, mainly for human protection applications, but also for ensuring the right performance of different sort of devices, facilities or installations. In the last decade, new energy dissipating composites based on the use of certain complex fluids have flourished, due to their non-linear relationship between stress and strain rate depending on the flow/field configuration. This manuscript intends to review the different approaches reported in the literature, analyses the fundamental physics behind them and assess their pros and cons from the perspective of their practical applications.
System and method for improving performance of a fluid sensor for an internal combustion engine
Kubinski, David [Canton, MI; Zawacki, Garry [Livonia, MI
2009-03-03
A system and method for improving sensor performance of an on-board vehicle sensor, such as an exhaust gas sensor, while sensing a predetermined substance in a fluid flowing through a pipe include a structure for extending into the pipe and having at least one inlet for receiving fluid flowing through the pipe and at least one outlet generally opposite the at least one inlet, wherein the structure redirects substantially all fluid flowing from the at least one inlet to the sensor to provide a representative sample of the fluid to the sensor before returning the fluid through the at least one outlet.
Description of a general method to compute the fluid-structure interaction
International Nuclear Information System (INIS)
Jeanpierre, F.; Gibert, R.J.; Hoffmann, A.; Livolant, M.
1979-01-01
The vibrational characteristics of a structure in air may be considerably modified when the structure is immersed in a dense fluid. Such fluid structure interaction effects are important for the seismic or flow induced vibrational studies of various nuclear equipments, as for example the PWR internals, the fast reactor vessels, heat exchangers and fuel elements. In some simple situations, the fluid effects can be simulate by added masses, but in general, they are much more complicated. A general formulation to calculate precisely the vibrational behaviour of structures containing dense fluids is presented in this paper. That formulation can be easily introduced in finite elements computer codes, the fluid being described by special fluid elements. Its use is in principle limited to the linear range: small movements of structures, small pressure fluctuations. (orig.)
Exact solutions for a system of nonlinear plasma fluid equations
International Nuclear Information System (INIS)
Prahovic, M.G.; Hazeltine, R.D.; Morrison, P.J.
1991-04-01
A method is presented for constructing exact solutions to a system of nonlinear plasma fluid equations that combines the physics of reduced magnetohydrodynamics and the electrostatic drift-wave description of the Charney-Hasegawa-Mima equation. The system has nonlinearities that take the form of Poisson brackets involving the fluid field variables. The method relies on modifying a class of simple equilibrium solutions, but no approximations are made. A distinguishing feature is that the original nonlinear problem is reduced to the solution of two linear partial differential equations, one fourth-order and the other first-order. The first-order equation has Hamiltonian characteristics and is easily integrated, supplying information about the general structure of solutions. 6 refs
Blair, Clancy
2006-04-01
This target article considers the relation of fluid cognitive functioning to general intelligence. A neurobiological model differentiating working memory/executive function cognitive processes of the prefrontal cortex from aspects of psychometrically defined general intelligence is presented. Work examining the rise in mean intelligence-test performance between normative cohorts, the neuropsychology and neuroscience of cognitive function in typically and atypically developing human populations, and stress, brain development, and corticolimbic connectivity in human and nonhuman animal models is reviewed and found to provide evidence of mechanisms through which early experience affects the development of an aspect of cognition closely related to, but distinct from, general intelligence. Particular emphasis is placed on the role of emotion in fluid cognition and on research indicating fluid cognitive deficits associated with early hippocampal pathology and with dysregulation of the hypothalamic-pituitary-adrenal axis stress-response system. Findings are seen to be consistent with the idea of an independent fluid cognitive construct and to assist with the interpretation of findings from the study of early compensatory education for children facing psychosocial adversity and from behavior genetic research on intelligence. It is concluded that ongoing development of neurobiologically grounded measures of fluid cognitive skills appropriate for young children will play a key role in understanding early mental development and the adaptive success to which it is related, particularly for young children facing social and economic disadvantage. Specifically, in the evaluation of the efficacy of compensatory education efforts such as Head Start and the readiness for school of children from diverse backgrounds, it is important to distinguish fluid cognition from psychometrically defined general intelligence.
International Nuclear Information System (INIS)
Vivian, Jacopo; Manente, Giovanni; Lazzaretto, Andrea
2015-01-01
Highlights: • General guidelines are proposed to select ORC working fluid and cycle layout. • Distance between critical and heat source temperature for optimal fluid selection. • Separate contributions of cycle efficiency and heat recovery factor. - Abstract: The selection of the most suitable working fluid and cycle configuration for a given heat source is a fundamental step in the search for the optimum design of Organic Rankine Cycles. In this phase cycle efficiency and heat source recovery factor lead to opposite design choices in the achievement of maximum system efficiency and, in turn, maximum power output. In this work, both separate and combined effects of these two performance factors are considered to supply a thorough understanding of the compromise resulting in maximum performance. This goal is pursued by carrying out design optimizations of four different ORC configurations operating with twenty-seven working fluids and recovering heat from sensible heat sources in the temperature range 120–180 °C. Optimum working fluids and thermodynamic parameters are those which simultaneously allow high cycle efficiency and high heat recovery from the heat source to be obtained. General guidelines are suggested to reach this target for any system configuration. The distance between fluid critical temperature and inlet temperature of the heat source is found to play a key role in predicting the optimum performance of all system configurations regardless of the inlet temperature of the heat source
Generalized fluid impulse functions for oscillating marine structures
Janardhanan, K.; Price, W. G.; Wu, Y.
1992-03-01
A selection of generalized impulse response functions is presented for a variety of rigid and flexible marine structures (i.e. mono-hull, SWATH, floating drydock and twin dock, fixed flexible pile). These functions are determined from calculated and experimental frequency-dependent hydrodynamic data, and the characteristics of these data depend on the type of structure considered. This information is reflected in the shape and duration of the generalized impulse response functions which are pre-requisites for a generalized integro-differential mathematical model describing the dynamic behaviour of the structures to seaway excitation.
Conformal collineations and anisotropic fluids in general relativity
International Nuclear Information System (INIS)
Duggal, K.L.; Sharma, R.
1986-01-01
Recently, Herrera et al. [L. Herrera, J. Jimenez, L. Leal, J. Ponce de Leon, M. Esculpi, and V. Galino, J. Math. Phys. 25, 3274 (1984)] studied the consequences of the existence of a one-parameter group of conformal motions for anisotropic matter. They concluded that for special conformal motions, the stiff equation of state (p = μ) is singled out in a unique way, provided the generating conformal vector field is orthogonal to the four-velocity. In this paper, the same problem is studied by using conformal collineations (which include conformal motions as subgroups). It is shown that, for a special conformal collineation, the stiff equation of state is not singled out. Non-Einstein Ricci-recurrent spaces are considered as physical models for the fluid matter
Exact solution of an electroosmotic flow for generalized Burgers fluid in cylindrical domain
Directory of Open Access Journals (Sweden)
Masood Khan
Full Text Available The present paper reports a theoretical study of the dynamics of an electroosmotic flow (EOF in cylindrical domain. The Cauchy momentum equation is first simplified by incorporating the electrostatic body force in the electric double layer and the generalized Burgers fluid constitutive model. The electric potential distribution is given by the linearized Poisson–Boltzmann equation. After solving the linearized Poisson–Boltzmann equation, the Cauchy momentum equation with electrostatic body force is solved analytically by using the temporal Fourier and finite Hankel transforms. The effects of important involved parameters are examined and presented graphically. The results obtained reveal that the magnitude of velocity increases with increase of the Debye–Huckel and electrokinetic parameters. Further, it is shown that the results presented for generalized Burgers fluid are quite general so that results for the Burgers, Oldroyd-B, Maxwell and Newtonian fluids can be obtained as limiting cases. Keywords: Generalized Burgers fluid, Electroosmotic flow, Fourier and Hankel transform
Steady flow of non-Newtonian fluids - monotonicity methods in generalized orlicz spaces
Czech Academy of Sciences Publication Activity Database
Wróblewska, Aneta
2010-01-01
Roč. 72, č. 11 (2010), s. 4136-4147 ISSN 0362-546X Institutional research plan: CEZ:AV0Z10190503 Keywords : non-Newtonian fluid * Orlicz spaces * modular convergence of symmetric gradients * general ized Minty method * smart fluids Subject RIV: BA - General Mathematics Impact factor: 1.279, year: 2010 http://www.sciencedirect.com/science/article/pii/S0362546X10000568
Steady flow of non-Newtonian fluids - monotonicity methods in generalized orlicz spaces
Czech Academy of Sciences Publication Activity Database
Wróblewska, Aneta
2010-01-01
Roč. 72, č. 11 (2010), s. 4136-4147 ISSN 0362-546X Institutional research plan: CEZ:AV0Z10190503 Keywords : non-Newtonian fluid * Orlicz spaces * modular convergence of symmetric gradients * generalized Minty method * smart fluids Subject RIV: BA - General Mathematics Impact factor: 1.279, year: 2010 http://www.sciencedirect.com/science/article/pii/S0362546X10000568
Safety features of subcritical fluid fueled systems
International Nuclear Information System (INIS)
Bell, C.R.
1995-01-01
Accelerator-driven transmutation technology has been under study at Los Alamos for several years for application to nuclear waste treatment, tritium production, energy generation, and recently, to the disposition of excess weapons plutonium. Studies and evaluations performed to date at Los Alamos have led to a current focus on a fluid-fuel, fission system operating in a neutron source-supported subcritical mode, using molten salt reactor technology and accelerator-driven proton-neutron spallation. In this paper, the safety features and characteristics of such systems are explored from the perspective of the fundamental nuclear safety objectives that any reactor-type system should address. This exploration is qualitative in nature and uses current vintage solid-fueled reactors as a baseline for comparison. Based on the safety perspectives presented, such systems should be capable of meeting the fundamental nuclear safety objectives. In addition, they should be able to provide the safety robustness desired for advanced reactors. However, the manner in which safety objectives and robustness are achieved is very different from that associated with conventional reactors. Also, there are a number of safety design and operational challenges that will have to be addressed for the safety potential of such systems to be credible
Safety features of subcritical fluid fueled systems
International Nuclear Information System (INIS)
Bell, C.R.
1994-01-01
Accelerator-driven transmutation technology has been under study at Los Alamos for several years for application to nuclear waste treatment, tritium production, energy generation, and recently, to the disposition of excess weapons plutonium. Studies and evaluations performed to date at Los Alamos have led to a current focus on a fluid-fuel, fission system operating in a neutron source-supported subcritical mode, using molten salt reactor technology and accelerator-driven proton-neutron spallation. In this paper, the safety features and characteristics of such systems are explored from the perspective of the fundamental nuclear safety objectives that any reactor-type system should address. This exploration is qualitative in nature and uses current vintage solid-fueled reactors as a baseline for comparison. Based on the safety perspectives presented, such systems should be capable of meeting the fundamental nuclear safety objectives. In addition, they should be able to provide the safety robustness desired for advanced reactors. However, the manner in which safety objectives and robustness are achieved in very different from that associated with conventional reactors. Also, there are a number of safety design and operational challenges that will have to be addressed for the safety potential of such systems to be credible
Safety features of subcritical fluid fueled systems
Energy Technology Data Exchange (ETDEWEB)
Bell, C.R. [Los Alamos National Laboratory, NM (United States)
1995-10-01
Accelerator-driven transmutation technology has been under study at Los Alamos for several years for application to nuclear waste treatment, tritium production, energy generation, and recently, to the disposition of excess weapons plutonium. Studies and evaluations performed to date at Los Alamos have led to a current focus on a fluid-fuel, fission system operating in a neutron source-supported subcritical mode, using molten salt reactor technology and accelerator-driven proton-neutron spallation. In this paper, the safety features and characteristics of such systems are explored from the perspective of the fundamental nuclear safety objectives that any reactor-type system should address. This exploration is qualitative in nature and uses current vintage solid-fueled reactors as a baseline for comparison. Based on the safety perspectives presented, such systems should be capable of meeting the fundamental nuclear safety objectives. In addition, they should be able to provide the safety robustness desired for advanced reactors. However, the manner in which safety objectives and robustness are achieved is very different from that associated with conventional reactors. Also, there are a number of safety design and operational challenges that will have to be addressed for the safety potential of such systems to be credible.
General Systems Theory and Instructional Systems Design.
Salisbury, David F.
1990-01-01
Describes basic concepts in the field of general systems theory (GST) and identifies commonalities that exist between GST and instructional systems design (ISD). Models and diagrams that depict system elements in ISD are presented, and two matrices that show how GST has been used in ISD literature are included. (11 references) (LRW)
Method of calibrating a fluid-level measurement system
Woodard, Stanley E. (Inventor); Taylor, Bryant D. (Inventor)
2010-01-01
A method of calibrating a fluid-level measurement system is provided. A first response of the system is recorded when the system's sensor(s) is (are) not in contact with a fluid of interest. A second response of the system is recorded when the system's sensor(s) is (are) fully immersed in the fluid of interest. Using the first and second responses, a plurality of expected responses of the system's sensor(s) is (are) generated for a corresponding plurality of levels of immersion of the sensor(s) in the fluid of interest.
Forced fluid dynamics from blackfolds in general supergravity backgrounds
Energy Technology Data Exchange (ETDEWEB)
Armas, Jay [Physique Théorique et Mathématique,Université Libre de Bruxelles and International Solvay Institutes,ULB-Campus Plaine CP231, B-1050 Brussels (Belgium); Gath, Jakob [Centre de Physique Théorique, École Polytechnique,CNRS UMR 7644, Université Paris-Saclay,F-91128 Palaiseau (France); Niarchos, Vasilis [Crete Center for Theoretical Physics, Institute of Theoretical and Computational Physics,Crete Center for Quantum Complexity and Nanotechnology,Department of Physics, University of Crete,Heraklion, 71303 (Greece); Obers, Niels A.; Pedersen, Andreas Vigand [The Niels Bohr Institute, Copenhagen University,Blegdamsvej 17, DK-2100 Copenhagen Ø (Denmark)
2016-10-27
We present a general treatment of the leading order dynamics of the collective modes of charged dilatonic p-brane solutions of (super)gravity theories in arbitrary backgrounds. To this end we employ the general strategy of the blackfold approach which is based on a long-wavelength derivative expansion around an exact or approximate solution of the (super)gravity equations of motion. The resulting collective mode equations are formulated as forced hydrodynamic equations on dynamically embedded hypersurfaces. We derive them in full generality (including all possible asymptotic fluxes and dilaton profiles) in a far-zone analysis of the (super)gravity equations and in representative examples in a near-zone analysis. An independent treatment based on the study of external couplings in hydrostatic partition functions is also presented. Special emphasis is given to the forced collective mode equations that arise in type IIA/B and eleven-dimensional supergravities, where besides the standard Lorentz force couplings our analysis reveals additional couplings to the background, including terms that arise from Chern-Simons interactions. We also present a general overview of the blackfold approach and some of the key conceptual issues that arise when applied to arbitrary backgrounds.
Concept of planetary gear system to control fluid mixture ratio
Mcgroarty, J. D.
1966-01-01
Mechanical device senses and corrects for fluid flow departures from the selected flow ratio of two fluids. This system has been considered for control of rocket engine propellant mixture control but could find use wherever control of the flow ratio of any two fluids is desired.
An intelligent data acquisition system for fluid mechanics research
Cantwell, E. R.; Zilliac, G.; Fukunishi, Y.
1989-01-01
This paper describes a novel data acquisition system for use with wind-tunnel probe-based measurements, which incorporates a degree of specific fluid dynamics knowledge into a simple expert system-like control program. The concept was developed with a rudimentary expert system coupled to a probe positioning mechanism operating in a small-scale research wind tunnel. The software consisted of two basic elements, a general-purpose data acquisition system and the rulebased control element to take and analyze data and supplying decisions as to where to measure, how many data points to take, and when to stop. The system was validated in an experiment involving a vortical flow field, showing that it was possible to increase the resolution of the experiment or, alternatively, reduce the total number of data points required, to achieve parity with the results of most conventional data acquisition approaches.
Studies of complexity in fluid systems
Energy Technology Data Exchange (ETDEWEB)
Nagel, Sidney R.
2000-06-12
This is the final report of Grant DE-FG02-92ER25119, ''Studies of Complexity in Fluids'', we have investigated turbulence, flow in granular materials, singularities in evolution of fluid surfaces and selective withdrawal fluid flows. We have studied numerical methods for dealing with complex phenomena, and done simulations on the formation of river networks. We have also studied contact-line deposition that occurs in a drying drop.
International Nuclear Information System (INIS)
Jakubov, T.S.; Mainwaring, D.E.
2006-01-01
In the present work a generalized Kelvin equation for a fluid confined in thick-walled cylindrical capillary is developed. This has been accomplished by including the potential energy function for interaction between a solid wall of a capillary and a confined fluid into the Kelvin equation. Using the Lennard-Jones 12-6 potential, an explicit form of the potential energy functions as expressed by hypergeometrical functions have been derived-firstly, for the interaction between a solid wall and a test atom placed at an arbitrary point in a long open-end capillary, and thereafter for the body-body interaction between the solid wall and a confined Lennard-Jones fluid. Further, this generalized Kelvin equation has been applied to detailed description hysteresis phenomena in such capillaries. All numerical calculations have been carried out for the model argon-graphite system at 90 K
Network Flow Simulation of Fluid Transients in Rocket Propulsion Systems
Bandyopadhyay, Alak; Hamill, Brian; Ramachandran, Narayanan; Majumdar, Alok
2011-01-01
Fluid transients, also known as water hammer, can have a significant impact on the design and operation of both spacecraft and launch vehicle propulsion systems. These transients often occur at system activation and shutdown. The pressure rise due to sudden opening and closing of valves of propulsion feed lines can cause serious damage during activation and shutdown of propulsion systems. During activation (valve opening) and shutdown (valve closing), pressure surges must be predicted accurately to ensure structural integrity of the propulsion system fluid network. In the current work, a network flow simulation software (Generalized Fluid System Simulation Program) based on Finite Volume Method has been used to predict the pressure surges in the feed line due to both valve closing and valve opening using two separate geometrical configurations. The valve opening pressure surge results are compared with experimental data available in the literature and the numerical results compared very well within reasonable accuracy (< 5%) for a wide range of inlet-to-initial pressure ratios. A Fast Fourier Transform is preformed on the pressure oscillations to predict the various modal frequencies of the pressure wave. The shutdown problem, i.e. valve closing problem, the simulation results are compared with the results of Method of Characteristics. Most rocket engines experience a longitudinal acceleration, known as "pogo" during the later stage of engine burn. In the shutdown example problem, an accumulator has been used in the feed system to demonstrate the "pogo" mitigation effects in the feed system of propellant. The simulation results using GFSSP compared very well with the results of Method of Characteristics.
Liquid Cooling System for CPU by Electroconjugate Fluid
Directory of Open Access Journals (Sweden)
Yasuo Sakurai
2014-06-01
Full Text Available The dissipated power of CPU for personal computer has been increased because the performance of personal computer becomes higher. Therefore, a liquid cooling system has been employed in some personal computers in order to improve their cooling performance. Electroconjugate fluid (ECF is one of the functional fluids. ECF has a remarkable property that a strong jet flow is generated between electrodes when a high voltage is applied to ECF through the electrodes. By using this strong jet flow, an ECF-pump with simple structure, no sliding portion, no noise, and no vibration seems to be able to be developed. And then, by the use of the ECF-pump, a new liquid cooling system by ECF seems to be realized. In this study, to realize this system, an ECF-pump is proposed and fabricated to investigate the basic characteristics of the ECF-pump experimentally. Next, by utilizing the ECF-pump, a model of a liquid cooling system by ECF is manufactured and some experiments are carried out to investigate the performance of this system. As a result, by using this system, the temperature of heat source of 50 W is kept at 60°C or less. In general, CPU is usually used at this temperature or less.
Generalized extended Navier-Stokes theory: multiscale spin relaxation in molecular fluids.
Hansen, J S
2013-09-01
This paper studies the relaxation of the molecular spin angular velocity in the framework of generalized extended Navier-Stokes theory. Using molecular dynamics simulations, it is shown that for uncharged diatomic molecules the relaxation time decreases with increasing molecular moment of inertia per unit mass. In the regime of large moment of inertia the fast relaxation is wave-vector independent and dominated by the coupling between spin and the fluid streaming velocity, whereas for small inertia the relaxation is slow and spin diffusion plays a significant role. The fast wave-vector-independent relaxation is also observed for highly packed systems. The transverse and longitudinal spin modes have, to a good approximation, identical relaxation, indicating that the longitudinal and transverse spin viscosities have same value. The relaxation is also shown to be isomorphic invariant. Finally, the effect of the coupling in the zero frequency and wave-vector limit is quantified by a characteristic length scale; if the system dimension is comparable to this length the coupling must be included into the fluid dynamical description. It is found that the length scale is independent of moment of inertia but dependent on the state point.
A general theory of non-equilibrium dynamics of lipid-protein fluid membranes
DEFF Research Database (Denmark)
Lomholt, Michael Andersen; Hansen, Per Lyngs; Miao, L.
2005-01-01
We present a general and systematic theory of non-equilibrium dynamics of multi-component fluid membranes, in general, and membranes containing transmembrane proteins, in particular. Developed based on a minimal number of principles of statistical physics and designed to be a meso...
On exact solutions for some oscillating motions of a generalized Oldroyd-B fluid
Khan, M.; Anjum, Asia; Qi, Haitao; Fetecau, C.
2010-02-01
This paper deals with exact solutions for some oscillating motions of a generalized Oldroyd-B fluid. The fractional calculus approach is used in the constitutive relationship of fluid model. Analytical expressions for the velocity field and the corresponding shear stress for flows due to oscillations of an infinite flat plate as well as those induced by an oscillating pressure gradient are determined using Fourier sine and Laplace transforms. The obtained solutions are presented under integral and series forms in terms of the Mittag-Leffler functions. For α = β = 1, our solutions tend to the similar solutions for ordinary Oldroyd-B fluid. A comparison between generalized and ordinary Oldroyd-B fluids is shown by means of graphical illustrations.
Slip effects on a generalized Burgers’ fluid flow between two side walls with fractional derivative
Directory of Open Access Journals (Sweden)
Shihao Han
2016-01-01
Full Text Available This paper presents a research for the 3D flow of a generalized Burgers’ fluid between two side walls generated by an exponential accelerating plate and a constant pressure gradient, where the no-slip assumption between the exponential accelerating plate and the Burgers’ fluid is no longer valid. The governing equations of the generalized Burgers’ fluid flow are established by using the fractional calculus approach. Exact analytic solutions for the 3D flow are established by employing the Laplace transform and the finite Fourier sine transform. Furthermore, some 3D and 2D figures for the fluid velocity and shear stress are plotted to analyze and discuss the effects of various parameters.
On exact solutions for oscillatory flows in a generalized Burgers fluid with slip condition
Energy Technology Data Exchange (ETDEWEB)
Hayat, Tasawar [Dept. of Mathematics, Quaid-i-Azam Univ., Islamabad (Pakistan); Dept. of Mathematics, Coll. of Sciences, KS Univ., Riyadh (Saudi Arabia); Najam, Saher [Theoretical Plasma Physics Div., PINSTECH, P.O. Nilore, Islamabad (Pakistan); Sajid, Muhammad; Mesloub, Said [Dept. of Mathematics, Coll. of Sciences, KS Univ., Riyadh (Saudi Arabia); Ayub, Muhammad [Dept. of Mathematics, Quaid-i-Azam Univ., Islamabad (Pakistan)
2010-05-15
An analysis is performed for the slip effects on the exact solutions of flows in a generalized Burgers fluid. The flow modelling is based upon the magnetohydrodynamic (MHD) nature of the fluid and modified Darcy law in a porous space. Two illustrative examples of oscillatory flows are considered. The results obtained are compared with several limiting cases. It has been shown here that the derived results hold for all values of frequencies including the resonant frequency. (orig.)
First general solutions for unidirectional motions of rate type fluids over an infinite plate
Directory of Open Access Journals (Sweden)
Constantin Fetecau
2015-09-01
Full Text Available Based on a simple but important remark regarding the governing equation for the non-trivial shear stress corresponding to the motion of a fluid over an infinite plate, exact solutions are established for the motion of Oldroyd-B fluids due to the plate that applies an arbitrary time-dependent shear stress to the fluid. These solutions, that allow us to provide the first exact solutions for motions of rate type fluids produced by an infinite plate that applies constant, constantly accelerating or oscillating shears stresses to the fluid, can easily be reduced to the similar solutions for Maxwell, second grade or Newtonian fluids performing the same motion. Furthermore, the obtained solutions are used to develop general solutions for the motion induced by a moving plate and to correct or recover as special cases different known results from the existing literature. Consequently, the motion problem of such fluids over an infinite plate that is moving in its plane or applies a shear stress to the fluid is completely solved.
Novel Fluid Preservation System, Phase I
National Aeronautics and Space Administration — To address NASA's need for a method to preserve blood and urine samples from astronauts collected during flight, Chromologic (CL) proposes to develop a novel Fluid...
Statistical mechanics of homogeneous partly pinned fluid systems.
Krakoviack, Vincent
2010-12-01
The homogeneous partly pinned fluid systems are simple models of a fluid confined in a disordered porous matrix obtained by arresting randomly chosen particles in a one-component bulk fluid or one of the two components of a binary mixture. In this paper, their configurational properties are investigated. It is shown that a peculiar complementarity exists between the mobile and immobile phases, which originates from the fact that the solid is prepared in presence of and in equilibrium with the adsorbed fluid. Simple identities follow, which connect different types of configurational averages, either relative to the fluid-matrix system or to the bulk fluid from which it is prepared. Crucial simplifications result for the computation of important structural quantities, both in computer simulations and in theoretical approaches. Finally, possible applications of the model in the field of dynamics in confinement or in strongly asymmetric mixtures are suggested.
Generalized Hamiltonians, functional integration and statistics of continuous fluids and plasmas
International Nuclear Information System (INIS)
Tasso, H.
1985-05-01
Generalized Hamiltonian formalism including generalized Poisson brackets and Lie-Poisson brackets is presented in Section II. Gyroviscous magnetohydrodynamics is treated as a relevant example in Euler and Clebsch variables. Section III is devoted to a short review of functional integration containing the definition and a discussion of ambiguities and methods of evaluation. The main part of the contribution is given in Section IV, where some of the content of the previous sections is applied to Gibbs statistics of continuous fluids and plasmas. In particular, exact fluctuation spectra are calculated for relevant equations in fluids and plasmas. (orig.)
Application of ADINA fluid element for transient response analysis of fluid-structure system
International Nuclear Information System (INIS)
Sakurai, Y.; Kodama, T.; Shiraishi, T.
1985-01-01
Pressure propagation and Fluid-Structure Interaction (FSI) in 3D space were simulated by general purpose finite element program ADINA using the displacement-based fluid element which presumes inviscid and compressible fluid with no net flow. Numerical transient solution was compared with the measured data of an FSI experiment and was found to fairly agree with the measured. In the next step, post analysis was conducted for a blowdown experiment performed with a 1/7 scaled reactor pressure vessel and a flexible core barrel and the code performance was found to be satisfactory. It is concluded that the transient response of the core internal structure of a PWR during the initial stage of LOCA can be analyzed by the displacement-based finite fluid element and the structural element. (orig.)
Generalized spin Sutherland systems revisited
Directory of Open Access Journals (Sweden)
L. Fehér
2015-04-01
Full Text Available We present generalizations of the spin Sutherland systems obtained earlier by Blom and Langmann and by Polychronakos in two different ways: from SU(n Yang–Mills theory on the cylinder and by constraining geodesic motion on the N-fold direct product of SU(n with itself, for any N>1. Our systems are in correspondence with the Dynkin diagram automorphisms of arbitrary connected and simply connected compact simple Lie groups. We give a finite-dimensional as well as an infinite-dimensional derivation and shed light on the mechanism whereby they lead to the same classical integrable systems. The infinite-dimensional approach, based on twisted current algebras (alias Yang–Mills with twisted boundary conditions, was inspired by the derivation of the spinless Sutherland model due to Gorsky and Nekrasov. The finite-dimensional method relies on Hamiltonian reduction under twisted conjugations of N-fold direct product groups, linking the quantum mechanics of the reduced systems to representation theory similarly as was explored previously in the N=1 case.
Fluid transportation mechanisms by a coupled system of elastic membranes and magnetic fluids
International Nuclear Information System (INIS)
Ido, Y.; Tanaka, K.; Sugiura, Y.
2002-01-01
The basic properties of the fluid transportation mechanism that is produced by the coupled waves propagating along a thin elastic membrane covering a magnetic fluid layer in a shallow and long rectangular vessel are investigated. It is shown that the progressive magnetic field induced by the rectangular pulses generates sinusoidal vibration of the displacement of elastic membrane and makes the system work more efficiently than the magnetic field induced by the pulse-width-modulation method
Dipolar fluid-wall systems. Beyond the image potential
International Nuclear Information System (INIS)
Boudh-hir, M.E.
1989-02-01
The case of dipolar fluid in front of an ideal wall is examined. The surface-fluid system is introduced as a limit case of a binary mixture Using the diagrammatic development, the expansion of the one-particle distribution function is given. 16 refs
Inhomogeneous generalizations of Bianchi Type VIh universes with stiff perfect fluid and radiation
Roy, S. R.; Prasad, A.
1995-03-01
Families of inhomogeneous models filled with a stiff perfect fluid and radiation have been derived in which there is no flow of total momentum. The models are generalizations of those of Bianchi Type VIh and are discussed for some particular forms of the arbitrary functions appearing in them.
Generalized Couette flow of a third-grade fluid with slip. The exact solutions
Energy Technology Data Exchange (ETDEWEB)
Ellahi, Rahmat [IIUI, Islamabad (Pakistan). Dept. of Mathematics; Hayat, Tasawar [Quaid-i-Azam Univ., Islamabad (Pakistan). Dept. of Mathematics; King Saud Univ., Riyadh (Saudi Arabia). Dept. of Mathematics; Mahomed, Fazal Mahmood [Univ. of the Witwatersrand, Wits (South Africa). Centre for Differential Equations, Continuum, Mechanics and Applications
2010-12-15
The present note investigates the influence of slip on the generalized Couette flows of a third-grade fluid. Two flow problems are considered. The resulting equations and the boundary conditions are nonlinear. Analytical solutions of the governing nonlinear problems are found in closed form. (orig.)
Concept research on general passive system
International Nuclear Information System (INIS)
Han Xu; Yang Yanhua; Zheng Mingguang
2009-01-01
This paper summarized the current passive techniques used in nuclear power plants. Through classification and analysis, the functional characteristics and inherent identification of passive systems were elucidated. By improving and extending the concept of passive system, the general passive concept was proposed, and space and time relativity was discussed and assumption of general passive system were illustrated. The function of idealized general passive system is equivalent with the current passive system, but the design of idealized general passive system is more flexible. (authors)
Urinary Analysis of Fluid Retention in the General Population: A Cross-Sectional Study.
Directory of Open Access Journals (Sweden)
Robert G Hahn
Full Text Available Renal conservation (retention of fluid might affect the outcome of hospital care and can be indicated by increased urinary concentrations of metabolic waste products. We obtained a reference material for further studies by exploring the prevalence of fluid retention in a healthy population.Spot urine sampling was performed in 300 healthy hospital workers. A previously validated algorithm summarized the urine-specific gravity, osmolality, creatinine, and color to a fluid retention index (FRI, where 4.0 is the cut-off for fluid retention consistent with dehydration. In 50 of the volunteers, we also studied the relationships between FRI, plasma osmolality, and water-retaining hormones.The cut-off for fluid retention (FRI ≥ 4.0 was reached by 38% of the population. No correlation was found between the FRI and the time of the day of urine sample collection, and the FRI was only marginally correlated with the time period spent without fluid intake. Volunteers with fluid retention were younger, generally men, and more often had albuminuria (88% vs. 34%, P < 0.001. Plasma osmolality and plasma sodium were somewhat higher in those with a high FRI (mean 294.8 vs. 293.4 mosmol/kg and 140.3 vs. 139.9 mmol/l. Plasma vasopressin was consistently below the limit of detection, and the plasma cortisol, aldosterone, and renin concentrations were similar in subjects with a high or low FRI. The very highest FRI values (≥ 5.0, N = 61 were always accompanied by albuminuria.Fluid retention consistent with moderate dehydration is common in healthy staff working in a Swedish hospital.
A General Nonlinear Fluid Model for Reacting Plasma-Neutral Mixtures
Energy Technology Data Exchange (ETDEWEB)
Meier, E T; Shumlak, U
2012-04-06
A generalized, computationally tractable fluid model for capturing the effects of neutral particles in plasmas is derived. The model derivation begins with Boltzmann equations for singly charged ions, electrons, and a single neutral species. Electron-impact ionization, radiative recombination, and resonant charge exchange reactions are included. Moments of the reaction collision terms are detailed. Moments of the Boltzmann equations for electron, ion, and neutral species are combined to yield a two-component plasma-neutral fluid model. Separate density, momentum, and energy equations, each including reaction transfer terms, are produced for the plasma and neutral equations. The required closures for the plasma-neutral model are discussed.
Variational methods for problems from plasticity theory and for generalized Newtonian fluids
Fuchs, Martin
2000-01-01
Variational methods are applied to prove the existence of weak solutions for boundary value problems from the deformation theory of plasticity as well as for the slow, steady state flow of generalized Newtonian fluids including the Bingham and Prandtl-Eyring model. For perfect plasticity the role of the stress tensor is emphasized by studying the dual variational problem in appropriate function spaces. The main results describe the analytic properties of weak solutions, e.g. differentiability of velocity fields and continuity of stresses. The monograph addresses researchers and graduate students interested in applications of variational and PDE methods in the mechanics of solids and fluids.
O'Keeffe, C J; Ren, Ruichao; Orkoulas, G
2007-11-21
Spatial updating grand canonical Monte Carlo algorithms are generalizations of random and sequential updating algorithms for lattice systems to continuum fluid models. The elementary steps, insertions or removals, are constructed by generating points in space either at random (random updating) or in a prescribed order (sequential updating). These algorithms have previously been developed only for systems of impenetrable spheres for which no particle overlap occurs. In this work, spatial updating grand canonical algorithms are generalized to continuous, soft-core potentials to account for overlapping configurations. Results on two- and three-dimensional Lennard-Jones fluids indicate that spatial updating grand canonical algorithms, both random and sequential, converge faster than standard grand canonical algorithms. Spatial algorithms based on sequential updating not only exhibit the fastest convergence but also are ideal for parallel implementation due to the absence of strict detailed balance and the nature of the updating that minimizes interprocessor communication. Parallel simulation results for three-dimensional Lennard-Jones fluids show a substantial reduction of simulation time for systems of moderate and large size. The efficiency improvement by parallel processing through domain decomposition is always in addition to the efficiency improvement by sequential updating.
Evaluation of New Fluid Mud Survey System at Field Sites
National Research Council Canada - National Science Library
Engler
1992-01-01
This technical note presents an intermediate evaluation of a fluid mud survey system with respect to operability, practicability, and repeatability based on field tests conducted at Calcasieu River, Louisiana...
Smart Fluid System Dually Responsive to Light and Electric Fields: An Electrophotorheological Fluid.
Yoon, Chang-Min; Jang, Yoonsun; Noh, Jungchul; Kim, Jungwon; Jang, Jyongsik
2017-10-24
Electrophotorheological (EPR) fluids, whose rheological activity is dually responsive to light and electric fields (E fields), is formulated by mixing photosensitive spiropyran-decorated silica (SP-sSiO 2 ) nanoparticles with zwitterionic lecithin and mineral oil. A reversible photorheological (PR) activity of the EPR fluid is developed via the binding and releasing mechanism of lecithin and merocyanine (MC, a photoisomerized form of SP) under ultraviolet (UV) and visible (VIS) light applications. Moreover, the EPR fluid exhibits an 8-fold higher electrorheological (ER) performance compared to the SP-sSiO 2 nanoparticle-based ER fluid (without lecithin) under an E field, which is attributed to the enhanced dielectric properties facilitated by the binding of the lecithin and SP molecules. Upon dual application of UV light and an E field, the EPR fluid exhibits high EPR performance (ca. 115.3 Pa) that far exceeds its separate PR (ca. 0.8 Pa) and ER (ca. 57.5 Pa) activities, because of the synergistic contributions of the PR and ER effects through rigid and fully connected fibril-like structures. Consequently, this study offers a strategy on formulation of dual-stimuli responsive smart fluid systems.
Reducing pressure oscillations in discrete fluid power systems
DEFF Research Database (Denmark)
Hansen, Anders Hedegaard; Pedersen, Henrik Clemmensen
2016-01-01
Discrete fluid power systems featuring transmission lines inherently include pressure oscillations. Experimental verification of a discrete fluid power power take off system for wave energy converters has shown the cylinder pressure to oscillate as force shifts are performed. This article investi...... investigates how cylinder pressure oscillations may be reduced by shaping the valve opening trajectory without the need for closed loop pressure feedback. Furthermore the energy costs of reducing pressure oscillations are investigated....
The fluid systems for the SLD Cherenkov ring imaging detector
International Nuclear Information System (INIS)
Abe, K.; Hasegawa, K.; Hasegawa, Y.; Iwasaki, Y.; Suekane, F.; Yuta, H.; Baird, K.; Jacques, P.; Kalelkar, M.; Plano, R.; Stamer, P.; Word, G.; Bean, A.; Caldwell, D.O.; Duboscq, J.; Huber, J.; Lu, A.; Mathys, L.; McHugh, S.; Yellin, S.; Ben-David, R.; Manly, S.; Snyder, J.; Turk, J.; Cavalli-Sforza, M.; Coyle, P.; Coyne, D.; Gagnon, P.; Liu, X.; Schneider, M.; Williams, D.A.; Coller, J.; Shank, J.T.; Whitaker, J.S.; d'Oliveira, A.; Johnson, R.A.; Martinez, J.; Nussbaum, M.; Santha, A.K.S.; Sokoloff, M.D.; Stockdale, I.; Wilson, R.J.
1992-10-01
We describe the design and operation of the fluid delivery, monitor and control systems for the SLD barrel Cherenkov Ring Imaging Detector (CRID). The systems deliver drift gas (C 2 H 6 + TMAE), radiator gas (C 5 F 12 + N 2 ) and radiator liquid (C 6 F 14 ). Measured critical quantities such as electron lifetime in the drift gas and ultra-violet (UV) transparencies of the radiator fluids, together with the operational experience, are also reported
Generalized Bekenstein-Hawking system: logarithmic correction
International Nuclear Information System (INIS)
Chakraborty, Subenoy
2014-01-01
The present work is a generalization of the recent work [arXiv.1206.1420] on the modified Hawking temperature on the event horizon. Here the Hawking temperature is generalized by multiplying the modified Hawking temperature by a variable parameter α representing the ratio of the growth rate of the apparent horizon to that of event horizon. It is found that both the first and the generalized second law of thermodynamics are valid on the event horizon for any fluid distribution. Subsequently, the Bekenstein entropy is modified on the event horizon and the thermodynamical laws are examined. Finally, an interpretation of the parameters involved is presented. (orig.)
Complex fluids in biological systems experiment, theory, and computation
2015-01-01
This book serves as an introduction to the continuum mechanics and mathematical modeling of complex fluids in living systems. The form and function of living systems are intimately tied to the nature of surrounding fluid environments, which commonly exhibit nonlinear and history dependent responses to forces and displacements. With ever-increasing capabilities in the visualization and manipulation of biological systems, research on the fundamental phenomena, models, measurements, and analysis of complex fluids has taken a number of exciting directions. In this book, many of the world’s foremost experts explore key topics such as: Macro- and micro-rheological techniques for measuring the material properties of complex biofluids and the subtleties of data interpretation Experimental observations and rheology of complex biological materials, including mucus, cell membranes, the cytoskeleton, and blood The motility of microorganisms in complex fluids and the dynamics of active suspensions Challenges and solut...
Magnetic nanofluids and magnetic composite fluids in rotating seal systems
International Nuclear Information System (INIS)
Borbath, T; Borbath, I; Boros, T; Bica, D; Vekas, L; Potencz, I
2010-01-01
Recent results are presented concerning the development of magnetofluidic leakage-free rotating seals for vacuum and high pressure gases, evidencing significant advantages compared to mechanical seals. The micro-pilot scale production of various types of magnetizable sealing fluids is shortly reviewed, in particular the main steps of the chemical synthesis of magnetic nanofluids and magnetic composite fluids with light hydrocarbon, mineral oil and synthetic oil carrier liquids. The behavior of different types of magnetizable fluids in the rotating sealing systems is analyzed. Design concepts, some constructive details and testing procedures of magnetofluidic rotating seals are presented such as the testing equipment. The main characteristics of several magnetofluidic sealing systems and their applications will be presented: vacuum deposition systems and liquefied gas pumps applications, mechanical and magnetic nanofluid combined seals, gas valves up to 40 bar equipped by rotating seal with magnetic nanofluids and magnetic composite fluids.
Considerations of a nonhomogeneous fluid in the deep groundwater flow system at Hanford
International Nuclear Information System (INIS)
Nelson, R.W.
1988-11-01
This report presents such a general theory capable of describing the flow on nonhomogeneous fluids in porous media, theory that is a composite from several disciplines including groundwater hydrology, soil physics, civil engineering, petroleum reservoir engineering, mechanics, and mathematical physics. The report discussed the conceptual basis for considering the flow of nonhomogeneous fluids. From this conceptual basis emphasis shifts to providing complete definitions and then appropriately describing those definitions in mathematical terms. Throughout the report, the necessary assumptions are stated in detail because the limitations of any theory are best assessed through careful scrutiny of the assumptions. From the mathematical definitions with appropriate functional dependence the results and constraints needed are derived to provide the general theory necessary to describe the flow of nonhomogeneous fluids in porous media. Particular attention is given to comparing the general theory with the classical theory of flow for a homogeneous fluid. Such comparison provides significant insight to the effects of variable fluid properties on subsurface flow systems. The comparisons also indicate the importance of carefully formulating subsurface flow models within the more general theoretical framework describing the flow of nonhomogeneous fluids in porous media. 29 refs.; 6 figs.; 1 tab
Overview of Fluid System Design for the KJRR
Energy Technology Data Exchange (ETDEWEB)
Kim, Seong Hoon; Park, Cheol; Kim, Young-Ki [KAERI, Daejeon (Korea, Republic of)
2016-05-15
This paper introduces the fluid system design to fulfill the above mentioned requirements. The considerations and design change experiences are also presented. The KJRR fluid system consists of four systems: Primary Cooling System (PCS), Safety Residual Heat Removal System (SRHRS), Pool Water management System (PWMS), and Hot Water Layer System (HWLS). The main purpose of the fluid system for a RR is to remove the heat generated in the core and to transfer it to the secondary cooling system in which the heat is dissipated in the atmosphere. In the open-pool type research reactor, it needs to cool, purify, and make up the pool water. The main purpose of the KJRR is to produce medical and industrial radioisotopes, such as Mo-99, Ir-192, I- 131 etc., and to irradiate silicon ingots for Neutron Transmutation Doping. The thermal power of the KJRR is 15 MW{sub t} and the maximum thermal neutron flux is 3.0 x 10{sup 14} n/cm{sup 2}s. The fuel type is LEU U-Mo plate type and the reflector is Beryllium and Graphite. The Reactor Structure Assembly is submerged in the reactor pool. The reactor core is cooled by a downward forced flow that is maintained by pumps. Due to the downward flow the fuel assembly can be fixed on the grid plate without using the special device. KAERI have been successfully operating HANARO and constructing the Jordan Research and Training Reactor (JRTR). Along with the KJRR project, the fluid system design for a medium power research reactor has been developed and matured from the economic and the safety point of view. The fluid system of the KJRR is introduced and the objective of each system is explained briefly. The fluid system in research reactors is designed to meet the requirements from the upstream design areas.
Energy Technology Data Exchange (ETDEWEB)
Zhao, Guangpu [School of Mathematical Science, Inner Mongolia University, Hohhot, Inner Mongolia 010021 (China); Jian, Yongjun, E-mail: jianyj@imu.edu.cn [School of Mathematical Science, Inner Mongolia University, Hohhot, Inner Mongolia 010021 (China); Chang, Long [School of Mathematics and Statistics, Inner Mongolia University of Finance and Economics, Hohhot, Inner Mongolia 010051 (China); Buren, Mandula [School of Mathematical Science, Inner Mongolia University, Hohhot, Inner Mongolia 010021 (China)
2015-08-01
By using the method of separation of variables, an analytical solution for the magnetohydrodynamic (MHD) flow of the generalized Maxwell fluids under AC electric field through a two-dimensional rectangular micropump is reduced. By the numerical computation, the variations of velocity profiles with the electrical oscillating Reynolds number Re, the Hartmann number Ha, the dimensionless relaxation time De are studied graphically. Further, the comparison with available experimental data and relevant researches is presented. - Highlights: • MHD flow of the generalized Maxwell fluids under AC electric field is analyzed. • The MHD flow is confined to a two-dimensional rectangular micropump. • Analytical solution is obtained by using the method of separation of variables. • The influences of related parameters on the MHD velocity are discussed.
International Nuclear Information System (INIS)
Zhao, Guangpu; Jian, Yongjun; Chang, Long; Buren, Mandula
2015-01-01
By using the method of separation of variables, an analytical solution for the magnetohydrodynamic (MHD) flow of the generalized Maxwell fluids under AC electric field through a two-dimensional rectangular micropump is reduced. By the numerical computation, the variations of velocity profiles with the electrical oscillating Reynolds number Re, the Hartmann number Ha, the dimensionless relaxation time De are studied graphically. Further, the comparison with available experimental data and relevant researches is presented. - Highlights: • MHD flow of the generalized Maxwell fluids under AC electric field is analyzed. • The MHD flow is confined to a two-dimensional rectangular micropump. • Analytical solution is obtained by using the method of separation of variables. • The influences of related parameters on the MHD velocity are discussed
Conway, Andrew R. A.; Cowan, Nelsin; Bunting, Michael F.; Therriault, David J.; Minkoff, Scott R. B.
2002-01-01
Studied the interrelationships among general fluid intelligence, short-term memory capacity, working memory capacity, and processing speed in 120 young adults and used structural equation modeling to determine the best predictor of general fluid intelligence. Results suggest that working memory capacity, but not short-term memory capacity or…
Linking rigid multibody systems via controllable thin fluid films
DEFF Research Database (Denmark)
Estupinan, Edgar Alberto; Santos, Ilmar
2009-01-01
, this paper gives a theoretical contribution to the combined fields of fluid–structure interaction and vibration control. The methodology is applied to a reciprocating linear compressor, where the dynamics of the mechanical components are described with help of multibody dynamics. The crank is linked......This work deals with the mathematical modelling of multibody systems interconnected via thin fluid films. The dynamics of the fluid films can be actively controlled by means of different types of actuators, allowing significant vibration reduction of the system components. In this framework...... to the rotor via a thin fluid film, where the hydrodynamic pressure is described by the Reynolds equation, which is modified to accommodate the controllable lubrication conditions. The fluid film forces are coupled to the set of nonlinear equations that describes the dynamics of the reciprocating linear...
