WorldWideScience

Sample records for two-phase ternary liquid

  1. Coal-Face Fracture With A Two-Phase Liquid

    Science.gov (United States)

    Collins, E. R., Jr.

    1985-01-01

    In new method for mining coal without explosive, two-phase liquid such as CO2 and water, injected at high pressure into deeper ends of holes drilled in coal face. Liquid permeates coal seam through existing microfractures; as liquid seeps back toward face, pressure eventually drops below critical value at which dissolved gas flashvaporizes, breaking up coal.

  2. Shock wave of vapor-liquid two-phase flow

    Institute of Scientific and Technical Information of China (English)

    Liangju ZHAO; Fei WANG; Hong GAO; Jingwen TANG; Yuexiang YUAN

    2008-01-01

    The shock wave of vapor-liquid two-phase flow in a pressure-gain steam injector is studied by build-ing a mathematic model and making calculations. The results show that after the shock, the vapor is nearly com-pletely condensed. The upstream Mach number and the volume ratio of vapor have a great effect on the shock. The pressure and Mach number of two-phase shock con-form to the shock of ideal gas. The analysis of available energy shows that the shock is an irreversible process with entropy increase.

  3. Experimental Two-Phase Liquid-Metal Magnetohydrodynamic Generator Program

    Science.gov (United States)

    1979-04-01

    efficiencies in excess of 0.8 are attainable. Initial measurements of local flow parameters in a NaK -nitrogen two-phase liquid - metal MHD generator...hot liquid metals . Thus, the concept of using surface-active aaents in MHD generators can be evaluated more rapidly and inexpensively with NaK , the...describe this aggregation of bchbles as a foam. When the Ba- NaK solution was transferred, helium was blown under the surface of the liquid metal with the

  4. Liquid-liquid equilibria for ternary polymer mixtures

    Science.gov (United States)

    Oh, Suk Yung; Bae, Young Chan

    2011-01-01

    A molecular thermodynamic model for multicomponent systems based on a closed-packed lattice model is presented based on two contributions; entropy and energy contribution. The calculated liquid-liquid equilibria of ternary chainlike mixtures agreed with Monte Carlo simulation results. The proposed model can satisfactorily predict Types 0, 1, 2 and 3 phase separations of the Treybal classification. The model parameters obtained from the binary systems were used to directly predict real ternary systems and the calculated results correlated well with experimental data using few adjustable parameters. Specific interactions in associated binary systems were considered using a secondary lattice.

  5. Liquid-liquid equilibria for ternary polymer mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Suk Yung [Division of Chemical Engineering and Molecular Thermodynamics Laboratory, Hanyang University, Seoul 133-791 (Korea, Republic of); Bae, Young Chan, E-mail: ycbae@hanyang.ac.kr [Division of Chemical Engineering and Molecular Thermodynamics Laboratory, Hanyang University, Seoul 133-791 (Korea, Republic of)

    2011-01-24

    Graphical abstract: We developed a molecular thermodynamic model for multicomponent systems and discribed the phase equilibrium for ternary polymer mixtures by using the model parameters obtained from the binary systems. Research highlights: {yields} Model parameters were obtained from the binary systems. {yields} The obtained parameters were directly used to predict the ternary data. {yields} The undetermined parameters were used to correlate the ternary data. {yields} The proposed model agreed well with the experimental data. - Abstract: A molecular thermodynamic model for multicomponent systems based on a closed-packed lattice model is presented based on two contributions; entropy and energy contribution. The calculated liquid-liquid equilibria of ternary chainlike mixtures agreed with Monte Carlo simulation results. The proposed model can satisfactorily predict Types 0, 1, 2 and 3 phase separations of the Treybal classification. The model parameters obtained from the binary systems were used to directly predict real ternary systems and the calculated results correlated well with experimental data using few adjustable parameters. Specific interactions in associated binary systems were considered using a secondary lattice.

  6. NUMERICAL SIMULATION OF CHARGED GAS-LIQUID TWO PHASE JET FLOW IN ELECTROSTATIC SPRAYING

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Multi-fluid k-ε-kp two phase turbulence model is used to simulate charged gas-liquid two phase coaxial jet, which is the transorting flow field in electrostatic spraying. Compared with the results of experiment, charged gas-liquid twophase turbulence can be well predicted by this model.

  7. Analysis of Developing Gas/liquid Two-Phase Flows

    Energy Technology Data Exchange (ETDEWEB)

    Elena A. Tselishcheva; Michael Z. Podowski; Steven P. Antal; Donna Post Guillen; Matthias Beyer; Dirk Lucas

    2010-06-01

    The goal of this work is to develop a mechanistically based CFD model that can be used to simulate process equipment operating in the churn-turbulent regime. The simulations were performed using a state-of-the-art computational multiphase fluid dynamics code, NPHASE–CMFD [Antal et al,2000]. A complete four-field model, including the continuous liquid field and three dispersed gas fields representing bubbles of different sizes, was first carefully tested for numerical convergence and accuracy, and then used to reproduce the experimental results from the TOPFLOW test facility at Forschungszentrum Dresden-Rossendorf e.V. Institute of Safety Research [Prasser et al,2007]. Good progress has been made in simulating the churn-turbulent flows and comparison the NPHASE-CMFD simulations with TOPFLOW experimental data. The main objective of the paper is to demonstrate capability to predict the evolution of adiabatic churn-turbulent gas/liquid flows. The proposed modelling concept uses transport equations for the continuous liquid field and for dispersed bubble fields [Tselishcheva et al, 2009]. Along with closure laws based on interaction between bubbles and continuous liquid, the effect of height on air density has been included in the model. The figure below presents the developing flow results of the study, namely total void fraction at different axial locations along the TOPFLOW facility test section. The complete model description, as well as results of simulations and validation will be presented in the full paper.

  8. Calculation of liquid-liquid equilibrium of aqueous two-phase systems using a chemical-theory-based excess Gibbs energy model

    Directory of Open Access Journals (Sweden)

    Pessôa Filho P. A.

    2004-01-01

    Full Text Available Mixtures containing compounds that undergo hydrogen bonding show large deviations from ideal behavior. These deviations can be accounted for through chemical theory, according to which the formation of a hydrogen bond can be treated as a chemical reaction. This chemical equilibrium needs to be taken into account when applying stability criteria and carrying out phase equilibrium calculations. In this work, we illustrate the application of the stability criteria to establish the conditions under which a liquid-phase split may occur and the subsequent calculation of liquid-liquid equilibrium using a chemical-theory-modified Flory-Huggins equation to describe the non ideality of aqueous two-phase systems composed of poly(ethylene glycol and dextran. The model was found to be able to correlate ternary liquid-liquid diagrams reasonably well by simple adjustment of the polymer-polymer binary interaction parameter.

  9. Characterization of annular two-phase gas-liquid flows in microgravity

    Science.gov (United States)

    Bousman, W. Scott; Mcquillen, John B.

    1994-01-01

    A series of two-phase gas-liquid flow experiments were developed to study annular flows in microgravity using the NASA Lewis Learjet. A test section was built to measure the liquid film thickness around the perimeter of the tube permitting the three dimensional nature of the gas-liquid interface to be observed. A second test section was used to measure the film thickness, pressure drop and wall shear stress in annular microgravity two-phase flows. Three liquids were studied to determine the effects of liquid viscosity and surface tension. The result of this study provide insight into the wave characteristics, pressure drop and droplet entrainment in microgravity annular flows.