Development of fluid and I and C systems design technology
International Nuclear Information System (INIS)
Sim, Yoon Sub; Park, C. K.; Kim, S. O.
2000-05-01
LMR is the reactor type that makes utilization of uranium resource very efficiently and the necessity of construction of a LMR in 2020's has been raised. However, the design technology required for construction has not been secured domestically. To fulfill the necessity, study has been made for the LMR system design technology and conceptual design of KALIMER systems for fluid, instrumentation, control, and protection have been developed. Also the computer code systems for the design and analysis of the KALIMER fluid systems have been developed. These study results are to used as the starting point of the next phase LMR design technology development research
Wireless Fluid-Level Measurement System Equips Boat Owners
2008-01-01
While developing a measurement acquisition system to be used to retrofit aging aircraft with vehicle health monitoring capabilities, Langley Research Center developed an innovative wireless fluid-level measurement system. The NASA technology was of interest to Tidewater Sensors LLC, of Newport News, Virginia, because of its many advantages over conventional fuel management systems, including its ability to provide an accurate measurement of volume while a boat is experiencing any rocking motion due to waves or people moving about on the boat. These advantages led the company to license this novel fluid-level measurement system from NASA for marine applications.
Development of fluid and I and C systems design technology
Energy Technology Data Exchange (ETDEWEB)
Sim, Yoon Sub; Park, C. K.; Kim, S. O. [and others
2000-05-01
LMR is the reactor type that makes utilization of uranium resource very efficiently and the necessity of construction of a LMR in 2020's has been raised. However, the design technology required for construction has not been secured domestically. To fulfill the necessity, study has been made for the LMR system design technology and conceptual design of KALIMER systems for fluid, instrumentation, control, and protection have been developed. Also the computer code systems for the design and analysis of the KALIMER fluid systems have been developed. These study results are to used as the starting point of the next phase LMR design technology development research.
Development of fluid and I and C systems design technology
Energy Technology Data Exchange (ETDEWEB)
Sim, Yoon Sub; Park, C K; Kim, S O [and others
2000-05-01
LMR is the reactor type that makes utilization of uranium resource very efficiently and the necessity of construction of a LMR in 2020's has been raised. However, the design technology required for construction has not been secured domestically. To fulfill the necessity, study has been made for the LMR system design technology and conceptual design of KALIMER systems for fluid, instrumentation, control, and protection have been developed. Also the computer code systems for the design and analysis of the KALIMER fluid systems have been developed. These study results are to used as the starting point of the next phase LMR design technology development research.
Towards a smart non-invasive fluid loss measurement system.
Suryadevara, N K; Mukhopadhyay, S C; Barrack, L
2015-04-01
In this article, a smart wireless sensing non-invasive system for estimating the amount of fluid loss, a person experiences while physical activity is presented. The system measures three external body parameters, Heart Rate, Galvanic Skin Response (GSR, or skin conductance), and Skin Temperature. These three parameters are entered into an empirically derived formula along with the user's body mass index, and estimation for the amount of fluid lost is determined. The core benefit of the developed system is the affluence usage in combining with smart home monitoring systems to care elderly people in ambient assisted living environments as well in automobiles to monitor the body parameters of a motorist.
Determining Rheological Parameters of Generalized Yield-Power-Law Fluid Model
Directory of Open Access Journals (Sweden)
Stryczek Stanislaw
2004-09-01
Full Text Available The principles of determining rheological parameters of drilling muds described by a generalized yield-power-law are presented in the paper. Functions between tangent stresses and shear rate are given. The conditions of laboratory measurements of rheological parameters of generalized yield-power-law fluids are described and necessary mathematical relations for rheological model parameters given. With the block diagrams, the methodics of numerical solution of these relations has been presented. Rheological parameters of an exemplary drilling mud have been calculated with the use of this numerical program.
Fluid spheres and R- and T-regions in general relativity
Energy Technology Data Exchange (ETDEWEB)
McVittie, G C; Wiltshire, R J [Kent Univ., Canterbury (UK)
1975-10-01
R- and T-regions of spacetime are first defined in a particular coordinate system and then with the aid of the Schwarzschild vacuum solution are shown to represent the outside and inside of a black hole respectively. A certain class of interior solutions, relating to a perfect fluid, are also considered and it is found that these R- and T-solutions have distinct physical properties. The R-solutions are static, spherically symmetric, permanent, and have a classical analogue, while the corresponding T-solutions, which are wholly time dependent, are cylindrical, temporary, and do not have a classical analogue. It is shown that these T-solutions cannot be generated from their R-region counterparts. Particular T-solutions are also presented in which the corresponding fluid occupies the whole of a T-region. The fluid would under certain circumstances be black body radiation while for other cases the internal pressure is always greater than the density.
DEFF Research Database (Denmark)
Hansen, Anders Hedegaard; Pedersen, Henrik C.
2014-01-01
Discrete fluid power technology attracts great attention because it enables energy efficiency and robust system architectures. However, the discrete nature of this technology naturally brings shifting phenomenons into the picture. For fluid power system the relative high inductance of fluid...
Spiral waves in driven dusty plasma medium: Generalized hydrodynamic fluid description
Kumar, Sandeep; Patel, Bhavesh; Das, Amita
2018-04-01
Spiral waves are observed in many natural phenomena. They have been extensively represented by the mathematical FitzHugh-Nagumo model [Barkley et al., Phys. Rev. A 42, 2489 (1990)] of excitable media. Also, in incompressible fluid simulations, the excitation of thermal spiral waves has been reported by Li et al. [Phys. of Fluids 22, 011701 (2010)]. In the present paper, the spatiotemporal development of spiral waves in the context of weak and strong coupling limits has been shown. While the weakly coupled medium has been represented by a simple fluid description, for strong coupling, a generalized visco-elastic fluid description has been employed. The medium has been driven by an external force in the form of a rotating electric field. It is shown that when the amplitude of force is small, the density perturbations in the medium are also small. In this case, the excitations do not develop as a spiral wave. Only when the amplitude of force is high so as to drive the density perturbations to nonlinear amplitudes does the spiral density wave formation occurs. The role of the forcing frequency and the effect of strong coupling and the sound velocity of medium in the formation and evolution of spiral waves have been investigated in detail.
Lagrange formalism for a system of several fluids interacting electromagnetically
International Nuclear Information System (INIS)
Vuillemin, M.
1964-01-01
After giving the Lagrange expression for a conducting fluid in an external electromagnetic field, the author shows that a Lagrange expression exists for describing the evolution of a system of interacting fluids obtained by adding the Lagrange expression of each fluid.to that of the electromagnetic field. By variation are obtained the fluid movement equation coupled to the Maxwell equations. It is shown that the study of small movements around a stationary state can be deduced from the Lagrange equation expanded to the second power order of the perturbation. It is then possible to deduce the normal mode equations and the study the stability by examining the modes which are marginally stable. (author) [fr
General systems theory mathematical foundations
Mesarovic, Mihajlo D
1975-01-01
In this book, we study theoretical and practical aspects of computing methods for mathematical modelling of nonlinear systems. A number of computing techniques are considered, such as methods of operator approximation with any given accuracy; operator interpolation techniques including a non-Lagrange interpolation; methods of system representation subject to constraints associated with concepts of causality, memory and stationarity; methods of system representation with an accuracy that is the best within a given class of models; methods of covariance matrix estimation;methods for low-rank mat
Hansen, J S; Daivis, Peter J; Dyre, Jeppe C; Todd, B D; Bruus, Henrik
2013-01-21
The extended Navier-Stokes theory accounts for the coupling between the translational and rotational molecular degrees of freedom. In this paper, we generalize this theory to non-zero frequencies and wavevectors, which enables a new study of spatio-temporal correlation phenomena present in molecular fluids. To discuss these phenomena in detail, molecular dynamics simulations of molecular chlorine are performed for three different state points. In general, the theory captures the behavior for small wavevector and frequencies as expected. For example, in the hydrodynamic regime and for molecular fluids with small moment of inertia like chlorine, the theory predicts that the longitudinal and transverse intrinsic angular velocity correlation functions are almost identical, which is also seen in the molecular dynamics simulations. However, the theory fails at large wavevector and frequencies. To account for the correlations at these scales, we derive a phenomenological expression for the frequency dependent rotational viscosity and wavevector and frequency dependent longitudinal spin viscosity. From this we observe a significant coupling enhancement between the molecular angular velocity and translational velocity for large frequencies in the gas phase; this is not observed for the supercritical fluid and liquid state points.
Body fluid matrix evaluation on a Roche cobas 8000 system.
Owen, William E; Thatcher, Mindy L; Crabtree, Karolyn J; Greer, Ryan W; Strathmann, Frederick G; Straseski, Joely A; Genzen, Jonathan R
2015-09-01
Chemical analysis of body fluids is commonly requested by physicians. Because most commercial FDA-cleared clinical laboratory assays are not validated by diagnostic manufacturers for "non-serum" and "non-plasma" specimens, laboratories may need to complete additional validation studies to comply with regulatory requirements regarding body fluid testing. The objective of this report is to perform recovery studies to evaluate potential body fluid matrix interferences for commonly requested chemistry analytes. Using an IRB-approved protocol, previously collected clinical body fluid specimens (biliary/hepatic, cerebrospinal, dialysate, drain, pancreatic, pericardial, peritoneal, pleural, synovial, and vitreous) were de-identified and frozen (-20°C) until experiments were performed. Recovery studies (spiking with high concentration serum, control, and/or calibrator) were conducted using 10% spiking solution by volume; n=5 specimens per analyte/body fluid investigated. Specimens were tested on a Roche cobas 8000 system (c502, c702, e602, and ISE modules). In all 80 analyte/body fluid combinations investigated (including amylase, total bilirubin, urea nitrogen, carbohydrate antigen 19-9, carcinoembryonic antigen, cholesterol, chloride, creatinine, glucose, potassium, lactate dehydrogenase, lipase, rheumatoid factor, sodium, total protein, triglycerides, and uric acid), the average percent recovery was within predefined acceptable limits (less than ±10% from the calculated ideal recovery). The present study provides evidence against the presence of any systematic matrix interference in the analyte/body fluid combinations investigated on the Roche cobas 8000 system. Such findings support the utility of ongoing body fluid validation initiatives conducted to maintain compliance with regulatory requirements. Copyright © 2015 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.
Determination of gas volume trapped in a closed fluid system
Hunter, W. F.; Jolley, J. E.
1971-01-01
Technique involves extracting known volume of fluid and measuring system before and after extraction, volume of entrapped gas is then computed. Formula derived from ideal gas laws is basis of this method. Technique is applicable to thermodynamic cycles and hydraulic systems.
Fluid Delivery System For Capillary Electrophoretic Applications.
Li, Qingbo; Liu, Changsheng; Kane, Thomas E.; Kernan, John R.; Sonnenschein, Bernard; Sharer, Michael V.
2002-04-23
An automated electrophoretic system is disclosed. The system employs a capillary cartridge having a plurality of capillary tubes. The cartridge has a first array of capillary ends projecting from one side of a plate. The first array of capillary ends are spaced apart in substantially the same manner as the wells of a microtitre tray of standard size. This allows one to simultaneously perform capillary electrophoresis on samples present in each of the wells of the tray. The system includes a stacked, dual carrousel arrangement to eliminate cross-contamination resulting from reuse of the same buffer tray on consecutive executions from electrophoresis. The system also has a gel delivery module containing a gel syringe/a stepper motor or a high pressure chamber with a pump to quickly and uniformly deliver gel through the capillary tubes. The system further includes a multi-wavelength beam generator to generate a laser beam which produces a beam with a wide range of wavelengths. An off-line capillary reconditioner thoroughly cleans a capillary cartridge to enable simultaneous execution of electrophoresis with another capillary cartridge. The streamlined nature of the off-line capillary reconditioner offers the advantage of increased system throughput with a minimal increase in system cost.
Farassat, Fereidoun; Myers, Michael K.
2011-01-01
This paper is the first part of a three part tutorial on multidimensional generalized functions (GFs) and their applications in aeroacoustics and fluid mechanics. The subject is highly fascinating and essential in many areas of science and, in particular, wave propagation problems. In this tutorial, we strive to present rigorously and clearly the basic concepts and the tools that are needed to use GFs in applications effectively and with ease. We give many examples to help the readers in understanding the mathematical ideas presented here. The first part of the tutorial is on the basic concepts of GFs. Here we define GFs, their properties and some common operations on them. We define the important concept of generalized differentiation and then give some interesting elementary and advanced examples on Green's functions and wave propagation problems. Here, the analytic power of GFs in applications is demonstrated with ease and elegance. Part 2 of this tutorial is on the diverse applications of generalized derivatives (GDs). Part 3 is on generalized Fourier transformations and some more advanced topics. One goal of writing this tutorial is to convince readers that, because of their powerful operational properties, GFs are absolutely essential and useful in engineering and physics, particularly in aeroacoustics and fluid mechanics.
General Systems Theory and Instructional Design.
Salisbury, David F.
The use of general systems theory in the field of instructional systems design (ISD) is explored in this paper. Drawing on work by Young, the writings of 12 representative ISD writers and researchers were surveyed to determine the use of 60 general systems theory concepts by the individual authors. The average number of concepts used by these…
General Logic-Systems and Consequence Operators
Herrmann, Robert A.
2005-01-01
In this paper, general logic-systems are investigated. It is shown that there are infinitely many finite consequence operators defined on a fixed language L that cannot be generated from a finite logic-system. It is shown that a set map is a finite consequence operator iff it is defined by a general logic-system.
LHC II system sensitivity to magnetic fluids
Cotae, Vlad
2005-01-01
Experiments have been designed to reveal the influences of ferrofluid treatment and static magnetic field exposure on the photosynthetic system II, where the light harvesting complex (LHC II) controls the ratio chlorophyll a/ chlorophyll b (revealing, indirectly, the photosynthesis rate). Spectrophotometric measurement of chlorophyll content revealed different influences for relatively low ferrofluid concentrations (10-30 mul/l) in comparison to higher concentrations (70-100 mul/l). The overlapped effect of the static magnetic field shaped better the stimulatory ferrofluid action on LHC II system in young poppy plantlets.
Overview of NSSS Fluid System Design of PGSFR
Energy Technology Data Exchange (ETDEWEB)
Han, Ji-Woong; Choi, Seok-Ki; Kim, Seong-O; Kim, Eui-Kwang; Kim, Dehee; Hong, Jonggan; Ye, Huee-Youl; Yeom, Sujin; Ryu, Seungho; Yoon, Jung; Choi, Sun Rock; Park, Jin-Seok; Lee, Tae-Ho Lee [KAERI, Daejeon (Korea, Republic of)
2016-05-15
In this paper an overview on the NSSS fluid system design of PGSFR is described based on the issued design documents. System concepts and major components design concepts for PHTS, IHTS, DHRS and SWRPRS were developed. Thermal-hydraulic characteristics were analyzed based on CFD simulation. The design bases and concepts for auxiliary systems were also developed. The upstream design requirements of fluid system such as system design requirements, component design requirements, I and C design requirements, BOP interface design requirements, design guides and P and IDs were produced. The control logic and computer code for the analysis for operational characteristics is under progress. The protection system consists of a safety grade PPS and a non-safety grade DPS (Diverse Protection System). The DPS provides a diverse method to trip the reactor to satisfy the requirements relative to ATWS (Anticipated Transients Without Scram) as well as Defense-In-Depth and Diversity.
Systems and methods for multi-fluid geothermal energy systems
Buscheck, Thomas A.
2017-09-19
A method for extracting geothermal energy from a geothermal reservoir formation. A production well is used to extract brine from the reservoir formation. At least one of nitrogen (N.sub.2) and carbon dioxide (CO.sub.2) may be used to form a supplemental working fluid which may be injected into a supplemental working fluid injection well. The supplemental working fluid may be used to augment a pressure of the reservoir formation, to thus drive a flow of the brine out from the reservoir formation.
Generalized Einstein relation for the mutual diffusion coefficient of a binary fluid mixture.
Felderhof, B U
2017-08-21
The method employed by Einstein to derive his famous relation between the diffusion coefficient and the friction coefficient of a Brownian particle is used to derive a generalized Einstein relation for the mutual diffusion coefficient of a binary fluid mixture. The expression is compared with the one derived by de Groot and Mazur from irreversible thermodynamics and later by Batchelor for a Brownian suspension. A different result was derived by several other workers in irreversible thermodynamics. For a nearly incompressible solution, the generalized Einstein relation agrees with the expression derived by de Groot and Mazur. The two expressions also agree to first order in solute density. For a Brownian suspension, the result derived from the generalized Smoluchowski equation agrees with both expressions.
Improved design features of KSNP+ BOP Fluid System
International Nuclear Information System (INIS)
Park, Heung Gyu; Yoon, Kyung Sup
2002-01-01
KOPEC (Korea Power Engineering Co.) in conjunction with the client KHNP (Korea Hydro and Nuclear Power Co.) has been developing the KSNP + (Improved Korean Standard Nuclear Power Plants) design concept since 1998. The main objective of the KSNP + is to enhance safety and economy of KSNP. The design concepts of the KSNP + will be implemented in Shin-Kori Units 1 and 2 Shin-Wolsung Units 1 and 2. This paper provides on an introduction to the improved design features of the KSNP + BOP fluid system consisting of 45 design improvement items. The design improvement concepts of the BOP fluid system have been developed as follows: optimization of system configuration and capacity, simplification of system, and adoption of advanced design features. Improved design features of the BOP fluid system allow additional benefits due to making a contribution to the optimization of plant arrangement and the reduction of operating costs during the plant life time. In conclusion, design improvement to the BOP fluid system have contributed to the KSNP + design concept being more reliable, safe and economically competitive
Gravitational equilibrium of a multi-body fluid system
International Nuclear Information System (INIS)
Eriguchi, Yoshiharu; Hachisu, Izumi.
1983-01-01
We have computed gravitational equilibrium sequences for systems consisting of N incompressible fluid bodies (N = 3, 4, 5). The component fluids are assumed congruent. The system seems to become a lobe-like shape for N = 3 case and a ring-like shape for N>=4 cases according as the fluid bodies come nearer to each other. For every sequence there is a critical equilibrium whose dimensionless angular momentum has the minimum value of the sequence. As the final outcome is nearly in equilibrium in the computation of a collapsing gas cloud, we can apply the present results to the interpretation of these dynamical calculations. For instance, the gas cloud can never fissure into any N-body equilibrium when its dimensionless angular momentum is below the critical value of the N-body sequence. (author)
On the spherical symmetry of static perfect fluids in general relativity
International Nuclear Information System (INIS)
Beig, R.; Simon, W.
1990-01-01
We present a theorem which establishes uniqueness, in particular spherical symmetry, of a wide class of general relativistic, static perfect-fluid models provided there exists a spherically symmetric model with the same equation of state and surface potential. The method of proof, which is inspired by recent work of Masood-ul-Alam, is illustrated by demonstrating uniqueness of a class of solutions due to Buchdahl which correspond to an extreme case of the inequality on the equation of state required by our theorem. 16 refs. (Authors)
Stability analysis on the free surface phenomena of a magnetic fluid for general use
International Nuclear Information System (INIS)
Mizuta, Yo
2011-01-01
This paper presents an analysis for elucidating a variety of physical processes on the interface (free surface) of magnetic fluid. The present analysis is composed of the magnetic and the fluid analysis, both of which have no limitations concerning the interface elevation or its profile. The magnetic analysis provides rigorous interface magnetic field under arbitrary distributions of applied magnetic field. For the fluid analysis, the equation for interface motion includes all nonlinear effects. Physical quantities such as the interface magnetic field or the interface stresses, obtained first as the wavenumber components, facilitate confirming the relations with those by the conventional theoretical analyses. The nonlinear effect is formulated as the nonlinear mode coupling between the interface profile and the applied magnetic field. The stability of the horizontal interface profile is investigated by the dispersion relation, and summarized as the branch line. Furthermore, the balance among the spectral components of the interface stresses are shown, within the sufficient range of the wavenumber space. - Research Highlights: → General, rigorous but compact analysis for free surface phenomena is shown. → Analysis is applied without limitations on the interface elevation or its profile. → Nonlinear effects are formulated as the nonlinear mode coupling. → Bifurcation of stability is summarized as the branch line. → Balance among the interface stresses are shown in the wavenumber space.
Johan, Wiklund; Reinhardt, Kotze; Beat, Birkhofer; Stefano, Ricci; Valentino, Meacci; Mats, Stading; Rainer, Haldenwang; SP-Technical Research Institute of Sweden; FPRC, Cape Peninsula University of Technology; Sika Services AG; Information Engineering Department - University of Florence; Information Engineering Department - University of Florence; SP-Technical Research Institute of Sweden; FPRC, Cape Peninsula University of Technology
2015-01-01
In this work we have presented the world's first commercially available embedded in-line fluids characterization system, "Flow-Viz". It has been specifically designed for the non-invasive, in-line, continuous, real-time velocity profile and rheological assessment of opaque, non-Newtonian industrial fluids. The Flow-Viz system has been successfully installed in pilot plants of international companies and used also for academic research. The technology has been applied to a wide range of fluids...
Gestalt Therapy and General System Theory.
Whitner, Phillip A.
While General Systems Theory (GST) concepts appear to be applicable in explaining some of the phenomena that occur in a Gestalt Therapy group, research is needed to support this assumption. General Systems Theory may not be a group theory per se. Instead, GST may be a theory about groups. A meta-theory exists where its value and usefulness is…
Majumdar, Alok K.; LeClair, Andre C.; Hedayat, Ali
2016-01-01
This paper presents a numerical model of pressurization of a cryogenic propellant tank for the Integrated Vehicle Fluid (IVF) system using the Generalized Fluid System Simulation Program (GFSSP). The IVF propulsion system, being developed by United Launch Alliance, uses boiloff propellants to drive thrusters for the reaction control system as well as to run internal combustion engines to develop power and drive compressors to pressurize propellant tanks. NASA Marshall Space Flight Center (MSFC) has been running tests to verify the functioning of the IVF system using a flight tank. GFSSP, a finite volume based flow network analysis software developed at MSFC, has been used to develop an integrated model of the tank and the pressurization system. This paper presents an iterative algorithm for converging the interface boundary conditions between different component models of a large system model. The model results have been compared with test data.
Numerical Modeling of an Integrated Vehicle Fluids System Loop for Pressurizing a Cryogenic Tank
LeClair, A. C.; Hedayat, A.; Majumdar, A. K.
2017-01-01
This paper presents a numerical model of the pressurization loop of the Integrated Vehicle Fluids (IVF) system using the Generalized Fluid System Simulation Program (GFSSP). The IVF propulsion system, being developed by United Launch Alliance to reduce system weight and enhance reliability, uses boiloff propellants to drive thrusters for the reaction control system as well as to run internal combustion engines to develop power and drive compressors to pressurize propellant tanks. NASA Marshall Space Flight Center (MSFC) conducted tests to verify the functioning of the IVF system using a flight-like tank. GFSSP, a finite volume based flow network analysis software developed at MSFC, has been used to support the test program. This paper presents the simulation of three different test series, comparison of numerical prediction and test data and a novel method of presenting data in a dimensionless form. The paper also presents a methodology of implementing a compressor map in a system level code.
Cellular Biotechnology Operations Support System Fluid Dynamics Investigation
2003-01-01
Aboard the International Space Station (ISS), the Tissue Culture Medium (TCM) is the bioreactor vessel in which cell cultures are grown. With its two syringe ports, it is much like a bag used to administer intravenous fluid, except it allows gas exchange needed for life. The TCM contains cell culture medium, and when frozen cells are flown to the ISS, they are thawed and introduced to the TCM through the syringe ports. In the Cellular Biotechnology Operations Support System-Fluid Dynamics Investigation (CBOSS-FDI) experiment, several mixing procedures are being assessed to determine which method achieves the most uniform mixing of growing cells and culture medium.
Computational Fluid and Particle Dynamics in the Human Respiratory System
Tu, Jiyuan; Ahmadi, Goodarz
2013-01-01
Traditional research methodologies in the human respiratory system have always been challenging due to their invasive nature. Recent advances in medical imaging and computational fluid dynamics (CFD) have accelerated this research. This book compiles and details recent advances in the modelling of the respiratory system for researchers, engineers, scientists, and health practitioners. It breaks down the complexities of this field and provides both students and scientists with an introduction and starting point to the physiology of the respiratory system, fluid dynamics and advanced CFD modeling tools. In addition to a brief introduction to the physics of the respiratory system and an overview of computational methods, the book contains best-practice guidelines for establishing high-quality computational models and simulations. Inspiration for new simulations can be gained through innovative case studies as well as hands-on practice using pre-made computational code. Last but not least, students and researcher...
Adaptation of systems to fluid changes; Adaptation des systemes aux changements de fluides
Energy Technology Data Exchange (ETDEWEB)
Clodic, D. [Ecole Nationale Superieure des Mines, 75 - Paris (France)
1996-12-31
Regulation constraints and the stoppage of CFCs production and HCFCs production in the future lead to rapid evolutions in the conceiving of refrigerating installations which are linked with refrigerant changes. The refrigerant/installation pair has become the aim of detailed analyses in order to understand the relation between the thermodynamical properties of fluids and the energy efficiency of refrigerating installations. The efficiency depends entirely on the global design of the installation while the choice of the fluid is only one element that contributes to this efficiency. This paper analyzes successively: the consequences of pure refrigerant substitution on volume and centrifugal compressors, and the constraints linked with the use of mixtures close to azeotropic compounds (R408A and R404A) and mixtures with temperature shift like R407C. In this last case, the replacement is deeply different in the case of water heat exchangers and in the case of air-circulation heat exchangers. (J.S.) 3 refs.
Numerical Cerebrospinal System Modeling in Fluid-Structure Interaction.
Garnotel, Simon; Salmon, Stéphanie; Balédent, Olivier
2018-01-01
Cerebrospinal fluid (CSF) stroke volume in the aqueduct is widely used to evaluate CSF dynamics disorders. In a healthy population, aqueduct stroke volume represents around 10% of the spinal stroke volume while intracranial subarachnoid space stroke volume represents 90%. The amplitude of the CSF oscillations through the different compartments of the cerebrospinal system is a function of the geometry and the compliances of each compartment, but we suspect that it could also be impacted be the cardiac cycle frequency. To study this CSF distribution, we have developed a numerical model of the cerebrospinal system taking into account cerebral ventricles, intracranial subarachnoid spaces, spinal canal and brain tissue in fluid-structure interactions. A numerical fluid-structure interaction model is implemented using a finite-element method library to model the cerebrospinal system and its interaction with the brain based on fluid mechanics equations and linear elasticity equations coupled in a monolithic formulation. The model geometry, simplified in a first approach, is designed in accordance with realistic volume ratios of the different compartments: a thin tube is used to mimic the high flow resistance of the aqueduct. CSF velocity and pressure and brain displacements are obtained as simulation results, and CSF flow and stroke volume are calculated from these results. Simulation results show a significant variability of aqueduct stroke volume and intracranial subarachnoid space stroke volume in the physiological range of cardiac frequencies. Fluid-structure interactions are numerous in the cerebrospinal system and difficult to understand in the rigid skull. The presented model highlights significant variations of stroke volumes under cardiac frequency variations only.
International Nuclear Information System (INIS)
Anon.
1991-01-01
Fluids engineering has played an important role in many applications, from ancient flood control to the design of high-speed compact turbomachinery. New applications of fluids engineering, such as in high-technology materials processing, biotechnology, and advanced combustion systems, have kept up unwaining interest in the subject. More accurate and sophisticated computational and measurement techniques are also constantly being developed and refined. On a more fundamental level, nonlinear dynamics and chaotic behavior of fluid flow are no longer an intellectual curiosity and fluid engineers are increasingly interested in finding practical applications for these emerging sciences. Applications of fluid technology to new areas, as well as the need to improve the design and to enhance the flexibility and reliability of flow-related machines and devices will continue to spur interest in fluids engineering. The objectives of the present seminar were: to exchange current information on arts, science, and technology of fluids engineering; to promote scientific cooperation between the fluids engineering communities of both nations, and to provide an opportunity for the participants and their colleagues to explore possible joint research programs in topics of high priority and mutual interest to both countries. The Seminar provided an excellent forum for reviewing the current state and future needs of fluids engineering for the two nations. With the Seminar ear-marking the first formal scientific exchange between Korea and the United States in the area of fluids engineering, the scope was deliberately left broad and general
A gun recoil system employing a magnetorheological fluid damper
International Nuclear Information System (INIS)
Li, Z C; Wang, J
2012-01-01
This research aims to design and control a full scale gun recoil buffering system which works under real firing impact loading conditions. A conventional gun recoil absorber is replaced with a controllable magnetorheological (MR) fluid damper. Through dynamic analysis of the gun recoil system, a theoretical model for optimal design and control of the MR fluid damper for impact loadings is derived. The optimal displacement, velocity and optimal design rules are obtained. By applying the optimal design theory to protect against impact loadings, an MR fluid damper for a full scale gun recoil system is designed and manufactured. An experimental study is carried out on a firing test rig which consists of a 30 mm caliber, multi-action automatic gun with an MR damper mounted to the fixed base through a sliding guide. Experimental buffering results under passive control and optimal control are obtained. By comparison, optimal control is better than passive control, because it produces smaller variation in the recoil force while achieving less displacement of the recoil body. The optimal control strategy presented in this paper is open-loop with no feedback system needed. This means that the control process is sensor-free. This is a great benefit for a buffering system under impact loading, especially for a gun recoil system which usually works in a harsh environment. (paper)
International Nuclear Information System (INIS)
Li Hongzhe; Tian Bo; Li Lili; Zhang Haiqiang
2010-01-01
The new soliton solutions for the variable-coefficient Boussinesq system, whose applications are seen in fluid dynamics, are studied in this paper with symbolic computation. First, the Painleve analysis is used to investigate its integrability properties. For the identified case we give, the Lax pair of the system is found, and then the Darboux transformation is constructed. At last, some new soliton solutions are presented via the Darboux method. Those solutions might be of some value in fluid dynamics. (general)
Simulating coupled dynamics of a rigid-flexible multibody system and compressible fluid
Hu, Wei; Tian, Qiang; Hu, HaiYan
2018-04-01
As a subsequent work of previous studies of authors, a new parallel computation approach is proposed to simulate the coupled dynamics of a rigid-flexible multibody system and compressible fluid. In this approach, the smoothed particle hydrodynamics (SPH) method is used to model the compressible fluid, the natural coordinate formulation (NCF) and absolute nodal coordinate formulation (ANCF) are used to model the rigid and flexible bodies, respectively. In order to model the compressible fluid properly and efficiently via SPH method, three measures are taken as follows. The first is to use the Riemann solver to cope with the fluid compressibility, the second is to define virtual particles of SPH to model the dynamic interaction between the fluid and the multibody system, and the third is to impose the boundary conditions of periodical inflow and outflow to reduce the number of SPH particles involved in the computation process. Afterwards, a parallel computation strategy is proposed based on the graphics processing unit (GPU) to detect the neighboring SPH particles and to solve the dynamic equations of SPH particles in order to improve the computation efficiency. Meanwhile, the generalized-alpha algorithm is used to solve the dynamic equations of the multibody system. Finally, four case studies are given to validate the proposed parallel computation approach.
Reviewing fluid systems for age-related degradation
International Nuclear Information System (INIS)
Smith, Stan
1991-01-01
Yankee Atomic Electric Company has developed the component degradation assessment tool (CoDAT), an expert system, that aids in handling and evaluating the large amounts of data required to support the license renewal process for nuclear power station fluid systems. In 1990, CoDAT evaluated the Yankee Nuclear Power Station fluid systems for age-related degradation. Its results are now being used to help focus the plant's maintenance programs and manage the expected degradation. CoDAT uses 'If-Then' rules, developed from industry codes, standards and publications, to determine the potential for 19 age-related degradation mechanisms. Other nuclear utilities pursuing the license renewal option also could use CoDAT. (author)
Generalized Cross-Gramian for Linear Systems
DEFF Research Database (Denmark)
Shaker, Hamid Reza
2012-01-01
The cross-gramian is a well-known matrix with embedded controllability and observability information. The cross-gramian is related to the Hankel operator and the Hankel singular values of a linear square system and it has several interesting properties. These properties make the cross...... square symmetric systems, the ordinary cross-gramian does not exist. To cope with this problem, a new generalized cross-gramian is introduced in this paper. In contrast to the ordinary cross-gramian, the generalized cross-gramian can be easily obtained for general linear systems and therefore can be used...
Instabilities in vertically vibrated fluid-grain systems.
King, P J; Lopez-Alcaraz, P; Pacheco-Martinez, H A; Clement, C P; Smith, A J; Swift, M R
2007-03-01
When a bed of fluid-immersed fine grains is exposed to vertical vibration a wealth of phenomena may be observed. At low frequencies a horizontal bed geometry is generally unstable and the bed breaks spatial symmetry, acquiring a tilt. At the same time it undergoes asymmetric granular convection. Fine binary mixtures may separate completely into layers or patterns of stripes. The separated regions may exhibit instabilities in which they undergo wave-like motion or exhibit quasi-periodic oscillations. We briefly review these and a number of related behaviours, identifying the physical mechanisms behind each. Finally, we discuss the magneto-vibratory separation of binary mixtures which results from exposing each component to a different effective gravity and describe the influence of a background fluid on this process.
Imaz Iglesia, I; Gómez López, L I; Fernández Martínez, J A; Mareca Doñate, R; Sangrador Arenas, L A
1996-01-01
To assess the informative usefulness of the Registry, to calculate the incidence rates of accident with biological fluids among health care workers and in the community, to know about the postaccident rate of seroconversion to HIV and to identify risk groups. A descriptive study of the HIV records file of the Registry of Accidental Contacts to Biological Fluids in the Clinic Hospital of Zaragoza was conducted, between January 1987 and September 1993. The registry includes the reports of health care workers and the general population of Health Area III in Aragón (Spain), except for the Calatayud's Hospital. Incidence rates, rate ratios and their 95% confidence intervals were calculated. A total number of 595 accidents were reported, in none of them and HIV infection occurred subsequently. The incidence rate in health care workers was of 1.7 reports per 100 workers per year, while in the community it was of 8.1 per 100,000 people. The housekeeping staff was the group with a higher incidence (rate = 6.7; 95% IC: 3-14.8) and the type of accident more frequently described was needlestick injury. The incidence of reported accidents has increased in the community and in health care workers, which may be due to the increase in the reporting. In health care workers, the incidence in 1993 was within the range reported from other countries. The perception of risk is universal after accidents with unknown biological fluids. The correct disposal of material with biological contamination should be the more important preventive action.
Educational Interpretations of General Systems Theory.
Hug, William E.; King, James E.
This chapter discusses General Systems Theory as it applies to education, classrooms, innovations, and instructional design. The principles of equifinality, open and closed systems, the individual as the key system, hierarchical structures, optimization, stability, cooperation, and competition are discussed, and their relationship to instructional…
On a generalized oscillator system: interbasis expansions
Energy Technology Data Exchange (ETDEWEB)
Kibler, M [Lyon-1 Univ., 69 - Villeurbanne (France). Inst. de Physique Nucleaire; Mardoyan, L G; Pogosyan, G S [Joint Inst. for Nuclear Research, Dubna (Russian Federation). Lab. of Theoretical Physics
1997-12-31
This article deals with a nonrelativistic quantum mechanical study of a dynamical system which generalizes the isotropic harmonic oscillator system in three dimensions. The Schroedinger equation for this generalized oscillator system is separable in spherical, cylindrical, and spheroidal (prolate and oblate) coordinates. The quantum mechanical spectrum of this system is worked out in some details. The problem of interbasis expansions of the wave functions is completely solved. The coefficients for the expansion of the cylindrical basis in terms of the spherical basis, and vice-versa, are found to be analytic continuations (to real values of their arguments) of Clebsch-Gordan coefficients for the group SU(2). The interbasis expansion coefficients for the prolate and oblate spheroidal bases in terms of the spherical or the cylindrical bases are shown to satisfy three-term recursion relations. Finally, a connection between the generalized oscillator system (projected on the z-line) and the Morse system (in one dimension) are discussed. 41 refs.,.
On a generalized oscillator system: interbasis expansions
International Nuclear Information System (INIS)
Kibler, M.; Mardoyan, L.G.; Pogosyan, G.S.
1996-01-01
This article deals with a nonrelativistic quantum mechanical study of a dynamical system which generalizes the isotropic harmonic oscillator system in three dimensions. The Schroedinger equation for this generalized oscillator system is separable in spherical, cylindrical, and spheroidal (prolate and oblate) coordinates. The quantum mechanical spectrum of this system is worked out in some details. The problem of interbasis expansions of the wave functions is completely solved. The coefficients for the expansion of the cylindrical basis in terms of the spherical basis, and vice-versa, are found to be analytic continuations (to real values of their arguments) of Clebsch-Gordan coefficients for the group SU(2). The interbasis expansion coefficients for the prolate and oblate spheroidal bases in terms of the spherical or the cylindrical bases are shown to satisfy three-term recursion relations. Finally, a connection between the generalized oscillator system (projected on the z-line) and the Morse system (in one dimension) are discussed. 41 refs.,
Fluid moderator control system reactor internals distribution system
International Nuclear Information System (INIS)
Fensterer, H.F.; Klassen, W.E.; Veronesi, L.; Boyle, D.E.; Salton, R.B.
1987-01-01
This patent describes a spectral shift pressurized water nuclear reactor employing a low neutron moderating fluid for the spectral shift including a reactor pressure vessel, a core comprising a plurality of fuel assemblies, a core support plate, apparatus comprising means for penetrating the reactor vessel for introducing the moderating fluid into the reactor vessel. Means associated with the core support plate for directly distributing the moderating fluid to and from the fuel assemblies comprises at least one inlet flow channel in the core plate; branch inlet feed lines connect to the inlet flow channel in the core plate; vertical inlet flow lines flow connected to the branch inlet feed lines; each vertical flow line communicates with a fuel assembly; the distribution means further comprise lines serving as return flow lines, each of which is connected to one of the fuel assemblies; branch exit flow lines in the core plate flow connected to the return flow lines of the fuel assembly; and at least one outlet flow channel flow connected to the branch exit flow lines; and a flow port interposed between the penetration means and the distribution means for flow connecting the penetration means with the distribution means
Pulmonary Circulation Transvascular Fluid Fluxes Do Not Change during General Anesthesia in Dogs
Directory of Open Access Journals (Sweden)
Olga Frlic
2018-02-01
Full Text Available General anesthesia (GA can cause abnormal lung fluid redistribution. Pulmonary circulation transvascular fluid fluxes (JVA are attributed to changes in hydrostatic forces and erythrocyte volume (EV regulation. Despite the very low hydraulic conductance of pulmonary microvasculature it is possible that GA may affect hydrostatic forces through changes in pulmonary vascular resistance (PVR, and EV through alteration of erythrocyte transmembrane ion fluxes (ionJVA. Furosemide (Fur was also used because of its potential to affect pulmonary hydrostatic forces and ionJVA. A hypothesis was tested that JVA, with or without furosemide treatment, will not change with time during GA. Twenty dogs that underwent castration/ovariectomy were randomly assigned to Fur (n = 10 (4 mg/kg IV or placebo treated group (Con, n = 10. Baseline arterial (BL and mixed venous blood were sampled during GA just before treatment with Fur or placebo and then at 15, 30 and 45 min post-treatment. Cardiac output (Q and pulmonary artery pressure (PAP were measured. JVA and ionJVA were calculated from changes in plasma protein, hemoglobin, hematocrit, plasma and whole blood ions, and Q. Variables were analyzed using random intercept mixed model (P < 0.05. Data are expressed as means ± SE. Furosemide caused a significant volume depletion as evident from changes in plasma protein and hematocrit (P < 0.001. However; Q, PAP, and JVA were not affected by time or Fur, whereas erythrocyte fluid flux was affected by Fur (P = 0.03. Furosemide also affected erythrocyte transmembrane K+ and Cl−, and transvascular Cl− metabolism (P ≤ 0.05. No other erythrocyte transmembrane or transvascular ion fluxes were affected by time of GA or Fur. Our hypothesis was verified as JVA was not affected by GA or ion metabolism changes due to Fur treatment. Furosemide and 45 min of GA did not cause significant hydrostatic changes based on Q and PAP. Inhibition of Na+/K+/2Cl− cotransport caused by Fur
Evolution system study of a generalized scheme of relativistic magnetohydrodynamic
International Nuclear Information System (INIS)
Mahjoub, Bechir.
1977-01-01
A generalized scheme of relativistic magnetohydrodynamics is studied with a thermodynamical differential relation proposed by Fokker; this scheme takes account of interaction between the fluid and the magnetic field. Taking account of an integrability condition of this relation, the evolution system corresponding to this scheme is identical to the one corresponding to the usual scheme; it has the same characteristics; it is non-strictly hyperbolic with the same hypothesis of compressibility and it has, with respect to the Cauchy problem, an unique solution in a Gevrey class of index α=3/2 [fr
General exact solution for homogeneous time-dependent self-gravitating perfect fluids
International Nuclear Information System (INIS)
Gaete, P.; Hojman, R.
1988-01-01
A procedure to obtain the general exact solution of Einstein equations for a self-gravitating spherically-symmetric static perfect fluid obeying an arbitrary equation of state, is applied to time-dependent Kantowsky-Sachs line elements (with spherical, planar and hyperbolic symmetry). As in the static case, the solution is generated by an arbitrary function of the independent variable and its first derivative. To illustrate the results, the whole family of (plane-symmetric) solutions with a ''gamma-law'' equation of state is explicity obtained in terms of simple known functions. It is also shown that, while in the static plane-symmtric line elements, every metric is in one to one correspondence with a ''partner-metric'' (both originated from the same generatrix function), in this case every generatrix function univocally determines one metric. (author) [pt
Analysis of Direct Samples of Early Solar System Aqueous Fluids
Zolensky, Michael E.; Bodnar, R J.; Fedele, L.; Yurimoto,H.; Itoh, S.; Fries, M.; Steele, A.
2012-01-01
Over the past three decades we have become increasingly aware of the fundamental importance of water, and aqueous alteration, on primitive solar-system bodies. Some carbonaceous and ordinary chondrites have been altered by interactions with liquid water within the first 10 million years after formation of their parent asteroids. Millimeter to centimeter-sized aggregates of purple halite containing aqueous fluid inclusions were found in the matrix of two freshly-fallen brecciated H chondrite falls, Monahans (1998, hereafter simply "Monahans") (H5) and Zag (H3-6) (Zolensky et al., 1999; Whitby et al., 2000; Bogard et al., 2001) In order to understand origin and evolution of the aqueous fluids inside these inclusions we much measure the actual fluid composition, and also learn the O and H isotopic composition of the water. It has taken a decade for laboratory analytical techniques to catch up to these particular nanomole-sized aqueous samples. We have recently been successful in (1) measuring the isotopic composition of H and O in the water in a few fluid inclusions from the Zag and Monahans halite, (2) mineralogical characterization of the solid mineral phases associated with the aqueous fluids within the halite, and (3) the first minor element analyses of the fluid itself. A Cameca ims-1270 equipped with a cryo-sample-stage of Hokkaido University was specially prepared for the O and H isotopic measurements. The cryo-sample-stage (Techno. I. S. Corp.) was cooled down to c.a. -190 C using liquid nitrogen at which the aqueous fluid in inclusions was frozen. We excavated the salt crystal surfaces to expose the frozen fluids using a 15 keV Cs+ beam and measured negative secondary ions. The secondary ions from deep craters of approximately 10 m in depth emitted stably but the intensities changed gradually during measurement cycles because of shifting states of charge compensation, resulting in rather poor reproducibility of multiple measurements of standard fluid
Interpretation of Fermion system equilibration by energy fluid motion
International Nuclear Information System (INIS)
Jang, S.
1990-01-01
We study the equilibration of fermion system with the help of both linear and non-linear master equations which are originated from the extended time-dependent Hartree-Fock equation of motion. We show how the non-linear master equation for nucleon occupation number transforms into the Navier-Stokes type of one dimensional equation for non-stationary flow of a compressible and viscous fluid. Physical consequences of these equations are investigated by providing illustrative examples
International Nuclear Information System (INIS)
Sieniutycz, S.; Berry, R.S.
1993-01-01
A Lagrangian with dissipative (e.g., Onsager's) potentials is constructed for the field description of irreversible heat-conducting fluids, off local equilibrium. Extremum conditions of action yield Clebsch representations of temperature, chemical potential, velocities, and generalized momenta, including a thermal momentum introduced recently [R. L. Selinger and F. R. S. Whitham, Proc. R. Soc. London, Ser. A 302, 1 (1968); S. Sieniutycz and R. S. Berry, Phys. Rev. A 40, 348 (1989)]. The basic question asked is ''To what extent may irreversibility, represented by a given form of the entropy source, influence the analytical form of the conservation laws for the energy and momentum?'' Noether's energy for a fluid with heat flow is obtained, which leads to a fundamental equation and extended Hamiltonian dynamics obeying the second law of thermodynamics. While in the case of the Onsager potentials this energy coincides numerically with the classical energy E, it contains an extra term (vanishing along the path) still contributing to an irreversible evolution. Components of the energy-momentum tensor preserve all terms regarded standardly as ''irreversible'' (heat, tangential stresses, etc.) generalized to the case when thermodynamics includes the state gradients and the so-called thermal phase, which we introduce here. This variable, the Lagrange multiplier of the entropy generation balance, is crucial for consistent treatment of irreversible processes via an action formalism. We conclude with the hypothesis that embedding the first and second laws in the context of the extremal behavior of action under irreversible conditions may imply accretion of an additional term to the classical energy
General digitalized system on nuclear power plants
International Nuclear Information System (INIS)
Akagi, Katsumi; Kadohara, Hozumi; Taniguchi, Manabu
2000-01-01
Hitherto, instrumentation control system in a PWR nuclear power plant has stepwisely adopted digital technology such as application of digital instrumentation control device to ordinary use (primary/secondary system control device, and so on), application of CRT display system to monitoring function, and so forth, to realize load reduction of an operator due to expansion of operation automation range, upgrading of reliability and maintenance due to self-diagnosis function, reduction of mass in cables due to multiple transfer, and upgrading of visual recognition due to information integration. In next term PWR plant instrumentation control system, under consideration of application practice of conventional digital technology, application of general digitalisation system to adopt digitalisation of overall instrumentation control system containing safety protection system, and central instrumentation system (new type of instrumentation system) and to intend to further upgrade economics, maintenance, operability/monitoring under security of reliability/safety is planned. And, together with embodiment of construction program of the next-term plant, verification at the general digitalisation proto-system aiming at establishment of basic technology on the system is carried out. Then, here was described on abstract of the general digitalisation system and characteristics of a digital type safety protection apparatus to be adopted in the next-term plant. (G.K.)
21 CFR 882.5550 - Central nervous system fluid shunt and components.
2010-04-01
... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Central nervous system fluid shunt and components... Central nervous system fluid shunt and components. (a) Identification. A central nervous system fluid... central nervous system to an internal delivery site or an external receptacle for the purpose of relieving...
A general coarse and fine mesh solution scheme for fluid flow modeling in VHTRS
International Nuclear Information System (INIS)
Clifford, I; Ivanov, K; Avramova, M.
2011-01-01
Coarse mesh Computational Fluid Dynamics (CFD) methods offer several advantages over traditional coarse mesh methods for the safety analysis of helium-cooled graphite-moderated Very High Temperature Reactors (VHTRs). This relatively new approach opens up the possibility for system-wide calculations to be carried out using a consistent set of field equations throughout the calculation, and subsequently the possibility for hybrid coarse/fine mesh or hierarchical multi scale CFD simulations. To date, a consistent methodology for hierarchical multi-scale CFD has not been developed. This paper describes work carried out in the initial development of a multi scale CFD solver intended to be used for the safety analysis of VHTRs. The VHTR is considered on any scale to consist of a homogenized two-phase mixture of fluid and stationary solid material of varying void fraction. A consistent set of conservation equations was selected such that they reduce to the single-phase conservation equations for the case where void fraction is unity. The discretization of the conservation equations uses a new pressure interpolation scheme capable of capturing the discontinuity in pressure across relatively large changes in void fraction. Based on this, a test solver was developed which supports fully unstructured meshes for three-dimensional time-dependent compressible flow problems, including buoyancy effects. For typical VHTR flow phenomena the new solver shows promise as an effective candidate for predicting the flow behavior on multiple scales, as it is capable of modeling both fine mesh single phase flows as well as coarse mesh flows in homogenized regions containing both fluid and solid materials. (author)
CAMAC instrumentation system: introduction and general description
International Nuclear Information System (INIS)
Costrell, L.
1976-01-01
The CAMAC instrumentation system is described in a general way in this introductory paper which is followed by papers that discuss the system in greater detail. This paper is an updated version of the introductory paper that appeared in the April 1973 IEEE Transactions on Nuclear Science
Integrability of some generalized Lotka - Volterra systems
Energy Technology Data Exchange (ETDEWEB)
Bountis, T.C.; Bier, M.; Hijmans, J.
1983-08-08
Several integrable systems of nonlinear ordinary differential equations of the Lotka-Volterra type are identified by the Painleve property and completely integrated. One such integrable case of N first order ode's is found, with N - 2 free parameters and N arbitrary. The concept of integrability of a general dynamical system, not necessarily derived from a hamiltonian, is also discussed.
Computational Fluid Dynamics Analysis of an Evaporative Cooling System
Directory of Open Access Journals (Sweden)
Kapilan N.
2016-11-01
Full Text Available The use of chlorofluorocarbon based refrigerants in the air-conditioning system increases the global warming and causes the climate change. The climate change is expected to present a number of challenges for the built environment and an evaporative cooling system is one of the simplest and environmentally friendly cooling system. The evaporative cooling system is most widely used in summer and in rural and urban areas of India for human comfort. In evaporative cooling system, the addition of water into air reduces the temperature of the air as the energy needed to evaporate the water is taken from the air. Computational fluid dynamics is a numerical analysis and was used to analyse the evaporative cooling system. The CFD results are matches with the experimental results.
Formal First Integrals of General Dynamical Systems
Directory of Open Access Journals (Sweden)
Jia Jiao
2016-01-01
Full Text Available The goal of this paper is trying to make a complete study on the integrability for general analytic nonlinear systems by first integrals. We will firstly give an exhaustive discussion on analytic planar systems. Then a class of higher dimensional systems with invariant manifolds will be considered; we will develop several criteria for existence of formal integrals and give some applications to illustrate our results at last.
Reviving the shear-free perfect fluid conjecture in general relativity
Sikhonde, Muzikayise E.; Dunsby, Peter K. S.
2017-12-01
Employing a Mathematica symbolic computer algebra package called xTensor, we present (1+3) -covariant special case proofs of the shear-free perfect fluid conjecture in general relativity. We first present the case where the pressure is constant, and where the acceleration is parallel to the vorticity vector. These cases were first presented in their covariant form by Senovilla et al. We then provide a covariant proof for the case where the acceleration and vorticity vectors are orthogonal, which leads to the existence of a Killing vector along the vorticity. This Killing vector satisfies the new constraint equations resulting from the vanishing of the shear. Furthermore, it is shown that in order for the conjecture to be true, this Killing vector must have a vanishing spatially projected directional covariant derivative along the velocity vector field. This in turn implies the existence of another basic vector field along the direction of the vorticity for the conjecture to hold. Finally, we show that in general, there exists a basic vector field parallel to the acceleration for which the conjecture is true.
International Nuclear Information System (INIS)
Myeong, Hyeon Guk
1999-06-01
This book deals with computational fluid dynamics with basic and history of numerical fluid dynamics, introduction of finite volume method using one-dimensional heat conduction equation, solution of two-dimensional heat conduction equation, solution of Navier-Stokes equation, fluid with heat transport, turbulent flow and turbulent model, Navier-Stokes solution by generalized coordinate system such as coordinate conversion, conversion of basic equation, program and example of calculation, application of abnormal problem and high speed solution of numerical fluid dynamics.
The role of fluid migration system in hydrocarbon accumulation in Maichen Sag, Beibuwan Basin
Liu, Hongyu; Yang, Jinxiu; Wu, Feng; Chen, Wei; Liu, Qianqian
2018-02-01
Fluid migration system is of great significance for hydrocarbon accumulation, including the primary migration and secondary migration. In this paper, the fluid migration system is analysed in Maichen Sag using seismic, well logging and core data. Results show that many factors control the hydrocarbon migration process, including hydrocarbon generation and expulsion period from source rocks, microfractures developed in the source rocks, the connected permeable sand bodies, the vertical faults cutting into/through the source rocks and related fault activity period. The spatial and temporal combination of these factors formed an effective network for hydrocarbon expulsion and accumulation, leading to the hydrocarbon reservoir distribution at present. Generally, a better understanding of the hydrocarbon migration system can explain the present status of hydrocarbon distribution, and help select future target zones for oil and gas exploration.
Ecological and general systems an introduction to systems ecology
Odum, Howard T.
1994-01-01
Using an energy systems language that combines energetics, kinetics, information, cybernetics, and simulation, Ecological and General Systems compares models of many fields of science, helping to derive general systems principles. First published as Systems Ecology in 1983, Ecological and General Systems proposes principles of self-organization and the designs that prevail by maximizing power and efficiency. Comparisons to fifty other systems languages are provided. Innovative presentations are given on earth homeostasis (Gaia); the inadequacy of presenting equations without network relationships and energy constraints; the alternative interpretation of high entropy complexity as adaptive structure; basic equations of ecological economics; and the energy basis of scientific hierarchy.
21 CFR 862.1455 - Lecithin/sphingomyelin ratio in amniotic fluid test system.
2010-04-01
... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Lecithin/sphingomyelin ratio in amniotic fluid... Clinical Chemistry Test Systems § 862.1455 Lecithin/sphingomyelin ratio in amniotic fluid test system. (a) Identification. A lecithin/sphingomyelin ratio in amniotic fluid test system is a device intended to measure the...
Modeling interfacial area transport in multi-fluid systems
Energy Technology Data Exchange (ETDEWEB)
Yarbro, Stephen Lee [Univ. of California, Berkeley, CA (United States)
1996-11-01
Many typical chemical engineering operations are multi-fluid systems. They are carried out in distillation columns (vapor/liquid), liquid-liquid contactors (liquid/liquid) and other similar devices. An important parameter is interfacial area concentration, which determines the rate of interfluid heat, mass and momentum transfer and ultimately, the overall performance of the equipment. In many cases, the models for determining interfacial area concentration are empirical and can only describe the cases for which there is experimental data. In an effort to understand multiphase reactors and the mixing process better, a multi-fluid model has been developed as part of a research effort to calculate interfacial area transport in several different types of in-line static mixers. For this work, the ensemble-averaged property conservation equations have been derived for each fluid and for the mixture. These equations were then combined to derive a transport equation for the interfacial area concentration. The final, one-dimensional model was compared to interfacial area concentration data from two sizes of Kenics in-line mixer, two sizes of concurrent jet and a Tee mixer. In all cases, the calculated and experimental data compared well with the highest scatter being with the Tee mixer comparison.
Conceptual design of intravenous fluids level monitoring system - a review
Verma, Prikshit; Padmani, Aniket; Boopathi, M.
2017-11-01
In today’s world of automation, there are advancements going on in all the fields. Each work is being automated day by day. However, if we see our current medical care system, some areas require manual caretaker and are loaded with heavy jobs, which consumes a lot of time. Nevertheless, since the work is related to human health, it should be properly done and that too with accuracy. An example of such a particular work is injecting saline or Intravenous (IV) fluids in a patient. The monitoring of such fluids needs utter attention as if the bottle of the fluid is not changed on time, it may lead to various problems for the patients like backflow of blood, blood loss etc. Various researches have been performed to overcome such critical situation. Different monitoring and alerting techniques are described in different researches. So, in our study, we will go through the researches done in this particular field and will see how different ideas are implemented.
Generalized fast feedback system in the SLC
International Nuclear Information System (INIS)
Hendrickson, L.; Allison, S.; Gromme, T.; Himel, T.; Krauter, K.; Rouse, F.; Sass, R.; Shoaee, H.
1992-01-01
A generalized fast feedback system has been developed to stabilize beams at various locations in the SLC. The system is designed to perform measurements and change actuator settings to control beam states such as position, angle and energy on a pulse to pulse basis. The software design is based on the state space formalism of digital control theory. The system is database-driven, facilitating the addition of new loops without requiring additional software. A communications system, KISNet, provides fast communications links between microprocessors for feedback loops which involve multiple micros. Feedback loops have been installed in seventeen locations throughout the SLC and have proven to be invaluable in stabilizing the machine. (author)
Generalized fast feedback system in the SLC
International Nuclear Information System (INIS)
Hendrickson, L.; Allison, S.; Gromme, T.; Himel, T.; Krauter, K.; Rouse, F.; Sass, R.; Shoaee, H.
1991-11-01
A generalized fast feedback system has been developed to stabilize beams at various locations in the SLC. The system is designed to perform measurements and change actuator settings to control beam states such as position, angle and energy on a pulse to pulse basis. The software design is based on the state space formalism of digital control theory. The system is database-driven, facilitating the addition of new loops without requiring additional software. A communications system, KISNet, provides fast communications links between microprocessors for feedback loops which involve multiple micros. Feedback loops have been installed in seventeen locations throughout the SLC and have proven to be invaluable in stabilizing the machine
General Atomic's radioactive gas recovery system
International Nuclear Information System (INIS)
Mahn, J.A.; Perry, C.A.
1975-01-01
General Atomic Company has developed a Radioactive Gas Recovery System for the HTGR which separates, for purposes of retention, the radioactive components from the non-radioactive reactor plant waste gases. This provides the capability for reducing to an insignificant level the amount of radioactivity released from the gas waste system to the atmosphere--a most significant improvement in reducing total activity release to the environment. (U.S.)
Invariant of dynamical systems: A generalized entropy
International Nuclear Information System (INIS)
Meson, A.M.; Vericat, F.
1996-01-01
In this work the concept of entropy of a dynamical system, as given by Kolmogorov, is generalized in the sense of Tsallis. It is shown that this entropy is an isomorphism invariant, being complete for Bernoulli schemes. copyright 1996 American Institute of Physics
General Systems Theory and Counterplan Competition.
Madsen, Arnie
1989-01-01
Discusses the trend in academic debate on policy questions toward a wide acceptance of counterplans, encouraging combinations of proposals which appear at face value able to coexist but upon deeper analysis are incompatible. Argues in opposition to this trend by applying concepts from general systems theory to competition. (KEH)
Fully coupled thermal-mechanical-fluid flow model for nonliner geologic systems
International Nuclear Information System (INIS)
Hart, R.D.
1981-01-01
A single model is presented which describes fully coupled thermal-mechanical-fluid flow behavior of highly nonlinear, dynamic or quasistatic, porous geologic systems. The mathematical formulation for the model utilizes the continuum theory of mixtures to describe the multiphase nature of the system, and incremental linear constitutive theory to describe the path dependency of nonlinear material behavior. The model, incorporated in an explicit finite difference numerical procedure, was implemented in two different computer codes. A special-purpose one-dimensional code, SNEAKY, was written for initial validation of the coupling mechanisms and testing of the coupled model logic. A general purpose commercially available code, STEALTH, developed for modeling dynamic nonlinear thermomechanical processes, was modified to include fluid flow behavior and the coupling constitutive model. The fully explicit approach in the coupled calculation facilitated the inclusion of the coupling mechanisms and complex constitutive behavior. Analytical solutions pertaining to consolidation theory for soils, thermoelasticity for solids, and hydrothermal convection theory provided verification of stress and fluid flow, stress and conductive heat transfer, and heat transfer and fluid flow couplings, respectively, in the coupled model. A limited validation of the adequacy of the coupling constitutive assumptions was also performed by comparison with the physical response from two laboratory tests. Finally, the full potential of the coupled model is illustrated for geotechnical applications in energy-resource related areas. Examples in the areas of nuclear waste isolation and cut-and-fill mining are cited
An analysis of the Rayleigh–Stokes problem for a generalized second-grade fluid
Bazhlekova, Emilia
2014-11-26
© 2014, The Author(s). We study the Rayleigh–Stokes problem for a generalized second-grade fluid which involves a Riemann–Liouville fractional derivative in time, and present an analysis of the problem in the continuous, space semidiscrete and fully discrete formulations. We establish the Sobolev regularity of the homogeneous problem for both smooth and nonsmooth initial data v, including v∈^{L2}(Ω). A space semidiscrete Galerkin scheme using continuous piecewise linear finite elements is developed, and optimal with respect to initial data regularity error estimates for the finite element approximations are derived. Further, two fully discrete schemes based on the backward Euler method and second-order backward difference method and the related convolution quadrature are developed, and optimal error estimates are derived for the fully discrete approximations for both smooth and nonsmooth initial data. Numerical results for one- and two-dimensional examples with smooth and nonsmooth initial data are presented to illustrate the efficiency of the method, and to verify the convergence theory.
An analysis of the Rayleigh–Stokes problem for a generalized second-grade fluid
Bazhlekova, Emilia; Jin, Bangti; Lazarov, Raytcho; Zhou, Zhi
2014-01-01
© 2014, The Author(s). We study the Rayleigh–Stokes problem for a generalized second-grade fluid which involves a Riemann–Liouville fractional derivative in time, and present an analysis of the problem in the continuous, space semidiscrete and fully discrete formulations. We establish the Sobolev regularity of the homogeneous problem for both smooth and nonsmooth initial data v, including v∈^{L2}(Ω). A space semidiscrete Galerkin scheme using continuous piecewise linear finite elements is developed, and optimal with respect to initial data regularity error estimates for the finite element approximations are derived. Further, two fully discrete schemes based on the backward Euler method and second-order backward difference method and the related convolution quadrature are developed, and optimal error estimates are derived for the fully discrete approximations for both smooth and nonsmooth initial data. Numerical results for one- and two-dimensional examples with smooth and nonsmooth initial data are presented to illustrate the efficiency of the method, and to verify the convergence theory.
International Nuclear Information System (INIS)
Bavio, José; Marrón, Beatriz
2014-01-01
Quality of service (QoS) for internet traffic management requires good traffic models and good estimation of sharing network resource. A link of a network processes all traffic and it is designed with certain capacity C and buffer size B. A Generalized Markov Fluid model (GMFM), introduced by Marrón (2011), is assumed for the sources because describes in a versatile way the traffic, allows estimation based on traffic traces, and also consistent effective bandwidth estimation can be done. QoS, interpreted as buffer overflow probability, can be estimated for GMFM through the effective bandwidth estimation and solving the optimization problem presented in Courcoubetis (2002), the so call inf-sup formulas. In this work we implement a code to solve the inf-sup problem and other optimization related with it, that allow us to do traffic engineering in links of data networks to calculate both, minimum capacity required when QoS and buffer size are given or minimum buffer size required when QoS and capacity are given
Probabilistic approach to diffusion in shear flows of generalized viscoelastic second-grade fluids
International Nuclear Information System (INIS)
Wafo Soh, C
2010-01-01
We study diffusion in point-source-driven shear flows of generalized second-grade fluids. We start by obtaining exact solutions of shear flows triggered by point sources under various boundary conditions. For unrestricted flows, we demonstrate that the velocity distribution is the probability density function of a coupled or uncoupled continuous-time random walk. In the first instance, the motion is described by a compound Poisson process with an explicit probability density function corresponding to the velocity distribution. The average waiting time in this situation is finite and is identified with the structural relaxation time. In the second case, we obtain an explicit formula for the probability density function in terms of special functions. In both cases, the probability density functions of the associated stochastic processes are leptokurtic at all finite times with variances linear in time. By using the method of images, we infer velocity fields for restricted flows from those of unrestricted flows. Equipped with some exact expressions of the velocity field, we analyze advection–diffusion via the Feynman–Kac formula, which lends itself naturally to Monte Carlo simulation
Energy Technology Data Exchange (ETDEWEB)
Paul, Sumit; Legner, Wolfgang; Hackner, Angelika; Mueller, Gerhard [EADS Innovation Works, Muenchen (Germany). Bereich Sensors, Electronics and Systems Integration; Baumbach, Volker [Airbus Operations GmbH, Bremen (Germany). Bereich Hydraulic Performance and Integrity
2011-07-01
A miniaturised sensor system for aviation hydraulic fluids is presented. The system consists of an optochemical sensor and a particle sensor. The optochemical sensor detects the form of the O-H absorption feature around 3500 cm{sup -1} to reveal the water and acid contamination in the fluid. The particle sensor uses a light barrier principle to derive its particle contamination number. (orig.)
Computational transport phenomena of fluid-particle systems
Arastoopour, Hamid; Abbasi, Emad
2017-01-01
This book concerns the most up-to-date advances in computational transport phenomena (CTP), an emerging tool for the design of gas-solid processes such as fluidized bed systems. The authors examine recent work in kinetic theory and CTP and illustrate gas-solid processes’ many applications in the energy, chemical, pharmaceutical, and food industries. They also discuss the kinetic theory approach in developing constitutive equations for gas-solid flow systems and how it has advanced over the last decade as well as the possibility of obtaining innovative designs for multiphase reactors, such as those needed to capture CO2 from flue gases. Suitable as a concise reference and a textbook supplement for graduate courses, Computational Transport Phenomena of Gas-Solid Systems is ideal for practitioners in industries involved with the design and operation of processes based on fluid/particle mixtures, such as the energy, chemicals, pharmaceuticals, and food processing. Explains how to couple the population balance e...
A general framework for intelligent recommender systems
Directory of Open Access Journals (Sweden)
Jose Aguilar
2017-07-01
Full Text Available In this paper, we propose a general framework for an intelligent recommender system that extends the concept of a knowledge-based recommender system. The intelligent recommender system exploits knowledge, learns, discovers new information, infers preferences and criticisms, among other things. For that, the framework of an intelligent recommender system is defined by the following components: knowledge representation paradigm, learning methods, and reasoning mechanisms. Additionally, it has five knowledge models about the different aspects that we can consider during a recommendation: users, items, domain, context and criticisms. The mix of the components exploits the knowledge, updates it and infers, among other things. In this work, we implement one intelligent recommender system based on this framework, using Fuzzy Cognitive Maps (FCMs. Next, we test the performance of the intelligent recommender system with specialized criteria linked to the utilization of the knowledge in order to test the versatility and performance of the framework.
Two-fluid equations for a nuclear system with arbitrary motions
Energy Technology Data Exchange (ETDEWEB)
Kim, Byoung Jae [Chungnam National University, Daejeon (Korea, Republic of); Kim, Kyung Doo [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)
2016-10-15
Ocean nuclear systems include a seabed-type plant, a floating-type plant, and a nuclear-propulsion ship. We asked ourselves, 'What governing equations should be used for ocean nuclear systems?' Since ocean nuclear systems are apt to move arbitrarily, the two-fluid model must be formulated in the non-inertial frame of reference that is undergoing acceleration with respect to an inertial frame. Two-phase flow systems with arbitrary motions are barely reported. Kim et al. (1996) added the centripetal and Euler acceleration forces to the homogeneous equilibrium momentum equation embedded in the RETRAN code. However, they did not look into the mass and energy equations. The purpose of this study is to derive general two-fluid equations in the non-inertial frame of reference, which can be used for safety analysis of ocean nuclear systems. The two-fluid equation forms for scalar properties such as mass, internal energy, and enthalpy equation in the moving frame are the same as those in the absolute frame. On the other hand, the fictitious effect must be included in the momentum equation.
General distributed control system for fusion experiments
International Nuclear Information System (INIS)
Klingner, P.L.; Levings, S.J.; Wilkins, R.W.
1986-01-01
A general control system using distributed LSI-11 microprocessors is being developed. Common software residues in each LSI-11 and is tailored to an application by control specifications downloaded from a host computer. The microprocessors, their control interfaces, and the micro-to-host communications are CAMAC based. The host computer also supports an operator interface, coordination of multiple microprocessors, and utilities to create and maintain the control specifications. Typical applications include monitoring safety interlocks as well as controlling vacuum systems, high voltage charging systems, and diagnostics
TITUS: a general finite element system
International Nuclear Information System (INIS)
Bougrelle, P.
1983-01-01
TITUS is a general finite element structural analysis system which performs linear/non-linear, static/dynamic analyses of heat-transfer/thermo-mechanical problems. One of the major features of TITUS is that it was designed by engineers, to address engineers in an industrial environment. This has resulted in an easy to use system, with a high-level free-formatted problem oriented language, a large selection of pre- and post processors and sophisticated graphic capabilities. TITUS has many references in civil, mechanical and nuclear engineering applications. The TITUS system is available on various types of machines, from large mainframes to mini computers
Medical Information Management System (MIMS): A generalized interactive information system
Alterescu, S.; Friedman, C. A.; Hipkins, K. R.
1975-01-01
An interactive information system is described. It is a general purpose, free format system which offers immediate assistance where manipulation of large data bases is required. The medical area is a prime area of application. Examples of the system's operation, commentary on the examples, and a complete listing of the system program are included.
Batey, Mark; Chamorro-Premuzic, Tomas; Furnham, Adrian
2009-01-01
Two studies examined the relationships between measures of intelligence, personality and divergent thinking (DT) in student samples. Study one investigated the incremental validity of measures of IQ and fluid intelligence with the Big Five Personality Inventory with regards to DT. Significant relationships of DT to fluid intelligence, Extraversion…
Smoothed particle hydrodynamics model for phase separating fluid mixtures. I. General equations
Thieulot, C; Janssen, LPBM; Espanol, P
We present a thermodynamically consistent discrete fluid particle model for the simulation of a recently proposed set of hydrodynamic equations for a phase separating van der Waals fluid mixture [P. Espanol and C.A.P. Thieulot, J. Chem. Phys. 118, 9109 (2003)]. The discrete model is formulated by
Computational fluid dynamics (CFD) studies of a miniaturized dissolution system.
Frenning, G; Ahnfelt, E; Sjögren, E; Lennernäs, H
2017-04-15
Dissolution testing is an important tool that has applications ranging from fundamental studies of drug-release mechanisms to quality control of the final product. The rate of release of the drug from the delivery system is known to be affected by hydrodynamics. In this study we used computational fluid dynamics to simulate and investigate the hydrodynamics in a novel miniaturized dissolution method for parenteral formulations. The dissolution method is based on a rotating disc system and uses a rotating sample reservoir which is separated from the remaining dissolution medium by a nylon screen. Sample reservoirs of two sizes were investigated (SR6 and SR8) and the hydrodynamic studies were performed at rotation rates of 100, 200 and 400rpm. The overall fluid flow was similar for all investigated cases, with a lateral upward spiraling motion and central downward motion in the form of a vortex to and through the screen. The simulations indicated that the exchange of dissolution medium between the sample reservoir and the remaining release medium was rapid for typical screens, for which almost complete mixing would be expected to occur within less than one minute at 400rpm. The local hydrodynamic conditions in the sample reservoirs depended on their size; SR8 appeared to be relatively more affected than SR6 by the resistance to liquid flow resulting from the screen. Copyright © 2017 Elsevier B.V. All rights reserved.
Mathematical models of incompressible fluids as singular limits of complete fluid systems
Czech Academy of Sciences Publication Activity Database
Feireisl, Eduard
2010-01-01
Roč. 78, č. 2 (2010), s. 523-560 ISSN 1424-9286 R&D Projects: GA ČR GA201/08/0315 Institutional research plan: CEZ:AV0Z10190503 Keywords : scale analysis * Navier-Stokes-Fourier system * incompressible limit Subject RIV: BA - General Mathematics Impact factor: 0.933, year: 2010 http://link.springer.com/article/10.1007%2Fs00032-010-0128-1
International Nuclear Information System (INIS)
Druzhinina, O V; Shestakov, A A
2002-01-01
A generalized direct Lyapunov method is put forward for the study of stability and attraction in general time systems of the following types: the classical dynamical system in the sense of Birkhoff, the general system in the sense of Zubov, the general system in the sense of Seibert, the general system with delay, and the general 'input-output' system. For such systems, with the help of generalized Lyapunov functions with respect to two filters, two quasifilters, or two filter bases, necessary and sufficient conditions for stability and attraction are obtained under minimal assumptions about the mathematical structure of the general system
DEFF Research Database (Denmark)
Fasano, Andrea; Rasmussen, Henrik K.
2017-01-01
A third order accurate, in time and space, finite element scheme for the numerical simulation of three- dimensional time-dependent flow of the molecular stress function type of fluids in a generalized formu- lation is presented. The scheme is an extension of the K-BKZ Lagrangian finite element me...
An optimal control method for fluid structure interaction systems via adjoint boundary pressure
Chirco, L.; Da Vià, R.; Manservisi, S.
2017-11-01
In recent year, in spite of the computational complexity, Fluid-structure interaction (FSI) problems have been widely studied due to their applicability in science and engineering. Fluid-structure interaction systems consist of one or more solid structures that deform by interacting with a surrounding fluid flow. FSI simulations evaluate the tensional state of the mechanical component and take into account the effects of the solid deformations on the motion of the interior fluids. The inverse FSI problem can be described as the achievement of a certain objective by changing some design parameters such as forces, boundary conditions and geometrical domain shapes. In this paper we would like to study the inverse FSI problem by using an optimal control approach. In particular we propose a pressure boundary optimal control method based on Lagrangian multipliers and adjoint variables. The objective is the minimization of a solid domain displacement matching functional obtained by finding the optimal pressure on the inlet boundary. The optimality system is derived from the first order necessary conditions by taking the Fréchet derivatives of the Lagrangian with respect to all the variables involved. The optimal solution is then obtained through a standard steepest descent algorithm applied to the optimality system. The approach presented in this work is general and could be used to assess other objective functionals and controls. In order to support the proposed approach we perform a few numerical tests where the fluid pressure on the domain inlet controls the displacement that occurs in a well defined region of the solid domain.
An automated fluid-transport device for a microfluidic system.
Feng, Jun; Yang, Xiu-Juan; Li, Xin-Chun; Yang, Hui; Chen, Zuan-Guang
2011-01-01
An automated fluid-transport device for a chip-based capillary electrophoresis system has been developed. The device mainly consists of six peristaltic micropumps, two vacuum micropumps, microvalves, multi-way joints, titanium tubes, and a macro-to-micro connector. Various solutions used for the cleaning and activation of chip channels, and electrophoresis separation, are allowed to automatically transport to chip reservoirs by the electric control module. The performance of the whole system was characterized by the analysis of fluorescein sodium using chip electrophoresis with LED-induced fluorescence detection. The peak-height variation (RSD) was 3.8% in six cycles of analyses. Additionally, compared with conventional manual operation, the developed device can spare 60% time for chip pretreatment. This microdevice offers high-efficiency pretreatment for microchips, thereby resulting in a remarkable improvement of analytical capacity for batch samples.
Generalized data management systems and scientific information
International Nuclear Information System (INIS)
Anon.
1978-01-01
This report aims to stimulate scientists of all disciplines to consider the advantages of using a generalized data management system (GDMS) for storage, manipulation and retrieval of the data they collect and often need to share. It should also be of interest to managers and programmers who need to make decisions on the management of scientific (numeric or non-numeric) data. Another goal of this report is to expose the features that a GDMS should have which are specifically necessary to support scientific data, such as data types and special manipulation functions. A GDMS is a system that provides generalized tools for the purpose of defining a database structure, for loading the data, for modification of the data, and for organizing the database for efficient retrieval and formatted output. A data management system is 'generalized' when it provides a user-oriented language for the different functions, so that it is possible to define any new database, its internal organization, and to retrieve and modify the data without the need to develop special purpose software (program) for each new database
Emergency notification systems for the general public
International Nuclear Information System (INIS)
Stearns, J.R.
1989-01-01
This paper describes various aspects of the design, installation, and evaluation of a system to alert the public in the event of an incident at a nuclear generating plant. It is based on experience in the development of alerting systems for 20 U.S. nuclear plants. An alerting system for the community surrounding a nuclear plant is generally referred to as a prompt notification system (PNS). The area within a 10-mile radius surrounding a nuclear plant where the public must be alerted is referred to as an emergency planning zone (EPZ). This circle is usually adjusted to follow the boundaries of local political jurisdictions and to enclose any concentration of population which my be on the border of the EPZ. The following aspects of PNS implementation are addressed in this paper: regulatory perspective, alternative alerting methods, PNS implementation and design, and evaluation and documentation
Therapeutic Options for Controlling Fluids in the Visual System
Curry, Kristina M.; Wotring, Virginia E.
2014-01-01
Visual Impairment/Intracranial Pressure (VIIP) is a newly recognized risk at NASA. The VIIP project examines the effect of long-term exposure to microgravity on vision of crewmembers before and after they return to Earth. Diamox (acetazolamide) is a medication which is used to decrease intraocular pressure; however, it carries a 3% risk of kidney stones. Astronauts are at a higher risk of kidney stones during spaceflight and the use Diamox would only increase the risk; therefore alternative therapies were investigated. Histamine 2 (H2) antagonist acid blockers such as cimetidine, ranitidine, famotidine and nizatidine are typically used to relieve the symptoms of gastroesophageal reflux disease (GERD). H2 receptors have been found in the human visual system, which has led to research on the use of H2 antagonist blockers to control fluid production in the human eye. Another potential therapeutic strategy is targeted at aquaporins, which are water channels that help maintain fluid homeostasis. Aquaporin antagonists are also known to affect intracranial pressure which can in turn alter intraocular pressure. Studies on aquaporin antagonists suggest high potential for effective treatment. The primary objective of this investigation is to review existing research on alternate medications or therapy to significantly reduce intracranial and intraocular pressure. A literature review was conducted. Even though we do not have all the answers quite yet, a considerable amount of information was discovered, and findings were narrowed, which should allow for more conclusive answers to be found in the near future.
Get with the System: General Systems Theory for Business Officials.
Graczyk, Sandra L.
1993-01-01
An introduction to general systems theory and an overview of vocabulary and concepts are presented to introduce school business officials to systems thinking and to foster its use as an analytical tool. The theory is then used to analyze a sample problem: planning changes to a district's administrative computer system. (eight references) (MLF)
Generalized projective synchronization between Lorenz system and Chen's system
International Nuclear Information System (INIS)
Li Guohui
2007-01-01
On the basis of active backstepping design, this paper presents the generalized projective synchronization between two different chaotic systems: Lorenz system and Chen's system. The proposed method combines backstepping methods and active control without having to calculate the Lyapunov exponents and the eigenvalues of the Jacobian matrix, which makes it simple and convenient. Numerical simulations show that this method works very well
Generalized Detectability for Discrete Event Systems
Shu, Shaolong; Lin, Feng
2011-01-01
In our previous work, we investigated detectability of discrete event systems, which is defined as the ability to determine the current and subsequent states of a system based on observation. For different applications, we defined four types of detectabilities: (weak) detectability, strong detectability, (weak) periodic detectability, and strong periodic detectability. In this paper, we extend our results in three aspects. (1) We extend detectability from deterministic systems to nondeterministic systems. Such a generalization is necessary because there are many systems that need to be modeled as nondeterministic discrete event systems. (2) We develop polynomial algorithms to check strong detectability. The previous algorithms are based on observer whose construction is of exponential complexity, while the new algorithms are based on a new automaton called detector. (3) We extend detectability to D-detectability. While detectability requires determining the exact state of a system, D-detectability relaxes this requirement by asking only to distinguish certain pairs of states. With these extensions, the theory on detectability of discrete event systems becomes more applicable in solving many practical problems. PMID:21691432
GENERAL EARTHQUAKE-OBSERVATION SYSTEM (GEOS).
Borcherdt, R.D.; Fletcher, Joe B.; Jensen, E.G.; Maxwell, G.L.; VanSchaack, J.R.; Warrick, R.E.; Cranswick, E.; Johnston, M.J.S.; McClearn, R.
1985-01-01
Microprocessor technology has permitted the development of a General Earthquake-Observation System (GEOS) useful for most seismic applications. Central-processing-unit control via robust software of system functions that are isolated on hardware modules permits field adaptability of the system to a wide variety of active and passive seismic experiments and straightforward modification for incorporation of improvements in technology. Various laboratory tests and numerous deployments of a set of the systems in the field have confirmed design goals, including: wide linear dynamic range (16 bit/96 dB); broad bandwidth (36 hr to 600 Hz; greater than 36 hr available); selectable sensor-type (accelerometer, seismometer, dilatometer); selectable channels (1 to 6); selectable record mode (continuous, preset, trigger); large data capacity (1. 4 to 60 Mbytes); selectable time standard (WWVB, master, manual); automatic self-calibration; simple field operation; full capability to adapt system in the field to a wide variety of experiments; low power; portability; and modest costs. System design goals for a microcomputer-controlled system with modular software and hardware components as implemented on the GEOS are presented. The systems have been deployed for 15 experiments, including: studies of near-source strong motion; high-frequency microearthquakes; crustal structure; down-hole wave propagation; teleseismicity; and earth-tidal strains.
International Nuclear Information System (INIS)
Nagai, Katsuaki; Ushijima, Satoru
2010-01-01
A numerical prediction method has been proposed to predict Bingham plastic fluids with free-surface in a two-dimensional container. Since the linear relationships between stress tensors and strain rate tensors are not assumed for non-Newtonian fluids, the liquid motions are described with Cauchy momentum equations rather than Navier-Stokes equations. The profile of a liquid surface is represented with the two-dimensional curvilinear coordinates which are represented in each computational step on the basis of the arbitrary Lagrangian-Eulerian (ALE) method. Since the volumes of the fluid cells are transiently changed in the physical space, the geometric conservation law is applied to the finite volume discretizations. As a result, it has been shown that the present method enables us to predict reasonably the Bingham plastic fluids with free-surface in a container.
Nagai, Katsuaki; Ushijima, Satoru
2010-06-01
A numerical prediction method has been proposed to predict Bingham plastic fluids with free-surface in a two-dimensional container. Since the linear relationships between stress tensors and strain rate tensors are not assumed for non-Newtonian fluids, the liquid motions are described with Cauchy momentum equations rather than Navier-Stokes equations. The profile of a liquid surface is represented with the two-dimensional curvilinear coordinates which are represented in each computational step on the basis of the arbitrary Lagrangian-Eulerian (ALE) method. Since the volumes of the fluid cells are transiently changed in the physical space, the geometric conservation law is applied to the finite volume discretizations. As a result, it has been shown that the present method enables us to predict reasonably the Bingham plastic fluids with free-surface in a container.
Zamir, Mair; Moore, James E; Fujioka, Hideki; Gaver, Donald P
2010-03-01
In the field of fluid flow within the human body, focus has been placed on the transportation of blood in the systemic circulation since the discovery of that system; but, other fluids and fluid flow phenomena pervade the body. Some of the most fascinating fluid flow phenomena within the human body involve fluids other than blood and a service other than transport--the lymphatic and pulmonary systems are two striking examples. While transport is still involved in both cases, this is not the only service which they provide and blood is not the only fluid involved. In both systems, filtration, extraction, enrichment, and in general some "treatment" of the fluid itself is the primary function. The study of the systemic circulation has also been conventionally limited to treating the system as if it were an open-loop system governed by the laws of fluid mechanics alone, independent of physiological controls and regulations. This implies that system failures can be explained fully in terms of the laws of fluid mechanics, which of course is not the case. In this paper we examine the clinical implications of these issues and of the special biofluid mechanics issues involved in the lymphatic and pulmonary systems.
Shin, Hyun Kyung; Choi, Bongsik; Talkner, Peter; Lee, Eok Kyun
2014-12-01
Based on the generalized Langevin equation for the momentum of a Brownian particle a generalized asymptotic Einstein relation is derived. It agrees with the well-known Einstein relation in the case of normal diffusion but continues to hold for sub- and super-diffusive spreading of the Brownian particle's mean square displacement. The generalized asymptotic Einstein relation is used to analyze data obtained from molecular dynamics simulations of a two-dimensional soft disk fluid. We mainly concentrated on medium densities for which we found super-diffusive behavior of a tagged fluid particle. At higher densities a range of normal diffusion can be identified. The motion presumably changes to sub-diffusion for even higher densities.
COTHERM: Modelling fluid-rock interactions in Icelandic geothermal systems
Thien, Bruno; Kosakowski, Georg; Kulik, Dmitrii
2014-05-01
Mineralogical alteration of reservoir rocks, driven by fluid circulation in natural or enhanced geothermal systems, is likely to influence the long-term performance of geothermal power generation. A key factor is the change of porosity due to dissolution of primary minerals and precipitation of secondary phases. Porosity changes will affect fluid circulation and solute transport, which, in turn, influence mineralogical alteration. This study is part of the Sinergia COTHERM project (COmbined hydrological, geochemical and geophysical modeling of geotTHERMal systems) that is an integrative research project aimed at improving our understanding of the sub-surface processes in magmatically-driven natural geothermal systems. We model the mineralogical and porosity evolution of Icelandic geothermal systems with 1D and 2D reactive transport models. These geothermal systems are typically high enthalphy systems where a magmatic pluton is located at a few kilometers depth. The shallow plutons increase the geothermal gradient and trigger the circulation of hydrothermal waters with a steam cap forming at shallow depth. We investigate two contrasting geothermal systems: Krafla, for which the water recharge consists of meteoritic water; and Reykjanes, for which the water recharge mainly consists of seawater. The initial rock composition is a fresh basalt. We use the GEM-Selektor geochemical modeling package [1] for calculation of kinetically controlled mineral equilibria between the rock and the ingression water. We consider basalt minerals dissolution kinetics according to Palandri & Kharaka [2]. Reactive surface areas are assumed to be geometric surface areas, and are corrected using a spherical-particle surface/mass relationship. For secondary minerals, we consider the partial equilibrium assuming that the primary mineral dissolution is slow, and the secondary mineral precipitation is fast. Comparison of our modeling results with the mineralogical assemblages observed in the
DEFF Research Database (Denmark)
Liniger, Jesper; Pedersen, Henrik Clemmensen; N. Soltani, Mohsen
2018-01-01
Recent field data indicates that pitch systems account for a substantial part of a wind turbines down time. Reducing downtime means increasing the total amount of energy produced during its lifetime. Both electrical and fluid power pitch systems are employed with a roughly 50/50 distribution. Fluid...... power pitch systems generally show higher reliability and have been favored on larger offshore wind turbines. Still general issues such as leakage, contamination and electrical faults make current systems work sub-optimal. Current field data for wind turbines present overall pitch system reliability...... and the reliability of component groups (valves, accumulators, pumps etc.). However, the failure modes of the components and more importantly the root causes are not evident. The root causes and failure mode probabilities are central for changing current pitch system designs and operational concepts to increase...
Safety System for Controlling Fluid Flow into a Suction Line
England, John Dwight (Inventor); Kelley, Anthony R. (Inventor); Cronise, Raymond J. (Inventor)
2018-01-01
A safety system includes a sleeve fitted within a pool's suction line at its inlet. The sleeve terminates with a plate that resides within the suction line. The plate has holes formed therethrough. A housing defining distinct channels is fitted in the sleeve so that the distinct channels lie within the sleeve. Each of the distinct channels has a first opening on one end thereof and a second opening on another end thereof. The second openings reside in the sleeve. The first openings are in fluid communication with the water in the pool, and are distributed around a periphery of an area of the housing that prevents coverage of all the first openings when a human interacts therewith. A first sensor is coupled to the sleeve to sense pressure therein, and a second pressure sensor is coupled to the plate to sense pressure in one of the plates' holes.
Identification of general linear mechanical systems
Sirlin, S. W.; Longman, R. W.; Juang, J. N.
1983-01-01
Previous work in identification theory has been concerned with the general first order time derivative form. Linear mechanical systems, a large and important class, naturally have a second order form. This paper utilizes this additional structural information for the purpose of identification. A realization is obtained from input-output data, and then knowledge of the system input, output, and inertia matrices is used to determine a set of linear equations whereby we identify the remaining unknown system matrices. Necessary and sufficient conditions on the number, type and placement of sensors and actuators are given which guarantee identificability, and less stringent conditions are given which guarantee generic identifiability. Both a priori identifiability and a posteriori identifiability are considered, i.e., identifiability being insured prior to obtaining data, and identifiability being assured with a given data set.
EXPERIMENTAL BUBBLE FORMATION IN A LARGE SCALE SYSTEM FOR NEWTONIAN AND NONNEWTONIAN FLUIDS
Energy Technology Data Exchange (ETDEWEB)
Leishear, R; Michael Restivo, M
2008-06-26
The complexities of bubble formation in liquids increase as the system size increases, and a photographic study is presented here to provide some insight into the dynamics of bubble formation for large systems. Air was injected at the bottom of a 28 feet tall by 30 inch diameter column. Different fluids were subjected to different air flow rates at different fluid depths. The fluids were water and non-Newtonian, Bingham plastic fluids, which have yield stresses requiring an applied force to initiate movement, or shearing, of the fluid. Tests showed that bubble formation was significantly different in the two types of fluids. In water, a field of bubbles was formed, which consisted of numerous, distributed, 1/4 to 3/8 inch diameter bubbles. In the Bingham fluid, large bubbles of 6 to 12 inches in diameter were formed, which depended on the air flow rate. This paper provides comprehensive photographic results related to bubble formation in these fluids.
Duality transformations for general abelian systems
International Nuclear Information System (INIS)
Savit, R.
1982-01-01
We describe the general structure of duality transformations for a very broad set of abelian statistical and field theoretic systems. This includes theories with many different types of fields and a large variety of kinds of interactions including, but not limited to nearest neighbor, next nearest neighbor, multi-spin interactions, etc. We find that the dual form of a theory does not depend directly on the dimensionality of the theory, but rather on the number of fields and number of different kinds of interactions. The dual forms we find have a generalized gauge symmetry and posses the usual property of having a temperature (or coupling constant) which is inverted from that of the original theory. Our results reduce to the well-known results in those particular cases that have heretofore been studied. Our procedure also suggests variations capable of generating other forms of the dual theory which may be useful in various specific cases. (orig.)
Pawaskar, Sainath Shrikant; Fisher, John; Jin, Zhongmin
2010-03-01
Contact detection in cartilage contact mechanics is an important feature of any analytical or computational modeling investigation when the biphasic nature of cartilage and the corresponding tribology are taken into account. The fluid flow boundary conditions will change based on whether the surface is in contact or not, which will affect the interstitial fluid pressurization. This in turn will increase or decrease the load sustained by the fluid phase, with a direct effect on friction, wear, and lubrication. In laboratory experiments or clinical hemiarthroplasty, when a rigid indenter or metallic prosthesis is used to apply load to the cartilage, there will not be any fluid flow normal to the surface in the contact region due to the impermeable nature of the indenter/prosthesis. In the natural joint, on the other hand, where two cartilage surfaces interact, flow will depend on the pressure difference across the interface. Furthermore, in both these cases, the fluid would flow freely in non-contacting regions. However, it should be pointed out that the contact area is generally unknown in advance in both cases and can only be determined as part of the solution. In the present finite element study, a general and robust algorithm was proposed to decide nodes in contact on the cartilage surface and, accordingly, impose the fluid flow boundary conditions. The algorithm was first tested for a rigid indenter against cartilage model. The algorithm worked well for two-dimensional four-noded and eight-noded axisymmetric element models as well as three-dimensional models. It was then extended to include two cartilages in contact. The results were in excellent agreement with the previous studies reported in the literature.
Computational fluid dynamics for turbomachinery internal air systems.
Chew, John W; Hills, Nicholas J
2007-10-15
Considerable progress in development and application of computational fluid dynamics (CFD) for aeroengine internal flow systems has been made in recent years. CFD is regularly used in industry for assessment of air systems, and the performance of CFD for basic axisymmetric rotor/rotor and stator/rotor disc cavities with radial throughflow is largely understood and documented. Incorporation of three-dimensional geometrical features and calculation of unsteady flows are becoming commonplace. Automation of CFD, coupling with thermal models of the solid components, and extension of CFD models to include both air system and main gas path flows are current areas of development. CFD is also being used as a research tool to investigate a number of flow phenomena that are not yet fully understood. These include buoyancy-affected flows in rotating cavities, rim seal flows and mixed air/oil flows. Large eddy simulation has shown considerable promise for the buoyancy-driven flows and its use for air system flows is expected to expand in the future.
Unbalance on power systems: a general review
Energy Technology Data Exchange (ETDEWEB)
Reineri, Claudio A.; Gomez Targarona, Juan C.