  10. Traveling waves, two-phase fingers, and eutectic colonies in thin-sample directional solidification of a ternary eutectic alloy

    Science.gov (United States)

    Akamatsu; Faivre

    2000-04-01

    We present an experimental investigation of the morphological transition of lamellar eutectic growth fronts called "formation of eutectic colonies" by the method of thin-sample directional solidification of a transparent model alloy, CBr4-C2Cl6. This morphological transition is due to the presence in the melt of traces of chemical components other than those of the base binary alloy (impurities). In this study, we use naphthalene as an impurity. The formation of eutectic colonies has generally been viewed as an impurity-driven Mullins-Sekerka instability of the envelope of the lamellar front. This traditional view neglects the strong interaction existing between the Mullins-Sekerka process and the dynamics of the lamellar pattern. This investigation brings to light several original features of the formation of eutectic colonies, in particular, the emission of long-wavelength traveling waves, and the appearance of dendritelike structures called two-phase fingers, which are connected with this interaction. We study the part played by these phenomena in the transition to eutectic colonies as a function of the impurity concentration. Recent theoretical results on the linear stability of ternary lamellar eutectic fronts [Plapp and Karma, Phys. Rev. E 60, 6865 (1999)] shed light on some aspects of the observed phenomena.

  11. Research of Characteristics of Gas-liquid Two-phase Pressure Drop in Microreactor

    Directory of Open Access Journals (Sweden)

    Li Dan

    2015-01-01

    Full Text Available With the research system of nitrogen and deionized water, this paper researches the pressure drop of gas-liquid two-phase flow in the circular microchannel with an inner diameter which is respectively 0.9mm and 0.5mm, analyzes the effect of microchannel diameter on gas-liquid two-phase frictional pressure drop in the microchannel reactor, and compares with the result of frictional pressure drop and the predicting result of divided-phase flow pattern. The result shows that, the gas-liquid two-phase frictional pressure drop in the microchannel significantly increases with the decreasing microchannel diameter; Lockhart-Martinelli relationship in divided-phase flow pattern can preferably predict the gas-liquid two-phase frictional pressure drop in the microchannel, but the Tabular constant needs to be corrected.

  12. Scaling analysis of gas-liquid two-phase flow pattern in microgravity

    Science.gov (United States)

    Lee, Jinho

    1993-01-01

    A scaling analysis of gas-liquid two-phase flow pattern in microgravity, based on the dominant physical mechanism, was carried out with the goal of predicting the gas-liquid two-phase flow regime in a pipe under conditions of microgravity. The results demonstrated the effect of inlet geometry on the flow regime transition. A comparison of the predictions with existing experimental data showed good agreement.

  13. Extraction of proteins with ionic liquid aqueous two-phase system based on guanidine ionic liquid.

    Science.gov (United States)

    Zeng, Qun; Wang, Yuzhi; Li, Na; Huang, Xiu; Ding, Xueqin; Lin, Xiao; Huang, Songyun; Liu, Xiaojie

    2013-11-15

    Eight kinds of green ionic liquids were synthesized, and an ionic liquid aqueous two-phase system (ILATPS) based on 1,1,3,3-tetramethylguandine acrylate (TMGA) guanidine ionic liquid was first time studied for the extraction of proteins. Single factor experiments proved that the extraction efficiency of bovine serum albumin (BSA) was influenced by the mass of IL, K2HPO4 and BSA, also related to the separation time and temperature. The optimum conditions were determined through orthogonal experiment by the five factors described above. The results showed that under the optimum conditions, the extraction efficiency could reach up to 99.6243%. The relative standard deviations (RSD) of extraction efficiencies in precision experiment, repeatability experiment and stability experiment were 0.8156% (n=5), 1.6173% (n=5) and 1.6292% (n=5), respectively. UV-vis and FT-IR spectra confirmed that there were no chemical interactions between BSA and ionic liquid in the extraction process, and the conformation of the protein was not changed after extraction. The conductivity, DLS and TEM were combined to investigate the microstructure of the top phase and the possible mechanism for the extraction. The results showed that hydrophobic interaction, hydrogen bonding interaction and the salt out effect played important roles in the transferring process, and the aggregation and embrace phenomenon was the main driving force for the separation. All these results proved that guanidine ionic liquid-based ATPSs have the potential to offer new possibility in the extraction of proteins.

  14. Research of Characteristics of Gas-liquid Two-phase Pressure Drop in Microreactor

    OpenAIRE

    Li Dan

    2015-01-01

    With the research system of nitrogen and deionized water, this paper researches the pressure drop of gas-liquid two-phase flow in the circular microchannel with an inner diameter which is respectively 0.9mm and 0.5mm, analyzes the effect of microchannel diameter on gas-liquid two-phase frictional pressure drop in the microchannel reactor, and compares with the result of frictional pressure drop and the predicting result of divided-phase flow pattern. The result shows that, the gas-liquid two-...

  15. Analysis of transient gas-liquid two-phase natural circulation

    Energy Technology Data Exchange (ETDEWEB)

    Kataoka, Isao; Matsumoto, Tadayoshi; Morita, Yu; Kawashima, Atsushi [Department of Mechanophysics Engineering, Osaka University, Suita, Osaka (Japan); Nakayama, Akio

    1999-07-01

    Analyses were made on the transient behavior of two-phase natural circulation in annular passage. Drift flux model was used in the analyses and several correlations of drift velocity were used and compared. Transient variation of void fraction, inlet liquid flux and length of two-phase region were predicted based on simplified model. It was revealed that in transient two-phase natural circulation, the condition for pressure difference between inlet and outlet is quite important and difficult to be specified. A simplified model for inlet pressure condition was assumed and transient two-phase natural circulation was reasonably predicted. The correlation of drift velocity was shown to have important effect on the flow behavior particularly for the transient variation of two-phase length. (author)

  16. Mixed Model for Silt-Laden Solid-Liquid Two-Phase Flows

    Institute of Scientific and Technical Information of China (English)

    唐学林; 徐宇; 吴玉林

    2003-01-01

    The kinetic theory of molecular gases was used to derive the governing equations for dense solid-liquid two-phase flows from a microscopic flow characteristics viewpoint by multiplying the Boltzmann equation for each phase by property parameters and integrating over the velocity space. The particle collision term was derived from microscopic terms by comparison with dilute two-phase flow but with consideration of the collisions between particles for dense two-phase flow conditions and by assuming that the particle-phase velocity distribution obeys the Maxwell equations. Appropriate terms from the dilute two-phase governing equations were combined with the dense particle collision term to develop the governing equations for dense solid-liquid turbulent flows. The SIMPLEC algorithm and a staggered grid system were used to solve the discretized two-phase governing equations with a Reynolds averaged turbulence model. Dense solid-liquid turbulent two-phase flows were simulated for flow in a duct. The simulation results agree well with experimental data.

  17. Numerical Study of Void Fraction Distribution Propagation in Gas-Liquid Two-Phase Flow

    Institute of Scientific and Technical Information of China (English)

    YANG Jianhui; LI Qing; LU Wenqiang

    2005-01-01

    A dynamic propagation model was developed for waves in two-phase flows by assuming that continuity waves and dynamic waves interact nonlinearly for certain flow conditions. The drift-flux model is solved with the one-dimensional continuity equation for gas-liquid two-phase flows as an initial-boundary value problem solved using the characteristic-curve method. The numerical results give the void fraction distribution propagation in a gas-liquid two-phase flow which shows how the flow pattern transition occurs. The numerical simulations of different flow patterns show that the void fraction distribution propagation is determined by the characteristics of the drift-flux between the liquid and gas flows and the void fraction range. Flow pattern transitions begin around a void fraction of 0.27 and end around 0.58. Flow pattern transitions do not occur for very high void concentrations.

  18. Numerical Simulation of Erosion-Corrosion in the Liquid Solid Two-Phase Flow

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Erosion-corrosion of liquid-solid two-phase flow occurring in a pipe with sudden expansion in cross section is numerically simulated in this paper. The global model for erosion-corrosion process includes three main components: the liquid-solid two-phase flow model, erosion model and corrosion model. The Euierian-Lagranglan approach is used to simulate liquid-solid two-phase flow, while the stochastic trajectory model was adopted to obtain properties of particle phase. Two-way coupling effect between the fluid and the particle phase is considered in the model. The accuracy of the models is tested by the data in the reference. The comparison shows that the model is basically correct and feasible.