2009-07-01
A general revision of different aspects in relation to the voltage unbalance in electric power systems is presented, that should necessarily be deeply known by technical operators and designers of facilities, installations, and electric equipment. Dissimilar unbalance definitions, unbalance measurement methods, their quantification and the interpretation of such magnitudes are revised. The causes of the unbalances in electric power systems were described and analyzed. The effects on power systems are also studied, specially those that have influence on: system operability, lost of efficiency of the three phase system and their impact in the definitions of traditional power. Similarly is studied the unbalance effect on certain loads, in particular: three-phase motors, power electronics and ASD's. Also methods to locate the origin of these problems, as well as the different normative or standards, and possible methods to mitigate their effects are deeply detailed. It is concluded in the necessity to deepen the study of the power system unbalance, because numerous non resolved aspects still exist whose solution requires of a deep knowledge on the part of the involved professionals. (author)
Weitz, Karl K [Pasco, WA; Moore, Ronald J [West Richland, WA
2010-07-13
A method and device are disclosed that provide for detection of fluid leaks in analytical instruments and instrument systems. The leak detection device includes a collection tube, a fluid absorbing material, and a circuit that electrically couples to an indicator device. When assembled, the leak detection device detects and monitors for fluid leaks, providing a preselected response in conjunction with the indicator device when contacted by a fluid.
SRAC95; general purpose neutronics code system
International Nuclear Information System (INIS)
Okumura, Keisuke; Tsuchihashi, Keichiro; Kaneko, Kunio.
1996-03-01
SRAC is a general purpose neutronics code system applicable to core analyses of various types of reactors. Since the publication of JAERI-1302 for the revised SRAC in 1986, a number of additions and modifications have been made for nuclear data libraries and programs. Thus, the new version SRAC95 has been completed. The system consists of six kinds of nuclear data libraries(ENDF/B-IV, -V, -VI, JENDL-2, -3.1, -3.2), five modular codes integrated into SRAC95; collision probability calculation module (PIJ) for 16 types of lattice geometries, Sn transport calculation modules(ANISN, TWOTRAN), diffusion calculation modules(TUD, CITATION) and two optional codes for fuel assembly and core burn-up calculations(newly developed ASMBURN, revised COREBN). In this version, many new functions and data are implemented to support nuclear design studies of advanced reactors, especially for burn-up calculations. SRAC95 is available not only on conventional IBM-compatible computers but also on scalar or vector computers with the UNIX operating system. This report is the SRAC95 users manual which contains general description, contents of revisions, input data requirements, detail information on usage, sample input data and list of available libraries. (author)
SRAC95; general purpose neutronics code system
Energy Technology Data Exchange (ETDEWEB)
Okumura, Keisuke; Tsuchihashi, Keichiro [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Kaneko, Kunio
1996-03-01
SRAC is a general purpose neutronics code system applicable to core analyses of various types of reactors. Since the publication of JAERI-1302 for the revised SRAC in 1986, a number of additions and modifications have been made for nuclear data libraries and programs. Thus, the new version SRAC95 has been completed. The system consists of six kinds of nuclear data libraries(ENDF/B-IV, -V, -VI, JENDL-2, -3.1, -3.2), five modular codes integrated into SRAC95; collision probability calculation module (PIJ) for 16 types of lattice geometries, Sn transport calculation modules(ANISN, TWOTRAN), diffusion calculation modules(TUD, CITATION) and two optional codes for fuel assembly and core burn-up calculations(newly developed ASMBURN, revised COREBN). In this version, many new functions and data are implemented to support nuclear design studies of advanced reactors, especially for burn-up calculations. SRAC95 is available not only on conventional IBM-compatible computers but also on scalar or vector computers with the UNIX operating system. This report is the SRAC95 users manual which contains general description, contents of revisions, input data requirements, detail information on usage, sample input data and list of available libraries. (author).
Positron emission tomography - a new technique for observing fluid behaviour in engineering systems
International Nuclear Information System (INIS)
Stewart, P.A.E.; Rogers, J.D.; Skelton, R.T.
1988-01-01
Positron emission tomography promises to become a powerful new technique for flow tracing and measurement within metal structures in general and operating engines in particular. The principles involved are outlined, and a mobile positron camera system being developed jointly by Rolls-Royce, Castrol, the University of Birmingham and the Rutherford-Appleton Laboratory of the SERC is described. Finally, illustrative examples of the camera's capability are presented drawn from its use to study lubricating fluid flow in the bearings of a Viper gas turbine engine on test up to 100% full power. (author)
General Anesthesia Inhibits the Activity of the "Glymphatic System".
Gakuba, Clement; Gaberel, Thomas; Goursaud, Suzanne; Bourges, Jennifer; Di Palma, Camille; Quenault, Aurélien; de Lizarrondo, Sara Martinez; Vivien, Denis; Gauberti, Maxime
2018-01-01
INTRODUCTION: According to the "glymphatic system" hypothesis, brain waste clearance is mediated by a continuous replacement of the interstitial milieu by a bulk flow of cerebrospinal fluid (CSF). Previous reports suggested that this cerebral CSF circulation is only active during general anesthesia or sleep, an effect mediated by the dilatation of the extracellular space. Given the controversies regarding the plausibility of this phenomenon and the limitations of currently available methods to image the glymphatic system, we developed original whole-brain in vivo imaging methods to investigate the effects of general anesthesia on the brain CSF circulation. METHODS: We used magnetic resonance imaging (MRI) and near-infrared fluorescence imaging (NIRF) after injection of a paramagnetic contrast agent or a fluorescent dye in the cisterna magna, in order to investigate the impact of general anesthesia (isoflurane, ketamine or ketamine/xylazine) on the intracranial CSF circulation in mice. RESULTS: In vivo imaging allowed us to image CSF flow in awake and anesthetized mice and confirmed the existence of a brain-wide CSF circulation. Contrary to what was initially thought, we demonstrated that the parenchymal CSF circulation is mainly active during wakefulness and significantly impaired during general anesthesia. This effect was especially significant when high doses of anesthetic agent were used (3% isoflurane). These results were consistent across the different anesthesia regimens and imaging modalities. Moreover, we failed to detect a significant change in the brain extracellular water volume using diffusion weighted imaging in awake and anesthetized mice. CONCLUSION: The parenchymal diffusion of small molecular weight compounds from the CSF is active during wakefulness. General anesthesia has a negative impact on the intracranial CSF circulation, especially when using a high dose of anesthetic agent.
Generalized reciprocity principle for discrete symplectic systems
Directory of Open Access Journals (Sweden)
Julia Elyseeva
2015-12-01
Full Text Available This paper studies transformations for conjoined bases of symplectic difference systems $Y_{i+1}=\\mathcal S_{i}Y_{i}$ with the symplectic coefficient matrices $\\mathcal S_i.$ For an arbitrary symplectic transformation matrix $P_{i}$ we formulate most general sufficient conditions for $\\mathcal S_{i},\\, P_{i}$ which guarantee that $P_{i}$ preserves oscillatory properties of conjoined bases $Y_{i}.$ We present examples which show that our new results extend the applicability of the discrete transformation theory.
TMI-2 in-vessel hydraulic systems utilize high water and high boron content fluids
International Nuclear Information System (INIS)
Baston, V.F.; Hofstetter, K.J.; Hofman, L.A.; Gallagher, R.E.
1987-01-01
Choice of a hydraulic fluid for use in the Three Mile Island Unit 2 (TMI-2) reactor vessel defueling equipment required consideration of the following constraints for the hydraulic fluid given an accidental spill into the reactor coolant system (RCS). The TMI-2 RCS hydraulic fluid utilized in the hydraulic operations utilized a solution composition of 95 wt% water and 5 wt% of the above base fluid. The TMI-2 hydraulic system utilizes pressures up to 3500 psi. The selected hydraulic fluid has been in use since December 1986 with minimal operational difficulties
Directory of Open Access Journals (Sweden)
Xin Zhang
2014-01-01
Full Text Available Vitamin D-binding protein (DBP is the main transport protein of vitamin D and plays an important role in the immune system and host defenses. The purpose of this study was to measure DBP levels in plasma and gingival crevicular fluid (GCF of patients with generalized aggressive periodontitis (GAgP, in comparison to healthy controls, with the goal of elucidating the relationship between DBP and GAgP. Fifty-nine GAgP patients and 58 healthy controls were recruited for the study; clinical parameters of probing depths (PD, bleeding index, and attachment loss (AL were recorded. DBP levels were measured by enzyme-linked immunosorbent assay. From the results, GAgP patients had higher plasma DBP concentrations (P<0.001 but lower GCF DBP concentrations (P<0.001 than healthy controls. In GAgP group, after controlling the potential confounders of age, gender, smoking status, and BMI index, GCF DBP concentrations correlated negatively with PD (P<0.001 and AL (P=0.009. Within the limits of the study, we concluded that decreased GCF DBP level and increased plasma DBP level are associated with periodontitis.
The search for and analysis of direct samples of early Solar System aqueous fluids.
Zolensky, Michael E; Bodnar, Robert J; Yurimoto, Hisayoshi; Itoh, Shoichi; Fries, Marc; Steele, Andrew; Chan, Queenie H-S; Tsuchiyama, Akira; Kebukawa, Yoko; Ito, Motoo
2017-05-28
We describe the current state of the search for direct, surviving samples of early, inner Solar System fluids-fluid inclusions in meteorites. Meteoritic aqueous fluid inclusions are not rare, but they are very tiny and their characterization is at the state of the art for most analytical techniques. Meteoritic fluid inclusions offer us a unique opportunity to study early Solar System brines in the laboratory. Inclusion-by-inclusion analyses of the trapped fluids in carefully selected samples will, in the immediate future, provide us detailed information on the evolution of fluids as they interacted with anhydrous solid materials. Thus, real data can replace calculated fluid compositions in thermochemical calculations of the evolution of water and aqueous reactions in comets, asteroids, moons and the terrestrial planets.This article is part of the themed issue 'The origin, history and role of water in the evolution of the inner Solar System'. © 2017 The Author(s).
General programmed system for physiological signal processing
Energy Technology Data Exchange (ETDEWEB)
Tournier, E; Monge, J; Magnet, C; Sonrel, C
1975-01-01
Improvements made to the general programmed signal acquisition and processing system, Plurimat S, are described, the aim being to obtain a less specialized system adapted to the biological and medical field. In this modified system the acquisition will be simplified. The standard processings offered will be integrated to a real advanced language which will enable the user to create his own processings, the loss of speed being compensated by a greater flexibility and universality. The observation screen will be large and the quality of the recording very good so that a large signal fraction may be displayed. The data will be easily indexed and filed for subsequent display and processing. This system will be used for two kinds of task: it can either be specialized, as an integral part of measurement and diagnostic preparation equipment used routinely in clinical work (e.g. vectocardiographic examination), or its versatility can be used for studies of limited duration to gain information in a given field or to study new diagnosis or treatment methods.
Heat transfer and fluid flow in nuclear systems
International Nuclear Information System (INIS)
Fenech, H.
1981-01-01
The present publication is an attempt to provide a bridge between fundamental principles and current design practice. It is intended to serve the need of: engineers, scientists and graduate students active in thermal and hydraulics problems and to those interested to keep abreast of the field. The text is addressed to readers with previous knowledge in heat transfer and fluid flow equvalent to a one year university graduate course in that field. Because of the high degree of specialization covered in the six chapters of the book, individual authors of international reputation and active in their respective area of specialization were selected to contribute their knowledge. Each of the six chapters or sub-chapters are self-contained. They are followed by problem sets to enable the reader to check his level of comprehension of the material presented. The nuclear systems covered in separate chapters include: the pressurized and boiling water reactors (PWR, BWR), the helium cooled high temperature reactors (HTGR and HTR), the breeders helium cooled (GCFR) and sodium cooled (LMFBR). In addition the heat-exchangers and steam generators commonly associated with the above systems are covered in Chapter 6
Energy Technology Data Exchange (ETDEWEB)
Vuillemin, M [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires
1964-07-01
After giving the Lagrange expression for a conducting fluid in an external electromagnetic field, the author shows that a Lagrange expression exists for describing the evolution of a system of interacting fluids obtained by adding the Lagrange expression of each fluid.to that of the electromagnetic field. By variation are obtained the fluid movement equation coupled to the Maxwell equations. It is shown that the study of small movements around a stationary state can be deduced from the Lagrange equation expanded to the second power order of the perturbation. It is then possible to deduce the normal mode equations and the study the stability by examining the modes which are marginally stable. (author) [French] Apres avoir rappele l'expression, du Lagrangien pour un fluide conducteur dans un champ electromagnetique exterieur, on montre qu'il existe un Lagrangien pour decrire l'evolution d'un systeme de fluides en.interaction que l'on obtient par la superposition du Lagrangien de chaque fluide et du Lagrangien du champ electromagnetique. On obtient par variation, les equations du mouvement des fluides, couplees aux equations de Maxwell. On montre que l'etude des petits mouvements autour d'un etat stationnaire se deduit du Lagrangien developpe au second1 ordre en puissance de la perturbation. On peut alors retrouver les equations des modes normaux et etudier la stabilite en recherchant les modes marginalement stables. (auteur)
A fully continuous supercritical fluid extraction system for contaminated soil
International Nuclear Information System (INIS)
Ryan, M.; Stiver, W.H.
2007-01-01
Brownfield sites are contaminated sites in an urban setting. There are hundreds of thousands of such sites, where contaminants migrate to the atmosphere, seep into groundwater, runoff into surface water and enter the food chain through plant uptake and soil ingestion. The Sydney Tar Ponds alone contain more than a million tonnes of contaminated soils and sediments. Soil vapour extraction, incineration, bioremediation, solvent extraction and land filling are among the remediation techniques that have been developed for brownfield sites over the years. However, no single technology is ideally suited to all cases because of the diversity of contaminants and diversity of site characterization. This paper focused on supercritical fluid extraction (SFE) which is well suited to sites contaminated with polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and heavy metal. A fully continuous laboratory-scale SFE process for a slurry-based system was designed and constructed to handle the supercritical carbon dioxide (SC-CO 2 ) and the soil slurry. The system continuously pumps carbon dioxide under supercritical conditions and soil slurry into a counter-current contacting column. The testing soil was Delhi loamy sand, spiked with 10 mg/g of naphthalene. The soil slurry ranged from 0.0028 g dry soil per g slurry to 0.072 g/g. The operating temperature was 43 degrees C and the operating pressure was 7.7 MPa. Near steady state, fully continuous flow was achieved with runs lasting up to 2 hours. The quantifiable recoveries of naphthalene from the soil slurry was demonstrated and the mass transfer coefficients for the system were quantified in order to provide the foundation to advance to a full-scale system and costing analysis. 14 refs., 1 tab., 3 figs
A fully continuous supercritical fluid extraction system for contaminated soil
Energy Technology Data Exchange (ETDEWEB)
Ryan, M.; Stiver, W.H. [Guelph Univ., ON (Canada). School of Engineering
2007-04-15
Brownfield sites are contaminated sites in an urban setting. There are hundreds of thousands of such sites, where contaminants migrate to the atmosphere, seep into groundwater, runoff into surface water and enter the food chain through plant uptake and soil ingestion. The Sydney Tar Ponds alone contain more than a million tonnes of contaminated soils and sediments. Soil vapour extraction, incineration, bioremediation, solvent extraction and land filling are among the remediation techniques that have been developed for brownfield sites over the years. However, no single technology is ideally suited to all cases because of the diversity of contaminants and diversity of site characterization. This paper focused on supercritical fluid extraction (SFE) which is well suited to sites contaminated with polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and heavy metal. A fully continuous laboratory-scale SFE process for a slurry-based system was designed and constructed to handle the supercritical carbon dioxide (SC-CO{sub 2}) and the soil slurry. The system continuously pumps carbon dioxide under supercritical conditions and soil slurry into a counter-current contacting column. The testing soil was Delhi loamy sand, spiked with 10 mg/g of naphthalene. The soil slurry ranged from 0.0028 g dry soil per g slurry to 0.072 g/g. The operating temperature was 43 degrees C and the operating pressure was 7.7 MPa. Near steady state, fully continuous flow was achieved with runs lasting up to 2 hours. The quantifiable recoveries of naphthalene from the soil slurry was demonstrated and the mass transfer coefficients for the system were quantified in order to provide the foundation to advance to a full-scale system and costing analysis. 14 refs., 1 tab., 3 figs.
Relative entropies in thermodynamics of complete fluid systems
Czech Academy of Sciences Publication Activity Database
Feireisl, Eduard
2012-01-01
Roč. 32, č. 9 (2012), s. 3059-3080 ISSN 1078-0947 R&D Projects: GA ČR GA201/09/0917 Institutional research plan: CEZ:AV0Z10190503 Keywords : relative entropy * Navier-Stokes-Fourier system * weak-strong uniqueness Subject RIV: BA - General Mathematics Impact factor: 1.005, year: 2012 http://www.aimsciences.org/journals/displayArticlesnew.jsp?paperID=7281
Long time behavior and attractors for energetically insulated fluid systems
Czech Academy of Sciences Publication Activity Database
Feireisl, Eduard
2010-01-01
Roč. 27, č. 4 (2010), s. 1587-1609 ISSN 1078-0947 R&D Projects: GA ČR GA201/09/0917 Institutional research plan: CEZ:AV0Z10190503 Keywords : Navier-Stokes-Fourier system * attractor * long time behavior Subject RIV: BA - General Mathematics Impact factor: 0.986, year: 2010 http://www.aimsciences.org/journals/displayArticles.jsp?paperID=5040
Fluid–fluid coexistence in colloidal systems with short-ranged strongly directional attraction
Kern, N.; Frenkel, D.
2003-01-01
We present a systematic numerical study of the phase behavior of square-well fluids with a "patchy" short-ranged attraction. In particular, we study the effect of the size and number of attractive patches on the fluid–fluid coexistence. The model that we use is a generalization of the hard sphere
Acceleration of coupled granular flow and fluid flow simulations in pebble bed energy systems
International Nuclear Information System (INIS)
Li, Yanheng; Ji, Wei
2013-01-01
Highlights: ► Fast simulation of coupled pebble flow and coolant flow in PBR systems is studied. ► Dimension reduction based on axisymmetric geometry shows significant speedup. ► Relaxation of coupling frequency is investigated and an optimal range is determined. ► A total of 80% efficiency increase is achieved by the two fast strategies. ► Fast strategies can be applied to simulating other general fluidized bed systems. -- Abstract: Fast and accurate approaches to simulating the coupled particle flow and fluid flow are of importance to the analysis of large particle-fluid systems. This is especially needed when one tries to simulate pebble flow and coolant flow in Pebble Bed Reactor (PBR) energy systems on a routine basis. As one of the Generation IV designs, the PBR design is a promising nuclear energy system with high fuel performance and inherent safety. A typical PBR core can be modeled as a particle-fluid system with strong interactions among pebbles, coolants and reactor walls. In previous works, the coupled Discrete Element Method (DEM)-Computational Fluid Dynamics (CFD) approach has been investigated and applied to modeling PBR systems. However, the DEM-CFD approach is computationally expensive due to large amounts of pebbles in PBR systems. This greatly restricts the PBR analysis for the real time prediction and inclusion of more physics. In this work, based on the symmetry of the PBR geometry and the slow motion characteristics of the pebble flow, two acceleration strategies are proposed. First, a simplified 3D-DEM/2D-CFD approach is proposed to speed up the DEM-CFD simulation without loss of accuracy. Pebble flow is simulated by a full 3D DEM, while the coolant flow field is calculated with a 2D CFD simulation by averaging variables along the annular direction in the cylindrical and annular geometries. Second, based on the slow motion of pebble flow, the impact of the coupling frequency on the computation accuracy and efficiency is
Acceleration of coupled granular flow and fluid flow simulations in pebble bed energy systems
Energy Technology Data Exchange (ETDEWEB)
Li, Yanheng, E-mail: liy19@rpi.edu [Department of Mechanical, Aerospace, and Nuclear Engineering, Rensselaer Polytechnic Institute, 110 8th Street, Troy, NY (United States); Ji, Wei, E-mail: jiw2@rpi.edu [Department of Mechanical, Aerospace, and Nuclear Engineering, Rensselaer Polytechnic Institute, 110 8th Street, Troy, NY (United States)
2013-05-15
Highlights: ► Fast simulation of coupled pebble flow and coolant flow in PBR systems is studied. ► Dimension reduction based on axisymmetric geometry shows significant speedup. ► Relaxation of coupling frequency is investigated and an optimal range is determined. ► A total of 80% efficiency increase is achieved by the two fast strategies. ► Fast strategies can be applied to simulating other general fluidized bed systems. -- Abstract: Fast and accurate approaches to simulating the coupled particle flow and fluid flow are of importance to the analysis of large particle-fluid systems. This is especially needed when one tries to simulate pebble flow and coolant flow in Pebble Bed Reactor (PBR) energy systems on a routine basis. As one of the Generation IV designs, the PBR design is a promising nuclear energy system with high fuel performance and inherent safety. A typical PBR core can be modeled as a particle-fluid system with strong interactions among pebbles, coolants and reactor walls. In previous works, the coupled Discrete Element Method (DEM)-Computational Fluid Dynamics (CFD) approach has been investigated and applied to modeling PBR systems. However, the DEM-CFD approach is computationally expensive due to large amounts of pebbles in PBR systems. This greatly restricts the PBR analysis for the real time prediction and inclusion of more physics. In this work, based on the symmetry of the PBR geometry and the slow motion characteristics of the pebble flow, two acceleration strategies are proposed. First, a simplified 3D-DEM/2D-CFD approach is proposed to speed up the DEM-CFD simulation without loss of accuracy. Pebble flow is simulated by a full 3D DEM, while the coolant flow field is calculated with a 2D CFD simulation by averaging variables along the annular direction in the cylindrical and annular geometries. Second, based on the slow motion of pebble flow, the impact of the coupling frequency on the computation accuracy and efficiency is
Fluid bed dryer and Aeropep solidification system. Amendment 1 to topical report
International Nuclear Information System (INIS)
1975-01-01
Information is presented on interfaces between the aerojet fluid bed dryer and the liquid radwaste system, plant ventilation system, and radioactive solid waste handling system for BWR and PWR type reactors. (U.S.)
Turbine airfoil cooling system with cooling systems using high and low pressure cooling fluids
Marsh, Jan H.; Messmann, Stephen John; Scribner, Carmen Andrew
2017-10-25
A turbine airfoil cooling system including a low pressure cooling system and a high pressure cooling system for a turbine airfoil of a gas turbine engine is disclosed. In at least one embodiment, the low pressure cooling system may be an ambient air cooling system, and the high pressure cooling system may be a compressor bleed air cooling system. In at least one embodiment, the compressor bleed air cooling system in communication with a high pressure subsystem that may be a snubber cooling system positioned within a snubber. A delivery system including a movable air supply tube may be used to separate the low and high pressure cooling subsystems. The delivery system may enable high pressure cooling air to be passed to the snubber cooling system separate from low pressure cooling fluid supplied by the low pressure cooling system to other portions of the turbine airfoil cooling system.
International Nuclear Information System (INIS)
Graf, U.
1986-01-01
A combination of several numerical methods is used to construct a procedure for effective calculation of complex three-dimensional fluid flow problems. The split coefficient matrix (SCM) method is used so that the differenced equations of the hyperbolic system do not disturb correct signal propagation. The semi-discretisation of the equations of the SCM method is done with the asymmetric, separated region, weighted residual (ASWR) method to give accurate solutions on a relatively coarse mesh. For the resulting system of ordinary differential equations, a general-purpose ordinary differential equation solver is used in conjunction with a method of fractional steps for an economic solution of the large system of linear equations. (orig.) [de
Toward multiscale modelings of grain-fluid systems
Chareyre, Bruno; Yuan, Chao; Montella, Eduard P.; Salager, Simon
2017-06-01
Computationally efficient methods have been developed for simulating partially saturated granular materials in the pendular regime. In contrast, one hardly avoid expensive direct resolutions of 2-phase fluid dynamics problem for mixed pendular-funicular situations or even saturated regimes. Following previous developments for single-phase flow, a pore-network approach of the coupling problems is described. The geometry and movements of phases and interfaces are described on the basis of a tetrahedrization of the pore space, introducing elementary objects such as bridge, meniscus, pore body and pore throat, together with local rules of evolution. As firmly established local rules are still missing on some aspects (entry capillary pressure and pore-scale pressure-saturation relations, forces on the grains, or kinetics of transfers in mixed situations) a multi-scale numerical framework is introduced, enhancing the pore-network approach with the help of direct simulations. Small subsets of a granular system are extracted, in which multiphase scenario are solved using the Lattice-Boltzman method (LBM). In turns, a global problem is assembled and solved at the network scale, as illustrated by a simulated primary drainage.
International Nuclear Information System (INIS)
Li, Jing; Alvi, Jahan Zeb; Pei, Gang; Ji, Jie; Li, Pengcheng; Fu, Huide
2016-01-01
Highlights: • A novel, flexible direct vapor generation solar ORC is proposed. • Technical feasibility of the system is discussed. • Fluid effect on collector efficiency is explored. • The system is more efficient than solar ORC with HTF. - Abstract: A novel solar organic Rankine cycle (ORC) system with direct vapor generation (DVG) is proposed. A heat storage unit is embedded in the ORC to guarantee the stability of power generation. Compared with conventional solar ORCs, the proposed system avoids the secondary heat transfer intermediate and shows good reaction to the fluctuation of solar radiation. The technical feasibility of the system is discussed. Performance is analyzed by using 17 dry and isentropic working fluids. Fluid effects on the efficiencies of ORC, collectors and the whole system are studied. The results indicate that the collector efficiency generally decreases while the ORC and system efficiencies increase with the increment in fluid critical temperature. At evaporation temperature of 120 °C and solar radiation of 800 Wm −2 , the ORC, collector and overall thermal efficiencies of R236fa are 10.59, 56.14 and 5.08% while their values for Benzene are 12.5, 52.58 and 6.57% respectively. The difference between collector efficiencies using R236fa and Benzene gets larger at lower solar radiation. The heat collection is strongly correlated with latent and sensible heat of the working fluid. Among the fluids, R123 exhibits the highest overall performance and seems to be suitable for the proposed system in the short term.
A new converter for improving efficiency of multi-actuators fluid power system
Energy Technology Data Exchange (ETDEWEB)
Xue, Yong; Shang, JianZhong; Yang, JunHong; Wang Zhuo [National University of Defense Technology, Changsha (China)
2016-05-15
This paper is concerned with the application of energy efficient fluid power in mobile robots system and proposes a new fluid power converter system which is analogous to a boost converter in power electronics. The fluid power converter system is based on the principle of pulse-width modulation. The fluid power converter has an effect akin to an electrical switched inductance transformer, wherein the output pressure or flow rate can be stepped up or down. Using an inductive reactance device (an inertia mass-block), the output flow and pressure can be varied to meet the load by a means that does not rely on dissipation of power (the resistance control). The simulation model based on the mathematics models of the components is built to analyse the performance of the fluid power converter. It is clearly shown that the fluid power converter has higher energy efficiency than conventional resistance control manners.
Relaxation and self-organization in two-dimensional plasma and neutral fluid flow systems
International Nuclear Information System (INIS)
Das, Amita
2008-01-01
Extensive numerical studies in the framework of a simplified two-dimensional model for neutral and plasma fluid for a variety of initial configurations and for both decaying and driven cases are carried out to illustrate relaxation toward a self-organized state. The dynamical model equation constitutes a simple choice for this purpose, e.g., the vorticity equation of the Navier-Stokes dynamics for the incompressible neutral fluids and the Hasegawa-Mima equation for plasma fluid flow system. Scatter plots are employed to observe a development of functional relationship, if any, amidst the generalized vorticity and its Laplacian. It is seen that they do not satisfy a linear relationship as the well known variational approach of enstrophy minimization subject to constancy of the energy integral for the two-dimensional (2D) system suggests. The observed nonlinear functional relationship is understood by separating the contribution to the scatter plot from spatial regions with intense vorticity patches and those of the background flow region where the background vorticity is weak or absent altogether. It is shown that such a separation has close connection with the known exact analytical solutions of the system. The analytical solutions are typically obtained by assuming a finite source of vorticity for the inner core of the localized structure, which is then matched with the solution in the outer region where vorticity is chosen to be zero. The work also demonstrates that the seemingly ad hoc choice of the linear vorticity source function for the inner region is in fact consistent with the self-organization paradigm of the 2D systems
Theoretical aspects concerning working fluids in hydraulic systems
Directory of Open Access Journals (Sweden)
Tița Irina
2017-01-01
Full Text Available Among the properties of working fluid, viscosity is the most important as it regards especially to pumps. In order to study the behavior of hydrostatic transmission it is important to create a reliable research instrument for dynamic simulation. Our research expertise being in SimHydraulics consequently this instrument is the suitable block diagram. The purpose of this paper is to present the possible ways to customize the properties of the working fluid in the block diagram.
Symmetry of Hamiltonian and conserved quantity for a system of generalized classical mechanics
International Nuclear Information System (INIS)
Zhang Yi
2011-01-01
This paper focuses on a new symmetry of Hamiltonian and its conserved quantity for a system of generalized classical mechanics. The differential equations of motion of the system are established. The definition and the criterion of the symmetry of Hamiltonian of the system are given. A conserved quantity directly derived from the symmetry of Hamiltonian of the generalized classical mechanical system is given. Since a Hamilton system is a special case of the generalized classical mechanics, the results above are equally applicable to the Hamilton system. The results of the paper are the generalization of a theorem known for the existing nonsingular equivalent Lagrangian. Finally, two examples are given to illustrate the application of the results. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)
Morparia, Kavita G; Reddy, Srijaya K; Olivieri, Laura J; Spaeder, Michael C; Schuette, Jennifer J
2018-04-01
The determination of fluid responsiveness in the critically ill child is of vital importance, more so as fluid overload becomes increasingly associated with worse outcomes. Dynamic markers of volume responsiveness have shown some promise in the pediatric population, but more research is needed before they can be adopted for widespread use. Our aim was to investigate effectiveness of respiratory variation in peak aortic velocity and pulse pressure variation to predict fluid responsiveness, and determine their optimal cutoff values. We performed a prospective, observational study at a single tertiary care pediatric center. Twenty-one children with normal cardiorespiratory status undergoing general anesthesia for neurosurgery were enrolled. Respiratory variation in peak aortic velocity (ΔVpeak ao) was measured both before and after volume expansion using a bedside ultrasound device. Pulse pressure variation (PPV) value was obtained from the bedside monitor. All patients received a 10 ml/kg fluid bolus as volume expansion, and were qualified as responders if stroke volume increased >15% as a result. Utility of ΔVpeak ao and PPV and to predict responsiveness to volume expansion was investigated. A baseline ΔVpeak ao value of greater than or equal to 12.3% best predicted a positive response to volume expansion, with a sensitivity of 77%, specificity of 89% and area under receiver operating characteristic curve of 0.90. PPV failed to demonstrate utility in this patient population. Respiratory variation in peak aortic velocity is a promising marker for optimization of perioperative fluid therapy in the pediatric population and can be accurately measured using bedside ultrasonography. More research is needed to evaluate the lack of effectiveness of pulse pressure variation for this purpose.
Contamination Control and Monitoring of Tap Water as Fluid in Industrial Tap Water Hydraulic Systems
DEFF Research Database (Denmark)
Conrad, Finn; Adelstorp, Anders
1998-01-01
Presentation of results and methods addressed to contamination control and monitoring of tap water as fluid in tap water hydraulic systems.......Presentation of results and methods addressed to contamination control and monitoring of tap water as fluid in tap water hydraulic systems....
Present State and Future Developments in Mechatronics and it's Influence on Fluid Power Systems
DEFF Research Database (Denmark)
Christensen, Georg Kronborg; Zhou, Jianjun; Conrad, Finn
1998-01-01
with electronics, software and mechanics. This synergetic integration is often called Mechatronics.The topic which is rather widespread will be treated in three sections: I) General overview of mechatronics and fluid power. In this section the general trends of mechatronics in fluid power is considered by relating...... trends in the neighbouring fields of software and electronic hardware to fluid power developments. II) Mechatronic case stories from IKS In this section the results of a conceptual design study : "Design of a frequency converter based hydraulic power supply" is presented together with a more detailed...
On the uniqueness of static perfect-fluid solutions in general relativity
International Nuclear Information System (INIS)
Beig, R.; Simon, W.
1990-01-01
Following earlier work of Masood-ul-Alam, we consider a uniqueness problem for nonrotating stellar models. Given a static, asymptotically flat perfect-fluid spacetime with barotropic equation of state ρ(p), and given another such spacetime which is spherically symmetric and has the same ρ(p) and the same surface potential: we prove that both are identical provided ρ(p) satisfies a certain differential inequality. This inequality is more natural and less restrictive that the conditions required by Masood-ul-Alam. 30 refs. (Authors)
Energy Technology Data Exchange (ETDEWEB)
Pickett, G. R., E-mail: g.pickett@lancaster.ac.uk [Lancaster University, Department of Physics (United Kingdom)
2014-12-15
As a specific offering towards his festschrift, we present a review the various properties of the excitation gas in superfluid {sup 3}He, which depend on Andreev reflection. This phenomenon dominates many of the properties of the normal fluid, especially at the lowest temperatures. We outline the ideas behind this dominance and describe a sample of the many experiments in this system which the operation of Andreev reflection has made possible, from temperature measurement, particle detection, vortex imaging to cosmological analogues.
Aquifer restoration system improvement using an acid fluid purge
International Nuclear Information System (INIS)
Hodder, E.A.; Peck, C.A.
1992-01-01
The implementation of a water pump acid purge procedure at a free-phase liquid hydrocarbon recovery site has increased water pump operational run times and improved the effectiveness of the aquifer restoration effort. Before introduction of this technique, pumps at some locations would fail within 14 days of operation due to CaSO 4 .2H 2 O (calcium sulfate) precipitate fouling. After acid purge implementation at these locations, pump operational life improved to an average of over 110 days. Other locations, where pump failures would occur within one month, were improved to approximately six months of operation. The increase in water pump run time has also improved the liquid hydrocarbon recovery rate by 2,000 gallons per day; representing a 20% increase for the aquifer restoration system. Other concepts tested in attempts to prolong pump life included: specially designed electric submersible pumps, submersible pump shrouds intended to reduce the fluid pressure shear that enhances CaSO 4 .2H 2 O precipitation, and high volume pneumatic gas lift pumps. Due to marginal pump life improvement or other undesirable operational features, these concepts were primarily ineffective. The purge apparatus utilizes an acid pump, hose, and discharge piping to deliver the solution directly into the inlet of an operating water pump. The water pumps used for this activity require stainless steel construction with Teflon or other acid resistant bearings and seals. Purges are typically conducted before sudden discharge pressure drops (greater than 15 psig) occur for the operating water pump. Depending on volume of precipitate accumulation and pump type, discharge pressure is restored after introduction of 10 to 40 gallons of hydrochloric acid solution. The acid purge procedure outlined herein eliminates operational downtime and does not require well head pump removal and the associated costs of industry cleaning procedures
Tilted Bianchi type I dust fluid cosmological model in general relativity
Indian Academy of Sciences (India)
Home; Journals; Pramana – Journal of Physics; Volume 58; Issue 3. Tilted Bianchi type I dust ﬂuid cosmological model in general ... In this paper, we have investigated a tilted Bianchi type I cosmological model ﬁlled with dust of perfect ﬂuid in general relativity. To get a determinate solution, we have assumed a condition ...
Tilted Bianchi type I dust fluid cosmological model in general relativity
Indian Academy of Sciences (India)
Tilted Bianchi type I dust ﬂuid cosmological model in general relativity ... In this paper, we have investigated a tilted Bianchi type I cosmological model ﬁlled with dust of perfect ﬂuid in general relativity. ... Pramana – Journal of Physics | News ...
Trumper, David; Kassis, Timothy; Griffith, Linda; Noh, Minkyun; Soenksen, Luis
2018-01-01
Precise fluid height sensing in open-channel microfluidics has long been a desirable feature for a wide range of applications. However, performing accurate measurements of the fluid level in small-scale reservoirs (<1mL) has proven to be an elusive goal, especially if direct fluid-sensor contact needs to be avoided. In particular, gravity-driven systems used in several microfluidic applications to establish pressure gradients and impose flow remain open-loop and largely unmonitored due to ...
46 CFR 153.430 - Heat transfer systems; general.
2010-10-01
... 46 Shipping 5 2010-10-01 2010-10-01 false Heat transfer systems; general. 153.430 Section 153.430... Temperature Control Systems § 153.430 Heat transfer systems; general. Each cargo cooling system required by... separated from all other cooling and heating systems; and (c) Allow manual regulation of the system's heat...
Multi-fluid renewable geo-energy systems and methods
Buscheck, Thomas A.
2017-08-22
A geo-energy production method for extracting thermal energy from a reservoir formation. A production well extracts brine from the reservoir formation. A plurality of working fluid injection ("WFI") wells may be arranged proximate to the production well to at least partially circumscribe the production well. A plurality of brine production ("BP") wells may be arranged in a vicinity of the WFI wells to at least partially circumscribe the WFI wells. A working fluid is injected into the WFI wells to help drive a flow of the brine up through the production and BP wells, together with at least a portion of the injected working fluid. Parasitic-load time-shifting and to storing of excess solar thermal energy may also be performed.
International Nuclear Information System (INIS)
Yang Yunqing; Chen Yong
2009-01-01
In this paper, we investigate the generalized Q-S synchronization between the generalized Lorenz canonical form and the Roessler system. Firstly, we transform an arbitrary generalized Lorenz system to the generalized Lorenz canonical form, and the relation between the parameter of the generalized Lorenz system and the parameter of the generalized Lorenz canonical form are shown. Secondly, we extend the scheme present by [Yan ZY. Chaos 2005;15:023902] to study the generalized Q-S synchronization between the generalized Lorenz canonical form and the Roessler system, the more general controller is obtained. By choosing different parameter in the generalized controller obtained here, without much extra effort, we can get the controller of synchronization between the Chen system and the Roessler system, the Lue system and the Roessler system, the classic Lorenz system and the Roessler system, the Hyperbolic Lorenz system and the Roessler system, respectively. Finally, numerical simulations are used to perform such synchronization and verify the effectiveness of the controller.
Miranda, Jose; Brandao, Rodolfo
2017-11-01
We study a family of generalized elastica-like equilibrium shapes that arise at the interface separating two fluids in a curved rotating Hele-Shaw cell. This family of stationary interface solutions consists of shapes that balance the competing capillary and centrifugal forces in such a curved flow environment. We investigate how the emerging interfacial patterns are impacted by changes in the geometric properties of the curved Hele-Shaw cell. A vortex-sheet formalism is used to calculate the two-fluid interface curvature, and a gallery of possible shapes is provided to highlight a number of peculiar morphological features. A linear perturbation theory is employed to show that the most prominent aspects of these complex stationary patterns can be fairly well reproduced by the interplay of just two interfacial modes. The connection of these dominant modes to the geometry of the curved cell, as well as to the fluid dynamic properties of the flow, is discussed. We thank CNPq (Brazilian Research Council) for financial support under Grant No. 304821/2015-2.
Generalized fluid equations for parallel transport in collisional to weakly collisional plasmas
International Nuclear Information System (INIS)
Zawaideh, E.; Najmabadi, F.; Conn, R.W.
1986-01-01
A new set of two-fluid equations that are valid from collisional to weakly collisional limits is derived. Starting from gyrokinetic equations in flux coordinates with no zero-order drifts, a set of moment equations describing plasma transport along the field lines of a space- and time-dependent magnetic field is derived. No restriction on the anisotropy of the ion distribution function is imposed. In the highly collisional limit, these equations reduce to those of Braginskii, while in the weakly collisional limit they are similar to the double adiabatic or Chew, Goldberger, and Low (CGL) equations [Proc. R. Soc. London, Ser. A 236, 112 (1956)]. The new set of equations also exhibits a physical singularity at the sound speed. This singularity is used to derive and compute the sound speed. Numerical examples comparing these equations with conventional transport equations show that in the limit where the ratio of the mean free path lambda to the scale length of the magnetic field gradient L/sub B/ approaches zero, there is no significant difference between the solution of the new and conventional transport equations. However, conventional fluid equations, ordinarily expected to be correct to the order (lambda/L/sub B/) 2 , are found to have errors of order (lambda/L/sub u/) 2 = (lambda/L/sub B/) 2 /(1-M 2 ) 2 , where L/sub u/ is the scale length of the flow velocity gradient and M is the Mach number. As such, the conventional equations may contain large errors near the sound speed (Mroughly-equal1)
SINDA/SINFLO computer routine, volume 1, revision A. [for fluid flow system analysis
Oren, J. A.; Williams, D. R.
1975-01-01
The SINFLO package was developed to modify the SINDA preprocessor to accept and store the input data for fluid flow systems analysis and adding the FLOSOL user subroutine to perform the flow solution. This reduced and simplified the user input required for analysis of flow problems. A temperature calculation method, the flow-hybrid method which was developed in previous VSD thermal simulator routines, was incorporated for calculating fluid temperatures. The calculation method accuracy was improved by using fluid enthalpy rather than specific heat for the convective term of the fluid temperature equation. Subroutines and data input requirements are described along with user subroutines, flow data storage, and usage of the plot program.
Ore-forming fluid system of bauxite in WZD area of northern Guizhou province, China
Cui, Tao
2017-12-01
The ore-forming fluid system of bauxite in Wuchuan-Zheng,an-Daozhen (short for WZD) Area of northern Guizhou Province was studied from the perspective of deposit formation mechanism. It was discovered that ore-forming fluids were mainly effective for transporting and leaching during the formation of bauxite. The means of transport mainly included colloidal transport, suspended transport and gravity flow transport. In the course of their leaching, fluids had a range of chemical reactions, as a result of which elements such as silicon and iron migrated downwards. In this process, properties of fluids changed as well.
Prospects of the use of nanofluids as working fluids for organic Rankine cycle power systems
DEFF Research Database (Denmark)
Mondejar, Maria E.; Andreasen, Jesper G.; Regidor, Maria
2017-01-01
The search of novel working fluids for organic Rankine cycle power systems is driven by the recent regulations imposing additional phase-out schedules for substances with adverse environmental characteristics. Recently, nanofluids (i.e. colloidal suspensions of nanoparticles in fluids) have been...... suggested as potential working fluids for organic Rankine cycle power systems due to their enhanced thermal properties, potentially giving advantages with respect to the design of the components and the cycle performance. Nevertheless, a number of challenges concerning the use of nanofluids must...... the prospects of using nanofluids as working fluids for organic Rankine cycle power systems. As a preliminary study, nanofluids consisting of a homogenous and stable mixture of different nanoparticles types and a selected organic fluid are simulated on a case study organic Rankine cycle unit for waste heat...
Large eddy simulation on thermal fluid mixing in a T-junction piping system
Energy Technology Data Exchange (ETDEWEB)
Selvam, P. Karthick; Kulenovic, R.; Laurien, E. [Stuttgart Univ. (Germany). Inst fuer Kernenergie und Energiesysteme (IKE)
2014-11-15
High cycle thermal fatigue damage caused in piping systems is an important problem encountered in the context of nuclear safety and lifetime management of a Nuclear Power Plant (NPP). The T-junction piping system present in the Residual Heat Removal System (RHRS) is more vulnerable to thermal fatigue cracking. In this numerical study, thermal mixing of fluids at temperature difference (?T) of 117 K between the mixing fluids is analyzed. Large Eddy Simulation (LES) is performed with conjugate heat transfer between the fluid and structure. LES is performed based on the Fluid-Structure Interaction (FSI) test facility at University of Stuttgart. The results show an intense turbulent mixing of fluids downstream of T-junction. Amplitude of temperature fluctuations near the wall region and its corresponding frequency distribution is analyzed. LES is performed using commercial CFD software ANSYS CFX 14.0.
Design study of general aviation collision avoidance system
Bates, M. R.; Moore, L. D.; Scott, W. V.
1972-01-01
The selection and design of a time/frequency collision avoidance system for use in general aviation aircraft is discussed. The modifications to airline transport collision avoidance equipment which were made to produce the simpler general aviation system are described. The threat determination capabilities and operating principles of the general aviation system are illustrated.
Reducing Fatigue Loading Due to Pressure Shift in Discrete Fluid Power Force Systems
DEFF Research Database (Denmark)
Hansen, Anders Hedegaard; Pedersen, Henrik Clemmensen
2016-01-01
power force system. The current paper investigates the correlation between pressure oscillations in the cylinder chambers and valve flow in the manifold. Furthermore, the correlation between the pressure shifting time and the pressure overshoot is investigated. The study therefore focus on how to shape......Discrete Fluid Power Force Systems is one of the topologies gaining focus in the pursuit of lowering energy losses in fluid power transmission systems. The cylinder based Fluid Power Force System considered in this article is constructed with a multi-chamber cylinder, a number of constant pressure...... oscillations in the cylinder chamber, especially for systems with long connections between the cylinder and the valve manifold. Hose pressure oscillations will induce oscillations in the produced piston force. Hence, pressure oscillations may increase the fatigue loading on systems employing a discrete fluid...
Generalized Reduced Order Modeling of Aeroservoelastic Systems
Gariffo, James Michael
Transonic aeroelastic and aeroservoelastic (ASE) modeling presents a significant technical and computational challenge. Flow fields with a mixture of subsonic and supersonic flow, as well as moving shock waves, can only be captured through high-fidelity CFD analysis. With modern computing power, it is realtively straightforward to determine the flutter boundary for a single structural configuration at a single flight condition, but problems of larger scope remain quite costly. Some such problems include characterizing a vehicle's flutter boundary over its full flight envelope, optimizing its structural weight subject to aeroelastic constraints, and designing control laws for flutter suppression. For all of these applications, reduced-order models (ROMs) offer substantial computational savings. ROM techniques in general have existed for decades, and the methodology presented in this dissertation builds on successful previous techniques to create a powerful new scheme for modeling aeroelastic systems, and predicting and interpolating their transonic flutter boundaries. In this method, linear ASE state-space models are constructed from modal structural and actuator models coupled to state-space models of the linearized aerodynamic forces through feedback loops. Flutter predictions can be made from these models through simple eigenvalue analysis of their state-transition matrices for an appropriate set of dynamic pressures. Moreover, this analysis returns the frequency and damping trend of every aeroelastic branch. In contrast, determining the critical dynamic pressure by direct time-marching CFD requires a separate run for every dynamic pressure being analyzed simply to obtain the trend for the critical branch. The present ROM methodology also includes a new model interpolation technique that greatly enhances the benefits of these ROMs. This enables predictions of the dynamic behavior of the system for flight conditions where CFD analysis has not been explicitly
Automotive mechatronic systems. General developments and examples
Energy Technology Data Exchange (ETDEWEB)
Isermann, R. [Technische Univ. Darmstadt (Germany). Inst. fuer Automatisierungstechnik, FG Regelungstechnik und Prozessautomatisierung
2006-08-15
Automobiles are showing an increasing integration of mechanics with digital electronics and information processing. This integration is between the components (hardware) and by the information-driven functions (software), resulting in integrated systems called mechatronic systems. Their development involves finding an optimal balance between the basic mechanical structure, sensor and actuator implementation, communication, automatic information processing and overall control. This contribution summarizes some ongoing developments for mechatronic systems in automobiles, shows design approaches and examples and considers the various embedded control functions and systems integrity. Some examples of automotive mechatronic systems are shown in more detail. Great progress can be observed in braking systems (ABS, ESP), the first brake-by-wire electro-hydraulic brake system (EHB), steering systems (electrical power steering, active front steering) and active suspension systems. (orig.)