  19. Experimental analysis on adjusting performance of vapor-liquid two-phase flow controller

    Institute of Scientific and Technical Information of China (English)

    LI Hui-jun; TU Shan

    2006-01-01

    The vapor-liquid self-adjusting controller is an innovative automatic regulating valve. In order to ensure adjusted objects run safely and economically, the controller automatically adjusts the liquid flux to keep liquid level at a required level according to physical properties of vapor-liquid two-phase fluid. The adjusting mechanics, the controller' s performance and influencing factors of its stability have been analyzed in this paper. The theoretical analysis and successful applications have demonstrated this controller can keep the liquid level steady with good performance. The actual application in industry has shown that the controller can satisfactorily meet the requirement of industrial production and has wide application areas.

  20. DYNAMIC MODELING STRATEGY FOR FLOW REGIME TRANSITION IN GAS-LIQUID TWO-PHASE FLOWS

    Energy Technology Data Exchange (ETDEWEB)

    X. Wang; X. Sun; H. Zhao

    2011-09-01

    In modeling gas-liquid two-phase flows, the concept of flow regime has been used to characterize the global interfacial structure of the flows. Nearly all constitutive relations that provide closures to the interfacial transfers in two-phase flow models, such as the two-fluid model, are often flow regime dependent. Currently, the determination of the flow regimes is primarily based on flow regime maps or transition criteria, which are developed for steady-state, fully-developed flows and widely applied in nuclear reactor system safety analysis codes, such as RELAP5. As two-phase flows are observed to be dynamic in nature (fully-developed two-phase flows generally do not exist in real applications), it is of importance to model the flow regime transition dynamically for more accurate predictions of two-phase flows. The present work aims to develop a dynamic modeling strategy for determining flow regimes in gas-liquid two-phase flows through the introduction of interfacial area transport equations (IATEs) within the framework of a two-fluid model. The IATE is a transport equation that models the interfacial area concentration by considering the creation and destruction of the interfacial area, such as the fluid particle (bubble or liquid droplet) disintegration, boiling and evaporation; and fluid particle coalescence and condensation, respectively. For the flow regimes beyond bubbly flows, a two-group IATE has been proposed, in which bubbles are divided into two groups based on their size and shape (which are correlated), namely small bubbles and large bubbles. A preliminary approach to dynamically identifying the flow regimes is provided, in which discriminators are based on the predicted information, such as the void fraction and interfacial area concentration of small bubble and large bubble groups. This method is expected to be applied to computer codes to improve their predictive capabilities of gas-liquid two-phase flows, in particular for the applications in

  1. Visualization and research of gas-liquid two phase flow structures in cylindrical channel

    Directory of Open Access Journals (Sweden)

    Stefański Sebastian

    2017-01-01

    Full Text Available Two-phase flows are commonly found in many industries, especially in systems, where efficient and correct functioning depend on specific values of flow parameters. In thermal engineering and chemical technology the most popular types of two-phase mixture are gas-liquid or liquid-vapour mixtures. Bubbles can create in flow different structures and determine diverse properties of flow (velocity of phase, void fraction, fluctuations of pressure, pipe vibrations, etc.. That type of flow is difficult to observe, especially in liquid-vapour mixture, where vapour is being made by heating the medium. Production of vapour and nucleation process are very complicated issues, which are important part of two-phase flow phenomenon. Gas-liquid flow structures were observed and described with figures, but type of structure depends on many parameters. Authors of this paper made an attempt to simulate gas-liquid flow with air and water. In the paper there was presented specific test stand built to observe two-phase flow structures, methodology of experiment and conditions which were maintained during observation. The paper presents also the structures which were observed and the analysis of results with reference to theoretical models and diagrams available in literature.

  2. Dynamic behavior of pipes conveying gas–liquid two-phase flow

    Energy Technology Data Exchange (ETDEWEB)

    An, Chen, E-mail: anchen@cup.edu.cn [Offshore Oil/Gas Research Center, China University of Petroleum-Beijing, Beijing 102249 (China); Su, Jian, E-mail: sujian@lasme.coppe.ufrj.br [Nuclear Engineering Program, COPPE, Universidade Federal do Rio de Janeiro, CP 68509, Rio de Janeiro 21941-972 (Brazil)

    2015-10-15

    Highlights: • Dynamic behavior of pipes conveying gas–liquid two-phase flow was analyzed. • The generalized integral transform technique (GITT) was applied. • Excellent convergence behavior and long-time stability were shown. • Effects of volumetric quality and volumetric flow rate on dynamic behavior were studied. • Normalized volumetric-flow-rate stability envelope of dynamic system was determined. - Abstract: In this paper, the dynamic behavior of pipes conveying gas–liquid two-phase flow was analytically and numerically investigated on the basis of the generalized integral transform technique (GITT). The use of the GITT approach in the analysis of the transverse vibration equation lead to a coupled system of second order differential equations in the dimensionless temporal variable. The Mathematica's built-in function, NDSolve, was employed to numerically solve the resulting transformed ODE system. The characteristics of gas–liquid two-phase flow were represented by a slip-ratio factor model that was devised and used for similar problems. Good convergence behavior of the proposed eigenfunction expansions is demonstrated for calculating the transverse displacement at various points of pipes conveying air–water two-phase flow. Parametric studies were performed to analyze the effects of the volumetric gas fraction and the volumetric flow rate on the dynamic behavior of pipes conveying air–water two-phase flow. Besides, the normalized volumetric-flow-rate stability envelope for the dynamic system was obtained.

  3. Ternary cluster decay within the liquid drop model

    CERN Document Server

    Royer, G; Dubillot, M; Leonard, E

    2008-01-01

    Longitudinal ternary and binary fission barriers of $^{36}$Ar, $^{56}$Ni and $^{252}$Cf nuclei have been determined within a rotational liquid drop model taking into account the nuclear proximity energy. For the light nuclei the heights of the ternary fission barriers become competitive with the binary ones at high angular momenta since the maximum lies at an outer position and has a much higher moment of inertia.

  4. Ternary cluster decay within the liquid drop model

    Science.gov (United States)

    Royer, G.; Degiorgio, K.; Dubillot, M.; Leonard, E.

    2008-05-01

    Longitudinal ternary and binary fission barriers of 36Ar, 56Ni and 252Cf nuclei have been determined within a rotational liquid drop model taking into account the nuclear proximity energy. For the light nuclei the heights of the ternary fission barriers become competitive with the binary ones at high angular momenta since the maximum lies at an outer position and has a much higher moment of inertia.

  5. Multi-scale symbolic time reverse analysis of gas-liquid two-phase flow structures

    Science.gov (United States)

    Wang, Hongmei; Zhai, Lusheng; Jin, Ningde; Wang, Youchen

    Gas-liquid two-phase flows are widely encountered in production processes of petroleum and chemical industry. Understanding the dynamic characteristics of multi-scale gas-liquid two-phase flow structures is of great significance for the optimization of production process and the measurement of flow parameters. In this paper, we propose a method of multi-scale symbolic time reverse (MSTR) analysis for gas-liquid two-phase flows. First, through extracting four time reverse asymmetry measures (TRAMs), i.e. Euclidean distance, difference entropy, percentage of constant words and percentage of reversible words, the time reverse asymmetry (TRA) behaviors of typical nonlinear systems are investigated from the perspective of multi-scale analysis, and the results show that the TRAMs are sensitive to the changing of dynamic characteristics underlying the complex nonlinear systems. Then, the MSTR analysis is used to study the conductance signals from gas-liquid two-phase flows. It is found that the multi-scale TRA analysis can effectively reveal the multi-scale structure characteristics and nonlinear evolution properties of the flow structures.