Preheating of fluid in a supercritical Brayton cycle power generation system at cold startup
Wright, Steven A.; Fuller, Robert L.
2016-07-12
Various technologies pertaining to causing fluid in a supercritical Brayton cycle power generation system to flow in a desired direction at cold startup of the system are described herein. A sensor is positioned at an inlet of a turbine, wherein the sensor is configured to output sensed temperatures of fluid at the inlet of the turbine. If the sensed temperature surpasses a predefined threshold, at least one operating parameter of the power generation system is altered.
Generalized fluid equations for parallel transport in collisional to weakly collisional plasmas
International Nuclear Information System (INIS)
Zawaideh, E.S.
1985-01-01
A new set of two-fluid equations which are valid from collisional to weakly collisional limits are derived. Starting from gyrokinetic equations in flux coordinates with no zeroth order drifts, a set of moment equations describing plasma transport along the field lines of a space and time dependent magnetic field are derived. No restriction on the anisotropy of the ion distribution function is imposed. In the highly collisional limit, these equations reduce to those of Braginskii while in the weakly collisional limit, they are similar to the double adiabatic or Chew, Goldberger, and Low (CGL) equations. The new transport equations are used to study the effects of collisionality, magnetic field structure, and plasma anisotropy on plasma parallel transport. Numerical examples comparing these equations with conventional transport equations show that the conventional equations may contain large errors near the sound speed (M approx. = 1). It is also found that plasma anisotropy, which is not included in the conventional equations, is a critical parameter in determining plasma transport in varying magnetic field. The new transport equations are also used to study axial confinement in multiple mirror devices from the strongly to weakly collisional regime. A new ion conduction model was worked out to extend the regime of validity of the transport equations to the low density multiple mirror regime
Generalized extended Navier-Stokes theory: Multiscale spin relaxation in molecular fluids
DEFF Research Database (Denmark)
Hansen, Jesper Schmidt
2013-01-01
This paper studies the relaxation of the molecular spin angular velocity in the framework of generalized extended Navier-Stokes theory. Using molecular dynamics simulations, it is shown that for uncharged diatomic molecules the relaxation time decreases with increasing molecular moment of inertia...
Multiple scales and singular limits for compressible rotating fluids with general initial data
Czech Academy of Sciences Publication Activity Database
Feireisl, Eduard; Novotný, A.
2014-01-01
Roč. 39, č. 6 (2014), s. 1104-1127 ISSN 0360-5302 Keywords : compressible Navier-Stokes equations * multiple scales * oscillatory integrals Subject RIV: BA - General Mathematics Impact factor: 1.013, year: 2014 http://www.tandfonline.com/doi/full/10.1080/03605302.2013.856917
Neutron kinetics of fluid-fuel systems by the quasi-static method
International Nuclear Information System (INIS)
Dulla, S.; Ravetto, P.; Rostagno, M.M.
2004-01-01
The quasi-static method for the neutron kinetics of nuclear reactors is generalized for application to neutron multiplying systems fueled by a fluid multiplying material, typically a mixture of fissile molten salts. The method is derived by the application of factorization formulae for both the neutron density and the delayed precursor concentrations and the projection of the balance equations upon a weighting function. A physically meaningful weight can be assumed as the solution of the adjoint model, which is constructed for the situation considered, including delayed neutrons. The quasi-static scheme is then applied to calculations of some transients for a typical configuration of a molten-salt reactor, in a multigroup diffusion model with a one-dimensional slug-flow velocity field. The physical features associated to the motion of the fissile material are highlighted
Acoustic Manipulation of Particles and Fluids in Microfluidic Systems
Johansson, Linda
2009-01-01
The downscaling and integration of biomedical analyses onto a single chip offers several advantages in speed, cost, parallelism and de-centralization. Acoustic radiation forces are attractive to use in these applications since they are strong, long-range and gentle. Lab-on-a-chip operations such as cell trapping, particle fluorescence activated cell sorting, fluid mixing and particle sorting performed by acoustic radiation forces are exploited in this thesis. Two different platforms are desig...
Analysis and hazard evaluation of heat-transfer fluids for the direct contact cooling system
International Nuclear Information System (INIS)
Hong, Joo Hi; Lee, Yeon Hee; Shin, You Hwan; Karng, Sarng Woo; Kim, Seo Young; Kim, Young Gil
2006-01-01
This paper discusses several low-temperature heat-transfer fluids, including water-based inorganic salt, organic salt, alcohol/glycol mixtures, silicones, and halogenated hydrocarbons in order to choose the best heat-transfer fluid for the newly designed direct contact refrigeration system. So, it contains a survey on commercial products such as propylene glycol and potassium formate as newly used in super market and food processing refrigeration. The stability of commercial fluids at the working temperature of -20 .deg. C was monitored as a function of time up to two months. And organic and inorganic compositions of candidate fluids were obtained by analytical instruments such as ES, XRF, AAS, ICP-AES, GC, and GC-MS. Analysis results indicate that commercial propylene glycol is very efficient and safe heat transfer fluids for the direct cooling system with liquid phase
Evolution paths of a general control system
International Nuclear Information System (INIS)
Speckert, G.C.
1983-01-01
Large systems are built by teams of people who communicate through a set of design tools to produce an information model which describes the system. The model can be analyzed for consistency and completeness. A system building methodology based upon this information model can be used for the construction, operation, and maintenance of the system. Operational procedure knowledge derived from operating experience can be used for autonomous operation. Advancing computer technology is improving the engineering tools available in each of these areas. A unified set of such tools provides the maximum amount of computer assistance to the system builders
Definition of Nonequilibrium Entropy of General Systems
Mei, Xiaochun
1999-01-01
The definition of nonequilibrium entropy is provided for the general nonequilibrium processes by connecting thermodynamics with statistical physics, and the principle of entropy increment in the nonequilibrium processes is also proved in the paper. The result shows that the definition of nonequilibrium entropy is not unique.
Performance of the mineral blended ester oil-based drilling fluid systems
Energy Technology Data Exchange (ETDEWEB)
Ismail, A.R.; Kamis, A.; Foo, K.S. [University Teknologi (Malaysia)
2001-06-01
A study was conducted in which the properties of ester oil-based drilling fluid systems were examined using a blended mixture of ester and synthetic mineral oil. Biodegradable invert emulsion ester-based fluids are preferred over mineral oil-based drilling fluids for environmental reasons, but they tend to cause alkaline hydrolysis resulting in solidification of the drilling fluid systems. The drilling fluid examined here consisted of Malaysian palm oil ester derivatives (methyl laureate ester or isopropyl laureate ester) blended with commercially available synthetic mineral oil. This mineral oil was added to reduce the problem of alkaline hydrolysis. This mixture, however, was found to be unstable and could not solve the problem at high temperature. The isopropyl laureate and mineral oil blended system was more stable towards the hydrolysis process up to 250 degrees F. In order to enhance the performance of an invert emulsion drilling fluid system, it was recommended that brine water content of the fluid system be lowered. 3 refs., 2 figs.
Technology for Space Station Evolution. Volume 3: EVA/Manned Systems/Fluid Management System
1990-01-01
NASA's Office of Aeronautics and Space Technology (OAST) conducted a workshop on technology for space station evolution 16-19 Jan. 1990 in Dallas, Texas. The purpose of this workshop was to collect and clarify Space Station Freedom technology requirements for evolution and to describe technologies that can potentially fill those requirements. These proceedings are organized into an Executive Summary and Overview and five volumes containing the Technology Discipline Presentations. Volume 3 consists of the technology discipline sections for Extravehicular Activity/Manned Systems and the Fluid Management System. For each technology discipline, there is a Level 3 subsystem description, along with the papers.
Towards a General Definition of Biometric Systems
Mirko Cubrilo; Miroslav Baca; Markus Schatten
2009-01-01
A foundation for closing the gap between biometrics in the narrower and the broader perspective is presented trough a conceptualization of biometric systems in both perspectives. A clear distinction between verification, identification and classification systems is made as well as shown that there are additional classes of biometric systems. In the end a Unified Modeling Language model is developed showing the connections between the two perspectives.
Frames and generalized shift-invariant systems
DEFF Research Database (Denmark)
Christensen, Ole
2004-01-01
With motivation from the theory of Hilbert-Schmidt operators we review recent topics concerning frames in L 2 (R) and their duals. Frames are generalizations of orthonormal bases in Hilbert spaces. As for an orthonormal basis, a frame allows each element in the underlying Hilbert space...... to be written as an unconditionally convergent infinite linear combination of the frame elements; however, in contrast to the situation for a basis, the coefficients might not be unique. We present the basic facts from frame theory and the motivation for the fact that most recent research concentrates on tight...... frames or dual frame pairs rather than general frames and their canonical dual. The corresponding results for Gabor frames and wavelet frames are discussed in detail....
Polydispersity effect on solid-fluid transition in hard sphere systems
Nogawa, T.; Watanabe, H.; Ito, N.
2010-01-01
The solid-fluid transition of the hard elastic particle system with size polydispersity is studied by molecular dynamics simulations. Using nonequilibrium relaxation from the mixed initial condition we determines the melting point where the first
National Aeronautics and Space Administration — Computational fluid dynamics (CFD) simulations are routinely used by NASA to optimize the design of propulsion systems. Current methods for CFD modeling rely on...
Finite Element Analysis of Fluid-Structure Interaction in a Blast-Resistant Window System (PREPRINT)
National Research Council Canada - National Science Library
Chung, Jae H; Consolazio, Gary R; Dinan, Robert J; Rinehart, Stephen A
2008-01-01
.... The influences of shock wave propagation and fluid venting inside the damping chamber of the flex-window system are quantified and the influences of such phenomena on panel deflections, deformations, and internal forces are presented.
Breakdown of Preservative Fluid MIL-PRF-46170 in Aircraft Hydraulic Systems
National Research Council Canada - National Science Library
Moorman, Jeffrey
2001-01-01
.... Additional information obtained from outside sources is also summarized for background. Laboratory pump testing showed rapid filter dogging with small amounts of preservative fluid (MU-PRF-46l70) in the system...
Magnetohydrodynamic pump with a system for promoting flow of fluid in one direction
Lemoff, Asuncion V [Union City, CA; Lee, Abraham P [Irvine, CA
2010-07-13
A magnetohydrodynamic pump for pumping a fluid. The pump includes a microfluidic channel for channeling the fluid, a MHD electrode/magnet system operatively connected to the microfluidic channel, and a system for promoting flow of the fluid in one direction in the microfluidic channel. The pump has uses in the medical and biotechnology industries for blood-cell-separation equipment, biochemical assays, chemical synthesis, genetic analysis, drug screening, an array of antigen-antibody reactions, combinatorial chemistry, drug testing, medical and biological diagnostics, and combinatorial chemistry. The pump also has uses in electrochromatography, surface micromachining, laser ablation, inkjet printers, and mechanical micromilling.
Development and Implementation of a Design Metric for Systems Containing Long-Term Fluid Loops
Steele, John W.
2016-01-01
John Steele, a chemist and technical fellow from United Technologies Corporation, provided a water quality module to assist engineers and scientists with a metric tool to evaluate risks associated with the design of space systems with fluid loops. This design metric is a methodical, quantitative, lessons-learned based means to evaluate the robustness of a long-term fluid loop system design. The tool was developed by a cross-section of engineering disciplines who had decades of experience and problem resolution.
Generalized oscillator systems and their parabosonic interpretation
Energy Technology Data Exchange (ETDEWEB)
Macfarlane, A J [Cambridge Univ. (United Kingdom). Dept. of Applied Mathematics and Theoretical Physics
1994-12-31
The Fock space description of various bosonic oscillator systems are carried out. All descriptions are based on a single creation - annihilation pair. Special attention is paid to the q-deformed Calogero-Vasiliev oscillator. 23 refs.
Energy information systems: a general overview
International Nuclear Information System (INIS)
Sen, B.K.
1991-01-01
The unprecedented energy crises that engulfed the world in early 1970s brought about a spurt in energy research all over the world, which in turn caused the rapid growth of literature in the field. In order to achieve effective bibliographical control, proper dissemination of information, and rapid access to the desired document, energy information systems of diverse scope came into being. The paper describes the special features of several information systems like (i) International Nuclear Information Systems, which covers world literature on nuclear science and technology (ii) Energy Information Services which takes cares of energy information transfer among the Commonwealth countries of the Asia and Pacific region; (ii) Information Network on New Energy Sources and Technologies for Asia And Pacific. This system is being developed to ensure smooth energy information transfer amongst non-commonwealth countries of Asia and the Pacific. (author)
Yoon, Young Dae
2017-10-01
A generalized, intuitive two-fluid picture of 2D non-driven collisionless magnetic reconnection is described using results from a full-3D numerical simulation. The relevant two-fluid equations simplify to the condition that the flux associated with canonical circulation Q =me ∇ ×ue +qe B is perfectly frozen into the electron fluid. Q is the curl of P =meue +qe A , which is the electron canonical momenrum. Since ∇ . Q = 0 , the Q flux tubes are incompressible and so have a fixed volume. Because they are perfectly frozen into the electron fluid, the Q flux tubes cannot reconnect. Following the behavior of these Q flux tubes provides an intuitive insight into 2D collisionless reconnection of B . In the reconnection geometry, a small perturbation to the central electron current sheet effectively brings a localized segment of a Q flux tube towards the X-point. This flux tube segment is convected downwards with the central electron current, effectively stretching the flux tube, decreasing its cross-section to maintain a fixed volume and so increasing the magnitude of Q . Also, because Q is the sum of the electron vorticity and the magnetic field, the two terms may change in such a way that one term becomes smaller while the other becomes larger while preserving constant Q flux. This allows magnetic reconnection, which is a conversion of magnetic field into particle velocity, to occur without any dissipation mechanism. The entire process has positive feedback with no restoring mechanism and therefore is an instability. The Q motion provides an interpretation for other phenomena as well, such as spiked central electron current filaments. The simulated reconnection rate was found to agree with a previous analytical calculation having the same geometry. Energy analysis shows that the magnetic energy is converted and propagated mainly in the form of the Poynting flux, while helicity analysis shows that the canonical helicity ∫ P . QdV as a whole must be considered when
Numerical fluid flow and heat transfer calculations on multiprocessor systems
Energy Technology Data Exchange (ETDEWEB)
Oehman, G.A.; Malen, T.E.; Kuusela, P.
1989-01-01
The first part of the report presents the basic principles of parallel processing, and factors influencing tbe efficiency of practical applications are discussed. In a multiprocessor computer, different parts of the program code are executed in parallel, i.e. simultaneous with respect to time, on different processors, and thus it becomes possible to decrease the overall computation time by a factor, which in the ideal case is equal to the number of processors. The application study starts from the numerical solution of the twodimesional Laplace equation, which describes the steady heat conduction in a solid plate and advances through the solution of the three dimensional Laplace equation to the case of study laminar fluid flow in a twodimensional box at Reynolds numbers up to 20. Hereby the stream function-vorticity method is first applied and the SIMPLER method. The conventional (sequential) numerical algoritms for these fluid flow and heat transfer problems are found not to be ideally suited for conversion to parallel computation, but sped-up ratios considerably above 50 % of the theoretical maximum are regularly achieved in the runs. The numerical procedures we coded in the OCCAM-2 language and the test runs were performed at who Akademi on the imperimental HATHI-computers containing 16 T4l4 and 100 INMOS T800 transputers respectively.
Numerical fluid flow and heat transfer calculations on multiprocessor systems
Energy Technology Data Exchange (ETDEWEB)
Oehman, G.A.; Malen, T.E.; Kuusela, P.
1989-12-31
The first part of the report presents the basic principles of parallel processing, and factors influencing tbe efficiency of practical applications are discussed. In a multiprocessor computer, different parts of the program code are executed in parallel, i.e. simultaneous with respect to time, on different processors, and thus it becomes possible to decrease the overall computation time by a factor, which in the ideal case is equal to the number of processors. The application study starts from the numerical solution of the twodimesional Laplace equation, which describes the steady heat conduction in a solid plate and advances through the solution of the three dimensional Laplace equation to the case of study laminar fluid flow in a twodimensional box at Reynolds numbers up to 20. Hereby the stream function-vorticity method is first applied and the SIMPLER method. The conventional (sequential) numerical algoritms for these fluid flow and heat transfer problems are found not to be ideally suited for conversion to parallel computation, but sped-up ratios considerably above 50 % of the theoretical maximum are regularly achieved in the runs. The numerical procedures we coded in the OCCAM-2 language and the test runs were performed at who Akademi on the imperimental HATHI-computers containing 16 T4l4 and 100 INMOS T800 transputers respectively.
Deicing System Protects General Aviation Aircraft
2007-01-01
Kelly Aerospace Thermal Systems LLC worked with researchers at Glenn Research Center on deicing technology with assistance from the Small Business Innovation Research (SBIR) program. Kelly Aerospace acquired Northcoast Technologies Ltd., a firm that had conducted work on a graphite foil heating element under a NASA SBIR contract and developed a lightweight, easy-to-install, reliable wing and tail deicing system. Kelly Aerospace engineers combined their experiences with those of the Northcoast engineers, leading to the certification and integration of a thermoelectric deicing system called Thermawing, a DC-powered air conditioner for single-engine aircraft called Thermacool, and high-output alternators to run them both. Thermawing, a reliable anti-icing and deicing system, allows pilots to safely fly through ice encounters and provides pilots of single-engine aircraft the heated wing technology usually reserved for larger, jet-powered craft. Thermacool, an innovative electric air conditioning system, uses a new compressor whose rotary pump design runs off an energy-efficient, brushless DC motor and allows pilots to use the air conditioner before the engine even starts
Harvey, Jason; Moore, Michael
2013-01-01
The General-Use Nodal Network Solver (GUNNS) is a modeling software package that combines nodal analysis and the hydraulic-electric analogy to simulate fluid, electrical, and thermal flow systems. GUNNS is developed by L-3 Communications under the TS21 (Training Systems for the 21st Century) project for NASA Johnson Space Center (JSC), primarily for use in space vehicle training simulators at JSC. It has sufficient compactness and fidelity to model the fluid, electrical, and thermal aspects of space vehicles in real-time simulations running on commodity workstations, for vehicle crew and flight controller training. It has a reusable and flexible component and system design, and a Graphical User Interface (GUI), providing capability for rapid GUI-based simulator development, ease of maintenance, and associated cost savings. GUNNS is optimized for NASA's Trick simulation environment, but can be run independently of Trick.
The antioxidant system of seminal fluid during in vitro storage of sterlet Acipenser ruthenus sperm.
Dzyuba, Viktoriya; Cosson, Jacky; Dzyuba, Borys; Yamaner, Gunes; Rodina, Marek; Linhart, Otomar
2016-04-01
The role of the seminal fluid antioxidant system in protection against damage to spermatozoa during in vitro sperm storage is unclear. This study investigated the effect of in vitro storage of sterlet Acipenser ruthenus spermatozoa together with seminal fluid for 36 h at 4 °C on spermatozoon motility rate and curvilinear velocity, thiobarbituric acid reactive substance level, and components of enzyme and non-enzyme antioxidant system (superoxide dismutase and catalase activity and uric acid concentration) in seminal fluid. Spermatozoon motility parameters after sperm storage were significantly decreased, while the level of thiobarbituric acid reactive substances, activity of superoxide dismutase and catalase, and uric acid concentration did not change. Our findings suggest that the antioxidant system of sterlet seminal fluid is effective in preventing oxidative stress during short-term sperm storage and prompt future investigations of changes in spermatozoon homeostasis and in spermatozoon plasma membrane structure which are other possible reasons of spermatozoon motility deterioration upon sperm storage.
Building a generalized distributed system model
Mukkamala, R.
1993-01-01
The key elements in the 1992-93 period of the project are the following: (1) extensive use of the simulator to implement and test - concurrency control algorithms, interactive user interface, and replica control algorithms; and (2) investigations into the applicability of data and process replication in real-time systems. In the 1993-94 period of the project, we intend to accomplish the following: (1) concentrate on efforts to investigate the effects of data and process replication on hard and soft real-time systems - especially we will concentrate on the impact of semantic-based consistency control schemes on a distributed real-time system in terms of improved reliability, improved availability, better resource utilization, and reduced missed task deadlines; and (2) use the prototype to verify the theoretically predicted performance of locking protocols, etc.
International Nuclear Information System (INIS)
Toda, Saburo; Yuki, Kazuhisa; Muramatsu, Toshiharu
2002-03-01
In a region where two fluids with different temperatures are mixed together, unsteady temperature fluctuation, i.e. thermal striping, occurs in going through the unstable mixing process of the fluids, and structural materials in the surrounding area may be damaged by high-cycle thermal fatigue. In this report, in order to clarify the relation between the thermal striping and temperature fluctuation of structural wall, PIV measuring system is applied to visualize the fluid mixing state in a T-junction area in which important parameters for the fluid mixing are the flow velocity and aperture ratios of a main pipe to a small pipe and an incidence angle of the small pipe to the main pipe as well as temperature difference of the two flows. As a result of visualization experiments in a isothermal field, it is confirmed that a jet-axis, which is a stream line flowing out from the center of the small pipe, vibrates unsteadily and that its behavior is strongly affected by circulating flow, Karman vortex formed behind the jet axis, and especially flow-fluctuation which exists as a background-flow in the main pipe. Especially, the frequency band of the flow-fluctuation in the main pipe almost corresponds to that of the vibration of the jet-axis where the ratio of flow rate is low. Furthermore, in order to estimate the vibration state of the jet-axis and to find out the conditions for preventing the thermal fatigue, the penetration depth of the jet-axis is generalized. From measurements of temperature fluctuation of wall, it is shown that a high power fluctuation area exists universally behind the junction point of the small pipe where the flow rate of the small pipe flow is relatively lower than that of the main pipe flow. The band of dominant frequency of the temperature fluctuation is almost the same as the flow-fluctuation and the jet-axis vibration mentioned above. In addition, visualization experiments of secondary flow formed in a 90-degree bend, which is installed
A Cryogenic Fluid System Simulation in Support of Integrated Systems Health Management
Barber, John P.; Johnston, Kyle B.; Daigle, Matthew
2013-01-01
Simulations serve as important tools throughout the design and operation of engineering systems. In the context of sys-tems health management, simulations serve many uses. For one, the underlying physical models can be used by model-based health management tools to develop diagnostic and prognostic models. These simulations should incorporate both nominal and faulty behavior with the ability to inject various faults into the system. Such simulations can there-fore be used for operator training, for both nominal and faulty situations, as well as for developing and prototyping health management algorithms. In this paper, we describe a methodology for building such simulations. We discuss the design decisions and tools used to build a simulation of a cryogenic fluid test bed, and how it serves as a core technology for systems health management development and maturation.
Instrument validation system of general application
International Nuclear Information System (INIS)
Filshtein, E.L.
1990-01-01
This paper describes the Instrument Validation System (IVS) as a software system which has the capability of evaluating the performance of a set of functionally related instrument channels to identify failed instruments and to quantify instrument drift. Under funding from Combustion Engineering (C-E), the IVS has been developed to the extent that a computer program exists whose use has been demonstrated. The initial development work shows promise for success and for wide application, not only to power plants, but also to industrial manufacturing and process control. Applications in the aerospace and military sector are also likely
49 CFR 659.21 - System security plan: general requirements.
2010-10-01
... 49 Transportation 7 2010-10-01 2010-10-01 false System security plan: general requirements. 659.21... State Oversight Agency § 659.21 System security plan: general requirements. (a) The oversight agency shall require the rail transit agency to implement a system security plan that, at a minimum, complies...
46 CFR 154.1200 - Mechanical ventilation system: General.
2010-10-01
... 46 Shipping 5 2010-10-01 2010-10-01 false Mechanical ventilation system: General. 154.1200 Section... CARGOES SAFETY STANDARDS FOR SELF-PROPELLED VESSELS CARRYING BULK LIQUEFIED GASES Design, Construction and Equipment Cargo Area: Mechanical Ventilation System § 154.1200 Mechanical ventilation system: General. (a...
Working fluid charge oriented off-design modeling of a small scale Organic Rankine Cycle system
International Nuclear Information System (INIS)
Liu, Liuchen; Zhu, Tong; Ma, Jiacheng
2017-01-01
Highlights: • Organic Rankine Cycle model considering working fluid charge has been established. • Overall solution algorithm of system off-design performance is proposed. • Variation trend of different zones in both heat exchangers can be observed. • Optimal working fluid charge volume for different output work has been estimated. - Abstract: Organic Rankine Cycle system is one of the most widely used technique for low-grade waste heat recovery. Developing of dynamic Organic Rankine Cycle models played an increasingly important part in system performance prediction. The present paper developed a working fluid charge oriented model for an small scale Organic Rankine Cycle to calculate the theoretical value of working fluid charge level for the system under rated condition. The two heat exchangers are divided into three different zones and related heat transfer correlations are employed to estimate the length variation of each zones. Steady state models have been applied to describe the performance of pump and expander. Afterwards, an overall solution algorithm based on the established model has been proposed in order to exact simulate the system’s off-design performance. Additionally, the impact of different working fluid charge volumes has also been discussed. Simulation results clearly shows the variation trend of different zones in both heat exchangers, as well as the variation trend of system operating parameters under various expander output work. Furthermore, the highest thermal efficiency can be reached 6.37% under rated conditions with a working fluid charge volume of 34.6 kg.
Dang, Cai-Ping; Braeken, Johan; Ferrer, Emilio; Liu, Chang
2012-01-01
This study explored the controversy surrounding working memory: whether it is a unitary system providing general purpose resources or a more differentiated system with domain-specific sub-components. A total of 348 participants completed a set of 6 working memory tasks that systematically varied in storage target contents and type of information…
Komathiraj, K.; Sharma, Ranjan
2018-05-01
In this paper, we present a formalism to generate a family of interior solutions to the Einstein-Maxwell system of equations for a spherically symmetric relativistic charged fluid sphere matched to the exterior Reissner-Nordström space-time. By reducing the Einstein-Maxwell system to a recurrence relation with variable rational coefficients, we show that it is possible to obtain closed-form solutions for a specific range of model parameters. A large class of solutions obtained previously are shown to be contained in our general class of solutions. We also analyse the physical viability of our new class of solutions.
International Nuclear Information System (INIS)
Schoenfelder, C.; Kellner, A.
1985-01-01
An approximated representative part of a PWR-feed-water-line was modelled and used to calculate the displacements of the piping system and the loads on it, caused by pressure pulse due to pump failure and subsequent check valve closure. The computation was performed with the code SAPHYR which contains the fluid code ROLAST and the structure code SAPIENS, calculating simultaneously and interactively. The results were compared with an uncoupled calculation without fluid/structure interaction. It was shown that neglecting the fluid/structure interaction can lead to considerable overestimations - in some cases up to a factor of 3 - of the loads on the structures. (orig.)
Experimental evaluation of SWCNT-water nanofluid as a secondary fluid in a refrigeration system
International Nuclear Information System (INIS)
Vasconcelos, Adriano Akel; Cárdenas Gómez, Abdul Orlando; Bandarra Filho, Enio Pedone; Parise, José Alberto Reis
2017-01-01
Highlights: • SWCNT-water nanofluid was used as secondary fluid for a refrigeration system. • For a given HTFS mass flow rate and inlet temperature, nanofluid performed better than base fluid. • Total power consumption was not significantly affected by volume concentration. • Nanoparticle volume fraction ranged from 0 to 0.21%. - Abstract: SWCNT-water (single walled carbon nanotube) nanofluid was tested as a secondary fluid for a 4–9 kW indirect vapor compression refrigeration system. The evaporator, with boiling refrigerant HCFC-22 extracting heat from the nanofluid, was of the brazed plate counter-flow type. A semi-hermetic compressor, an electronic expansion valve (EEV) and an air-cooled condenser were the other main components of the refrigeration cycle. Tests were carried out with the experimental apparatus operating over a range of different volumetric fractions of nanoparticles (0–0.21%) as well as nanofluid inlet temperatures (30–40 °C) and mass flow rates (40–80 g/s). Overall, the performance of the system working with nanofluid as a secondary fluid was superior to that where just the base fluid (i.e., pure water) circulated in the secondary fluid loop, at the same mass flow rate and inlet temperature. The enhanced thermal conductivity of the nanofluid is believed to be the main reason why the refrigeration system with the nanofluid loop, if compared to that with pure water, presented a higher refrigerating capacity.
Soenksen, L R; Kassis, T; Noh, M; Griffith, L G; Trumper, D L
2018-03-13
Precise fluid height sensing in open-channel microfluidics has long been a desirable feature for a wide range of applications. However, performing accurate measurements of the fluid level in small-scale reservoirs (sensor contact needs to be avoided. In particular, gravity-driven systems used in several microfluidic applications to establish pressure gradients and impose flow remain open-loop and largely unmonitored due to these sensing limitations. Here we present an optimized self-shielded coplanar capacitive sensor design and automated control system to provide submillimeter fluid-height resolution (∼250 μm) and control of small-scale open reservoirs without the need for direct fluid contact. Results from testing and validation of our optimized sensor and system also suggest that accurate fluid height information can be used to robustly characterize, calibrate and dynamically control a range of microfluidic systems with complex pumping mechanisms, even in cell culture conditions. Capacitive sensing technology provides a scalable and cost-effective way to enable continuous monitoring and closed-loop feedback control of fluid volumes in small-scale gravity-dominated wells in a variety of microfluidic applications.
Resolution of holograms produced by the fluid experiment system and the holography ground system
Brooks, Howard L.
1987-01-01
The Fluid Experiment System (FES) was developed to study low temperature crystal growth of triglycine sulfate from solution in a low gravity environment onboard Spacelab. The first flight of FES was in 1985. FES uses an optical system to take holograms of the growing crystal to be analyzed after the mission in the Holography Ground System (HGS) located in the Test Laboratory at Marshall Space Flight Center. Microscopic observation of the images formed by the reconstructed holograms is critical to determining crystal growth rate and particle velocity. FES and HGS were designed for a resolution of better than 20 micrometers, but initial observation of the flight holograms show a limit of 80 micrometers. The resolution of the FES holograms is investigated, as well as the role of beam intensity ratio and exposure time on the resolution of HGS produced holograms.
Directory of Open Access Journals (Sweden)
Dominique Brun-Battistini
2017-10-01
Full Text Available Richard C. Tolman analyzed the relation between a temperature gradient and a gravitational field in an equilibrium situation. In 2012, Tolman’s law was generalized to a non-equilibrium situation for a simple dilute relativistic fluid. The result in that scenario, obtained by introducing the gravitational force through the molecular acceleration, couples the heat flux with the metric coefficients and the gradients of the state variables. In the present paper it is shown, by explicitly describing the single particle orbits as geodesics in Boltzmann’s equation, that a gravitational field drives a heat flux in this type of system. The calculation is devoted solely to the gravitational field contribution to this heat flux in which a Newtonian limit to the Schwarzschild metric is assumed. The corresponding transport coefficient, which is obtained within a relaxation approximation, corresponds to the dilute fluid in a weak gravitational field. The effect is negligible in the non-relativistic regime, as evidenced by the direct evaluation of the corresponding limit.
Polydispersity effect on solid-fluid transition in hard sphere systems
Nogawa, T.
2010-02-01
The solid-fluid transition of the hard elastic particle system with size polydispersity is studied by molecular dynamics simulations. Using nonequilibrium relaxation from the mixed initial condition we determines the melting point where the first order transition between the solid, fcc crystal, and fluid states occurs. It is found that the density gap between the bistable states decreases with increasing the strength of the polydispersity and continuously approaches to zero at the critical point. © 2010.
Cabaleiro Alvarez, David
2016-01-01
This PhD Thesis aims to characterize different conventional thermal fluids and propose new nanofluids based on their thermophysical, rheological, (solid-liquid) phase equilibria and their capability to heat transfer or heat storage. The selected conventional fluids are commonly used in the majority of heat transfer systems such as ethylene glycol (EG), propylene glycol (PG), a (ethylene glycol + water) mixture at 50 vol.% (EG+W), or the (diphenyl ether + biphenyl) mixtures. The nanofluids wer...
Generalized projective synchronization of a unified chaotic system
International Nuclear Information System (INIS)
Yan Jianping; Li Changpin
2005-01-01
In the present paper, a simple but efficient control technique of the generalized projective synchronization is applied to a unified chaotic system. Numerical simulations show that this method works very well, which can also be applied to other chaotic systems
Fluid-structure interaction in BWR suppression pool systems. Final report
International Nuclear Information System (INIS)
Nickell, R.E.
1979-09-01
The discharge of safety relief valves or a severe loss-of-coolant event in a boiling-water-cooled reactor steam supply system triggers a complex pressure suppression system that is based upon sub-surface steam condensation in large pools of water. The physical problems fall into two categories. The first is referred to as vent clearing and describes the process of expelling non-condensables from the system prior to steam flow. The second category covers a variety of phenomena related to the transient overexpansion of a condensable volume and the subsequent inertially-driven volume decrease. The dynamic loading of either event, depending upon fluid-structural design parameters, can be of concern in safety analysis. This report describes the development of a method for calculating the loads and the structural response for both types of problems. The method is embedded in a computer code, called PELE-IC, that couples a two-dimensional, incompressible eulerian fluid algorithm to a finite element shell algorithm. The fluid physics is based upon the SOLA algorithm, which provideds a trial velocity field using the Navier-Stokes equations that is subsequently corrected iteratively so that incompressibility, fluid-structure interface compatibility, and boundary conditions are satisfied. These fluid and fluid-structure algorithms have been extensively verified through calculations of known solutions from the classical literature, and by comparison to air and steam blowdown experiments
Muszynska, Agnes; Bently, Donald E.
1991-01-01
Perturbation techniques used for identification of rotating system dynamic characteristics are described. A comparison between two periodic frequency-swept perturbation methods applied in identification of fluid forces of rotating machines is presented. The description of the fluid force model identified by inputting circular periodic frequency-swept force is given. This model is based on the existence and strength of the circumferential flow, most often generated by the shaft rotation. The application of the fluid force model in rotor dynamic analysis is presented. It is shown that the rotor stability is an entire rotating system property. Some areas for further research are discussed.
An exponential observer for the generalized Rossler chaotic system
International Nuclear Information System (INIS)
Sun, Y.-J.
2009-01-01
In this paper, the generalized Rossler chaotic system is considered and the state observation problem of such a system is investigated. Based on the time-domain approach, a state observer for the generalized Rossler chaotic system is developed to guarantee the global exponential stability of the resulting error system. Moreover, the guaranteed exponential convergence rate can be arbitrarily pre-specified. Finally, a numerical example is provided to illustrate the feasibility and effectiveness of the obtained result.
A simple observer of the generalized Chen chaotic systems
International Nuclear Information System (INIS)
Sun, Y.-J.
2009-01-01
In this paper, the generalized Chen chaotic system is considered and the state observation problem of such a system is investigated. Based on the time-domain approach, a simple observer for the generalized Chen chaotic system is proposed to guarantee the global exponential stability of the resulting error system. Furthermore, the guaranteed exponential convergence rate can be correctly estimated. Finally, a numerical example is provided to illustrate the use of the main result.
A simple observer design of the generalized Lorenz chaotic systems
International Nuclear Information System (INIS)
Sun, Y.-J.
2010-01-01
In this Letter, the generalized Lorenz chaotic system is considered and the state observation problem of such a system is investigated. Based on the time-domain approach, a simple observer for the generalized Lorenz chaotic system is developed to guarantee the global exponential stability of the resulting error system. Moreover, the guaranteed exponential convergence rate can be correctly estimated. Finally, a numerical example is given to show the effectiveness of the obtained result.
Development of fluid system design technology for integral reactor
Energy Technology Data Exchange (ETDEWEB)
Lee, D. J.; Chang, M. H.; Kang, D. J. and others
1999-03-01
This study presents the technology development of the system design concepts of SMART, a multi-purposed integral reactor with enhanced safety and operability, for use in diverse usages and applications of the nuclear energy. This report contains the following; - Design characteristics - Performance and safety related design criteria - System description: Primary system, Secondary system, Residual heat removal system, Make-up system, Component cooling system, Safety system - Development of design computer code: Steam generator performance(ONCESG), Pressurizer performance(COLDPZR), Steam generator flow instability(SGINS) - Development of component module and modeling using MMS computer code - Design calculation: Steam generator thermal sizing, Analysis of feed-water temperature increase at a low flow rate, Evaluation of thermal efficiency in the secondary system, Inlet orifice throttling coefficient for the prevention of steam generator flow instability, Analysis of Nitrogen gas temperature in the pressurizer during heat-up process, evaluation of water chemistry and erosion etc. The results of this study can be utilized not only for the foundation technology of the next phase basic system design of the SMART but also for the basic model in optimizing the system concepts for future advanced reactors. (author)
Client-Controlled Case Information: A General System Theory Perspective
Fitch, Dale
2004-01-01
The author proposes a model for client control of case information via the World Wide Web built on principles of general system theory. It incorporates the client into the design, resulting in an information structure that differs from traditional human services information-sharing practices. Referencing general system theory, the concepts of…
Tsai, Tien-Lung; Shau, Wen-Yi; Hu, Fu-Chang
2006-01-01
This article generalizes linear path analysis (PA) and simultaneous equations models (SiEM) to deal with mixed responses of different types in a recursive or triangular system. An efficient instrumental variable (IV) method for estimating the structural coefficients of a 2-equation partially recursive generalized path analysis (GPA) model and…
Groves, Curtis Edward
2014-01-01
Spacecraft thermal protection systems are at risk of being damaged due to airflow produced from Environmental Control Systems. There are inherent uncertainties and errors associated with using Computational Fluid Dynamics to predict the airflow field around a spacecraft from the Environmental Control System. This paper describes an approach to quantify the uncertainty in using Computational Fluid Dynamics to predict airflow speeds around an encapsulated spacecraft without the use of test data. Quantifying the uncertainty in analytical predictions is imperative to the success of any simulation-based product. The method could provide an alternative to traditional "validation by test only" mentality. This method could be extended to other disciplines and has potential to provide uncertainty for any numerical simulation, thus lowering the cost of performing these verifications while increasing the confidence in those predictions. Spacecraft requirements can include a maximum airflow speed to protect delicate instruments during ground processing. Computational Fluid Dynamics can be used to verify these requirements; however, the model must be validated by test data. This research includes the following three objectives and methods. Objective one is develop, model, and perform a Computational Fluid Dynamics analysis of three (3) generic, non-proprietary, environmental control systems and spacecraft configurations. Several commercially available and open source solvers have the capability to model the turbulent, highly three-dimensional, incompressible flow regime. The proposed method uses FLUENT, STARCCM+, and OPENFOAM. Objective two is to perform an uncertainty analysis of the Computational Fluid Dynamics model using the methodology found in "Comprehensive Approach to Verification and Validation of Computational Fluid Dynamics Simulations". This method requires three separate grids and solutions, which quantify the error bars around Computational Fluid Dynamics
Groves, Curtis Edward
2014-01-01
Spacecraft thermal protection systems are at risk of being damaged due to airflow produced from Environmental Control Systems. There are inherent uncertainties and errors associated with using Computational Fluid Dynamics to predict the airflow field around a spacecraft from the Environmental Control System. This paper describes an approach to quantify the uncertainty in using Computational Fluid Dynamics to predict airflow speeds around an encapsulated spacecraft without the use of test data. Quantifying the uncertainty in analytical predictions is imperative to the success of any simulation-based product. The method could provide an alternative to traditional validation by test only mentality. This method could be extended to other disciplines and has potential to provide uncertainty for any numerical simulation, thus lowering the cost of performing these verifications while increasing the confidence in those predictions.Spacecraft requirements can include a maximum airflow speed to protect delicate instruments during ground processing. Computational Fluid Dynamics can be used to verify these requirements; however, the model must be validated by test data. This research includes the following three objectives and methods. Objective one is develop, model, and perform a Computational Fluid Dynamics analysis of three (3) generic, non-proprietary, environmental control systems and spacecraft configurations. Several commercially available and open source solvers have the capability to model the turbulent, highly three-dimensional, incompressible flow regime. The proposed method uses FLUENT, STARCCM+, and OPENFOAM. Objective two is to perform an uncertainty analysis of the Computational Fluid Dynamics model using the methodology found in Comprehensive Approach to Verification and Validation of Computational Fluid Dynamics Simulations. This method requires three separate grids and solutions, which quantify the error bars around Computational Fluid Dynamics predictions
Directory of Open Access Journals (Sweden)
X. Wang
2018-01-01
Full Text Available This study defines reasonable reservoir temperatures and cooling processes of subsurface geothermal fluids in the Chabu high-temperature geothermal system. This system lies in the south-central part of the Shenzha-Xietongmen hydrothermal active belt and develops an extensive sinter platform with various and intense hydrothermal manifestations. All the geothermal spring samples collected systematically from the sinter platform are divided into three groups by cluster analysis of major elements. Samples of group 1 and group 3 are distributed in the central part and northern periphery of the sinter platform, respectively, while samples of group 2 are scattered in the transitional zone between groups 1 and 3. The hydrochemical characteristics show that the geothermal waters of the research area have generally mixed with shallow cooler waters in reservoirs. The reasonable reservoir temperatures and the mixing processes of the subsurface geothermal fluids could be speculated by combining the hydrochemical characteristics of geothermal springs, calculated results of the chemical geothermometers, and silica-enthalpy mixing models. Contour maps are applied to measured emerging temperatures, mass flow rates, total dissolved solids of spring samples, and reasonable subsurface temperatures. They indicate that the major cooling processes of the subsurface geothermal fluids gradually transform from adiabatic boiling to conduction from the central part to the peripheral belt. The geothermal reservoir temperatures also show an increasing trend. The point with the highest reservoir temperature (256°C appears in the east-central part of the research area, which might be the main up-flow zone. The cooling processes of the subsurface geothermal fluids in the research area can be shown on an enthalpy-chloride plot. The deep parent fluid for the Chabu geothermal field has a Cl− concentration of 290 mg/L and an enthalpy of 1550 J/g (with a water temperature of
Iacopini, David; Maestrelli, Daniele; Jihad, Ali; Bond, Clare; Bonini, Marco
2017-04-01
In recent years enormous attention has been paid to the understanding of the process and mechanism controlling the gas seepage and more generally the fluid expulsion affecting the earth system from onshore to offshore environment. This is because of their demonstrated impact to our environment, climate change and during subsea drilling operation. Several example from active and paleo system has been so far characterized and proposed using subsurface exploration, geophysical and geochemical monitoring technology approaches with the aims to explore what trigger and drive the overpressure necessary maintain the fluid/gas/material expulsion and what are the structure that act as a gateway for gaseous fluid and unconsolidated rock. In this contribution we explore a series of fluid escape structure (ranging from seepage pipes to large blowout pipes structure of km length) using 3D and partial stack seismic data from two distinctive passive margin from the north sea (Loyal field, West Shetland) and the Equatorial Brazil (Ceara' Basin). We will focuses on the characterization of the plumbing system internal architecture and, for selected example, exploring the AVO response (using partial stack) of the internal fluid/unconsolidated rock. The detailed seismic mapping and seismic attributes analysis of the conduit system helped us to recover some detail from the signal response of the chimney internal structures. We observed: (1) small to medium seeps and pipes following structural or sedimentary discontinuities (2) large pipes (probably incipient mud volcanoes) and blowup structures propagating upward irrespective of pre-existing fault by hydraulic fracturing and assisted by the buoyancy of a fluidised and mobilised mud-hydrocarbon mixture. The reflector termination observed inside the main conduits, the distribution of stacked bright reflectors and the AVO analysis suggests an evolution of mechanisms (involving mixture of gas, fluid and probably mud) during pipe birth and
Analysis of the susceptibility in a fluid system with Neumann – plus boundary conditions
Directory of Open Access Journals (Sweden)
Djondjorov Peter
2018-01-01
Full Text Available The behaviour of the local and total susceptibilities of a fluid system bounded by different surfaces is studied in the framework of the Ginsburg-Landau Ising type model. The case of a plain geometry, Neumann-infinity boundary conditions under variations of the temperature and an external ordering field is considered. Exact analytic expressions for the order parameter, local and total susceptibilities in such a system are presented. They are used to analyse the phase behaviour of fluids confined in regions close to the bulk critical point of the respective infinite system.
Bakker, Ronald J.
2018-06-01
The program AqSo_NaCl has been developed to calculate pressure - molar volume - temperature - composition (p-V-T-x) properties, enthalpy, and heat capacity of the binary H2O-NaCl system. The algorithms are designed in BASIC within the Xojo programming environment, and can be operated as stand-alone project with Macintosh-, Windows-, and Unix-based operating systems. A series of ten self-instructive interfaces (modules) are developed to calculate fluid inclusion properties and pore fluid properties. The modules may be used to calculate properties of pure NaCl, the halite-liquidus, the halite-vapourus, dew-point and bubble-point curves (liquid-vapour), critical point, and SLV solid-liquid-vapour curves at temperatures above 0.1 °C (with halite) and below 0.1 °C (with ice or hydrohalite). Isochores of homogeneous fluids and unmixed fluids in a closed system can be calculated and exported to a.txt file. Isochores calculated for fluid inclusions can be corrected according to the volumetric properties of quartz. Microthermometric data, i.e. dissolution temperatures and homogenization temperatures, can be used to calculated bulk fluid properties of fluid inclusions. Alternatively, in the absence of total homogenization temperature the volume fraction of the liquid phase in fluid inclusions can be used to obtain bulk properties.
DEFF Research Database (Denmark)
Larsson, Hilde Kristina
the velocity and pressure distributions in a fluid. CFD also enables the modelling of several fluids simultaneously, e.g. gas bubbles in a liquid, as well as the presence of turbulence and dissolved chemicals in a fluid, and many other phenomena. This makes CFD an appreciated tool for studying flow structures......, mixing, and other mass transfer phenomena in chemical and biochemical reactor systems. In this project, four selected case studies are investigated in order to explore the capabilities of CFD. The selected cases are a 1 ml stirred microbioreactor, an 8 ml magnetically stirred reactor, a Rushton impeller...... and an ion-exchange reaction are also modelled and compared to experimental data. The thesis includes a comprehensive overview of the fundamentals behind a CFD software, as well as a more detailed review of the fluid dynamic phenomena investigated in this project. The momentum and continuity equations...