  6. Ionic liquids for two-phase systems and their application for purification, extraction and biocatalysis.

    Science.gov (United States)

    Oppermann, Sebastian; Stein, Florian; Kragl, Udo

    2011-02-01

    The development of biotechnological processes using novel two-phase systems based on molten salts known as ionic liquids (ILs) got into the focus of interest. Many new approaches for the beneficial application of the interesting solvent have been published over the last years. ILs bring beneficial properties compared to organic solvents like nonflammability and nonvolatility. There are two possible ways to use the ILs: first, the hydrophobic ones as a substitute for organic solvents in pure two-phase systems with water and second, the hydrophilic ones in aqueous two-phase systems (ATPS). To effectively utilise IL-based two-phase systems or IL-based ATPS in biotechnology, extensive experimental work is required to gain the optimal system parameters to ensure selective extraction of the product of interest. This review will focus on the most actual findings dealing with the basic driving forces for the target extraction in IL-based ATPS as well as presenting some selected examples for the beneficial application of ILs as a substitute for organic solvents. Besides the research focusing on IL-based two-phase systems, the "green aspect" of ILs, due to their negligible vapour pressure, is widely discussed. We will present the newest results concerning ecotoxicity of ILs to get an overview of the state of the art concerning ILs and their utilisation in novel two-phase systems in biotechnology.

  7. IMPROVED SUBGRID SCALE MODEL FOR DENSE TURBULENT SOLID-LIQUID TWO-PHASE FLOWS

    Institute of Scientific and Technical Information of China (English)

    TANG Xuelin; QIAN Zhongdong; WU Yulin

    2004-01-01

    The dense solid-phase governing equations for two-phase flows are obtained by using the kinetic theory of gas molecules. Assuming that the solid-phase velocity distributions obey the Maxwell equations, the collision term for particles under dense two-phase flow conditions is also derived.In comparison with the governing equations of a dilute two-phase flow, the solid-particle's governing equations are developed for a dense turbulent solid-liquid flow by adopting some relevant terms from the dilute two-phase governing equations. Based on Cauchy-Helmholtz theorem and Smagorinsky model,a second-order dynamic sub-grid-scale (SGS) model, in which the sub-grid-scale stress is a function of both the strain-rate tensor and the rotation-rate tensor, is proposed to model the two-phase governing equations by applying dimension analyses. Applying the SIMPLEC algorithm and staggering grid system to the two-phase discretized governing equations and employing the slip boundary conditions on the walls, the velocity and pressure fields, and the volumetric concentration are calculated. The simulation results are in a fairly good agreement with experimental data in two operating cases in a conduit with a rectangular cross-section and these comparisons imply that these models are practical.

  8. Well-posed Euler model of shock-induced two-phase flow in bubbly liquid

    Science.gov (United States)

    Tukhvatullina, R. R.; Frolov, S. M.

    2017-07-01

    A well-posed mathematical model of non-isothermal two-phase two-velocity flow of bubbly liquid is proposed. The model is based on the two-phase Euler equations with the introduction of an additional pressure at the gas bubble surface, which ensures the well-posedness of the Cauchy problem for a system of governing equations with homogeneous initial conditions, and the Rayleigh-Plesset equation for radial pulsations of gas bubbles. The applicability conditions of the model are formulated. The model is validated by comparing one-dimensional calculations of shock wave propagation in liquids with gas bubbles with a gas volume fraction of 0.005-0.3 with experimental data. The model is shown to provide satisfactory results for the shock propagation velocity, pressure profiles, and the shock-induced motion of the bubbly liquid column.

  9. Liquid-liquid equilibria for binary and ternary polymer solutions with PC-SAFT

    DEFF Research Database (Denmark)

    Lindvig, Thomas; Michelsen, Michael Locht; Kontogeorgis, Georgios

    2004-01-01

    Two algorithms for evaluating liquid-liquid equilibria (LLE) for binary and ternary polymer solutions are presented. The binary algorithm provides the temperature versus concentration cloud-point curve at fixed pressure, whereas the ternary algorithm provides component 1 versus component 2...

  10. Numerical simulation of the two-phase flow produced by spraying a liquid by a nozzle

    Science.gov (United States)

    Simakov, N. N.

    2017-07-01

    A numerical experiment on the simulation of the two-phase flow formed during spraying of a liquid by a nozzle has been described. The radial and axial velocity profiles of the droplets and gas in the free spray and in the two-phase flow through a cylindrical apparatus have been calculated and represented taking into account the early drag crisis of droplets and peculiarities of turbulent friction in the gas, which was detected in previous experiments. The distinguishing feature of the numerical model of the two-phase flow is that it employs the differential equations describing the nonstationary flow of a compressible gas as the initial equations. In transition to their difference analog, the familiar Lax-Wendorff algorithm has been used. A comparison of the results of calculations based on this model with experimental data has demonstrated their concordance.

  11. Gas-liquid two-phase flow across a bank of micropillars

    Science.gov (United States)

    Krishnamurthy, Santosh; Peles, Yoav

    2007-04-01

    Adiabatic nitrogen-water two-phase flow across a bank of staggered circular micropillars, 100μm long with a diameter of 100μm and a pitch-to-diameter ratio of 1.5, was investigated experimentally for Reynolds number ranging from 5 to 50. Flow patterns, void fraction, and pressure drop were obtained, discussed, and compared to large scale as well as microchannel results. Two-phase flow patterns were determined by flow visualization, and a flow map was constructed as a function of gas and liquid superficial velocities. Significant deviations from conventional scale systems, with respect to flow patterns and trend lines, were observed. A unique flow pattern, driven by surface tension, was observed and termed bridge flow. The applicability of conventional scale models to predict the void fraction and two-phase frictional pressure drop was also assessed. Comparison with a conventional scale void fraction model revealed good agreement, but was found to be in a physically wrong form. Thus, a modified physically based model for void fraction was developed. A two-phase frictional multiplier was found to be a strong function of mass flux, unlike in previous microchannel studies. It was observed that models from conventional scale systems did not adequately predict the two-phase frictional multiplier at the microscale, thus, a modified model accounting for mass flux was developed.

  12. Computer code for gas-liquid two-phase vortex motions: GLVM

    Science.gov (United States)

    Yeh, T. T.

    1986-01-01

    A computer program aimed at the phase separation between gas and liquid at zero gravity, induced by vortex motion, is developed. It utilizes an explicit solution method for a set of equations describing rotating gas-liquid flows. The vortex motion is established by a tangential fluid injection. A Lax-Wendroff two-step (McCormack's) numerical scheme is used. The program can be used to study the fluid dynamical behavior of the rotational two-phase fluids in a cylindrical tank. It provides a quick/easy sensitivity test on various parameters and thus provides the guidance for the design and use of actual physical systems for handling two-phase fluids.

  13. Bioproduction of benzaldehyde in a solid-liquid two-phase partitioning bioreactor using Pichia pastoris.

    Science.gov (United States)

    Jain, Ashu N; Khan, Tanya R; Daugulis, Andrew J

    2010-11-01

    The bioproduction of benzaldehyde from benzyl alcohol using Pichia pastoris was examined in a solid-liquid two-phase partitioning bioreactor (TPPB) to reduce substrate and product inhibition. Rational polymer selection identified Elvax 40W as an effective sequestering phase, possessing partition coefficients for benzyl alcohol and benzaldehyde of 3.5 and 35.4, respectively. The use of Elvax 40W increased the overall mass of benzaldehyde produced by approx. 300% in a 5 l bioreactor, relative to a single phase biotransformation. The two-phase system had a molar yield of 0.99, indicating that only minor losses occurred. These results provide a promising starting point for solid-liquid TPPBs to enhance benzaldehyde production, and suggest that multiple, targeted polymers may provide relief for transformations characterized by multiple inhibitory substrates/product/by-products.