A high-force controllable MR fluid damper–liquid spring suspension system
International Nuclear Information System (INIS)
Raja, Pramod; Wang, Xiaojie; Gordaninejad, Faramarz
2014-01-01
The goal of the present research is to investigate the feasibility of incorporating a liquid spring in a semi-active suspension system for use in heavy off-road vehicles. A compact compressible magneto-rheological (MR) fluid damper–liquid spring (CMRFD–LS) with high spring rate is designed, developed and tested. Compressible MR fluids with liquid spring and variable damping characteristics are used. These fluids can offer unique functions in reducing the volume/weight of vehicle struts and improving vehicle dynamic stability and safety. The proposed device consists of a cylinder and piston–rod arrangement with an internal annular MR fluid valve. The internal pressures in the chambers on either side of the piston develop the spring force, while the pressure difference across the MR valve produces the damping force, when the fluid flows through the MR valve. Harmonic characterization of the CMRFD–LS is performed and the force–displacement results are presented. A fluid-mechanics based model is also developed to predict the performance of the system at different operating conditions and compared to the experimental results. Good agreement between the experimental results and theoretical predictions has been achieved. (paper)
Controlling general projective synchronization of fractional order Rossler systems
International Nuclear Information System (INIS)
Shao Shiquan
2009-01-01
This paper proposed a method to achieve general projective synchronization of two fractional order Rossler systems. First, we construct the fractional order Rossler system's corresponding approximation integer order system. Then, a control method based on a partially linear decomposition and negative feedback of state errors was utilized on the integer order system. Numerical simulations show the effectiveness of the proposed method.
Client-controlled case information: a general system theory perspective.
Fitch, Dale
2004-07-01
The author proposes a model for client control of case information via the World Wide Web built on principles of general system theory. It incorporates the client into the design, resulting in an information structure that differs from traditional human services information-sharing practices. Referencing general system theory, the concepts of controller and controlled system, as well as entropy and negentropy, are applied to the information flow and autopoietic behavior as they relate to the boundary-maintaining functions of today's organizations. The author's conclusions synthesize general system theory and human services values to lay the foundation for an information-sharing framework for human services in the 21st century.
Generalized projective synchronization of chaotic systems via adaptive learning control
International Nuclear Information System (INIS)
Yun-Ping, Sun; Jun-Min, Li; Hui-Lin, Wang; Jiang-An, Wang
2010-01-01
In this paper, a learning control approach is applied to the generalized projective synchronisation (GPS) of different chaotic systems with unknown periodically time-varying parameters. Using the Lyapunov–Krasovskii functional stability theory, a differential-difference mixed parametric learning law and an adaptive learning control law are constructed to make the states of two different chaotic systems asymptotically synchronised. The scheme is successfully applied to the generalized projective synchronisation between the Lorenz system and Chen system. Moreover, numerical simulations results are used to verify the effectiveness of the proposed scheme. (general)
Electrohydrodynamic aspects of two-fluid microfluidic systems
DEFF Research Database (Denmark)
Goranovic, Goran
The goal of this thesis has been to explore fundamental theoretical principles behind micro Total Analysis Systems (µTAS), also known as lab-on-chip systems, as well as to make use of computer simulations as an evaluation technique in the process of developing and optimizing µTAS devises. This in...
An Innovative Improvement of Engineering Learning System Using Computational Fluid Dynamics Concept
Hung, T. C.; Wang, S. K.; Tai, S. W.; Hung, C. T.
2007-01-01
An innovative concept of an electronic learning system has been established in an attempt to achieve a technology that provides engineering students with an instructive and affordable framework for learning engineering-related courses. This system utilizes an existing Computational Fluid Dynamics (CFD) package, Active Server Pages programming,…
Microcontroller-driven fluid-injection system for atomic force microscopy.
Kasas, S; Alonso, L; Jacquet, P; Adamcik, J; Haeberli, C; Dietler, G
2010-01-01
We present a programmable microcontroller-driven injection system for the exchange of imaging medium during atomic force microscopy. Using this low-noise system, high-resolution imaging can be performed during this process of injection without disturbance. This latter circumstance was exemplified by the online imaging of conformational changes in DNA molecules during the injection of anticancer drug into the fluid chamber.
Systems and Methods for Determining Water-Cut of a Fluid Mixture
Karimi, Muhammad Akram; Shamim, Atif; Arsalan, Muhammad
2017-01-01
Provided in some embodiments are systems and methods for measuring the water content (or water-cut) of a fluid mixture. Provided in some embodiments is a water-cut sensor system that includes a helical T-resonator, a helical ground conductor, and a
Systems and Methods for Determining Water-Cut of a Fluid Mixture
Karimi, Muhammad Akram; Shamim, Atif; Arsalan, Muhammad
2017-01-01
Provided in some embodiments are systems and methods for measuring the water content (or water-cut) of a fluid mixture. Provided in some embodiments is a water-cut sensor system that includes a T-resonator, a ground conductor, and a separator. The T
The Cocos Ridge hydrothermal system revealed by microthermometry of fluid and melt inclusions
Brandstätter, J.; Kurz, W.; Krenn, K.
2017-12-01
Microthermometric analyses of fluid and melt inclusions in hydrothermal veins and in the Cocos Ridge (CCR) basalt were used to reveal the CCR thermal history at IODP Site 344-U1414 and to constrain fluid source and flow. Hydrothermal veins are hosted by lithified sediments and CCR basalt . Site 344-U1414, located 1 km seaward of the Middle American Trench offshore Costa Rica, serves to evaluate fluid/rock interaction, the hydrologic system and geochemical processes linked with the tectonic evolution of the incoming Cocos Plate from the Early Miocene up to recent times. The veins in the sedimentary rocks are mainly filled by blocky calcite, containing numerous fluid inclusions, and sometimes crosscut fibrous quartz/chalcedony veins. The veins in the basalt can be differentiated into three types: antitaxial fibrous calcite veins, composite veins with fibrous calcite and clay minerals at the vein margins and spherulitic quartz in the center, and syntaxial blocky aragonite veins surrounded by a clay selvage in the uppermost CCR basalt sections. Secondary minerals, clay minerals, fibrous calcite, quartz/chalcedony and pyrite also filled vesicles in the basalt. Fluid inclusions were mainly found in the aragonite veins and rarely in quartz in the composite veins and vesicles. Blocky veins with embedded wall rock fragments appear in the sediments and in the basalt indicate hydraulic fracturing. The occurrence of decrepitated fluid inclusions show high homogenization temperatures up to 400 °C. Decrepitated fluid inclusions are formed by increased internal overpressure, related to isobaric heating. Elongated fluid inclusion planes, arc-like fluid inclusions and low homogenization temperatures indicate subsequent isobaric cooling. The results obtained so far from Raman spectroscopy and microthermometry indicate CO2 inclusions and petrographic observations suggest the presence of silicate melt inclusions in phenocrysts in the basalt (mainly in clinopyroxene and plagioclase
Kuwajima, Mariko; Sawaguchi, Toshiyuki
2010-10-01
General fluid intelligence (gF) is a major component of intellect in both adults and children. Whereas its neural substrates have been studied relatively thoroughly in adults, those are poorly understood in children, particularly preschoolers. Here, we hypothesized that gF and visuospatial working memory share a common neural system within the lateral prefrontal cortex (LPFC) during the preschool years (4-6 years). At the behavioral level, we found that gF positively and significantly correlated with abilities (especially accuracy) in visuospatial working memory. Optical topography revealed that the LPFC of preschoolers was activated and deactivated during the visuospatial working memory task and the gF task. We found that the spatio-temporal features of neural activity in the LPFC were similar for both the visuospatial working memory task and the gF task. Further, 2 months of training for the visuospatial working memory task significantly increased gF in the preschoolers. These findings suggest that a common neural system in the LPFC is recruited to improve the visuospatial working memory and gF in preschoolers. Efficient recruitment of this neural system may be important for good performance in these functions in preschoolers, and behavioral training using this system would help to increase gF at these ages.
Directory of Open Access Journals (Sweden)
Petropoulos Christos J
2005-11-01
Full Text Available Abstract Background Central nervous system (CNS exposure to HIV is a universal facet of systemic infection. Because of its proximity to and shared barriers with the brain, cerebrospinal fluid (CSF provides a useful window into and model of human CNS HIV infection. Methods Prospective study of the relationships of CSF to plasma HIV RNA, and the effects of: 1 progression of systemic infection, 2 CSF white blood cell (WBC count, 3 antiretroviral therapy (ART, and 4 neurological performance. One hundred HIV-infected subjects were cross-sectionally studied, and 28 were followed longitudinally after initiating or changing ART. Results In cross-sectional analysis, HIV RNA levels were lower in CSF than plasma (median difference 1.30 log10 copies/mL. CSF HIV viral loads (VLs correlated strongly with plasma VLs and CSF WBC counts. Higher CSF WBC counts associated with smaller differences between plasma and CSF HIV VL. CSF VL did not correlate with blood CD4 count, but CD4 counts In subjects starting ART, those with lower CD4 counts had slower initial viral decay in CSF than in plasma. In all subjects, including five with persistent plasma viremia and four with new-onset ADC, CSF HIV eventually approached or reached the limit of viral detection and CSF pleocytosis resolved. Conclusion CSF HIV infection is common across the spectrum of infection and is directly related to CSF pleocytosis, though whether the latter is a response to or a contributing cause of CSF infection remains uncertain. Slowing in the rate of CSF response to ART compared to plasma as CD4 counts decline indicates a changing character of CSF infection with systemic immunological progression. Longer-term responses indicate that CSF infection generally responds well to ART, even in the face of systemic virological failure due to drug resistance. We present simple models to explain the differing relationships of CSF to plasma HIV in these settings.
Generalized thermalization for integrable system under quantum quench.
Muralidharan, Sushruth; Lochan, Kinjalk; Shankaranarayanan, S
2018-01-01
We investigate equilibration and generalized thermalization of the quantum Harmonic chain under local quantum quench. The quench action we consider is connecting two disjoint harmonic chains of different sizes and the system jumps between two integrable settings. We verify the validity of the generalized Gibbs ensemble description for this infinite-dimensional Hilbert space system and also identify equilibration between the subsystems as in classical systems. Using Bogoliubov transformations, we show that the eigenstates of the system prior to the quench evolve toward the Gibbs Generalized Ensemble description. Eigenstates that are more delocalized (in the sense of inverse participation ratio) prior to the quench, tend to equilibrate more rapidly. Further, through the phase space properties of a generalized Gibbs ensemble and the strength of stimulated emission, we identify the necessary criterion on the initial states for such relaxation at late times and also find out the states that would potentially not be described by the generalized Gibbs ensemble description.
General review of solar-powered closed sorption refrigeration systems
International Nuclear Information System (INIS)
Sarbu, Ioan; Sebarchievici, Calin
2015-01-01
Highlights: • Provide review of development in solar sorption refrigeration technologies. • Theoretical basis and applications of absorption and adsorption cycles are discussed. • Thermodynamic properties of most common working pairs have been reviewed. • Development of hybrid or thermal energy storage adsorption systems was explored. • A comparison between solar-powered absorption and adsorption systems was performed. - Abstract: The negative environmental impacts of burning fossil fuels have forced the energy research community seriously to consider renewable sources, such as naturally available solar energy. Thermally powered refrigeration technologies are classified into two categories: thermo-mechanical technology and sorption technology (open systems or closed systems). This paper provides a detailed review of the solar closed sorption (absorption and adsorption) refrigeration systems, which utilise working pairs (fluids). After an introduction of the basic principles of these systems, the history of development and recent advances in solar sorption refrigeration technologies are reported. The adsorption cooling typically has a lower heat source temperature requirement than the absorption cooling. Based on the coefficient of performance (COP), the absorption systems are preferred over the adsorption systems, and the higher temperature issues can be easily handled with solar adsorption systems. The thermodynamic properties of most common working fluids, as well as the use of ternary mixtures in solar-powered absorption systems, have been reviewed in this study. The paper also refers to new approaches to increase the efficiency and sustainability of the basic adsorption cycles, such as the development of hybrid or thermal energy storage adsorption systems. This research shows that solar-powered closed sorption refrigeration technologies can be attractive alternatives not only to serve the needs for air-conditioning, refrigeration, ice making, thermal
Control of optical transport parameters of 'porous medium – supercritical fluid' systems
Energy Technology Data Exchange (ETDEWEB)
Zimnyakov, D A; Ushakova, O V; Yuvchenko, S A [Yuri Gagarin State Technical University of Saratov, Saratov (Russian Federation); Bagratashvili, V N [M. V. Lomonosov Moscow State University, Moscow (Russian Federation)
2015-11-30
The possibility of controlling optical transport parameters (in particular, transport scattering coefficient) of porous systems based on polymer fibres, saturated with carbon dioxide in different phase states (gaseous, liquid and supercritical) has been experimentally studied. An increase in the pressure of the saturating medium leads to a rise of its refractive index and, correspondingly, the diffuse-transmission coefficient of the system due to the decrease in the transport scattering coefficient. It is shown that, in the case of subcritical saturating carbon dioxide, the small-angle diffuse transmission of probed porous layers at pressures close to the saturated vapour pressure is determined by the effect of capillary condensation in pores. The immersion effect in 'porous medium – supercritical fluid' systems, where the fluid pressure is used as a control parameter, is considered. The results of reconstructing the values of transport scattering coefficient of probed layers for different refractive indices of a saturating fluid are presented. (radiation scattering)
International Nuclear Information System (INIS)
Tupper, B.O.J.
1983-01-01
The work of a previous article is extended to show that space-times which are the exact solutions of the field equations for a perfect fluid also may be exact solutions of the field equations for a viscous magnetohydrodynamic fluid. Conditions are found for this equivalence to exist and viscous magnetohydrodynamic solutions are found for a number of known perfect fluid space-times. (author)
The fluid-filling system for the Borexino solar neutrino detector
Benziger, J.; Cadonati, L.; Calaprice, F.; Chen, M.; Corsi, A.; Dalnoki-Veress, F.; Fernholz, R.; Ford, R.; Galbiati, C.; Goretti, A.; Harding, E.; Ianni, Aldo; Ianni, Andrea; Kidner, S.; Leung, M.; Loeser, F.; McCarty, K.; McKinsey, D.; Nelson, A.; Pocar, A.; Salvo, C.; Schimizzi, D.; Shutt, T.; Sonnenschein, A.
2009-09-01
The system for controlled filling of the nested flexible scintillator containment vessels in the Borexino solar neutrino detector is described. The design and operation principles of pressure and shape monitoring systems are presented for gas filling, gas displacement by water, and water displacement by scintillator. System specifications for safety against overstressing the flexible nylon vessels are defined as well as leak-tightness and cleanliness requirements. The fluid-filling system was a major engineering challenge for the Borexino detector.
The Interplay Between Saline Fluid Flow and Dynamic Permeability in Magmatic-Hydrothermal Systems
Weis, P.
2014-12-01
Magmatic-hydrothermal ore deposits document the interplay between saline fluid flow and rock permeability. Numerical simulations of multi-phase flow of variably miscible, compressible H20-NaCl fluids in concert with a dynamic permeability model can reproduce characteristics of porphyry copper and epithermal gold systems. This dynamic permeability model incorporates depth-dependent permeability profiles characteristic for tectonically active crust as well as pressure- and temperature-dependent relationships describing hydraulic fracturing and the transition from brittle to ductile rock behavior. In response to focused expulsion of magmatic fluids from a crystallizing upper crustal magma chamber, the hydrothermal system self-organizes into a hydrological divide, separating an inner part dominated by ascending magmatic fluids under near-lithostatic pressures from a surrounding outer part dominated by convection of colder meteoric fluids under near-hydrostatic pressures. This hydrological divide also provides a mechanism to transport magmatic salt through the crust, and prevents the hydrothermal system to become "clogged" by precipitation of solid halite due to depressurization of saline, high-temperature magmatic fluids. The same physical processes at similar permeability ranges, crustal depths and flow rates are relevant for a number of active systems, including geothermal resources and excess degassing at volcanos. The simulations further suggest that the described mechanism can separate the base of free convection in high-enthalpy geothermal systems from the magma chamber as a driving heat source by several kilometers in the vertical direction in tectonic settings with hydrous magmatism. This hydrology would be in contrast to settings with anhydrous magmatism, where the base of the geothermal systems may be closer to the magma chamber.
Mitri, Farid G
2012-08-01
This work presents the general theory of resonance scattering (GTRS) by an elastic spherical shell immersed in a nonviscous fluid and placed arbitrarily in an acoustic beam. The GTRS formulation is valid for a spherical shell of any size and material regardless of its location relative to the incident beam. It is shown here that the scattering coefficients derived for a spherical shell immersed in water and placed in an arbitrary beam equal those obtained for plane wave incidence. Numerical examples for an elastic shell placed in the field of acoustical Bessel beams of different types, namely, a zero-order Bessel beam and first-order Bessel vortex and trigonometric (nonvortex) beams are provided. The scattered pressure is expressed using a generalized partial-wave series expansion involving the beam-shape coefficients (BSCs), the scattering coefficients of the spherical shell, and the half-cone angle of the beam. The BSCs are evaluated using the numerical discrete spherical harmonics transform (DSHT). The far-field acoustic resonance scattering directivity diagrams are calculated for an albuminoidal shell immersed in water and filled with perfluoropropane gas, by subtracting an appropriate background from the total far-field form function. The properties related to the arbitrary scattering are analyzed and discussed. The results are of particular importance in acoustical scattering applications involving imaging and beam-forming for transducer design. Moreover, the GTRS method can be applied to investigate the scattering of any beam of arbitrary shape that satisfies the source-free Helmholtz equation, and the method can be readily adapted to viscoelastic spherical shells or spheres.
DYNAPO 4 - a fluid system and frames analysis computer program
International Nuclear Information System (INIS)
Lefter, J.D.; Ahdout, H.
1982-01-01
DYNAPO 4 is a user oriented specialized computer program, capable of analyzing three-dimensional linear elastic piping systems or frames for static loads, dynamic loads represented by acceleration response spectra, transient dynamic loads represented by harmonic, polynomial of second order, and time history forcing functions. DYNAPO 4 has plotting capability, which plots the input configuration of the piping system or of the structure and also plots its deformed shape after the load is applied. DYNAPO 4 performs the analysis for ASME Section III Class 1, Class 2, and 3, piping, and provides the user with stress reports as per ASME and ANSI Code requirements. 3 refs
Stability properties of a general class of nonlinear dynamical systems
Gléria, I. M.; Figueiredo, A.; Rocha Filho, T. M.
2001-05-01
We establish sufficient conditions for the boundedness of the trajectories and the stability of the fixed points in a class of general nonlinear systems, the so-called quasi-polynomial vector fields, with the help of a natural embedding of such systems in a family of generalized Lotka-Volterra (LV) equations. A purely algebraic procedure is developed to determine such conditions. We apply our method to obtain new results for LV systems, by a reparametrization in time variable, and to study general nonlinear vector fields, originally far from the LV format.
Stability properties of a general class of nonlinear dynamical systems
Energy Technology Data Exchange (ETDEWEB)
Gleria, I.M. [Filho Instituto de Fisica, Universidade de Brasilia, Campus Universitario Darcy Ribeiro, Brasilia (Brazil). E-mail: iram@ucb.br; Figueiredo, A. [Filho Instituto de Fisica, Universidade de Brasilia, Campus Universitario Darcy Ribeiro, Brasilia (Brazil). E-mail: annibal@helium.fis.unb.br; Rocha, T.M. [Filho Instituto de Fisica, Universidade de Brasilia, Campus Universitario Darcy Ribeiro, Brasilia (Brazil). E-mail: marciano@helium.fis.unb.br
2001-05-04
We establish sufficient conditions for the boundedness of the trajectories and the stability of the fixed points in a class of general nonlinear systems, the so-called quasi-polynomial vector fields, with the help of a natural embedding of such systems in a family of generalized Lotka-Volterra (LV) equations. A purely algebraic procedure is developed to determine such conditions. We apply our method to obtain new results for LV systems, by a reparametrization in time variable, and to study general nonlinear vector fields, originally far from the LV format. (author)
Role of the Enteric Nervous System in the Fluid and Electrolyte Secretion of Rotavirus Diarrhea
Lundgren, Ove; Peregrin, Attila Timar; Persson, Kjell; Kordasti, Shirin; Uhnoo, Ingrid; Svensson, Lennart
2000-01-01
The mechanism underlying the intestinal fluid loss in rotavirus diarrhea, which often afflicts children in developing countries, is not known. One hypothesis is that the rotavirus evokes intestinal fluid and electrolyte secretion by activation of the nervous system in the intestinal wall, the enteric nervous system (ENS). Four different drugs that inhibit ENS functions were used to obtain experimental evidence for this hypothesis in mice in vitro and in vivo. The involvement of the ENS in rotavirus diarrhea indicates potential sites of action for drugs in the treatment of the disease.
Leak detection system for a high temperature fluid pipe
International Nuclear Information System (INIS)
Puyal, C.; Meuwisse, C.
1989-01-01
The leak detection system is made by a cable with at least two isolated electrical conductors, close to the wall of the pipe. The material of the cable is chosen so as to change its electrical characteristics if a leak causes heating of the cable. A detector at one end of the cable can measure the modifications of the electrical characteristics [fr
Generalized Synchronization of Time-Delayed Discrete Systems
International Nuclear Information System (INIS)
Jing Jianyi; Min Lequan
2009-01-01
This paper establishes two theorems for two time-delayed (chaotic) discrete systems to achieve time-delayed generalized synchronization (TDGS). These two theorems uncover the general forms of two TDGS systems via a prescribed transformation. As examples, we convert the Lorenz three-dimensional chaotic map to an equal time-delayed system as the driving system, and construct the TDGS driven systems according to the Theorems 1 and 2. Numerical simulations demonstrate the effectiveness of the proposed theorems. (interdisciplinary physics and related areas of science and technology)
Generalized decompositions of dynamic systems and vector Lyapunov functions
Ikeda, M.; Siljak, D. D.
1981-10-01
The notion of decomposition is generalized to provide more freedom in constructing vector Lyapunov functions for stability analysis of nonlinear dynamic systems. A generalized decomposition is defined as a disjoint decomposition of a system which is obtained by expanding the state-space of a given system. An inclusion principle is formulated for the solutions of the expansion to include the solutions of the original system, so that stability of the expansion implies stability of the original system. Stability of the expansion can then be established by standard disjoint decompositions and vector Lyapunov functions. The applicability of the new approach is demonstrated using the Lotka-Volterra equations.
Inderbitzen, K. E.; Wheat, C. G.; Baker, P. A.; Fisher, A. T.
2014-12-01
Currently, fluid circulation patterns and the evolution of rock/fluid compositions as circulation occurs in subseafloor hydrothermal systems are poorly constrained. Sedimented spreading centers provide a unique opportunity to study subsurface flow because sediment acts as an insulating blanket that traps heat from the cooling magma body and limits: (a) potential flow paths for seawater to recharge the aquifer in permeable upper basaltic basement and (b) points of altered fluid egress. This also allows for a range of thermal and geochemical gradients to exist near the sediment-water interface. Models of fluid circulation patterns in this type of hydrologic setting have been generated (eg. Stein and Fisher, 2001); however fluid chemistry datasets have not previously been used to test the model's viability. We address this issue by integrating the existing circulation model with fluid compositional data collected from sediment pore waters and high temperature hydrothermal vents located in Middle Valley on the Juan de Fuca Ridge. Middle Valley hosts a variety of hydrologic regimes: including areas of fluid recharge (Site 855), active venting (Site 858/1036; Dead Dog vent field), recent venting (Site 856/1035; Bent Hill Massive Sulfide deposit) and a section of heavily sedimented basement located between recharge and discharge sites (Site 857). We will present new results based on thermal and geochemical data from the area of active venting (Sites 858 and 1036), that was collected during Ocean Drilling Program Legs 139 and 169 and a subsequent heat flow/gravity coring effort. These results illuminate fine scale controls on secondary recharge and fluid flow within the sediment section at Site 858/1036. The current status of high temperature vents in this area (based on observations made in July, 2014) will also be outlined.
Towards generalized synchronization of strictly different chaotic systems
Energy Technology Data Exchange (ETDEWEB)
Femat, R. [Matematicas Aplicadas y Sistemas Computacionales, IPICYT, Apdo. Postal 3-90, 78291 Tangamanga, San Luis Potosi S.L.P. (Mexico)]. E-mail: rfemat@ipicyt.edu.mx; Kocarev, L. [Institute for Nonlinear Science, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0402 (United States)]. E-mail: lkocarev@ucsd.edu; Gerven, L. van [Department of Mechanical Engineering, Technische Universiteit Eindhoven (Netherlands); Monsivais-Perez, M.E. [Matematicas Aplicadas y Sistemas Computacionales, IPICYT, Camino a la Presa San Jose 2055, 78216 Lomas 4a Sec., San Luis Potosi S.L.P. (Mexico)
2005-07-11
This contribution addresses the problem of the generalized synchronization (GS) in different chaotic systems, and departs from chaotic systems in a triangular from, which can be derived from Lie derivatives. A state-feedback (full knowledge of both master and slave systems) scheme is designed, which achieves GS. The work includes illustrative examples; moreover an experimental setup is used to corroborate the obtained results.
Energy Technology Data Exchange (ETDEWEB)
Kerbel, G.D.
1981-01-20
A study is made of a scale model in three dimensions of a guiding center plasma within the purview of gyroelastic (also known as finite gyroradius-near theta pinch) magnetohydrodynamics. The (nonlinear) system sustains a particular symmetry called isorrhopy which permits the decoupling of fluid modes from drift modes. Isorrhopic equilibria are analyzed within the framework of geometrical optics resulting in (local) dispersion relations and ray constants. A general scheme is developed to evolve an arbitrary linear perturbation of a screwpinch equilibrium as an invertible integral transform (over the complete set of generalized eigenfunctions defined naturally by the equilibrium). Details of the structure of the function space and the associated spectra are elucidated. Features of the (global) dispersion relation owing to the presence of gyroelastic stabilization are revealed. An energy principle is developed to study the stability of the tubular screwpinch.
International Nuclear Information System (INIS)
Kerbel, G.D.
1981-01-01
A study is made of a scale model in three dimensions of a guiding center plasma within the purview of gyroelastic (also known as finite gyroradius-near theta pinch) magnetohydrodynamics. The (nonlinear) system sustains a particular symmetry called isorrhopy which permits the decoupling of fluid modes from drift modes. Isorrhopic equilibria are analyzed within the framework of geometrical optics resulting in (local) dispersion relations and ray constants. A general scheme is developed to evolve an arbitrary linear perturbation of a screwpinch equilibrium as an invertible integral transform (over the complete set of generalized eigenfunctions defined naturally by the equilibrium). Details of the structure of the function space and the associated spectra are elucidated. Features of the (global) dispersion relation owing to the presence of gyroelastic stabilization are revealed. An energy principle is developed to study the stability of the tubular screwpinch
Experimental system model of a primary active fluid
International Nuclear Information System (INIS)
Deseigne, Julien
2010-01-01
Collective motion, such as flocks of birds or shoals of fish, is ubiquitous in nature. Such fundamentally out-of-equilibrium phenomena may be described with the new conceptual background of polar active matter, a system of polar particles which enables to use provided energy in order to move in their own directions. A 2D experimental system of vibrated polar disks that interact only by contact has been set up. These disks behave as random walkers, whose trajectories are characterized by a persistence length greater than their size and controlled by the angular fluctuations of their polarity. The interplay between the hard-core repulsion and the persistence of the motion leads to complex alignment modes. For instance, only 10 pc of the binary collisions correspond to an effective ferromagnetic alignment. Yet, spontaneous collective motion inside the system characterized by giant fluctuations of density have been observed. These results reveal the robustness of the polar order observed in theoretical and numerical models of 2D polar active matter on substrate
The role of brain barriers in fluid movement in the CNS: is there a 'glymphatic' system?
Abbott, N Joan; Pizzo, Michelle E; Preston, Jane E; Janigro, Damir; Thorne, Robert G
2018-03-01
Brain fluids are rigidly regulated to provide stable environments for neuronal function, e.g., low K + , Ca 2+ , and protein to optimise signalling and minimise neurotoxicity. At the same time, neuronal and astroglial waste must be promptly removed. The interstitial fluid (ISF) of the brain tissue and the cerebrospinal fluid (CSF) bathing the CNS are integral to this homeostasis and the idea of a glia-lymph or 'glymphatic' system for waste clearance from brain has developed over the last 5 years. This links bulk (convective) flow of CSF into brain along the outside of penetrating arteries, glia-mediated convective transport of fluid and solutes through the brain extracellular space (ECS) involving the aquaporin-4 (AQP4) water channel, and finally delivery of fluid to venules for clearance along peri-venous spaces. However, recent evidence favours important amendments to the 'glymphatic' hypothesis, particularly concerning the role of glia and transfer of solutes within the ECS. This review discusses studies which question the role of AQP4 in ISF flow and the lack of evidence for its ability to transport solutes; summarizes attributes of brain ECS that strongly favour the diffusion of small and large molecules without ISF flow; discusses work on hydraulic conductivity and the nature of the extracellular matrix which may impede fluid movement; and reconsiders the roles of the perivascular space (PVS) in CSF-ISF exchange and drainage. We also consider the extent to which CSF-ISF exchange is possible and desirable, the impact of neuropathology on fluid drainage, and why using CSF as a proxy measure of brain components or drug delivery is problematic. We propose that new work and key historical studies both support the concept of a perivascular fluid system, whereby CSF enters the brain via PVS convective flow or dispersion along larger caliber arteries/arterioles, diffusion predominantly regulates CSF/ISF exchange at the level of the neurovascular unit associated with
General solution for first order elliptic systems in the plane
International Nuclear Information System (INIS)
Mshimba, A.S.
1990-01-01
It is shown that a system of 2n real-valued partial differential equations of first order, which under certain assumptions can be transformed to the so-called 'complex normal form', admits a general solution. 15 refs
JIT supply chain; an investigation through general system theory
Directory of Open Access Journals (Sweden)
O P Mishra
2013-03-01
Full Text Available This paper explains theoretical approach of the four theories of General system Theory (GST developed by Yourdon (1989 [Yourdon, E. (1989. Modern Structured Analysis. Yourdon Press, Prentice-Hall International, Englewood Cliffs, New Jersey. Senge] while applying it in information technology and subsequently used by caddy (2007 [Caddy I.N., & Helou, M.M. (2007. Supply chains and their management: Application of general systems theory. Journal of Retailing and Consumer Services, 14, 319–327.] in field of supply chain and management. JIT philosophy in core activities of supply chain i.e. procurement, production processes, and logistics are discussed through general system theory. The growing structure of the supply chain poses the implication restrictions and requires a heavy support system, many times a compromise is done while implementing JIT. The study would be useful to understand the general trends generated naturally regarding the adoption of the JIT philosophy in the supply chain.
Generalized synchronization and coherent structures in spatially extended systems
International Nuclear Information System (INIS)
Basnarkov, Lasko; Duane, Gregory S.; Kocarev, Ljupco
2014-01-01
We study the synchronization of a coupled pair of one-dimensional Kuramoto–Sivashinsky systems, with equations augmented by a third-space-derivative term. With two different values of a system parameter, the two systems synchronize in the generalized sense. The phenomenon persists even in the extreme case when one of the equations is missing the extra term. Master–slave synchronization error is small, so the generalized synchronization relationship is useful for predicting the state of the master from that of the slave, or conversely, for controlling the slave. The spatial density of coupling points required to bring about generalized synchronization appears to be related to the wavelength of traveling wave solutions, and more generally to the width of coherent structures in the separate systems
Calculation Sheet for the Basic Design of the ATLAS Fluid System
Energy Technology Data Exchange (ETDEWEB)
Park, Hyun Sik; Moon, S. K.; Yun, B. J.; Kwon, T. S.; Choi, K. Y.; Cho, S.; Park, C. K.; Lee, S. J.; Kim, Y. S.; Song, C. H.; Baek, W. P.; Hong, S. D
2007-03-15
The basic design of an integral effect test loop for pressurized water reactors (PWRs), the ATLAS (Advanced Thermal-hydraulic Test Loop for Accident Simulation), has been carried out by Thermal-Hydraulics Safety Research Team in Korea Atomic Energy Research Institute (KAERI). The ATLAS facility has been designed to have the length scale of 1/2 and area scale of 1/144 compared with the reference plant, APR1400, and is scaled for full pressure and temperature conditions. This report includes calculation sheets for the basic design of ATLAS fluid systems, which are consisted of a reactor pressure vessel with core simulator, the primary loop piping, a pressurizer, reactor coolant pumps, steam generators, the secondary system, the safety system, the auxiliary system, and the heat loss compensation system. The present calculation sheets will be used to help understanding the basic design of the ATLAS fluid system and its based scaling methodology.
Modeling and Control of Magnetic Fluid Deformable Mirrors for Adaptive Optics Systems
Wu, Zhizheng; Ben Amara, Foued
2013-01-01
Modeling and Control of Magnetic Fluid Deformable Mirrors for Adaptive Optics Systems presents a novel design of wavefront correctors based on magnetic fluid deformable mirrors (MFDM) as well as corresponding control algorithms. The presented wavefront correctors are characterized by their linear, dynamic response. Various mirror surface shape control algorithms are presented along with experimental evaluations of the performance of the resulting adaptive optics systems. Adaptive optics (AO) systems are used in various fields of application to enhance the performance of optical systems, such as imaging, laser, free space optical communication systems, etc. This book is intended for undergraduate and graduate students, professors, engineers, scientists and researchers working on the design of adaptive optics systems and their various emerging fields of application. Zhizheng Wu is an associate professor at Shanghai University, China. Azhar Iqbal is a research associate at the University of Toronto, Canada. Foue...
Calculation Sheet for the Basic Design of the ATLAS Fluid System
International Nuclear Information System (INIS)
Park, Hyun Sik; Moon, S. K.; Yun, B. J.; Kwon, T. S.; Choi, K. Y.; Cho, S.; Park, C. K.; Lee, S. J.; Kim, Y. S.; Song, C. H.; Baek, W. P.; Hong, S. D.
2007-03-01
The basic design of an integral effect test loop for pressurized water reactors (PWRs), the ATLAS (Advanced Thermal-hydraulic Test Loop for Accident Simulation), has been carried out by Thermal-Hydraulics Safety Research Team in Korea Atomic Energy Research Institute (KAERI). The ATLAS facility has been designed to have the length scale of 1/2 and area scale of 1/144 compared with the reference plant, APR1400, and is scaled for full pressure and temperature conditions. This report includes calculation sheets for the basic design of ATLAS fluid systems, which are consisted of a reactor pressure vessel with core simulator, the primary loop piping, a pressurizer, reactor coolant pumps, steam generators, the secondary system, the safety system, the auxiliary system, and the heat loss compensation system. The present calculation sheets will be used to help understanding the basic design of the ATLAS fluid system and its based scaling methodology
International Nuclear Information System (INIS)
Xi, Huan; Li, Ming-Jia; He, Ya-Ling; Tao, Wen-Quan
2015-01-01
In the present study, we proposed a graphical criterion called CE diagram by achieving the Pareto optimal solutions of the annual cash flow and exergy efficiency. This new graphical criterion enables both working fluid selection and thermodynamic system comparison for waste heat recovery. It's better than the existing criterion based on single objective optimization because it is graphical and intuitionistic in the form of diagram. The features of CE diagram were illustrated by studying 5 examples with different heat-source temperatures (ranging between 100 °C to 260 °C), 26 chlorine-free working fluids and two typical ORC systems including basic organic Rankine cycle(BORC) and recuperative organic Rankine cycle (RORC). It is found that the proposed graphical criterion is feasible and can be applied to any closed loop waste heat recovery thermodynamic systems and working fluids. - Highlights: • A graphical method for ORC system comparison/working fluid selection was proposed. • Multi-objectives genetic algorithm (MOGA) was applied for optimizing ORC systems. • Application cases were performed to demonstrate the usage of the proposed method.
Study of the hard-disk system at high densities: the fluid-hexatic phase transition.
Mier-Y-Terán, Luis; Machorro-Martínez, Brian Ignacio; Chapela, Gustavo A; Del Río, Fernando
2018-06-21
Integral equations of uniform fluids have been considered unable to predict any characteristic feature of the fluid-solid phase transition, including the shoulder that arises in the second peak of the fluid-phase radial distribution function, RDF, of hard-core systems obtained by computer simulations, at fluid densities very close to the structural two-step phase transition. This reasoning is based on the results of traditional integral approximations, like Percus-Yevick, PY, which does not show such a shoulder in hard-core systems, neither in two nor three dimensions. In this work, we present results of three Ansätze, based on the PY theory, that were proposed to remedy the lack of PY analytical solutions in two dimensions. This comparative study shows that one of those Ansätze does develop a shoulder in the second peak of the RDF at densities very close to the phase transition, qualitatively describing this feature. Since the shoulder grows into a peak at still higher densities, this integral equation approach predicts the appearance of an orientational order characteristic of the hexatic phase in a continuous fluid-hexatic phase transition.
On the generalized entropy pseudoadditivity for complex systems
International Nuclear Information System (INIS)
Wang, Qiuping A.; Nivanen, Laurent; Le Mehaute, Alain; Pezeril, Michel
2002-01-01
We show that Abe's general pseudoadditivity for entropy prescribed by thermal equilibrium in nonextensive systems holds not only for entropy, but also for energy. The application of this general pseudoadditivity to Tsallis entropy tells us that the factorization of the probability of a composite system into a product of the probabilities of the subsystems is just a consequence of the existence of thermal equilibrium and not due to the independence of the subsystems. (author)
Energy Technology Data Exchange (ETDEWEB)
Morrison, P.J., E-mail: morrison@physics.utexas.edu [Department of Physics and Institute for Fusion Studies, University of Texas, Austin (United States); Vanneste, J. [School of Mathematics and Maxwell Institute for Mathematical Sciences, University of Edinburgh (United Kingdom)
2016-05-15
A method, called beatification, is presented for rapidly extracting weakly nonlinear Hamiltonian systems that describe the dynamics near equilibria of systems possessing Hamiltonian form in terms of noncanonical Poisson brackets. The procedure applies to systems like fluids and plasmas in terms of Eulerian variables that have such noncanonical Poisson brackets, i.e., brackets with nonstandard and possibly degenerate form. A collection of examples of both finite and infinite dimensions is presented.
Fluid shut-down system for a nuclear reactor
International Nuclear Information System (INIS)
Barclay, F.W.; Frey, J.R.; Wilson, J.N.; Besant, R.W.
1975-01-01
A nuclear reactor shut-down system is described which comprises a fluidic vortex valve for releasably maintaining a liquid neutron poison outside of the reactor core, the poison being contained by a reservoir and biased by pressure for flow into poison tubes within the reactor. The upper ends of the poison tubes communicate with the supply port of the vortex valve. A continuous gas flow into the control port maintains normal controlled operation. Shut-down is effected by interruption of the control input. One embodiment comprises three groups of poison tubes and one vortex valve associated with each group wherein shut-down is effected by poison release in two out of the three groups. Preferably, each vortex valve comprises three control ports which operate on a ''voting'' or two-out-of-three basis. (Official Gazette)
Designing generalized conic concentrators for conventional optical systems
Eichhorn, W. L.
1985-01-01
Generalized nonimaging concentrators can be incorporated into conventional optical systems in situations where flux concentration rather than imaging is required. The parameters of the concentrator for maximum flux concentration depend on the design of the particular optical system under consideration. Rationale for determining the concentrator parameters is given for one particular optical system and the procedure used for calculation of these parameters is outlined. The calculations are done for three concentrators applicable to the optical system.
A deep crustal fluid channel into the San Andreas Fault system near Parkfield, California
Becken, M.; Ritter, O.; Park, S.K.; Bedrosian, P.A.; Weckmann, U.; Weber, M.
2008-01-01
Magnetotelluric (MT) data from 66 sites along a 45-km-long profile across the San Andreas Fault (SAF) were inverted to obtain the 2-D electrical resistivity structure of the crust near the San Andreas Fault Observatory at Depth (SAFOD). The most intriguing feature of the resistivity model is a steeply dipping upper crustal high-conductivity zone flanking the seismically defined SAF to the NE, that widens into the lower crust and appears to be connected to a broad conductivity anomaly in the upper mantle. Hypothesis tests of the inversion model suggest that upper and lower crustal and upper-mantle anomalies may be interconnected. We speculate that the high conductivities are caused by fluids and may represent a deep-rooted channel for crustal and/or mantle fluid ascent. Based on the chemical analysis of well waters, it was previously suggested that fluids can enter the brittle regime of the SAF system from the lower crust and mantle. At high pressures, these fluids can contribute to fault-weakening at seismogenic depths. These geochemical studies predicted the existence of a deep fluid source and a permeable pathway through the crust. Our resistivity model images a conductive pathway, which penetrates the entire crust, in agreement with the geochemical interpretation. However, the resistivity model also shows that the upper crustal branch of the high-conductivity zone is located NE of the seismically defined SAF, suggesting that the SAF does not itself act as a major fluid pathway. This interpretation is supported by both, the location of the upper crustal high-conductivity zone and recent studies within the SAFOD main hole, which indicate that pore pressures within the core of the SAF zone are not anomalously high, that mantle-derived fluids are minor constituents to the fault-zone fluid composition and that both the volume of mantle fluids and the fluid pressure increase to the NE of the SAF. We further infer from the MT model that the resistive Salinian block
Subseafloor Microbial Life in Venting Fluids from the Mid Cayman Rise Hydrothermal System
Huber, J. A.; Reveillaud, J.; Reddington, E.; McDermott, J. M.; Sylva, S. P.; Breier, J. A.; German, C. R.; Seewald, J.
2012-12-01
in Piccard vent fluids, a basalt-hosted black smoker site located at ~4950 m with a maximum temperature of 403 °C. However, hyperthermophilic and thermophilic heterotrophs of the genus Thermococcus were isolated from Piccard vent fluids, but not Von Damm. These obligate anaerobes, growing optimally at 55-90 °C, are ubiquitous at hydrothermal systems and serve as a readily cultivable indicator organism of subseafloor populations. Finally, molecular analysis of vent fluids is on-going and will define the microbial population structure in this novel ecosystem and allow for direct comparisons with other deep-sea and subsurface habitats as part of our continuing efforts to explore the deep microbial biosphere on Earth.
Incremental and developmental perspectives for general-purpose learning systems
Directory of Open Access Journals (Sweden)
Fernando Martínez-Plumed
2017-02-01
Full Text Available The stupefying success of Articial Intelligence (AI for specic problems, from recommender systems to self-driving cars, has not yet been matched with a similar progress in general AI systems, coping with a variety of (dierent problems. This dissertation deals with the long-standing problem of creating more general AI systems, through the analysis of their development and the evaluation of their cognitive abilities. It presents a declarative general-purpose learning system and a developmental and lifelong approach for knowledge acquisition, consolidation and forgetting. It also analyses the use of the use of more ability-oriented evaluation techniques for AI evaluation and provides further insight for the understanding of the concepts of development and incremental learning in AI systems.
Dilational viscoelastic properties of fluid interfaces - III mixed surfactant systems
Energy Technology Data Exchange (ETDEWEB)
Djabbarah, N.F.; Wasan, D.T.
1982-01-01
The surface viscosity and elasticity of solutions of mixed surfactants were determined using the longitudinal wave technique combined with tracer particle measurements. The recent analysis of Maru et al., which was restricted to insoluble monolayers and to monolayers adsorbed from a single surfactant solution, has now been extended to multicomponent solutions. This analysis can be used not only to estimate the ''net'' viscoelastic properties at gas-liquid interfaces but also to estimate the composition as well as the intrinsic viscoelastic properties. Furthermore, when accompanied by separate measurements of shear viscoelastic properties, the above analysis can be used for the determination of dilational viscosity and elasticity. Surface viscoelasticity measurements were conducted on aqueous solutions of sodium lauryl sulfate and sodium lauryl sulfate-lauryl alcohol. Net surface viscosity and elasticity of sodium lauryl sulfate solutions increased with bulk concentration and reached a maximum at a concentration in the neighborhood of the critical micelle concentration. The presence of small amount of lauryl alcohol caused almost an order of magnitude increase in intrinsic surface viscosity and a similar increase in compositional surface elasticity. A comparison between the values of intrinsic surface viscosity and those of surface shear viscosity indicated that surface dilational viscosity exceeds surface shear viscosity by at least two orders of magnitude. These appear to be the first set of data presented hitherto for the surface dilational properties in addition to surface shear properties for the same mixed surfactant systems.
Fluid transient analysis and design considerations in TVA PWR feedwater systems and steam generators
International Nuclear Information System (INIS)
Kelley, B.T.
1979-01-01
TVA has evaluated a number of fluid transients in an effort to discover areas of potential problems and to improve overall unit operation. The transients recently or currently being evaluated fall into four major areas - accident analyses, fast valving, heater drain systems, and steam generators. A discussion of each area follows
Research Summary 3-D Computational Fluid Dynamics (CFD) Model Of The Human Respiratory System
The U.S. EPA’s Office of Research and Development (ORD) has developed a 3-D computational fluid dynamics (CFD) model of the human respiratory system that allows for the simulation of particulate based contaminant deposition and clearance, while being adaptable for age, ethnicity,...
Modelling dynamic liquid-gas systems: Extensions to the volume-of-fluid solver
CSIR Research Space (South Africa)
Heyns, Johan A
2013-06-01
Full Text Available This study presents the extension of the volume-of-fluid solver, interFoam, for improved accuracy and efficiency when modelling dynamic liquid-gas systems. Examples of these include the transportation of liquids, such as in the case of fuel carried...
Cerebrospinal fluid pleocytosis in infectious and noninfectious central nervous system disease
DEFF Research Database (Denmark)
Baunbæk Egelund, Gertrud; Ertner, Gideon; Langholz Kristensen, Kristina
2017-01-01
Cerebrospinal fluid (CSF) analysis is the most important tool for assessing central nervous system (CNS) disease. An elevated CSF leukocyte count rarely provides the final diagnosis, but is almost always an indicator of inflammation within the CNS.The present study investigated the variety...
RELAP5 two-phase fluid model and numerical scheme for economic LWR system simulation
International Nuclear Information System (INIS)
Ransom, V.H.; Wagner, R.J.; Trapp, J.A.
1981-01-01
The RELAP5 two-phase fluid model and the associated numerical scheme are summarized. The experience accrued in development of a fast running light water reactor system transient analysis code is reviewed and example of the code application are given
International Nuclear Information System (INIS)
Chupin, A.; Hu, L. W.; Buongiorno, J.