  14. A Heat Transfer Investigation of Liquid and Two-Phase Methane

    Science.gov (United States)

    VanNoord, Jonathan

    2010-01-01

    A heat transfer investigation was conducted for liquid and two-phase methane. The tests were conducted at the NASA Glenn Research Center Heated Tube Facility (HTF) using resistively heated tube sections to simulate conditions encountered in regeneratively cooled rocket engines. This testing is part of NASA s Propulsion and Cryogenics Advanced Development (PCAD) project. Nontoxic propellants, such as liquid oxygen/liquid methane (LO2/LCH4), offer potential benefits in both performance and safety over equivalently sized hypergolic propulsion systems in spacecraft applications. Regeneratively cooled thrust chambers are one solution for high performance, robust LO2/LCH4 engines, but cooling data on methane is limited. Several test runs were conducted using three different diameter Inconel 600 tubes, with nominal inner diameters of 0.0225-, 0.054-, and 0.075-in. The mass flow rate was varied from 0.005 to 0.07 lbm/sec. As the current focus of the PCAD project is on pressure fed engines for LO2/LCH4, the average test section outlet pressures were targeted to be 200 psia or 500 psia. The heat flux was incrementally increased for each test condition while the test section wall temperatures were monitored. A maximum average heat flux of 6.2 Btu/in.2 sec was achieved and, at times, the temperatures of the test sections reached in excess of 1800 R. The primary objective of the tests was to produce heat transfer correlations for methane in the liquid and two-phase regime. For two-phase flow testing, the critical heat flux values were determined where the fluid transitions from nucleate boiling to film boiling. A secondary goal of the testing was to measure system pressure drops in the two-phase regime.

  15. STABILITY OF VORTEX STREET IN GAS-LIQUID TWO-PHASE FLOW

    Institute of Scientific and Technical Information of China (English)

    Li Yong-guang; Lin Zong-hu

    2003-01-01

    The stability of the Karmen vortex street in gas-liquid two-phase flow was studied experimentally and theoretically. The values of the parameter h/l characterizing the vortex street structure (I.e., the ratio of the vortex street width to the distance between two vortexes) for a stable vortex street in gas-liquid two-phase flow were obtained for the first time. The parameter h/l was proved to be a variable, not a constant as in single-phase flow. H/l is related to the upstream fluid void fraction. In gas-liquid two-phase fluid flow to form a steady vortex street is more difficult than in a single-phase fluid flow. Because in the unsteady vortex shedding the vortex shedding band frequency is broader than the one in the single phase fluid flow, so it is easier to induce the cross-cylinder resonance than in the single phase fluid flow, and this case should give rise to the attention of engineers.

  16. Studies on Molecular Interaction in Ternary Liquid Mixtures

    Directory of Open Access Journals (Sweden)

    R. Uvarani

    2010-01-01

    Full Text Available Ultrasonic velocity, density and viscosity for the ternary liquid mixtures of cyclohexanone with 1-propanol and 1-butanol in carbon tetrachloride were measured at 303 K. The acoustical parameters and their excess values were calculated. The trends in the variation of these excess parameters were used to discuss the nature and strength of the interactions present between the component molecules.

  17. Facile synthesis and properties of CdSe quantum dots in a novel two-phase liquid/liquid system

    Science.gov (United States)

    Wang, Jidong; Wang, Xiaoyu; Tang, Hengshan; Gao, Zehua; He, Shengquan; Ke, Dandan; Zheng, Yue; Han, Shumin

    2017-10-01

    High-quantity CdSe QDs were synthesized in a novel two-phase liquid/liquid system. This system, ODE/water was stable and as-used solvents were almost nontoxic. The methodology leading to the successful synthesis of CdSe QDs was a typical, one-pot approach and the obtained CdSe QDs with zinc-blende phase structure exhibited excellent optical properties, narrow size distribution, higher particle uniformity and crystallinity. The mechanism of nucleation and growth of CdSe QDs were discussed by the possible thermodynamic equilibrium existing in ODE/water interface. This two-phase liquid/liquid system would broaden the synthesis of other semiconductor QDs.

  18. Shadow imaging in bubbly gas-liquid two-phase flow in porous structures

    Science.gov (United States)

    Altheimer, Marco; Häfeli, Richard; Wälchli, Carmen; Rudolf von Rohr, Philipp

    2015-09-01

    Shadow imaging is used for the investigation of bubbly gas-liquid two-phase flow in a porous structure. The porous structure is made of Somos WaterShed XC 11122, a clear epoxy resin used in rapid prototyping. Optical access is provided by using an aqueous solution of sodium iodide and zinc iodide having the same refractive index as the structure material (). Nitrogen is injected into the continuous phase at volumetric transport fractions in the range of resulting in a hold-up of . The obtained images of overlapping bubble shadows are processed to measure the bubble dimensions. Therefore, a new processing sequence is developed to determine bubble dimensions from overlapping bubble shadows by ellipse fitting. The accuracy of the bubble detection and sizing routine is assessed processing synthetic images. It is shown that the developed technique is suitable for volumetric two-phase flow measurements. Important global quantities such as gas hold-up and total interfacial area can be measured with only one camera. Operation parameters for gas-liquid two-phase flows are determined to improve mass and heat transfer between the phases.

  19. Liquid-liquid extraction of enzymes by affinity aqueous two-phase systems

    Directory of Open Access Journals (Sweden)

    Xu Yan

    2003-12-01

    Full Text Available From analytical to commercial scale, aqueous two-phase systems have their application in the purification, characterization and study of biomaterials. In order to improve the selectivity of the systems, the biospecific affinity ligands were introduced. In the affinity partitioning aqueous two-phase system, have many enzymes been purified. This review discusses the partitioning of some enzymes in the affinity aqueous two-phase systems in regard to the different ligands, including reactive dyes, metal ions and other ligands. Some integration of aqueous two-phase system with other techniques for more effective purification of enzymes are also presented.Tanto em escala de laboratório como industrial, os sistemas de duas fases aquosas podem ser utilizados para a purificação, caracterização e estudos de biomateriais. Para aumentar a seletividade desse sistema, ligantes de afinidade bioespecíficos podem ser utilizados. No sistema de duas fases aquosas por afinidade, muitas enzimas podem ser purificadas. Neste artigo de revisão, a partição de algumas enzimas por esse tipo de afinidade, utilizando diferentes ligantes como corantes e íons metálicos, são discutidas. Além disso, a integração desse sistema de duas fases aquosas com outras técnicas de purificação estão sendo apresentados, com o objetivo mostrar a melhoria da eficiência do processo.

  20. One- and two-phase anaerobic digestion of ley crop silage with and without liquid recirculation

    Energy Technology Data Exchange (ETDEWEB)

    Nordberg, Aa.

    1996-10-01

    In this study the effects of liquid recirculation on hydrolysis and methanogenesis in one- and two-phase biogas processes were investigated in comparison with water-diluted processes. The operation of a water-diluted one-phase process resulted in process imbalances at a low loading rate. In a water-diluted two-phase process the fibre degrading capability was lost. The reason for the poor process performance was due to a deficiency in trace elements, since the supplementation of cobalt resulted in an increased conversion rate of acetate. The recirculation of process liquid resulted in an accumulation of different compounds which initially stabilized one-phase processes and stimulated the hydrolysis and the methane production in the liquefaction-acidogenesis stage of a two-phase process. However, upon continuous recirculation the concentration of free ammonia reached toxic levels, which resulted in a decrease in the methane yield both in the methanogenic reactor of the two-phase process and in the one-phase process. Due to the decreased methane production, acids started to accumulate which subsequently inhibited the hydrolysis in the one-phase process. The systematic variation in the processes were evaluated using principal component analysis and principal component regression. The interpretation of the dynamic behaviour of the processes was facilitated by the use of score plots and loading plots. The results indicate that ley crops do not meet the nutrient requirements of the bacteria in anaerobic digestion. Thus, the low content of trace elements and the high content of protein which subsequently will cause toxic levels of ammonia in digesting system with low water consumption, suggests co-digestion with supplementary feedstocks. 95 refs, 5 figs, 3 tabs

  1. On intermittent flow characteristics of gas–liquid two-phase flow

    Energy Technology Data Exchange (ETDEWEB)

    Thaker, Jignesh; Banerjee, Jyotirmay, E-mail: jbaner@gmail.com

    2016-12-15

    Highlights: • Unified correlations for intermittent flow characteristics are developed. • Influence of inflow conditions on intermittent flow characteristics is analysed. • Developed correlations can be used for effective design of piping components. - Abstract: Flow visualisation experiments are reported for intermittent regime of gas–liquid two-phase flow. Intermittent flow characteristics, which include plug/slug frequency, liquid plug/slug velocity, liquid plug/slug length, and plug/slug bubble length are determined by image processing of flow patterns captured at a rate of 1600 frames per second (FPS). Flow characteristics are established as a function of inlet superficial velocity of both the phases (in terms of Re{sub SL} and Re{sub SG}). The experimental results are first validated with the existing correlations for slug flow available in literature. It is observed that the correlations proposed in literature for slug flow do not accurately predict the flow characteristics in the plug flow regime. The differences are clearly highlighted in this paper. Based on the measured database for both plug and slug flow regime, modified correlations for the intermittent flow regime are proposed. The correlations reported in the present paper, which also include plug flow characteristics will aid immensely to the effective design and optimization of operating conditions for safer operation of two-phase flow piping systems.