2008-01-01
Water-based nano-fluid, colloidal dispersions of nano-particles in water; have been shown experimentally to increase the critical heat flux and surface wettability at very low concentrations. The use of nano-fluids to enhance accidents management would allow either to increase the safe margins in case of severe accidents or to upgrade the power of an existing power plant with constant margins. Building on the initial work, computational fluid dynamics simulations of the nano-fluid injection system have been performed to evaluate the feasibility of a nano-fluid injection system for in-vessel retention application. A preliminary assessment was also conducted on the emergency core cooling system of the European Pressurized Reactor (EPR) to implement a nano-fluid injection system for improving the management of loss of coolant accidents. Several design options were compared/or their respective merits and disadvantages based on criteria including time to injection, safety impact, and materials compatibility. (authors)
Computation of the effect of pipe plasticity on pressure-pulse propagation in a fluid system
International Nuclear Information System (INIS)
Youngdahl, C.K.; Kot, C.A.
1975-04-01
A simple computational model is developed for incorporating the effect of elastic-plastic deformation of piping on pressure-transient propagation in a fluid system. A computer program (PLWV) is described that incorporates this structural interaction model into a one-dimensional method-of-characteristics procedure for fluid-hammer analysis. Computed results are shown to be in good agreement with available experimental data. The most significant effect of plastic deformation is to limit the peak pressure of a pulse leaving a pipe to approximately the yield pressure of the pipe, if the pipe is sufficiently long. 7 references. (U.S.)
A new fluid distribution system for scale-flexible expanded bed adsorption
DEFF Research Database (Denmark)
Hubbuch, Jürgen; Heebøll-Nielsen, Anders; Hobley, Timothy John
2002-01-01
of axial dispersion was 6.1 x 10(-6) m(2) (.) s(-1) and 29 theoretical plates were measured. When the rotation rate was raised to 10 rpm, the coefficient of axial dispersion increased to 8.08 x 10(-6) m(2 .) s(-1) and the number of theoretical plates decreased to 22.......A new fluid distribution system designed for expanded bed adsorption was introduced and studied in a 150-cm diameter column. Based on fluid application through a rotating distributor, it eradicates the need for perforated plates, meshes, or local mixers. The effect of rotation rate on column...
Tweed, L. E. L.; Spiegelman, M. W.; Kelemen, P. B.
2017-12-01
Computational thermodynamics has yielded great insights into petrological processes. However, on its own it cannot capture the inherently dynamic nature of many of these processes which depend on the interaction between time-dependent processes including advection, diffusion and chemical reaction. To understand this interplay, and to move away from a purely equilibrium view, requires the integration of computational thermodynamics and fluid mechanics. A key aspect of doing this is the treatment of chemical reactions as time-dependent, irreversible processes. Such a development is integral to understanding a host of petrological questions from the open system evolution of magma chambers to the dynamics of melt migration beneath mid-ocean ridges and flux melting of the mantle wedge in subduction zones. A simple thermodynamically consistent reactive model is developed that can be integrated with conservation equations for mass, momentum and energy. The model rests on the thermodynamic characterization of an independent set of reactions and has the advantage of being completely general and easily extensible to systems comprising multiple solid and liquid phases. The underlying theory is described in detail in another contribution in this session. Here we apply the framework to experimentally constrained simple systems of petrological interest including the fo-qz binary and the fo-qz-k2o ternary. These systems contain a variety of phase topologies including eutectic and peritectic reactions. As the model allows for the seamless exhaustion and stabilization of phases, we can explore the effect that these discontinuous changes have on the compositional and dynamic evolution of the system. To do this we track how the systems respond to sudden changes in intensive variables that perturb them from equilibrium. Such changes are rife in crustal magmatic systems. Simulations for decompression melting are also run to explore the interplay between reactive and advective fluxes
Schaef, Herbert T.; McGrail, B. Peter
2015-07-28
Downhole fluid injection systems are provided that can include a first well extending into a geological formation, and a fluid injector assembly located within the well. The fluid injector assembly can be configured to inject a liquid CO2/H2O-emulsion into the surrounding geological formation. CO2 sequestration methods are provided that can include exposing a geological formation to a liquid CO2/H2O-emulsion to sequester at least a portion of the CO2 from the emulsion within the formation. Hydrocarbon material recovery methods are provided that can include exposing a liquid CO2/H2O-emulsion to a geological formation having the hydrocarbon material therein. The methods can include recovering at least a portion of the hydrocarbon material from the formation.
System and technique for characterizing fluids using ultrasonic diffraction grating spectroscopy
Greenwood, Margaret S [Richland, WA
2008-07-08
A system for determining property of multiphase fluids based on ultrasonic diffraction grating spectroscopy includes a diffraction grating on a solid in contact with the fluid. An interrogation device delivers ultrasound through the solid and a captures a reflection spectrum from the diffraction grating. The reflection spectrum exhibits peaks whose relative size depends on the properties of the various phases of the multiphase fluid. For example, for particles in a liquid, the peaks exhibit dependence on the particle size and the particle volume fraction. Where the exact relationship is know know a priori, data from different peaks of the same reflection spectrum or data from the peaks of different spectra obtained from different diffraction gratings can be used to resolve the size and volume fraction.
Xie, Lei; Choi, Young-Tai; Liao, Chang-Rong; Wereley, Norman M.
2015-05-01
A key requirement for the commercialization of various magnetorheological fluid (MRF)-based applications is sedimentation stability. In this study, a high viscosity linear polysiloxane (HVLP), which has been used for shock absorbers in heavy equipment, is proposed as a new carrier fluid in highly stable MRFs. The HVLP is known to be a thixotropic (i.e., shear thinning) fluid that shows very high viscosity at very low shear rate and low viscosity at higher shear rate. In this study, using the shear rheometer, the significant thixotropic behavior of the HVLP was experimentally confirmed. In addition, a HVLP carrier fluid-based MRF (HVLP MRF) with 26 vol. % was synthesized and its sedimentation characteristics were experimentally investigated. But, because of the opacity of the HVLP MRF, no mudline can be visually observed. Hence, a vertical axis inductance monitoring system (VAIMS) applied to a circular column of fluid was used to evaluate sedimentation behavior by correlating measured inductance with the volume fraction of dispersed particles (i.e., Fe). Using the VAIMS, Fe concentration (i.e., volume fraction) was monitored for 28 days with a measurement taken every four days, as well as one measurement after 96 days to characterize long-term sedimentation stability. Finally, the concentration of the HVLP MRF as a function of the depth in the column and time, as well as the concentration change versus the depth in the column, are presented and compared with those of a commercially available MRF (i.e., Lord MRF-126CD).
Experience of using heat citric acid disinfection method in central dialysis fluid delivery system.
Sakuma, Koji; Uchiumi, Nobuko; Sato, Sumihiko; Aida, Nobuhiko; Ishimatsu, Taketo; Igoshi, Tadaaki; Kodama, Yoshihiro; Hotta, Hiroyuki
2010-09-01
We applied the heat citric acid disinfection method in the main part of the central dialysis fluid delivery system (MPCDDS), which consists of a multiple-patient dialysis fluid supply unit, dialysis console units, and dialysis fluid piping. This disinfection method has been used for single-patient dialysis machines, but this is the first trial in the MPCDDS. We examined, by points of safety and disinfection effect, whether this disinfection method is comparable to conventional disinfection methods in Japan. The conventional disinfection method is a combination of two disinfectants, sodium hypochlorite and acetic acid, used separately for protein removal and decalcification. Consequently, total microbial counts and endotoxin concentrations fully satisfied the microbiological requirements for standard dialysis fluid of ISO 11663. From our results and discussion, this heat citric acid disinfection method is proved to be safe and reliable for MPCDDS. However, to satisfy the microbiological requirements for ultrapure dialysis fluid, further consideration for this method in MPCDDS including the reverse osmosis device composition and piping is necessary.
Arciniega-Ceballos, A.; Spina, L.; Scheu, B.; Dingwell, D. B.
2015-12-01
We have investigated the dynamics of Newtonian fluids with viscosities (10-1000 Pa s; corresponding to mafic to intermediate silicate melts) during slow decompression, in a Plexiglas shock tube. As an analogue fluid we used silicon oil saturated with Argon gas for 72 hours. Slow decompression, dropping from 10 MPa to ambient pressure, acts as the excitation mechanism, initiating several processes with their own distinct timescales. The evolution of this multi-timescale phenomenon generates complex non-stationary microseismic signals, which have been recorded with 7 high-dynamic piezoelectric sensors located along the conduit. Correlation analysis of these time series with the associated high-speed imaging enables characterization of distinct phases of the dynamics of these viscous fluids and the extraction of the time and the frequency characteristics of the individual processes. We have identified fluid-solid elastic interaction, degassing, fluid mass expansion and flow, bubble nucleation, growth, coalescence and collapse, foam building and vertical wagging. All these processes (in fine and coarse scales) are sequentially coupled in time, occur within specific pressure intervals, and exhibit a localized distribution in space. Their coexistence and interactions constitute the stress field and driving forces that determine the dynamics of the system. Our observations point to the great potential of this experimental approach in the understanding of volcanic processes and volcanic seismicity.
A variational theory for frictional flow of fluids in inhomogeneous porous systems
Energy Technology Data Exchange (ETDEWEB)
Sieniutycz, Stanislaw [Faculty of Chemical Engineering, Warsaw University of Technology, 00-645 Warsaw, 1 Warynskiego Street (Poland)
2007-04-15
For nonlinear steady paths of a fluid in an inhomogeneous isotropic porous medium a Fermat-like principle of minimum time is formulated which shows that the fluid streamlines are curved by a location dependent hydraulic conductivity. The principle describes an optimal nature of nonlinear paths in steady Darcy's flows of fluids. An expression for the total resistance of the path leads to a basic analytical formula for an optimal shape of a steady trajectory. In the physical space an optimal curved path ensures the maximum flux or shortest transition time of the fluid through the porous medium. A sort of 'law of bending' holds for the frictional fluid flux in Lagrange coordinates. This law shows that - by minimizing the total resistance - a ray spanned between two given points takes the shape assuring that its relatively large part resides in the region of lower flow resistance (a 'rarer' region of the medium). Analogies and dissimilarities with other systems (e.g. optical or thermal ones) are also discussed. (author)
International Nuclear Information System (INIS)
Khashan, Saud A; Furlani, Edward P
2013-01-01
A study is presented of coupled particle–fluid transport and field-directed particle capture in microfluidic systems with passive magnetic functionality. These systems consist of a microfluidic flow cell on a substrate that contains embedded magnetic elements. Two systems are considered that utilize soft- and hard-magnetic elements, respectively. In the former, an external field is applied to magnetize the elements, and in the latter, they are permanently magnetized. The field produced by the magnetized elements permeates into the flow cell giving rise to an attractive force on magnetic particles that flow through it. The systems are studied using a novel numerical/closed-form modelling approach that combines numerical transport analysis with closed-form field analysis. Particle–fluid transport is computed using computational fluid dynamics (CFD), while the magnetic force that governs particle capture is obtained in closed form. The CFD analysis takes into account dominant particle forces and two-way momentum transfer between the particles and the fluid. The two-way particle–fluid coupling capability is an important feature of the model that distinguishes it from more commonly used and simplified one-way coupling analysis. The model is used to quantify the impact of two-way particle–fluid coupling on both the capture efficiency and the flow pattern in the systems considered. Many effects such as particle-induced flow-enhanced capture efficiency and flow circulation are studied that cannot be predicted using one-way coupling analysis. In addition, dilute particle dispersions are shown to exhibit significant localized particle–fluid coupling near the capture regions, which contradicts the commonly held view that two-way coupling can be ignored when analysing high-gradient magnetic separation involving such particle systems. Overall, the model demonstrates that two-way coupling needs to be taken into account for rigorous predictions of capture efficiency
Bravo-Berguño, D.; Mereu, R.; Cavalcante, P.; Carlini, M.; Ianni, A.; Goretti, A.; Gabriele, F.; Wright, T.; Yokley, Z.; Vogelaar, R. B.; Calaprice, F.; Inzoli, F.
2018-03-01
A comprehensive monitoring system for the thermal environment inside the Borexino neutrino detector was developed and installed in order to reduce uncertainties in determining temperatures throughout the detector. A complementary thermal management system limits undesirable thermal couplings between the environment and Borexino's active sections. This strategy is bringing improved radioactive background conditions to the region of interest for the physics signal thanks to reduced fluid mixing induced in the liquid scintillator. Although fluid-dynamical equilibrium has not yet been fully reached, and thermal fine-tuning is possible, the system has proven extremely effective at stabilizing the detector's thermal conditions while offering precise insights into its mechanisms of internal thermal transport. Furthermore, a Computational Fluid-Dynamics analysis has been performed, based on the empirical measurements provided by the thermal monitoring system, and providing information into present and future thermal trends. A two-dimensional modeling approach was implemented in order to achieve a proper understanding of the thermal and fluid-dynamics in Borexino. It was optimized for different regions and periods of interest, focusing on the most critical effects that were identified as influencing background concentrations. Literature experimental case studies were reproduced to benchmark the method and settings, and a Borexino-specific benchmark was implemented in order to validate the modeling approach for thermal transport. Finally, fully-convective models were applied to understand general and specific fluid motions impacting the detector's Active Volume.
Generalized File Management System or Proto-DBMS?
Braniff, Tom
1979-01-01
The use of a data base management system (DBMS) as opposed to traditional data processing is discussed. The generalized file concept is viewed as an entry level step to the DBMS. The transition process from one system to the other is detailed. (SF)
Minimal solution of general dual fuzzy linear systems
International Nuclear Information System (INIS)
Abbasbandy, S.; Otadi, M.; Mosleh, M.
2008-01-01
Fuzzy linear systems of equations, play a major role in several applications in various area such as engineering, physics and economics. In this paper, we investigate the existence of a minimal solution of general dual fuzzy linear equation systems. Two necessary and sufficient conditions for the minimal solution existence are given. Also, some examples in engineering and economic are considered
General Systems Theory Approaches to Organizations: Some Problems in Application
Peery, Newman S., Jr.
1975-01-01
Considers the limitations of General Systems Theory (GST) as a major paradigm within administrative theory and concludes that most systems formulations overemphasize growth and show little appreciation for intraorganizational conflict, diversity of values, and political action within organizations. Suggests that these limitations are mainly due to…
What Should Instructional Designers Know about General Systems Theory?
Salisbury, David F.
1989-01-01
Describes basic concepts in the field of general systems theory (GST) and explains the relationship between instructional systems design (ISD) and GST. Benefits of integrating GST into the curriculum of ISD graduate programs are discussed, and a short bibliography on GST is included. (LRW)
Distributed Systems of Generalizing as the Basis of Workplace Learning
Virkkunen, Jaakko; Pihlaja, Juha
2004-01-01
This article proposes a new way of conceptualizing workplace learning as distributed systems of appropriation, development and the use of practice-relevant generalizations fixed within mediational artifacts. This article maintains that these systems change historically as technology and increasingly sophisticated forms of production develop.…
On the integrability of some generalized Lotka-Volterra systems
Bier, M.; Hijmans, J.; Bountis, T. C.
1983-08-01
Several integrable systems of nonlinear ordinary differential equations of the Lotka-Volterra type are identified by the Painleveproperty and completely integrated. One such integrable case of N first order ode's is found, with N-2 free parameters and N arbitrary. The concept of integrability of a general dynamical system, not necessarily derived from a Hamiltonian, is also discussed.
The efficacy of an automated feedback system for general practitioners
Bindels, Rianne; Hasman, Arie; Kester, Arnold D.; Talmon, Jan L.; de Clercq, Paul A.; Winkens, Ron A. G.
2003-01-01
OBJECTIVE: An automated feedback system that produces comments about the non-adherence of general practitioners (GPs) to accepted practice guidelines for ordering diagnostic tests was developed. Before implementing the automated feedback system in daily practice, we assessed the potential effect of
Time-dependent generalized Gibbs ensembles in open quantum systems
Lange, Florian; Lenarčič, Zala; Rosch, Achim
2018-04-01
Generalized Gibbs ensembles have been used as powerful tools to describe the steady state of integrable many-particle quantum systems after a sudden change of the Hamiltonian. Here, we demonstrate numerically that they can be used for a much broader class of problems. We consider integrable systems in the presence of weak perturbations which break both integrability and drive the system to a state far from equilibrium. Under these conditions, we show that the steady state and the time evolution on long timescales can be accurately described by a (truncated) generalized Gibbs ensemble with time-dependent Lagrange parameters, determined from simple rate equations. We compare the numerically exact time evolutions of density matrices for small systems with a theory based on block-diagonal density matrices (diagonal ensemble) and a time-dependent generalized Gibbs ensemble containing only a small number of approximately conserved quantities, using the one-dimensional Heisenberg model with perturbations described by Lindblad operators as an example.
Rout, D.; Panigrahi, M. K.; Pati, J. K.
2017-12-01
Giant quartz reefs are anomalous features indicating extensive mobilization of silica in the crust. Such reefs in the Abitibi belt, Canada and elsewhere are believed to be the result of activity of fluid of diverse sources on terrain boundaries. The Bundelkhand granitoid complex constituting a major part of the Bundelkhnad Craton in north-Central India is traversed by numerous such quartz reefs all across for a length of about 500 km. There are about 20 major reefs having dimensions of 35 to 40 km in length, 50 to 60 m in width standing out as prominent ridges in the region. Almost all are aligned parallel to each other in a sub-vertical to vertical manner following the NE-SW to NNE-SSW trend. Fluid inclusion petrography in quartz from these reefs reveal four types of inclusions viz. aqueous biphase (type-I), pure carbonic (type-II), aqueous carbonic (type-III) and polyphase (type-IV) inclusions. The type-I aqueous biphase inclusions are the dominant type in all the samples studied so far. Salinities calculated from temperature of melting of last ice (Tm) values are low to moderate, ranging from 0.18 to 18.19 wt% NaCl equivalents. Temperature of liquid-vapor homogenization (Th) values of these inclusions show a wide range from 101 ºC to 386 ºC (cluster around 150-250 ºC) essentially into liquid phase ruling out boiling during its course of evolution. Besides, aqueous Biphase inclusions, some data on pure CO2 inclusions furnish a near constant value of TmCO2 at -56.6 ºC in the Bundelkhand Craton indicating absence of CH4. Bivariate plot between Th and salinity suggest three possible water types which are controlling the overall activity of fluid in quartz reefs of Bundelkhand Craton viz. low-T low saline, high-T low saline and moderate-T and moderate saline. A low saline and CO2-bearing and higher temperature nature resembles a metamorphic fluid that may be a source for these giant quartz reefs. The low temperature low-salinity component could be a meteoric
High-pressure fluid-phase equilibria: Experimental methods and systems investigated (2005-2008)
DEFF Research Database (Denmark)
Fonseca, José; Dohrn, Ralf; Peper, Stephanie
2011-01-01
%) have carbon dioxide as one of the components. Information on 206 pure components, 535 ternary systems of which 355 (66%) contain carbon dioxide, 163 multicomponent and complex systems, and 207 systems with hydrates is given. A continuation of the review series is planned, covering the years from 2009...... points, the solubility of high-boiling substances in supercritical fluids, the solubility of gases in liquids and the solubility (sorption) of volatile components in polymers are included. Most of experimental data in the literature has been given for binary systems. Of the 1469 binary systems, 796 (54...
Zafar, A. A.; Riaz, M. B.; Shah, N. A.; Imran, M. A.
2018-03-01
The objective of this article is to study some unsteady Couette flows of an Oldroyd-B fluid with non-integer derivatives. The fluid fills an annular region of two infinite co-axial circular cylinders. Flows are due to the motion of the outer cylinder, that rotates about its axis with an arbitrary time-dependent velocity while the inner cylinder is held fixed. Closed form solutions of dimensionless velocity field and tangential tension are obtained by means of the finite Hankel transform and the theory of Laplace transform for fractional calculus. Several results in the literature including the rotational flows through an infinite cylinder can be obtained as limiting cases of our general solutions. Finally, the control of the fractional framework on the dynamics of fluid is analyzed by numerical simulations and graphical illustrations.
A General Water Resources Regulation Software System in China
LEI, X.
2017-12-01
To avoid iterative development of core modules in water resource normal regulation and emergency regulation and improve the capability of maintenance and optimization upgrading of regulation models and business logics, a general water resources regulation software framework was developed based on the collection and analysis of common demands for water resources regulation and emergency management. It can provide a customizable, secondary developed and extensible software framework for the three-level platform "MWR-Basin-Province". Meanwhile, this general software system can realize business collaboration and information sharing of water resources regulation schemes among the three-level platforms, so as to improve the decision-making ability of national water resources regulation. There are four main modules involved in the general software system: 1) A complete set of general water resources regulation modules allows secondary developer to custom-develop water resources regulation decision-making systems; 2) A complete set of model base and model computing software released in the form of Cloud services; 3) A complete set of tools to build the concept map and model system of basin water resources regulation, as well as a model management system to calibrate and configure model parameters; 4) A database which satisfies business functions and functional requirements of general water resources regulation software can finally provide technical support for building basin or regional water resources regulation models.
Generalized Calogero-Sutherland systems from many-matrix models
International Nuclear Information System (INIS)
Polychronakos, Alexios P.
1999-01-01
We construct generalizations of the Calogero-Sutherland-Moser system by appropriately reducing a model involving many unitary matrices. The resulting systems consist of particles on the circle with internal degrees of freedom, coupled through modifications of the inverse-square potential. The coupling involves SU(M) non-invariant (anti) ferromagnetic interactions of the internal degrees of freedom. The systems are shown to be integrable and the spectrum and wavefunctions of the quantum version are derived
Ownens, Albert K.; Lavelle, Thomas M.; Hervol, David S.
2010-01-01
A Dual Brayton Power Conversion System (DBPCS) has been tested at the NASA Glenn Research Center using Nitrogen (N2) as the working fluid. This system uses two closed Brayton cycle systems that share a common heat source and working fluid but are otherwise independent. This system has been modeled using the Numerical Propulsion System Simulation (NPSS) environment. This paper presents the results of a numerical study that investigated system performance changes resulting when the working fluid is changed from gaseous (N2) to gaseous carbon dioxide (CO2).
A Generalized Evolution Criterion in Nonequilibrium Convective Systems
Ichiyanagi, Masakazu; Nisizima, Kunisuke
1989-04-01
A general evolution criterion, applicable to transport processes such as the conduction of heat and mass diffusion, is obtained as a direct version of the Le Chatelier-Braun principle for stationary states. The present theory is not based on any radical departure from the conventional one. The generalized theory is made determinate by proposing the balance equations for extensive thermodynamic variables which will reflect the character of convective systems under the assumption of local equilibrium. As a consequence of the introduction of source terms in the balance equations, there appear additional terms in the expression of the local entropy production, which are bilinear in terms of the intensive variables and the sources. In the present paper, we show that we can construct a dissipation function for such general cases, in which the premises of the Glansdorff-Prigogine theory are accumulated. The new dissipation function permits us to formulate a generalized evolution criterion for convective systems.
Fracture Characterization in Reactive Fluid-Fractured Rock Systems Using Tracer Transport Data
Mukhopadhyay, S.
2014-12-01
Fractures, whether natural or engineered, exert significant controls over resource exploitation from contemporary energy sources including enhanced geothermal systems and unconventional oil and gas reserves. Consequently, fracture characterization, i.e., estimating the permeability, connectivity, and spacing of the fractures is of critical importance for determining the viability of any energy recovery program. While some progress has recently been made towards estimating these critical fracture parameters, significant uncertainties still remain. A review of tracer technology, which has a long history in fracture characterization, reveals that uncertainties exist in the estimated parameters not only because of paucity of scale-specific data but also because of knowledge gaps in the interpretation methods, particularly in interpretation of tracer data in reactive fluid-rock systems. We have recently demonstrated that the transient tracer evolution signatures in reactive fluid-rock systems are significantly different from those in non-reactive systems (Mukhopadhyay et al., 2013, 2014). For example, the tracer breakthrough curves in reactive fluid-fractured rock systems are expected to exhibit a long pseudo-state condition, during which tracer concentration does not change by any appreciable amount with passage of time. Such a pseudo-steady state condition is not observed in a non-reactive system. In this paper, we show that the presence of this pseudo-steady state condition in tracer breakthrough patterns in reactive fluid-rock systems can have important connotations for fracture characterization. We show that the time of onset of the pseudo-steady state condition and the value of tracer concentration in the pseudo-state condition can be used to reliably estimate fracture spacing and fracture-matrix interface areas.
Gradient descent learning algorithm overview: a general dynamical systems perspective.
Baldi, P
1995-01-01
Gives a unified treatment of gradient descent learning algorithms for neural networks using a general framework of dynamical systems. This general approach organizes and simplifies all the known algorithms and results which have been originally derived for different problems (fixed point/trajectory learning), for different models (discrete/continuous), for different architectures (forward/recurrent), and using different techniques (backpropagation, variational calculus, adjoint methods, etc.). The general approach can also be applied to derive new algorithms. The author then briefly examines some of the complexity issues and limitations intrinsic to gradient descent learning. Throughout the paper, the author focuses on the problem of trajectory learning.
Generalized Einstein-Aether theories and the Solar System
International Nuclear Information System (INIS)
Bonvin, Camille; Durrer, Ruth; Ferreira, Pedro G.; Zlosnik, Tom G.; Starkman, Glenn
2008-01-01
It has been shown that generalized Einstein-Aether theories may lead to significant modifications to the nonrelativistic limit of the Einstein equations. In this paper we study the effect of a general class of such theories on the Solar System. We consider corrections to the gravitational potential in negative and positive powers of distance from the source. Using measurements of the perihelion shift of Mercury and time delay of radar signals to Cassini, we place constraints on these corrections. We find that a subclass of generalized Einstein-Aether theories is compatible with these constraints
A general sensitivity theory for simulations of nonlinear systems
International Nuclear Information System (INIS)
Kenton, M.A.
1981-01-01
A general sensitivity theory is developed for nonlinear lumped-parameter system simulations. The point-of-departure is general perturbation theory, which has long been used for linear systems in nuclear engineering and reactor physics. The theory allows the sensitivity of particular figures-of-merit of the system behavior to be calculated with respect to any parameter.An explicit procedure is derived for applying the theory to physical systems undergoing sudden events (e.g., reactor scrams, tank ruptures). A related problem, treating figures-of-merit defined as functions of extremal values of system variables occurring at sudden events, is handled by the same procedure. The general calculational scheme for applying the theory to numerical codes is discussed. It is shown that codes which use pre-packaged implicit integration subroutines can be augmented to include sensitivity theory: a companion set of subroutines to solve the sensitivity problem is listed. This combined system analysis code is applied to a simple model for loss of post-accident heat removal in a liquid metal-cooled fast breeder reactor. The uses of the theory for answering more general sensitivity questions are discussed. One application of the theory is to systematically determine whether specific physical processes in a model contribute significantly to the figures-of-merit. Another application of the theory is for selecting parameter values which enable a model to match experimentally observed behavior
Energy Cost of Avoiding Pressure Oscillations in a Discrete Fluid Power Force System
DEFF Research Database (Denmark)
Hansen, Anders Hedegaard; Pedersen, Henrik Clemmensen
2015-01-01
In secondary valve controlled discrete fluid power force systems the valve opening trajectory greatly influences the pressure dynamics in the actuator chambers. For discrete fluid power systems featuring hoses of significant length pressure oscillations due to fast valve switching is well......-known. This paper builds upon theoretical findings on how shaping of the valve opening may reduce the cylinder pressure oscillations. The current paper extents the work by implementing the valve opening characteristics reducing the pressure oscillations on a full scale power take-off test-bench for wave energy...... will present measurements comparing pressure dynamics for two valve opening algorithms. In addition the paper will give a theoretical investigation of the energy loss during valve shifting and finally measurements of average power output from the power take-off system in various sea states are compared...
Symmetries and conservation laws for generalized Hamiltonian systems
International Nuclear Information System (INIS)
Cantrijn, F.; Sarlet, W.
1981-01-01
A class of dynamical systems which locally correspond to a general first-order system of Euler-Lagrange equations is studied on a contact manifold. These systems, called self-adjoint, can be regarded as generalizations of (time-dependent) Hamiltonian systems. It is shown that each one-parameter family of symmetries of the underlying contact form defines a parameter-dependent constant of the motion and vice versa. Next, an extension of the classical concept of canonical transformations is introduced. One-parameter families of canonical transformations are studied and shown to be generated as solutions of a self-adjoint system. Some of the results are illustrated on the Emden equation. (author)
On a p-adic Cubic Generalized Logistic Dynamical System
International Nuclear Information System (INIS)
Mukhamedov, Farrukh; Rozali, Wan Nur Fairuz Alwani Wan
2013-01-01
Applications of p-adic numbers mathematical physics, quantum mechanics stimulated increasing interest in the study of p-adic dynamical system. One of the interesting investigations is p-adic logistics map. In this paper, we consider a new generalization, namely we study a dynamical system of the form f a (x) = ax(1−x 2 ). The paper is devoted to the investigation of a trajectory of the given system. We investigate the generalized logistic dynamical system with respect to parameter a and we restrict ourselves for the investigation of the case |a| p < 1. We study the existence of the fixed points and their behavior. Moreover, we describe their size of attractors and Siegel discs since the structure of the orbits of the system is related to the geometry of the p-adic Siegel discs.
Safdar, Rabia; Imran, M.; Khalique, Chaudry Masood
2018-06-01
Exact solutions for velocity field and tangential stress for rotational flow of a generalized Burgers' fluid within an infinite circular pipe are derived by using the methods of Laplace and finite Hankel transformations. Firstly we take the position of fluid at rest and then the fluid flow due to the rotation of the pipe around the axis of flow having time dependant angular velocity. The exact solutions are presented in terms of the generalized Ga,b,c (., t) -functions. The corresponding results can be freely specified for the same results of Burgers', Oldroyd B, Maxwell, second grade and Newtonian fluids (performing the same motion) as particular cases of the results obtained earlier. The impact of the different parameters, individually and in comparison, are represented by graphical demonstrations. Secondly the numerical solutions for velocity and stress are also obtained with the help of Laplace transformation, Gaver Stehfest's algorithm and MATHCAD. Finally a comparison of both methods for the same problem is done and shows the consistency of results.
Development of Fluid and I and C System Design Technology for LMR
International Nuclear Information System (INIS)
Kim, S. O.; Sim, Y. S.; Choi, S. K.
2007-06-01
The basic concept of fluid and I and C systems of KALIMER-600 was developed and the computer codes required to materialize system concept were also implemented through the R and D program. Based on the analysis results of the design characteristics for the similar reactor types developed in the foreign countries, the system design technologies with adoption of the innovative ideas were developed. With the development, expansion and reinforcement of the methodologies required according to the progress of development and design of the system and the experimental verification of the developed computer code, the excellent and innovative outcomes were produced
Development of Fluid and I and C Systems Design Technology for LMR
International Nuclear Information System (INIS)
Kim, Seong O; Sim, Y. S.; Choi, S. K.; Kim, E. K.; Wi, M. H.; Eho, J. H.; Hur, S.; Seong, S. H.; Kim, S. Y.; Jeon, W. D.
2005-03-01
The basic concept of fluid and I and C system of KALIMER-600 was developed and the computer codes required to materialize system concept were also implemented through the R and D program. Based on the analysis results of the design characteristics for the similar reactor types developed in a foreign country, the system design technologies with adoption of the innovative ideas were developed. With the development, expansion and reinforcement of the methodologies required according to the progress of development and design of the system and the experimental verification of the developed computer code, the excellent and innovative outcomes were produced
Pressure Feedback in Fluid Power Systems--Active Damping Explained and Exemplified
DEFF Research Database (Denmark)
Pedersen, Henrik Clemmensen; Andersen, Torben O.
2018-01-01
Fluid power systems are inherently nonlinear and typically suffer from very poor damping. Despite these characteristics, it is not uncommon that traditional linear type controllers are applied. This typically results in conservative adjustment of the controllers, or when more advanced controllers...... a given system, and how to adjust the parameters of the pressure feedback to obtain the best results. This is done for both a traditional symmetric cylinder servo system and a system with a differential cylinder using both pressure and nonpressure compensated proportional valves. Based on the presented...
Cu-As Decoupling in Hydrothermal Systems: A Link Between Pyrite Chemistry and Fluid Composition
Reich, M.; Tardani, D.; Deditius, A.; Chryssoulis, S.; Wrage, J.; Sanchez-Alfaro, P.; Andrea, H.; Cinthia, J.
2016-12-01
Chemical zonations in pyrite have been recognized in most hydrothermal ore deposit types, showing in some cases marked oscillatory alternation of metals and metalloids in pyrite growth zones (e.g., of Cu-rich, As-(Au)-depleted zones and As-(Au)-rich, Cu-depleted zones). This decoupled geochemical behavior of Cu and As has been interpreted as a result of chemical changes in ore-forming fluids, although direct evidence connecting fluctuations in hydrothermal fluid composition with metal partitioning into pyrite growth zones is still lacking. Here we report a comprehensive trace element database of pyrite from an active hydrothermal system, the Tolhuaca Geothermal System (TGS) in southern Chile. We combined high-spatial resolution and X-ray mapping capabilities of electron microprobe analysis (EMPA) with low detection limits and depth-profiling capabilities of secondary-ion mass spectrometry (SIMS) in a suite of pyrite samples retrieved from a 1 km drill hole that crosses the argillic and propylitic alteration zones of the geothermal system. We show that the concentrations of precious metals (e.g., Au, Ag), metalloids (e.g., As, Sb, Se, Te), and base and heavy metals (e.g., Cu, Co, Ni, Pb) in pyrite at the TGS are significant. Among the elements analyzed, arsenic, Cu and Co are the most abundant with concentrations that vary from sub-ppm levels to a few wt. %. Pyrites from the deeper propylitic zone do not show significant zonation and high Cu-(Co)-As concentrations correlate with each other. In contrast, well-developed zonations were detected in pyrite from the shallow argillic alteration zone, where Cu(Co)-rich, As-depleted cores alternate with Cu(Co)-depleted, As-rich rims. These microanalytical data were contrasted with chemical data of fluid inclusion in quartz veins (high Cu/Na and low As/Na) and borehole fluids (low Cu/Na and high As/Na) reported at the TGS, showing a clear correspondence between Cu and As concentrations in pyrite-forming fluids and chemical
Hardin, G. R.; Sani, R. L.; Henry, D.; Roux, B.
1990-01-01
The buoyancy-driven instability of a monocomponent or binary fluid completely contained in a vertical circular cylinder is investigated, including the influence of the Soret effect for the binary mixture. The Boussinesq approximation is used, and the resulting linear stability problem is solved using a Galerkin technique. The analysis considers fluid mixtures ranging from gases to liquid metals. The flow structure is found to depend strongly on both the cylinder aspect ratio and the magnitude of the Soret effect. The predicted stability limits are shown to agree closely with experimental observations.
Solution of generalized control system equations at steady state
International Nuclear Information System (INIS)
Vilim, R.B.
1987-01-01
Although a number of reactor systems codes feature generalized control system models, none of the models offer a steady-state solution finder. Indeed, if a transient is to begin from steady-state conditions, the user must provide estimates for the control system initial conditions and run a null transient until the plant converges to steady state. Several such transients may have to be run before values for control system demand signals are found that produce the desired plant steady state. The intent of this paper is (a) to present the control system equations assumed in the SASSYS reactor systems code and to identify the appropriate set of initial conditions, (b) to describe the generalized block diagram approach used to represent these equations, and (c) to describe a solution method and algorithm for computing these initial conditions from the block diagram. The algorithm has been installed in the SASSYS code for use with the code's generalized control system model. The solution finder greatly enhances the effectiveness of the code and the efficiency of the user in running it
Structure-Preserving Methods for the Navier-Stokes-Cahn-Hilliard System to Model Immiscible Fluids
Sarmiento, Adel F.
2017-12-03
This work presents a novel method to model immiscible incompressible fluids in a stable manner. Here, the immiscible behavior of the flow is described by the incompressible Navier-Stokes-Cahn-Hilliard model, which is based on a diffuse interface method. We introduce buoyancy effects in the model through the Boussinesq approximation in a consistent manner. A structure-preserving discretization is used to guarantee the linear stability of the discrete problem and to satisfy the incompressibility of the discrete solution at every point in space by construction. For the solution of the model, we developed the Portable Extensible Toolkit for Isogeometric Analysis with Multi-Field discretizations (PetIGA-MF), a high-performance framework that supports structure-preserving spaces. PetIGA-MF is built on top of PetIGA and the Portable Extensible Toolkit for Scientific Computation (PETSc), sharing all their user-friendly, performance, and flexibility features. Herein, we describe the implementation of our model in PetIGA-MF and the details of the numerical solution. With several numerical tests, we verify the convergence, scalability, and validity of our approach. We use highly-resolved numerical simulations to analyze the merging and rising of droplets. From these simulations, we detailed the energy exchanges in the system to evaluate quantitatively the quality of our simulations. The good agreement of our results when compared against theoretical descriptions of the merging, and the small errors found in the energy analysis, allow us to validate our approach. Additionally, we present the development of an unconditionally energy-stable generalized-alpha method for the Swift-Hohenberg model that offers control over the numerical dissipation. A pattern formation example demonstrates the energy-stability and convergence of our method.
Fluid-structure interaction in non-rigid pipeline systems - large scale validation experiments
International Nuclear Information System (INIS)
Heinsbroek, A.G.T.J.; Kruisbrink, A.C.H.
1993-01-01
The fluid-structure interaction computer code FLUSTRIN, developed by DELFT HYDRAULICS, enables the user to determine dynamic fluid pressures, structural stresses and displacements in a liquid-filled pipeline system under transient conditions. As such, the code is a useful tool to process and mechanical engineers in the safe design and operation of pipeline systems in nuclear power plants. To validate FLUSTRIN, experiments have been performed in a large scale 3D test facility. The test facility consists of a flexible pipeline system which is suspended by wires, bearings and anchors. Pressure surges, which excite the system, are generated by a fast acting shut-off valve. Dynamic pressures, structural displacements and strains (in total 70 signals) have been measured under well determined initial and boundary conditions. The experiments have been simulated with FLUSTRIN, which solves the acoustic equations using the method of characteristics (fluid) and the finite element method (structure). The agreement between experiments and simulations is shown to be good: frequencies, amplitudes and wave phenomena are well predicted by the numerical simulations. It is demonstrated that an uncoupled water hammer computation would render unreliable and useless results. (author)
Scaling of two-phase flow transients using reduced pressure system and simulant fluid
International Nuclear Information System (INIS)
Kocamustafaogullari, G.; Ishii, M.
1987-01-01
Scaling criteria for a natural circulation loop under single-phase flow conditions are derived. Based on these criteria, practical applications for designing a scaled-down model are considered. Particular emphasis is placed on scaling a test model at reduced pressure levels compared to a prototype and on fluid-to-fluid scaling. The large number of similarty groups which are to be matched between modell and prototype makes the design of a scale model a challenging tasks. The present study demonstrates a new approach to this clasical problen using two-phase flow scaling parameters. It indicates that a real time scaling is not a practical solution and a scaled-down model should have an accelerated (shortened) time scale. An important result is the proposed new scaling methodology for simulating pressure transients. It is obtained by considerung the changes of the fluid property groups which appear within the two-phase similarity parameters and the single-phase to two-phase flow transition prameters. Sample calculations are performed for modeling two-phase flow transients of a high pressure water system by a low-pressure water system or a Freon system. It is shown that modeling is possible for both cases for simulation pressure transients. However, simulation of phase change transitions is not possible by a reduced pressure water system without distortion in either power or time. (orig.)
Heinzelmann, F.; Bristogianni, T.; Teuffel, P.; Stouffs, R.; Sariyildiz, S.
2013-01-01
The paper describes a novel system to alter and redirect sunlight under large span roofs with the help of a fluid lens system. Focus lies on the computational design, testing, measurement and evaluation of the performance of a physical prototype.
General framework and key technologies of national nuclear emergency system
International Nuclear Information System (INIS)
Yuan Feng; Li Xudong; Zhu Guangying; Song Yafeng; Zeng Suotian; Shen Lifeng
2014-01-01
Nuclear emergency is the important safeguard for the sustainable development of nuclear energy, and is the significant part of national public crisis management. The paper gives the definition of nuclear emergency system explicitly based on the analysis of the characteristics of the nuclear emergency, and through the research of the structure and general framework, the general framework of the national nuclear emergency management system (NNEMS) is obtained, which is constructed in four parts, including one integrative platform, six layers, eight applications and two systems, then the paper indicate that the architecture of national emergency system that should be laid out by three-tiers, i.e. national, provincial and organizations with nuclear facilities, and also describe the functions of the NNEMS on the nuclear emergency's workflow. Finally, the paper discuss the key technology that NNIEMS needed, such as WebGIS, auxiliary decision-making, digitalized preplan and the conformity and usage of resources, and analyze the technical principle in details. (authors)
International Nuclear Information System (INIS)
Lue Xing; Zhu Hongwu; Yao Zhenzhi; Meng Xianghua; Zhang Cheng; Zhang Chunyi; Tian Bo
2008-01-01
In this paper, the multisoliton solutions in terms of double Wronskian determinant are presented for a generalized variable-coefficient nonlinear Schroedinger equation, which appears in space and laboratory plasmas, arterial mechanics, fluid dynamics, optical communications and so on. By means of the particularly nice properties of Wronskian determinant, the solutions are testified through direct substitution into the bilinear equations. Furthermore, it can be proved that the bilinear Baecklund transformation transforms between (N - 1)- and N-soliton solutions
Locally Hamiltonian systems with symmetry and a generalized Noether's theorem
International Nuclear Information System (INIS)
Carinena, J.F.; Ibort, L.A.
1985-01-01
An analysis of global aspects of the theory of symmetry groups G of locally Hamiltonian dynamical systems is carried out for particular cases either of the symmetry group, or the differentiable manifold M supporting the symplectic structure, or the action of G on M. In every case it is obtained a generalization of Noether's theorem. It has been looked at the classical Noether's theorem for Lagrangian systems from a modern perspective
Generalized Tellegen Principle and Physical Correctness of System Representations
Directory of Open Access Journals (Sweden)
Vaclav Cerny
2006-06-01
Full Text Available The paper deals with a new problem of physical correctness detection in the area of strictly causal system representations. The proposed approach to the problem solution is based on generalization of Tellegen's theorem well known from electrical engineering. Consequently, mathematically as well as physically correct results are obtained. Some known and often used system representation structures are discussed from the developed point of view as an addition.
Matsumae, Mitsunori; Sato, Osamu; Hirayama, Akihiro; Hayashi, Naokazu; Takizawa, Ken; Atsumi, Hideki; Sorimachi, Takatoshi
2016-07-15
Cerebrospinal fluid (CSF) plays an essential role in maintaining the homeostasis of the central nervous system. The functions of CSF include: (1) buoyancy of the brain, spinal cord, and nerves; (2) volume adjustment in the cranial cavity; (3) nutrient transport; (4) protein or peptide transport; (5) brain volume regulation through osmoregulation; (6) buffering effect against external forces; (7) signal transduction; (8) drug transport; (9) immune system control; (10) elimination of metabolites and unnecessary substances; and finally (11) cooling of heat generated by neural activity. For CSF to fully mediate these functions, fluid-like movement in the ventricles and subarachnoid space is necessary. Furthermore, the relationship between the behaviors of CSF and interstitial fluid in the brain and spinal cord is important. In this review, we will present classical studies on CSF circulation from its discovery over 2,000 years ago, and will subsequently introduce functions that were recently discovered such as CSF production and absorption, water molecule movement in the interstitial space, exchange between interstitial fluid and CSF, and drainage of CSF and interstitial fluid into both the venous and the lymphatic systems. Finally, we will summarize future challenges in research. This review includes articles published up to February 2016.
On the System and Engineering Design of the General Purpose ...
Indian Academy of Sciences (India)
Home; Journals; Resonance – Journal of Science Education; Volume 13; Issue 5. On the System and Engineering Design of the General Purpose Electronic Digital Computer at TIFR. Rangaswamy Narasimhan. Classics Volume 13 Issue 5 May 2008 pp 490-501 ...
An Application of General System Theory (GST) to Group Therapy.
Matthews, Charles O.
1992-01-01
Demonstrates the compatibility of General System Theory (GST) with the traditional counseling literature in explicating a therapy group's progression through Tuckman's (1965, 1977) developmental stages (forming, storming, norming, performing, and adjourning). Description uses both traditional group literature and GST concepts. (Author/NB)
On the general procedure for modelling complex ecological systems
International Nuclear Information System (INIS)
He Shanyu.
1987-12-01
In this paper, the principle of a general procedure for modelling complex ecological systems, i.e. the Adaptive Superposition Procedure (ASP) is shortly stated. The result of application of ASP in a national project for ecological regionalization is also described. (author). 3 refs
Analysis and design of generalized BICM-T system
Malik, Muhammad Talha; Hossain, Md Jahangir; Alouini, Mohamed-Slim
2014-01-01
-T). In this paper, we analyze a generalized BICM-T system that uses a nonequally spaced signal constellation in conjunction with a bit-level multiplexer in an additive white Gaussian noise (AWGN) channel. As such, one can exploit the full benefit of BICM
Fluid dynamics of acoustic and hydrodynamic cavitation in hydraulic power systems
Ferrari, A.
2017-01-01
Cavitation is the transition from a liquid to a vapour phase, due to a drop in pressure to the level of the vapour tension of the fluid. Two kinds of cavitation have been reviewed here: acoustic cavitation and hydrodynamic cavitation. As acoustic cavitation in engineering systems is related to the propagation of waves through a region subjected to liquid vaporization, the available expressions of the sound speed are discussed. One of the main effects of hydrodynamic cavitation in the nozzles ...
DEFF Research Database (Denmark)
Andersen, T. O.; Hansen, M. R.; Conrad, Finn
2003-01-01
The development within the engineering industry is ever more in the direction of an integration of electronics both on the component level and system level. This implies improved and more intelligentcomponents with increased funtionality at the same time as the variant creation is made in the ele...... and control can be useful in analysis, synthesis, design and application of mechatronic systems with fluid power actuation. The focus is on system aspects and describes several projects from education and research that utilises the mentioned methods and techniques....
Systems and methods for the detection of low-level harmful substances in a large volume of fluid
Carpenter, Michael V.; Roybal, Lyle G.; Lindquist, Alan; Gallardo, Vincente
2016-03-15
A method and device for the detection of low-level harmful substances in a large volume of fluid comprising using a concentrator system to produce a retentate and analyzing the retentate for the presence of at least one harmful substance. The concentrator system performs a method comprising pumping at least 10 liters of fluid from a sample source through a filter. While pumping, the concentrator system diverts retentate from the filter into a container. The concentrator system also recirculates at least part of the retentate in the container again through the filter. The concentrator system controls the speed of the pump with a control system thereby maintaining a fluid pressure less than 25 psi during the pumping of the fluid; monitors the quantity of retentate within the container with a control system, and maintains a reduced volume level of retentate and a target volume of retentate.
A dural lymphatic vascular system that drains brain interstitial fluid and macromolecules.