  2. Gas-liquid two-phase flows in double inlet cyclones for natural gas separation

    DEFF Research Database (Denmark)

    Yang, Yan; Wang, Shuli; Wen, Chuang

    2017-01-01

    The gas-liquid two-phase flow within a double inlet cyclone for natural gasseparation was numerically simulated using the discrete phase model. The numericalapproach was validated with the experimental data, and the comparison resultsagreed well with each other. The simulation results showed......-outlet. The swirling flow was concentric dueto the design of the double inlet for the cyclonic separator, which greatly improvedthe separating efficiency. The separating efficiency was greater than 90% with theparticle diameter of more than 100 μm....

  3. NUMERICAL CALCULATION OF SOLID-LIQUID TWO PHASE FLOW BETWEEN STAY VANES IN HYDRAULIC TURBINE

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In this paper, an energy equation of silt-laden water flow is educed based on the energy equation of continuum fluid flow. The dissipation functions of liquid phase and solid phase are presented respectively. Then the extremity law of energy dissipation rate is introduced for the research of the silt-laden water flow and a new mathematical model is developed. The corresponding procedure based on the finite difference method (FDM) is developed to calculate the two phase flow in hydraulic turbine. The method is applied to analyze the silt-laden water flow between stay vanes, and the numerical results are in good agreement with the experimental ones.

  4. Prediction of gas-liquid two-phase flow regime in microgravity

    Science.gov (United States)

    Lee, Jinho; Platt, Jonathan A.

    1993-01-01

    An attempt is made to predict gas-liquid two-phase flow regime in a pipe in a microgravity environment through scaling analysis based on dominant physical mechanisms. Simple inlet geometry is adopted in the analysis to see the effect of inlet configuration on flow regime transitions. Comparison of the prediction with the existing experimental data shows good agreement, though more work is required to better define some physical parameters. The analysis clarifies much of the physics involved in this problem and can be applied to other configurations.

  5. Enzymatic hydrolysis of penicillin in mixed ionic liquids/water two-phase system.

    Science.gov (United States)

    Jiang, Yangyang; Xia, Hansong; Guo, Chen; Mahmood, Iram; Liu, Huizhou

    2007-01-01

    In this paper, an integrated process involving the mixed ionic liquids/water two-phase system (MILWS) is proposed to improve the efficiency for enzymatic hydrolysis of penicillin G. First, hydrophilic [C4mim]BF4 (1-butyl-3-methylimidazolium tetrafluoraborate) and NaH2PO4 salt form an ionic liquids aqueous two-phase system (ILATPS), which could extract penicillin from its fermentation broth efficiently. Second, a hydrophobic [C4mim]PF6 (1-butyl-3-methylimidazolium hexafluoraphosphate) is introduced into the ionic liquids-rich phase of ILATPS containing penicillin and converses it into MILWS. Penicillin is hydrolyzed by penicillin acylase in the water phase of MILWS at pH 5. The byproduct phenylacetic acid (PAA) is partitioned into the ionic liquids mixture phase, while the intended product 6-aminopenicillanic acid (6-APA) is precipitated at this pH. In comparison with a similar butyl acetate/water system (BAWS) at pH 4, MILWS exhibits two advantages. (1) The selectivity between PAA and penicillin is greatly optimized at pH 5 by varying the mole ratio of [C4mim]PF6/[C4mim]BF4 in MILWS, whereas in BAWS the unalterable nature of the organic solvent restricts the optimized pH for maximum selectivity between PAA and penicillin at pH 4. (2) The pH for 6-APA precipitation in BAWS is 4, whereas it shifts to pH 5 in MILWS due to the complexation between negatively charged 6-APA and the cationic surface of the ionic liquids micelle. As a result, the removal of the two products from the enzyme sphere at relatively high pH is permitted in MILWS, which is beneficial for enzymatic activity and stability in comparison with the acidic pH 4 environment in BAWS.

  6. Thermal Lattice Boltzmann Simulations for Vapor-Liquid Two-Phase Flows in Two Dimensions

    Science.gov (United States)

    Wei, Yikun; Qian, Yuehong

    2011-11-01

    A lattice Boltzmann model with double distribution functions is developed to simulate thermal vapor-liquid two-phase flows. In this model, the so-called mesoscopic inter-particle pseudo-potential for the single component multi-phase lattice Boltzmann model is used to simulate the fluid dynamics and the internal energy field is simulated by using a energy distribution function. Theoretical results for large-scale dynamics including the internal energy equation can be derived and numerical results for the coexistence curve of vapor-liquid systems are in good agreement with the theoretical predictions. It is shown from numerical simulations that the model has the ability to mimic phase transitions, bubbly flows and slugging flows. This research is support in part by the grant of Education Ministry of China IRT0844 and the grant of Shanghai CST 11XD1402300.

  7. Theoretical analysis and numerical computation of dilute solid/liquid two_phase pipe flow

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Starting with the kinetic theory for dilute solid/liquid two_phase flow, a mathematical model is established to predict the flow in a horizontal square pipe and the predictions are compared with LDV measurements. The present model predicts correctly two types of patterns of the vertical distribution of particle concentration observed in experiments, and also gives different patterns of the distribution of particle fluctuating energy. In the core region of the pipe, the predicted mean velocity of particles is smaller than that of liquid, but near the pipe bottom the reverse case occurs. In addition, full attention is paid to the mechanism for the vertical distribution of the average properties of particles such as concentration and mean velocity. From the kinetic_theory point of view, the cause of formation for different patterns of the vertical concentration distribution is not only related to the lift force exerted on a particle, but also related to the distribution of particle fluctuating energy.

  8. Simulation of plasma discharge in liquids: A detailed two-phase fluid approach

    Science.gov (United States)

    Charchi Aghdam, Ali; Farouk, Tanvir; Reacting Systems; Advanced Energy Research Laboratory Team

    2015-09-01

    Plasma discharge in liquids has gained great attention recently due to its applications in biomedical engineering, fuel processing, and water treatment and so on. Despite the tremendous interest, a comprehensive understanding of the underlying physics still remains limited. In the current work, an attempt is made to present a mathematical multi-physics model to describe the discharge of plasma in liquids. An in-house modeling platform is developed for simulating plasma formation in multiphase fluids. The model resolves a detailed two-phase fluid including viscous effects, surface tension, gravitational forces and electrical body force. All the governing equations are solved for gas and liquid phases. Electric field and charged species equations along with the plasma reaction kinetics are solved to get the charge distribution in the different phases as well as at the gas-liquid interface to obtain the electric body force acting at the interface. By coupling the above sub-models, a comprehensive multi-physics model for plasma discharge in liquids is constructed which is able to capture several physical aspects of the phenomena especially the role of the bubble, its motion and distortion on plasma characteristics.

  9. A Hydrodynamic Model for Slug Frequency in Horizontal Gas-Liquid Two-Phase Flow

    Institute of Scientific and Technical Information of China (English)

    刘磊; 孙贺东; 胡志华; 周芳德

    2003-01-01

    The prediction of slug frequency has important significance on gas-liquid two-phase flow. A hydrodynamic model was put forward to evaluate slug frequency for horizontal two-phase flow, based on the dependence of slug frequency on the frequency of unstable interfacial wave. Using air and water, experimental verification of the model was carried out in a large range of flow parameters. Six electrical probes were installed at different positions of a horizontal plexiglass pipe to detect slug frequency development. The pipe is 30 m long and its inner diameter is 24 ram. It is observed experimentally that the interracial wave frequency at the inlet is about i to 3 times the frequency of stable slug. The slug frequencies predicted by the model fit well with Tronconi (1990) model and the experimental data. The combination of the hydrodynamic model and the experimental data results in a conclusion that the frequency of equilibrium liquid slug is approximately half the minimum frequency of interfacial wave.

  10. Effects of Gravity on Cocurrent Two-Phase Gas-Liquid Flows Through Packed Columns

    Science.gov (United States)

    Motil, Brian J.; Balakotaiah, Vemuri; Kamotani, Yasuhiro

    2001-01-01

    This work presents the experimental results of research on the influence of gravity on flow pattern transitions, pressure drop and flow characteristics for cocurrent gas-liquid two-phase flow through packed columns. The flow pattern transition data indicates that the pulse flow regime exists over a wider range of gas and liquid flow rates under reduced gravity conditions compared to normal gravity cocurrent down-flow. This is illustrated by comparing the flow regime transitions found in reduced gravity with the transitions predicted by Talmor. Next, the effect of gravity on the total pressure drop in a packed column is shown to depend on the flow regime. The difference is roughly equivalent to the liquid static head for bubbly flow but begins to decrease at the onset of pulse flow. As the spray flow regime is approached by increasing the gas to liquid ratio, the effect of gravity on pressure drop becomes negligible. Finally, gravity tends to suppress the amplitude of each pressure pulse. An example of this phenomenon is presented.

  11. Cloud Point and Liquid-Liquid Equilibrium Behavior of Thermosensitive Polymer L61 and Salt Aqueous Two-Phase System.

    Science.gov (United States)

    Rao, Wenwei; Wang, Yun; Han, Juan; Wang, Lei; Chen, Tong; Liu, Yan; Ni, Liang

    2015-06-25

    The cloud point of thermosensitive triblock polymer L61, poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO), was determined in the presence of various electrolytes (K2HPO4, (NH4)3C6H5O7, and K3C6H5O7). The cloud point of L61 was lowered by the addition of electrolytes, and the cloud point of L61 decreased linearly with increasing electrolyte concentration. The efficacy of electrolytes on reducing cloud point followed the order: K3C6H5O7 > (NH4)3C6H5O7 > K2HPO4. With the increase in salt concentration, aqueous two-phase systems exhibited a phase inversion. In addition, increasing the temperature reduced the concentration of salt needed that could promote phase inversion. The phase diagrams and liquid-liquid equilibrium data of the L61-K2HPO4/(NH4)3C6H5O7/K3C6H5O7 aqueous two-phase systems (before the phase inversion but also after phase inversion) were determined at T = (25, 30, and 35) °C. Phase diagrams of aqueous two-phase systems were fitted to a four-parameter empirical nonlinear expression. Moreover, the slopes of the tie-lines and the area of two-phase region in the diagram have a tendency to rise with increasing temperature. The capacity of different salts to induce aqueous two-phase system formation was the same order as the ability of salts to reduce the cloud point.

  12. The application of axisymmetric lattice Boltzmann two-phase model on simulations of liquid film dewetting

    Science.gov (United States)

    Wang, Lei; Sun, Jianglong

    2017-08-01

    An axisymmetric two-phase lattice Boltzmann method is applied to simulate the dewetting dynamics of a thin liquid film on a substrate. Initially, a circular dry spot exists in the center of the liquid film. A contact line forms around the dry spot and expands outwards. The liquid films dewetting on smooth and rough substrates are investigated. For a smooth substrate, the effects of the contact angle (θeq), Ohnesorge number (Oh), and viscosity ratio (λμ) are studied. It is observed that the contact line recedes with a constant velocity V and that if θeq > 45°, V has a linear relationship with θeq, which has never been mentioned in previous literatures. For a rough substrate, well-distributed pillars are set up to represent the roughness. There are two states for the liquid film dewetting on a rough substrate: Cassie and Wenzel states. By comparison, it is found that the speed of the liquid film dewetting on the rough substrate of the Cassie state is slightly faster than that on the smooth substrate but much faster than that on the rough substrate of the Wenzel state, i.e., Wenzel state can obviously hold back the movement of the receding contact line. The corresponding mechanism is analyzed. The effect of the geometric factors of the pillars on the dewetting speed is discussed in detail. It is indicated that both the width and the depth of the grooves in roughness can significantly affect the dewetting speed. The results are helpful to design structured substrates for controlling the dewetting process of the liquid film.

  13. THE FRICTIONAL RESISTANCE CHARACTERISTICS OF GAS-LIQUID TWO-PHASE FLOW IN HELICAL-COILED TUBES

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    This paper deal with the frictional resistance characteristics of gas-liquid two-phase flow in vertical-upward helical-coiled tubes under the system pressure 0.1-0.6MPa.By means of dimension analysis and π theorem, the correlation formulas were obtained for calculating the frictional resistance coefficients of gas-liquid two-phase flow in helical-coiled tubes.The calculated results agree well with the experimental results.

  14. A Unified Detail-Preserving Liquid Simulation by Two-Phase Lattice Boltzmann Modeling.

    Science.gov (United States)

    Guo, Yulong; Liu, Xiaopei; Xu, Xuemiao

    2016-02-19

    Traditional methods in graphics to simulate liquid-air dynamics under different scenarios usually employ separate approaches with sophisticated interface tracking/reconstruction techniques. In this paper, we propose a novel unified approach which is easy and effective to produce a variety of liquid-air interface phenomena. These phenomena, such as complex surface splashes, bubble interactions, as well as surface tension effects, can co-exist in one single simulation, and are created within the same computational framework. Such a framework is unique in that it is free from any complicated interface tracking/reconstruction procedures. Our approach is developed from the two-phase lattice Boltzmann method with the mean field model, which provides a unified framework for interface dynamics but is numerically unstable under turbulent conditions. Considering the drawbacks of the existing approaches, we propose techniques to suppress oscillation for significant stability enhancement, as well as derive a new subgrid-scale model to further improve stability, faithfully preserving liquid-air interface details without excessive diffusion by taking into account the density variation. The whole framework is highly parallel, enabling very efficient implementation. Comparisons to the related approaches show superiority on stable simulation with detail preservation and multiphase phenomena simultaneously involved. A set of animation results demonstrate the effectiveness of our method.

  15. Experimental Study of gas-liquid two-phase flow affected by wall surface wettability

    Energy Technology Data Exchange (ETDEWEB)

    Takamasa, T. [Faculty of Marine Technology, Tokyo University of Marine Science and Technology, 2-1-6 Etchujima, Koto, Tokyo 135-8533 (Japan); Hazuku, T. [Faculty of Marine Technology, Tokyo University of Marine Science and Technology, 2-1-6 Etchujima, Koto, Tokyo 135-8533 (Japan)], E-mail: hazuku@kaiyodai.ac.jp; Hibiki, T. [School of Nuclear Engineering, Purdue University, 400 Central Drive, West Lafayette, IN 47907-2017 (United States)

    2008-12-15

    To evaluate the effect of wall surface wettability on the characteristics of upward gas-liquid two-phase flow in a vertical pipe, an experimental study was performed using three test pipes: an acrylic pipe, a hydrophilic pipe and a hydrophobic pipe. Basic flow characteristics such as flow patterns, pressure drop and void fraction were measured in these three pipes. In the hydrophilic pipe, a slug to churn flow transition boundary was shifted to a higher gas velocity at a given liquid velocity, whereas a churn to annular flow transition boundary was shifted to a lower gas velocity at a given liquid velocity. In the hydrophobic pipe, an inverted-churn flow regime was observed in the region where the churn flow regime was observed in the acrylic pipe, while a droplet flow regime was observed in the region where an annular flow regime was observed in the acrylic pipe. At a high gas flow rate, the mean void fraction in the hydrophobic pipe was higher than in the acrylic pipe. The effect of surface wettability on frictional pressure loss was confirmed to be insignificant under the present experimental conditions.