Aspelund, Aleksanteri; Antila, Salli; Proulx, Steven T; Karlsen, Tine Veronica; Karaman, Sinem; Detmar, Michael; Wiig, Helge; Alitalo, Kari
2015-06-29
The central nervous system (CNS) is considered an organ devoid of lymphatic vasculature. Yet, part of the cerebrospinal fluid (CSF) drains into the cervical lymph nodes (LNs). The mechanism of CSF entry into the LNs has been unclear. Here we report the surprising finding of a lymphatic vessel network in the dura mater of the mouse brain. We show that dural lymphatic vessels absorb CSF from the adjacent subarachnoid space and brain interstitial fluid (ISF) via the glymphatic system. Dural lymphatic vessels transport fluid into deep cervical LNs (dcLNs) via foramina at the base of the skull. In a transgenic mouse model expressing a VEGF-C/D trap and displaying complete aplasia of the dural lymphatic vessels, macromolecule clearance from the brain was attenuated and transport from the subarachnoid space into dcLNs was abrogated. Surprisingly, brain ISF pressure and water content were unaffected. Overall, these findings indicate that the mechanism of CSF flow into the dcLNs is directly via an adjacent dural lymphatic network, which may be important for the clearance of macromolecules from the brain. Importantly, these results call for a reexamination of the role of the lymphatic system in CNS physiology and disease. © 2015 Aspelund et al.
Chaotic Behavior of a Generalized Sprott E Differential System
Oliveira, Regilene; Valls, Claudia
A chaotic system with only one equilibrium, a stable node-focus, was introduced by Wang and Chen [2012]. This system was found by adding a nonzero constant b to the Sprott E system [Sprott, 1994]. The coexistence of three types of attractors in this autonomous system was also considered by Braga and Mello [2013]. Adding a second parameter to the Sprott E differential system, we get the autonomous system ẋ = ayz + b,ẏ = x2 - y,ż = 1 - 4x, where a,b ∈ ℝ are parameters and a≠0. In this paper, we consider theoretically some global dynamical aspects of this system called here the generalized Sprott E differential system. This polynomial differential system is relevant because it is the first polynomial differential system in ℝ3 with two parameters exhibiting, besides the point attractor and chaotic attractor, coexisting stable limit cycles, demonstrating that this system is truly complicated and interesting. More precisely, we show that for b sufficiently small this system can exhibit two limit cycles emerging from the classical Hopf bifurcation at the equilibrium point p = (1/4, 1/16, 0). We also give a complete description of its dynamics on the Poincaré sphere at infinity by using the Poincaré compactification of a polynomial vector field in ℝ3, and we show that it has no first integrals in the class of Darboux functions.
Development of fluid I and C systems design technology for LMR
International Nuclear Information System (INIS)
Sim, Yoon Sub; Kim, S. O.; Kim, Y. S.
2002-04-01
LMR can make the utilization of the uranium resources much more efficiently and reduce the storage load of high level nuclear waste but the technology for designing the systems of LMR was not secured domestically. Based on this technical requirement, research was made for the LMR system technology and a conceptual design for the fluid and IC systems for the LMR was developed and established. Also required computer code systems for the analysis and design of the systems were developed. Design requirements for each system were revised, analysis was made for various system design features, performance, sodium-water reaction, and operation stability. The developed codes were verified against experimental data produced locally and acquired through international cooperation
SOCIAL AUDIT OF THE MUNICIPAL SYSTEM OF GENERAL EDUCATION
Directory of Open Access Journals (Sweden)
T. I. Zerchaninova
2013-01-01
Full Text Available The paper deals with the theory and practice of social audit of the municipal system of general education. The authors have developed a conceptual model of social audit to accurately identify both the short- and long-term development prospects of the given system. The paper describes the social audit procedures in Berezovsky municipal district of Sverdlovsk region including four stages: the content analysis of municipal documents concerning the development strategy of the general education system, diagnosis of the current conditions and problems, effectiveness evaluation of the municipal system of general education, and practical recommendations for improving the education quality. The above mentioned audit demonstrates that the indices of education development are unsystematically tracked, obstructing therefore the adjustment process. To solve the given problems the following measures are recommended: personnel policy development, creating the regional managerial reserve and organizing management workshops, informing the teachers about the modern educational tools, and updating the municipal program of the «Educational System Development of Berezovsky Municipal District for 20011–20015». However, the above suggestions target only the current problems disregarding the challenges of tomorrow which require the advancing strategy. In authors’ opinion, the main emphasis should be re-placed on the quality improvement of the municipal educational services instead of the infrastructure reinforcement.
SOCIAL AUDIT OF THE MUNICIPAL SYSTEM OF GENERAL EDUCATION
Directory of Open Access Journals (Sweden)
T. I. Zerchaninova
2015-03-01
Full Text Available The paper deals with the theory and practice of social audit of the municipal system of general education. The authors have developed a conceptual model of social audit to accurately identify both the short- and long-term development prospects of the given system. The paper describes the social audit procedures in Berezovsky municipal district of Sverdlovsk region including four stages: the content analysis of municipal documents concerning the development strategy of the general education system, diagnosis of the current conditions and problems, effectiveness evaluation of the municipal system of general education, and practical recommendations for improving the education quality. The above mentioned audit demonstrates that the indices of education development are unsystematically tracked, obstructing therefore the adjustment process. To solve the given problems the following measures are recommended: personnel policy development, creating the regional managerial reserve and organizing management workshops, informing the teachers about the modern educational tools, and updating the municipal program of the «Educational System Development of Berezovsky Municipal District for 20011–20015». However, the above suggestions target only the current problems disregarding the challenges of tomorrow which require the advancing strategy. In authors’ opinion, the main emphasis should be re-placed on the quality improvement of the municipal educational services instead of the infrastructure reinforcement.
Generalized Predictive Control for Non-Stationary Systems
DEFF Research Database (Denmark)
Palsson, Olafur Petur; Madsen, Henrik; Søgaard, Henning Tangen
1994-01-01
This paper shows how the generalized predictive control (GPC) can be extended to non-stationary (time-varying) systems. If the time-variation is slow, then the classical GPC can be used in context with an adaptive estimation procedure of a time-invariant ARIMAX model. However, in this paper prior...... knowledge concerning the nature of the parameter variations is assumed available. The GPC is based on the assumption that the prediction of the system output can be expressed as a linear combination of present and future controls. Since the Diophantine equation cannot be used due to the time......-variation of the parameters, the optimal prediction is found as the general conditional expectation of the system output. The underlying model is of an ARMAX-type instead of an ARIMAX-type as in the original version of the GPC (Clarke, D. W., C. Mohtadi and P. S. Tuffs (1987). Automatica, 23, 137-148) and almost all later...
Generalized Truncated Methods for an Efficient Solution of Retrial Systems
Directory of Open Access Journals (Sweden)
Ma Jose Domenech-Benlloch
2008-01-01
Full Text Available We are concerned with the analytic solution of multiserver retrial queues including the impatience phenomenon. As there are not closed-form solutions to these systems, approximate methods are required. We propose two different generalized truncated methods to effectively solve this type of systems. The methods proposed are based on the homogenization of the state space beyond a given number of users in the retrial orbit. We compare the proposed methods with the most well-known methods appeared in the literature in a wide range of scenarios. We conclude that the proposed methods generally outperform previous proposals in terms of accuracy for the most common performance parameters used in retrial systems with a moderated growth in the computational cost.
Generalization of uncertainty relation for quantum and stochastic systems
Koide, T.; Kodama, T.
2018-06-01
The generalized uncertainty relation applicable to quantum and stochastic systems is derived within the stochastic variational method. This relation not only reproduces the well-known inequality in quantum mechanics but also is applicable to the Gross-Pitaevskii equation and the Navier-Stokes-Fourier equation, showing that the finite minimum uncertainty between the position and the momentum is not an inherent property of quantum mechanics but a common feature of stochastic systems. We further discuss the possible implication of the present study in discussing the application of the hydrodynamic picture to microscopic systems, like relativistic heavy-ion collisions.
Tardani, Daniele; Reich, Martin; Deditius, Artur P.; Chryssoulis, Stephen; Sánchez-Alfaro, Pablo; Wrage, Jackie; Roberts, Malcolm P.
2017-05-01
Over the past few decades several studies have reported that pyrite hosts appreciable amounts of trace elements which commonly occur forming complex zoning patterns within a single mineral grain. These chemical zonations in pyrite have been recognized in a variety of hydrothermal ore deposit types (e.g., porphyry Cu-Mo-Au, epithermal Au deposits, iron oxide-copper-gold, Carlin-type and Archean lode Au deposits, among others), showing, in some cases, marked oscillatory alternation of metals and metalloids in pyrite growth zones (e.g., of Cu-rich, As-(Au, Ag)-depleted zones and As-(Au, Ag)-rich, Cu-depleted zones). This decoupled geochemical behavior of Cu and As has been interpreted as a result of chemical changes in ore-forming fluids, although direct evidence connecting fluctuations in hydrothermal fluid composition with metal partitioning into pyrite growth zones is still lacking. In this study, we report a comprehensive trace element database of pyrite from the Tolhuaca Geothermal System (TGS) in southern Chile, a young and active hydrothermal system where fewer pyrite growth rims and mineralization events are present and the reservoir fluid (i.e. ore-forming fluid) is accessible. We combined the high-spatial resolution and X-ray mapping capabilities of electron microprobe analysis (EMPA) with low detection limits and depth-profiling capacity of secondary-ion mass spectrometry (SIMS) in a suite of pyrite samples retrieved from a ∼1 km drill hole that crosses the argillic (20-450 m) and propylitic (650-1000 m) alteration zones of the geothermal system. We show that the concentrations of precious metals (e.g., Au, Ag), metalloids (e.g., As, Sb, Se, Te), and base and heavy metals (e.g., Cu, Co, Ni, Pb) in pyrite at the TGS are significant. Among the elements analyzed, As and Cu are the most abundant with concentrations that vary from sub-ppm levels to a few wt.% (i.e., up to ∼5 wt.% As, ∼1.5 wt.% Cu). Detailed wavelength-dispersive spectrometry (WDS) X
Dynamic analysis of an accelerator-driven fluid-fueled subcritical radioactive waste burning system
International Nuclear Information System (INIS)
Woosley, M.L. Jr.; Rydin, R.A.
1998-01-01
The recent revival of interest in accelerator-driven subcritical fluid-fueled systems is documented. Several important applications of these systems are mentioned, and this is used to motivate the need for dynamic analysis of the nuclear kinetics of such systems. A physical description of the Los alamos National Laboratory accelerator-based conversion (ABC) concept is provided. This system is used as the basis for the kinetics study in this research. The current approach to the dynamic simulation of an accelerator-driven subcritical fluid-fueled system includes four functional elements: a discrete ordinates model is used to calculate the flux distribution for the source-driven system; a nodal convection model is used to calculate time-dependent isotope and temperature distributions that impact reactivity; a nodal importance weighting model is used to calculate the reactivity impact of temperature and isotope distributions and to feed this information back to the time-dependent nodal convection model; and a transient driver is used to simulate transients, model the balance of plant, and record simulation data. Specific transients that have been analyzed with the current modeling system are discussed. These transients include loss-of-flow and loss-of-cooling accidents, xenon and samarium transients, and cold-plug and overfueling events. The results of various transients have uncovered unpredictable behavior, unresolved design issues, and the need for active control. The need for the development of a nodal-coupling spatial kinetics model is mentioned
Supercritical fluid analytical methods
International Nuclear Information System (INIS)
Smith, R.D.; Kalinoski, H.T.; Wright, B.W.; Udseth, H.R.
1988-01-01
Supercritical fluids are providing the basis for new and improved methods across a range of analytical technologies. New methods are being developed to allow the detection and measurement of compounds that are incompatible with conventional analytical methodologies. Characterization of process and effluent streams for synfuel plants requires instruments capable of detecting and measuring high-molecular-weight compounds, polar compounds, or other materials that are generally difficult to analyze. The purpose of this program is to develop and apply new supercritical fluid techniques for extraction, separation, and analysis. These new technologies will be applied to previously intractable synfuel process materials and to complex mixtures resulting from their interaction with environmental and biological systems
The Nature of Living Systems: An Exposition of the Basic Concepts in General Systems Theory.
Miller, James G.
General systems theory is a set of related definitions, assumptions, and propositions which deal with reality as an integrated hierarchy of organizations of matter and energy. In this paper, the author defines the concepts of space, time, matter, energy, and information in terms of their meaning in general systems theory. He defines a system as a…
Lotka-Volterra representation of general nonlinear systems.
Hernández-Bermejo, B; Fairén, V
1997-02-01
In this article we elaborate on the structure of the generalized Lotka-Volterra (GLV) form for nonlinear differential equations. We discuss here the algebraic properties of the GLV family, such as the invariance under quasimonomial transformations and the underlying structure of classes of equivalence. Each class possesses a unique representative under the classical quadratic Lotka-Volterra form. We show how other standard modeling forms of biological interest, such as S-systems or mass-action systems, are naturally embedded into the GLV form, which thus provides a formal framework for their comparison and for the establishment of transformation rules. We also focus on the issue of recasting of general nonlinear systems into the GLV format. We present a procedure for doing so and point at possible sources of ambiguity that could make the resulting Lotka-Volterra system dependent on the path followed. We then provide some general theorems that define the operational and algorithmic framework in which this is not the case.
Near-surface gravity actuated pipe (GAP{sup TM}) system for Brazilian deepwater fluid transfer
Energy Technology Data Exchange (ETDEWEB)
Fromage, Lionel; Brown, Paul A. [SBM Offshore (Monaco)
2009-12-19
The recent discovery of new deep water and ultra-deep water oil and gas fields offshore Brazil, including pre-salt reservoirs, has become a focal point for field development Operators and Contractors. The aggressive nature of fluids (sour, high density) in combination with deeper waters implies potential flow assurance issues. These issues challenge riser and pipeline technology to find cost effective solutions for hydrocarbon fluid transfer in field development scenarios involving phased tied-back. The near-surface GAP{sup TM}, system (Gravity Actuated Pipe{sup TM}), which has been in operation for more than two years on the Kikeh field offshore Malaysia in 1325 m of water between a Dry Tree Unit (SPAR) and a turret-moored FPSO, is considered to meet these challenges since such a product is quasi independent of water depth and takes advantage of being near surface to optimize flow assurance. Furthermore the GAP{sup TM} has undergone technical upgrades when compared to the Kikeh project in order to make it suitable for the more hostile met ocean conditions offshore Brazil. This paper presents the design features, the construction and assembly plans in Brazil and the offshore installation of a GAP fluid transfer system for operation in Brazilian deep waters. (author)
Pogorelova, T N; Gunko, V O; Linde, V A
2014-01-01
Metabolism of glutamine and glutamic acid has been investigated in the placenta and amniotic fluid under conditions of placental insufficiency. The development of placental insufficiency is characterized by the increased content of glutamic acid and a decrease of glutamine in both placenta and amniotic fluid. These changes changes were accompanied by changes in the activity of enzymes involved in the metabolism of these amino acids. There was a decrease in glutamate dehydrogenase activity and an increase in glutaminase activity with the simultaneous decrease of glutamine synthetase activity. The compensatory decrease in the activity of glutamine keto acid aminotransferase did not prevent a decrease in the glutamine level. The impairments in the system glutamic acid-glutamine were more pronounced during the development of premature labor.
Acoustically Driven Fluid and Particle Motion in Confined and Leaky Systems
Barnkob, Rune; Nama, Nitesh; Ren, Liqiang; Huang, Tony Jun; Costanzo, Francesco; Kähler, Christian J.
2018-01-01
The acoustic motion of fluids and particles in confined and acoustically leaky systems is receiving increasing attention for its use in medicine and biotechnology. A number of contradicting physical and numerical models currently exist, but their validity is uncertain due to the unavailability of hard-to-access experimental data for validation. We provide experimental benchmarking data by measuring 3D particle trajectories and demonstrate that the particle trajectories can be described numerically without any fitting parameter by a reduced-fluid model with leaky impedance-wall conditions. The results reveal the hitherto unknown existence of a pseudo-standing wave that drives the acoustic streaming as well as the acoustic radiation force on suspended particles.
Bhandari, Pradeep; Birur, Gajanana; Prina, Mauro; Ramirez, Brenda; Paris, Anthony; Novak, Keith; Pauken, Michael
2006-01-01
This viewgraph presentation reviews the heat rejection and heat recovery system for thermal control of the Mars Science Laboratory (MSL). The MSL mission will use mechanically pumped fluid loop based architecture for thermal control of the spacecraft and rover. The architecture is designed to harness waste heat from an Multi Mission Radioisotope Thermo-electric Generator (MMRTG) during Mars surface operations for thermal control during cold conditions and also reject heat during the cruise aspect of the mission. There are several test that are being conducted that will insure the safety of this concept. This architecture can be used during any future interplanetary missions utilizing radioisotope power systems for power generation.
Bonomi, U
1977-01-01
The general outlines for the isolation of viruses from the cerebro-spinal fluid are described. It is suggested to associate to the virus cultivation of the cerebrospinal fluid even the cultivation from other pathological materials as faringeal swabs and stools and the search for antibodies in the blood serum. Researches of viruses in cerebro-spinal fluid done by the Service of Microbiology of the Hospital of Verona have given in 55 cases examined during the year 1976 2 positive isolates; in both mumps virus has been isolated.
International Nuclear Information System (INIS)
Heijden, Harm van der; Mullen, Joost van der
2002-01-01
A general ray-trace method for calculating the effects of radiative transfer in a control volume (CV) fluid code is presented. The method makes use of the structured CV grid of the fluid code, and is suited for geometries with a point or axis of symmetry. In particular, the specific equations for spherical and cylindrical (without z dependence) configurations are developed. The application of this method to local thermal equilibrium (LTE) and non-LTE plasma models is discussed. Various opportunities for sacrificing precision for calculation speed are pointed out. As a case study, the effects of radiative transfer in a sulphur lamp are calculated. Since an LTE description of the molecular radiation yields a computed spectrum that differs significantly from a measured one, the possibility of a non-LTE vibrational distribution of the radiating S 2 -B state is investigated. The results indicate that the vibrational populations may be inversed. (author)
Generalized shift-invariant systems and approximately dual frames
DEFF Research Database (Denmark)
Benavente, Ana; Christensen, Ole; Zakowicz, Maria I.
2017-01-01
Dual pairs of frames yield a procedure for obtaining perfect reconstruction of elements in the underlying Hilbert space in terms of superpositions of the frame elements. However, practical constraints often force us to apply sequences that do not exactly form dual frames. In this article, we...... consider the important case of generalized shift-invariant systems and provide various ways of estimating the deviation from perfect reconstruction that occur when the systems do not form dual frames. The deviation from being dual frames will be measured either in terms of a perturbation condition...
On finite capacity queueing systems with a general vacation policy
Directory of Open Access Journals (Sweden)
Jacqueline Loris-Teghem
2000-01-01
Full Text Available We consider a Poisson arrival queueing system with finite capacity and a general vacation policy as described in Loris-Teghem [Queueing Systems 3 (1988, 41-52]. From our previous results regarding the stationary queue length distributions immediately after a departure and at an arbitrary epoch, we derive a relation between both distributions which extends a result given in Frey and Takahashi [Operations Research Letters 21 (1997, 95-100] for the particular case of an exhaustive service multiple vacation policy.
A generalization of Fermat's principle for classical and quantum systems
Elsayed, Tarek A.
2014-09-01
The analogy between dynamics and optics had a great influence on the development of the foundations of classical and quantum mechanics. We take this analogy one step further and investigate the validity of Fermat's principle in many-dimensional spaces describing dynamical systems (i.e., the quantum Hilbert space and the classical phase and configuration space). We propose that if the notion of a metric distance is well defined in that space and the velocity of the representative point of the system is an invariant of motion, then a generalized version of Fermat's principle will hold. We substantiate this conjecture for time-independent quantum systems and for a classical system consisting of coupled harmonic oscillators. An exception to this principle is the configuration space of a charged particle in a constant magnetic field; in this case the principle is valid in a frame rotating by half the Larmor frequency, not the stationary lab frame.
International Nuclear Information System (INIS)
Jog, C.J.; Solomon, P.M.
1984-01-01
We examine the consequences of treating a galactic disk as a two-fluid system for the stability of the entire disk and for the stability and form of the gas in the disk. We find that the existence of even a small fraction of the total disk surface density in a cold fluid (that is, the gas) makes it much harder to stabilize the entire two-fluid disk. (C/sub s/,min)/sub 2-f/, the critical stellar velocity dispersion for a two-fluid disk in an increasing function of μ/sub g//μ/sub s/, the gas fraction, and μ/sub t//kappa, where μ/sub g/, μ/sub s/, and μ/sub t/ are the gaseous, stellar, and total disk surface densities and kappa is the epicyclic frequency. In the Galaxy, we find that (C/sub s/,min)/sub 2-f/ as a function of R peaks when μ/sub t//kappa peaks-at galactocentric radii of Rapprox.5-7 kpc; two-fluid instabilities are most likely to occur in this region. This region is coincident with the peak in the molecular cloud distribution in the Galaxy. At the higher effective gas density resulting from the growth of a two-fluid instability, the gas may become unstble, even when originally the gas by itself is stable. The wavelength of a typical (induced) gas instability in the inner galaxy is approx.400 pc, and it contains approx.10 7 M/sub sun/ of interstellar matter; these instabilities may be identified with clusters of giant molecular clouds. We suggest that many of the spiral features seen in gas-rich spiral galaxies may be material arms or arm segments resulting from sheared two-fluid gravitational instabilities. The analysis presented here is applicable to any general disk galaxy consisting of stars and gas
Analysis and design of generalized BICM-T system
Malik, Muhammad Talha
2014-09-01
The performance of bit-interleaved coded modulation (BICM) using convolutional codes in nonfading channels can be significantly improved if the coded bits are not interleaved at all. This particular BICM system is referred to as BICM trivial (BICM-T). In this paper, we analyze a generalized BICM-T system that uses a nonequally spaced signal constellation in conjunction with a bit-level multiplexer in an additive white Gaussian noise (AWGN) channel. As such, one can exploit the full benefit of BICM-T by jointly optimizing different system modules to further improve its performance. We also investigate the performance of the considered BICM-T system in the Gaussian mixture noise (GMN) channel because of its practical importance. The presented numerical results show that an optimized BICM-T system can offer gains up to 1.5 dB over a non-optimized BICM-T system in the AWGN channel for a target bit error rate of $10^{-6}$. The presented results for the GMN channel interestingly reveal that if the strength of the impulsive noise component, i.e., the noise component due to some ambient phenomenon in the GMN, is below a certain threshold level, then the BICM-T system performs significantly better as compared to traditional BICM system.
A Systems-Theoretical Generalization of Non-Local Correlations
von Stillfried, Nikolaus
Non-local correlations between quantum events are not due to a causal interaction in the sense of one being the cause for the other. In principle, the correlated events can thus occur simultaneously. Generalized Quantum Theory (GQT) formalizes the idea that non-local phenomena are not exclusive to quantum mechanics, e.g. due to some specific properties of (sub)atomic particles, but that they instead arise as a consequence of the way such particles are arranged into systems. Non-local phenomena should hence occur in any system which fulfils the necessary systems-theoretical parameters. The two most important parameters with respect to non-local correlations seem to be a conserved global property of the system as a whole and sufficient degrees of freedom of the corresponding property of its subsystems. Both factors place severe limitations on experimental observability of the phenomena, especially in terms of replicability. It has been suggested that reported phenomena of a so-called synchronistic, parapsychological or paranormal kind could be understood as instances of systems-inherent non-local correlations. From a systems-theoretical perspective, their phenomenology (including the favorable conditions for their occurrence and their lack of replicability) displays substantial similarities to non-local correlations in quantum systems and matches well with systems-theoretical parameters, thus providing circumstantial evidence for this hypothesis.
Optimal design of a general warm standby system
International Nuclear Information System (INIS)
Yun, Won Young; Cha, Ji Hwan
2010-01-01
Redundancy or standby is a technique that has been widely applied to improving system reliability and availability in the stage of system design. In this paper, we consider a standby system with two units in which the first unit (unit 1) starts its operation under active state and the other unit (unit 2) is under cold standby state at the starting point. After a specified time s (switching time), the state of unit 2 is changed to warm standby state and, as soon as the operating unit 1 fails, the state of unit 2 is changed to active state. If unit 1 fails before time s, the system fails. Units can fail at both active and warm standby states. A general method for modeling the standby system is adopted and system performance measures (system reliability and mean life) based on the proposed model are derived. Three models - a perfect switching model and two imperfect switching models - are considered in this paper. Two imperfect switching models include an imperfect switching probability and a preliminary warm-up period which is required for the change from cold standby state to warm standby state. We consider the problem of determining the optimal switching time which maximizes the expected system life and related allocation problem is also discussed. Some numerical examples are studied.
Energy Technology Data Exchange (ETDEWEB)
Moller, Nancy; Weare J. H.
2008-05-29
Successful exploitation of the vast amount of heat stored beneath the earth’s surface in hydrothermal and fluid-limited, low permeability geothermal resources would greatly expand the Nation’s domestic energy inventory and thereby promote a more secure energy supply, a stronger economy and a cleaner environment. However, a major factor limiting the expanded development of current hydrothermal resources as well as the production of enhanced geothermal systems (EGS) is insufficient knowledge about the chemical processes controlling subsurface fluid flow. With funding from past grants from the DOE geothermal program and other agencies, we successfully developed advanced equation of state (EOS) and simulation technologies that accurately describe the chemistry of geothermal reservoirs and energy production processes via their free energies for wide XTP ranges. Using the specific interaction equations of Pitzer, we showed that our TEQUIL chemical models can correctly simulate behavior (e.g., mineral scaling and saturation ratios, gas break out, brine mixing effects, down hole temperatures and fluid chemical composition, spent brine incompatibilities) within the compositional range (Na-K-Ca-Cl-SO4-CO3-H2O-SiO2-CO2(g)) and temperature range (T < 350°C) associated with many current geothermal energy production sites that produce brines with temperatures below the critical point of water. The goal of research carried out under DOE grant DE-FG36-04GO14300 (10/1/2004-12/31/2007) was to expand the compositional range of our Pitzer-based TEQUIL fluid/rock interaction models to include the important aluminum and silica interactions (T < 350°C). Aluminum is the third most abundant element in the earth’s crust; and, as a constituent of aluminosilicate minerals, it is found in two thirds of the minerals in the earth’s crust. The ability to accurately characterize effects of temperature, fluid mixing and interactions between major rock-forming minerals and hydrothermal and
Design and simulation of a new bidirectional actuator for haptic systems featuring MR fluid
Hung, Nguyen Quoc; Tri, Diep Bao; Cuong, Vo Van; Choi, Seung-Bok
2017-04-01
In this research, a new configuration of bidirectional actuator featuring MR fluid (BMRA) is proposed for haptic application. The proposed BMRA consists of a driving disc, a driving housing and a driven disc. The driving disc is placed inside the driving housing and rotates counter to each other by a servo DC motor and a bevel gear system. The driven shaft is also placed inside the housing and next to the driving disc. The gap between the two disc and the gap between the discs and the housing are filled with MR fluid. On the driven disc, two mutual magnetic coils are placed. By applying currents to the two coils mutually, the torque at the output shaft, which is fixed to the driven disc, can be controlled with positive, zero or negative value. This make the actuator be suitable for haptic application. After a review of MR fluid and its application, configuration of the proposed BMRA is presented. The modeling of the actuator is then derived based on Bingham rheological model of MRF and magnetic finite element analysis (FEA). The optimal design of the actuator is then performed to minimize the mass of the BMRA. From the optimal design result, performance characteristics of the actuator is simulated and detailed design of a prototype actuator is conducted.
Experimental evaluation of a non-azeotropic working fluid for geothermal heat pump system
International Nuclear Information System (INIS)
Zhao, L.
2004-01-01
Geothermal energy resources are found in many countries. A reasonable and efficient utilization of these resources has been a worldwide concern. The application of geothermal heat pump systems (GHPS) can help increase the efficiency of using geothermal energy and reduce the thermal pollution to the earth surface. However, this is only possible with a proper working fluid. In this paper, a non-azeotropic working fluid (R290/R600a/R123) is presented for a GHPS where geothermal water at 40-45 deg. C and heating network water at 70-80 deg. C serve as the low and high temperature heat sources. Experimental results show that the coefficient of performance (COP) of a GHPS using the working fluid is above 3.5 with the condensation temperature above 80 deg. C and the condensation pressure below 18 bar, while the temperature of the geothermal water is reduced from 40-46 deg. C to 31-36 deg. C
Resummed memory kernels in generalized system-bath master equations
International Nuclear Information System (INIS)
Mavros, Michael G.; Van Voorhis, Troy
2014-01-01
Generalized master equations provide a concise formalism for studying reduced population dynamics. Usually, these master equations require a perturbative expansion of the memory kernels governing the dynamics; in order to prevent divergences, these expansions must be resummed. Resummation techniques of perturbation series are ubiquitous in physics, but they have not been readily studied for the time-dependent memory kernels used in generalized master equations. In this paper, we present a comparison of different resummation techniques for such memory kernels up to fourth order. We study specifically the spin-boson Hamiltonian as a model system bath Hamiltonian, treating the diabatic coupling between the two states as a perturbation. A novel derivation of the fourth-order memory kernel for the spin-boson problem is presented; then, the second- and fourth-order kernels are evaluated numerically for a variety of spin-boson parameter regimes. We find that resumming the kernels through fourth order using a Padé approximant results in divergent populations in the strong electronic coupling regime due to a singularity introduced by the nature of the resummation, and thus recommend a non-divergent exponential resummation (the “Landau-Zener resummation” of previous work). The inclusion of fourth-order effects in a Landau-Zener-resummed kernel is shown to improve both the dephasing rate and the obedience of detailed balance over simpler prescriptions like the non-interacting blip approximation, showing a relatively quick convergence on the exact answer. The results suggest that including higher-order contributions to the memory kernel of a generalized master equation and performing an appropriate resummation can provide a numerically-exact solution to system-bath dynamics for a general spectral density, opening the way to a new class of methods for treating system-bath dynamics
International Nuclear Information System (INIS)
Harvego, Edwin A.; Schultz, Richard R.; Crane, Ryan L.
2011-01-01
With the resurgence of nuclear power and increased interest in advanced nuclear reactors as an option to supply abundant energy without the associated greenhouse gas emissions of the more conventional fossil fuel energy sources, there is a need to establish internationally recognized standards for the verification and validation (V and V) of software used to calculate the thermal–hydraulic behavior of advanced reactor designs for both normal operation and hypothetical accident conditions. To address this need, ASME (American Society of Mechanical Engineers) Standards and Certification has established the V and V 30 Committee, under the jurisdiction of the V and V Standards Committee, to develop a consensus standard for verification and validation of software used for design and analysis of advanced reactor systems. The initial focus of this committee will be on the V and V of system analysis and computational fluid dynamics (CFD) software for nuclear applications. To limit the scope of the effort, the committee will further limit its focus to software to be used in the licensing of High-Temperature Gas-Cooled Reactors. Although software verification will be an important and necessary part of the standard, much of the initial effort of the committee will be focused on the validation of existing software and new models that could be used in the licensing process. In this framework, the Standard should conform to Nuclear Regulatory Commission (NRC) and other regulatory practices, procedures and methods for licensing of nuclear power plants as embodied in the United States (U.S.) Code of Federal Regulations and other pertinent documents such as Regulatory Guide 1.203, “Transient and Accident Analysis Methods” and NUREG-0800, “NRC Standard Review Plan”. In addition, the Standard should be consistent with applicable sections of ASME NQA-1-2008 “Quality Assurance Requirements for Nuclear Facility Applications (QA)”. This paper describes the general
a New ER Fluid Based Haptic Actuator System for Virtual Reality
Böse, H.; Baumann, M.; Monkman, G. J.; Egersdörfer, S.; Tunayar, A.; Freimuth, H.; Ermert, H.; Khaled, W.
The concept and some steps in the development of a new actuator system which enables the haptic perception of mechanically inhomogeneous virtual objects are introduced. The system consists of a two-dimensional planar array of actuator elements containing an electrorheological (ER) fluid. When a user presses his fingers onto the surface of the actuator array, he perceives locally variable resistance forces generated by vertical pistons which slide in the ER fluid through the gaps between electrode pairs. The voltage in each actuator element can be individually controlled by a novel sophisticated switching technology based on optoelectric gallium arsenide elements. The haptic information which is represented at the actuator array can be transferred from a corresponding sensor system based on ultrasonic elastography. The combined sensor-actuator system may serve as a technology platform for various applications in virtual reality, like telemedicine where the information on the consistency of tissue of a real patient is detected by the sensor part and recorded by the actuator part at a remote location.
Binary blend of carbon dioxide and fluoro ethane as working fluid in transcritical heat pump systems
Directory of Open Access Journals (Sweden)
Zhang Xian-Ping
2015-01-01
Full Text Available As an eco-friendly working fluid, carbon dioxide or R744 is expected to substitute for the existing working fluids used in heat pump systems. It is, however, challenged by the much higher heat rejection pressure in transcritical cycle compared with the traditional subcritical cycle using freons. There exists a worldwide tendency to utilize blend refrigerants as alternatives. Therefore, a new binary blend R744/R161 in this research is proposed in order to decrease the heat rejection pressure. Meanwhile, on mixing R744 with R161, the flammability and explosivity of R161 can be suppressed because of the extinguishing effect of R744. A transcritical thermodynamic model is developed, and then the system performances of heat pump using R744/R161 blend are investigated and compared with those of pure R744 system under the same operation conditions. The variations of heat rejection pressure, heating coefficient of performance, unit volumetric heating capacity, discharge temperature of compressor and the mass fraction of R744/R161 are researched. The results show that R744/R161 mixture can reduce the heat rejection pressure of transcritical heat pump system.
Cooling Systems Design in Hot Stamping Tools by a Thermal-Fluid-Mechanical Coupled Approach
Directory of Open Access Journals (Sweden)
Tao Lin
2014-06-01
Full Text Available Hot stamping tools with cooling systems are the key facilities for hot stamping process of Ultrahigh strength steels (UHSS in automotive industry. Hot stamping tools have significant influence on the final microstructure and properties of the hot stamped parts. In serials production, the tools should be rapidly cooled by cooling water. Hence, design of hot stamping tools with cooling systems is important not only for workpieces of good quality but also for the tools with good cooling performance and long life. In this paper, a new multifield simulation method was proposed for the design of hot stamping tools with cooling system. The deformation of the tools was also analyzed by this method. Based on MpCCI (Mesh-based parallel Code Coupling Interface, thermal-fluid simulation and thermal-fluid-mechanical coupled simulation were performed. Subsequently, the geometrical parameters of the cooling system are investigated for the design. The results show that, both the distance between the ducts and the distance between the ducts and the tools loaded contour have significant influence on the quenching effect. And better quenching effect can be achieved with the shorter distance from the tool surface and with smaller distance between ducts. It is also shown that, thermal expansion is the main reason for deformation of the hot forming tools, which causes the distortion of the cooling ducts, and the stress concentration at corner of the ducts.
Investigation of fluid flow in various geometries related to nuclear reactor using PIV system
International Nuclear Information System (INIS)
Kansal, A.K.; Maheshwari, N.K.; Singh, R.K.; Vijayan, P.K.; Saha, D.; Singh, R.K.; Joshi, V.M.
2011-01-01
Particle Image Velocimetry (PIV) is a non-intrusive technique for simultaneously measuring the velocities at many points in a fluid flow. The PIV system used is comprised of Nd:YAG laser source, CCD (Charged Coupled Device) camera, timing controller (to control the laser and camera) and software used for analyzing the flow velocities. Several case studies related to nuclear reactor were performed with the PIV system. Some of the cases like flow in circular tube, submerged jet, natural convection in a water pool, flow field of moderator inlet diffuser of 500 MWe Pressurised Heavy Water Reactor (PHWR) and fluidic flow control device (FFCD) used in advanced accumulator of Emergency Core Cooling System (ECCS) have been studied using PIV system. Theoretical studies have been performed and comparisons with PIV results are also given in the present studies. (author)
Solar System constraints to general f(R) gravity
International Nuclear Information System (INIS)
Chiba, Takeshi; Smith, Tristan L.; Erickcek, Adrienne L.
2007-01-01
It has been proposed that cosmic acceleration or inflation can be driven by replacing the Einstein-Hilbert action of general relativity with a function f(R) of the Ricci scalar R. Such f(R) gravity theories have been shown to be equivalent to scalar-tensor theories of gravity that are incompatible with Solar System tests of general relativity, as long as the scalar field propagates over Solar System scales. Specifically, the parameterized post-Newtonian (PPN) parameter in the equivalent scalar-tensor theory is γ=1/2, which is far outside the range allowed by observations. In response to a flurry of papers that questioned the equivalence of f(R) theory to scalar-tensor theories, it was recently shown explicitly, without resorting to the scalar-tensor equivalence, that the vacuum field equations for 1/R gravity around a spherically symmetric mass also yield γ=1/2. Here we generalize this analysis to f(R) gravity and enumerate the conditions that, when satisfied by the function f(R), lead to the prediction that γ=1/2
Solution of generalized shifted linear systems with complex symmetric matrices
International Nuclear Information System (INIS)
Sogabe, Tomohiro; Hoshi, Takeo; Zhang, Shao-Liang; Fujiwara, Takeo
2012-01-01
We develop the shifted COCG method [R. Takayama, T. Hoshi, T. Sogabe, S.-L. Zhang, T. Fujiwara, Linear algebraic calculation of Green’s function for large-scale electronic structure theory, Phys. Rev. B 73 (165108) (2006) 1–9] and the shifted WQMR method [T. Sogabe, T. Hoshi, S.-L. Zhang, T. Fujiwara, On a weighted quasi-residual minimization strategy of the QMR method for solving complex symmetric shifted linear systems, Electron. Trans. Numer. Anal. 31 (2008) 126–140] for solving generalized shifted linear systems with complex symmetric matrices that arise from the electronic structure theory. The complex symmetric Lanczos process with a suitable bilinear form plays an important role in the development of the methods. The numerical examples indicate that the methods are highly attractive when the inner linear systems can efficiently be solved.
Directory of Open Access Journals (Sweden)
Susan Ebrahimi
2017-11-01
Full Text Available Introduction The Masjed- Daghi gold deposit lies in an area of widespread Cenozoic volcanic and plutonic rocks at the intersection of the Alborz- Azarbaijan and Urumieh- Dokhtar belts. The area was covered by a detailed exploration program, including geological maps at 1:1,000 scales (~8 km², several hundred meters of trenches and systematic sampling for Au, Ag, Pb, Zn, Cu, As, Hg analysis, and 16 diamond drill holes at a total of 1200 meters (Mohammadi et al, 2005. The vein type gold deposit in Masjed- Daghi is closely associated with a porphyry type Cu-Au deposit. Our study focuses on the gold bearing veins system in an attempt to understand the characteristics of ore fluids and mechanisms of ore formation, and to develop exploration criteria for Masjed Daghi and similar occurrences in Alborz and other Cenozoic magmatic assemblages in Iran. Materials and methods Various rock types, alteration assemblages and mineral parageneses were characterized by transmitting and reflected light microscopy, X-ray diffraction (XRD and electron microprobe analysis. Microprobe analyses were performed using a JEOL 8600 Superprobe electron microprobe at Saskatchewan University. Operating conditions were an accelerating voltage of 15 kV and a beam current of 50 nA. Representative samples from drill holes were selected for fluid inclusion studies. Fluid inclusion data were obtained using a fluid Inc. adapted USGS gas flow heating and freezing system at the Department of Geological Science at the University of Saskatchewan, Canada. To investigate the source of ore fluids, representative sulfidic samples from drill holes were selected for sulfur isotope studies. Isotopic analyses were performed using a Thermo Finnigan DeltaPlus at the G.G. Hatch Stable Isotope Laboratories, University of Ottawa. The standard error of analyses is less than ±0.1 per mil. Results Auriferous quartz veins in Masjed- Daghi are associated with porphyry style mineralization. Various
Directory of Open Access Journals (Sweden)
Kai Yang
2014-08-01
Full Text Available One way to increase the thermal efficiency of vehicle diesel engines is to recover waste heat by using an organic Rankine cycle (ORC system. Tests were conducted to study the running performances of diesel engines in the whole operating range. The law of variation of the exhaust energy rate under various engine operating conditions was also analyzed. A diesel engine-ORC combined system was designed, and relevant evaluation indexes proposed. The variation of the running performances of the combined system under various engine operating conditions was investigated. R245fa and R152a were selected as the components of the mixed working fluid. Thereafter, six kinds of mixed working fluids with different compositions were presented. The effects of mixed working fluids with different compositions on the running performances of the combined system were revealed. Results show that the running performances of the combined system can be improved effectively when mass fraction R152a in the mixed working fluid is high and the engine operates with high power. For the mixed working fluid M1 (R245fa/R152a, 0.1/0.9, by mass fraction, the net power output of the combined system reaches the maximum of 34.61 kW. Output energy density of working fluid (OEDWF, waste heat recovery efficiency (WHRE, and engine thermal efficiency increasing ratio (ETEIR all reach their maximum values at 42.7 kJ/kg, 10.90%, and 11.29%, respectively.
Davis, Mary Kathleen
Understanding fluid chemistry in the subduction zone environment is key to unraveling the details of element transport from the slab to the surface. Solubilities of cations, such as silicon, in water strongly affect both the physical and chemical properties of supercritical metamorphic fluids. Modeling the thermodynamics of fluid-rock interactions requires therefore a profound understanding of cation dissolution and aqueous speciation. In situ Raman experiments of the silica-water, alumina-water, and alumina water systems were performed in an externally heated Bassett-type diamond-anvil cell at the Department of Geological Sciences, University of Michigan. Natural quartz samples and synthetic ruby samples were used in the experiments. Samples were loaded in the sample chamber with a water pressure medium. All experiments used rhenium gaskets of uniform thickness with a 500 mum drill hole for the sample chamber. Temperature was measured using K-type thermocouples encompassing both the upper and lower diamond anvils. Pressures are obtained on the basis of the Raman shift of the 464 cm-1 quartz mode where possible or the Raman shift of the tips of the diamond anvils according to a method developed in this work. This work characterizes the state of stress in the diamond anvil cell, which is used as the basis for the pressure calibration using only the diamond anvils. Raman measurements of silicate fluid confirm the presence of H4 SiO4 and H6Si2O7 in solution and expand the pressure range for in-situ structural observations in the silica-water system. Additionally, we identify the presence of another silica species present at mantle conditions, which occurs at long time scales in the diamond cell. This study provides the first in situ data in the alumina-water and alumina-silica-water systems at pressures and temperatures relevant to the slab environment. Al(OH) 3 appears to be the dominant form of alumina present under these conditions and in the alumina
DEFF Research Database (Denmark)
Ostergaard, Christian; Benfield, Thomas
2009-01-01
ABSTRACT: INTRODUCTION: Macrophage Migration Inhibitory Factor (MIF) plays an essential pathophysiological role in septic shock; however, its role in central nervous system infection (CNS) remains to be defined. METHODS: The aim of the present study was to investigate cerebrospinal fluid (CSF......-22725) vs. 3240ng/L (1563-9302), respectively, P=0.003), and in patients with impaired consciousness (8614 ng/L (3344-20935) vs. 2625 ng/L (1561-7530), respectively, P=0.02). CSF MIF levels correlated significantly to the meningeal inflammation (Psystemic inflammatory response (P>0...
International Nuclear Information System (INIS)
Combescure, A.
1983-05-01
The buckling of shells subjected to seismic type of loads is not very well known. To study this type of phenomenon, theoretical and experimental investigations on structures consisting of two shells separed by a thin fluid layer , and submitted to a seismic type of load have been performed. The objectives of these investigations are the following: study coupling between buckling modes vibrations modes and buckling, and the effects of this coupling on the level of pressure; study of the appearance on such structures of dynamic instabilities processes; qualification of computer codes of the CEASEMT system; and, qualification or criticism of the methodology used in the design based on a ''static equivalent'' idea
Reliability Based Design of Fluid Power Pitch Systems for Wind Turbines
DEFF Research Database (Denmark)
Liniger, Jesper; N. Soltani, Mohsen; Pedersen, Henrik Clemmensen
2017-01-01
Priority Number. The Failure Mode and Effect Criticality Analysis is based on past research concerning failure analysis of wind turbine drive trains. Guidelines are given to select the severity, occurrence and detection score that make up the risk priority number. The usability of the method is shown...... in a case study of a fluid power pitch system applied to wind turbines. The results show a good agreement to recent field failure data for offshore turbines where the dominating failure modes are related to valves, accumulators and leakage. The results are further used for making design improvements...
International Nuclear Information System (INIS)
Wei, Guang-Mei
2006-01-01
Generalized two-dimensional variable-coefficient Burgers model is of current value in fluid mechanics, acoustics and cosmic-ray astrophysics. In this paper, Painleve analysis leads to the constraints on the variable coefficients for such a model to pass the Painleve test and to an auto-Baecklund transformation. Moreover, four transformations from this model are constructed, to the standard two-dimensional and one-dimensional Burgers models with the relevant constraints on the variable coefficients via symbolic computation. By virtue of the given transformations the properties and solutions of this model can be obtained from those of the standard two-dimensional and one-dimensional ones
Generalized reconfigurable memristive dynamical system (MDS) for neuromorphic applications.
Bavandpour, Mohammad; Soleimani, Hamid; Linares-Barranco, Bernabé; Abbott, Derek; Chua, Leon O
2015-01-01
This study firstly presents (i) a novel general cellular mapping scheme for two dimensional neuromorphic dynamical systems such as bio-inspired neuron models, and (ii) an efficient mixed analog-digital circuit, which can be conveniently implemented on a hybrid memristor-crossbar/CMOS platform, for hardware implementation of the scheme. This approach employs 4n memristors and no switch for implementing an n-cell system in comparison with 2n (2) memristors and 2n switches of a Cellular Memristive Dynamical System (CMDS). Moreover, this approach allows for dynamical variables with both analog and one-hot digital values opening a wide range of choices for interconnections and networking schemes. Dynamical response analyses show that this circuit exhibits various responses based on the underlying bifurcation scenarios which determine the main characteristics of the neuromorphic dynamical systems. Due to high programmability of the circuit, it can be applied to a variety of learning systems, real-time applications, and analytically indescribable dynamical systems. We simulate the FitzHugh-Nagumo (FHN), Adaptive Exponential (AdEx) integrate and fire, and Izhikevich neuron models on our platform, and investigate the dynamical behaviors of these circuits as case studies. Moreover, error analysis shows that our approach is suitably accurate. We also develop a simple hardware prototype for experimental demonstration of our approach.