  16. Bubble Generation in a Flowing Liquid Medium and Resulting Two-Phase Flow in Microgravity

    Science.gov (United States)

    Pais, S. C.; Kamotani, Y.; Bhunia, A.; Ostrach, S.

    1999-01-01

    The present investigation reports a study of bubble generation under reduced gravity conditions, using both a co-flow and a cross-flow configuration. This study may be used in the conceptual design of a space-based thermal management system. Ensuing two-phase flow void fraction can be accurately monitored using a single nozzle gas injection system within a continuous liquid flow conduit, as utilized in the present investigation. Accurate monitoring of void fraction leads to precise control of heat and mass transfer coefficients related to a thermal management system; hence providing an efficient and highly effective means of removing heat aboard spacecraft or space stations. Our experiments are performed in parabolic flight aboard the modified DC-9 Reduced Gravity Research Aircraft at NASA Lewis Research Center, using an air-water system. For the purpose of bubble dispersion in a flowing liquid, we use both a co-flow and a cross-flow configuration. In the co-flow geometry, air is introduced through a nozzle in the same direction with the liquid flow. On the other hand, in the cross-flow configuration, air is injected perpendicular to the direction of water flow, via a nozzle protruding inside the two-phase flow conduit. Three different flow conduit (pipe) diameters are used, namely, 1.27 cm, 1.9 cm and 2.54 cm. Two different ratios of nozzle to pipe diameter (D(sub N))sup * are considered, namely (D(sub N))sup * = 0.1 and 0.2, while superficial liquid velocities are varied from 8 to 70 cm/s depending on flow conduit diameter. It is experimentally observed that by holding all other flow conditions and geometry constant, generated bubbles decrease in size with increase in superficial liquid velocity. Detached bubble diameter is shown to increase with air injection nozzle diameter. Likewise, generated bubbles grow in size with increasing pipe diameter. Along the same lines, it is shown that bubble frequency of formation increases and hence the time to detachment of a

  17. Velocity field measurement in gas-liquid metal two-phase flow with use of PIV and neutron radiography techniques

    Energy Technology Data Exchange (ETDEWEB)

    Saito, Y.; Mishima, K. [Kyoto Univ. Kumatori, Research Reactor Institute, Osaka (Japan); Tobita, Y.; Suzuki, T. [O-arai Engineering Center, Power Reactor and Nuclear Fuel Development Corporation (Japan); Matsubayashi, M. [Japan Atomic Energy Institute, Tokai Research Establishment (Japan)

    2001-07-01

    Neutron radiography and PIV (Particle Image Velocimetry) techniques were applied to measurements of velocity field in gas-liquid metal two-phase flow. Visualization and measurements of two-phase flow were conducted using molten lead bismuth and nitrogen gas as working fluids and particles made of gold-cadmium (AuCd{sub 3}) inter-metallic alloy were employed as the tracer. Discrimination method between bubble and tracer images in two-phase flow was developed based on the {sigma}-scaling method. Time-averaged liquid velocity fields, gas velocity fields and void profile were calculated from discriminated images, respectively. From these measurements, the basic characteristics of gas-liquid metal two-phase mixture were clarified. (author)

  18. The investigation of gas–liquid two-phase transient flow based on Steger–Warming flux vector splitting method in pipelines

    National Research Council Canada - National Science Library

    Jiang, Jin; Fu, You; Zhang, Lisheng; Li, Yanhui; Ji, Weidong; Liu, Yameng

    2016-01-01

    In this article, two fluid conservation equations of gas–liquid two-phase transient flows are deduced with an improved mass transfer model between two phases and applied to liquid-column separation transients in pipelines...

  19. Gas-Liquid Two-Phase Flows Through Packed Bed Reactors in Microgravity

    Science.gov (United States)

    Motil, Brian J.; Balakotaiah, Vemuri

    2001-01-01

    The simultaneous flow of gas and liquid through a fixed bed of particles occurs in many unit operations of interest to the designers of space-based as well as terrestrial equipment. Examples include separation columns, gas-liquid reactors, humidification, drying, extraction, and leaching. These operations are critical to a wide variety of industries such as petroleum, pharmaceutical, mining, biological, and chemical. NASA recognizes that similar operations will need to be performed in space and on planetary bodies such as Mars if we are to achieve our goals of human exploration and the development of space. The goal of this research is to understand how to apply our current understanding of two-phase fluid flow through fixed-bed reactors to zero- or partial-gravity environments. Previous experiments by NASA have shown that reactors designed to work on Earth do not necessarily function in a similar manner in space. Two experiments, the Water Processor Assembly and the Volatile Removal Assembly have encountered difficulties in predicting and controlling the distribution of the phases (a crucial element in the operation of this type of reactor) as well as the overall pressure drop.

  20. A New Void Fraction Measurement Method for Gas-Liquid Two-Phase Flow in Small Channels

    OpenAIRE

    Huajun Li; Haifeng Ji; Zhiyao Huang; Baoliang Wang; Haiqing Li; Guohua Wu

    2016-01-01

    Based on a laser diode, a 12 × 6 photodiode array sensor, and machine learning techniques, a new void fraction measurement method for gas-liquid two-phase flow in small channels is proposed. To overcome the influence of flow pattern on the void fraction measurement, the flow pattern of the two-phase flow is firstly identified by Fisher Discriminant Analysis (FDA). Then, according to the identification result, a relevant void fraction measurement model which is developed by Support Vector Mach...

  1. Aqueous two phase system based on ionic liquid for isolation of quinine from human plasma sample.

    Science.gov (United States)

    Flieger, J; Czajkowska-Żelazko, A

    2015-01-01

    Aqueous two phase system was applied for selective extraction of quinine from human plasma. Bi-phase was constructed from ionic liquid: butyl-methyl-imidazolium chloride after addition kosmotropic salts K₃PO₄ or KH₂PO₄. Quinine was determined in plasma samples after drinking of tonic containing quinine. Determination was performed by HPLC on 5-μm Zorbax SB-CN column and eluent containing 40% acetonitrile (v/v), 20 mM phosphate buffer at pH 3 and 40 mM NaPF₆ using external standard method. The spectrophotometric detection was set λ=214 nm. Selective fluorescence detection was performed at excitation of 325 nm and emission of 375 nm. Proposed strategy provides suitable sample purification and gives extraction yields in the range of 89-106%. The determination coefficient (R(2)) has a value ≥0.997 in the range of 50-800 ng/ml quinine concentration. The limit of quantification was set at 27.9 ng/ml and the detection limit was found to be 8.4 ng/ml under fluorescence detection.

  2. Flow regimes of adiabatic gas-liquid two-phase under rolling conditions

    Science.gov (United States)

    Yan, Chaoxing; Yan, Changqi; Sun, Licheng; Xing, Dianchuan; Wang, Yang; Tian, Daogui

    2013-07-01

    Characteristics of adiabatic air/water two-phase flow regimes under vertical and rolling motion conditions were investigated experimentally. Test sections are two rectangular ducts with the gaps of 1.41 and 10 mm, respectively, and a circular tube with 25 mm diameter. Flow regimes were recorded by a high speed CCD-camera and were identified by examining the video images. The experimental results indicate that the characteristics of flow patterns in 10 mm wide rectangular duct under vertical condition are very similar to those in circular tube, but different from the 1.41 mm wide rectangular duct. Channel size has a significant influence on flow pattern transition, boundary of which in rectangular channels tends asymptotically towards that in the circular tube with increasing the width of narrow side. Flow patterns in rolling channels are similar to each other, nevertheless, the effect of rolling motion on flow pattern transition are significantly various. Due to the remarkable influences of the friction shear stress and surface tension in the narrow gap duct, detailed flow pattern maps of which under vertical and rolling conditions are indistinguishable. While for the circular tube with 25 mm diameter, the transition from bubbly to slug flow occurs at a higher superficial liquid velocity and the churn flow covers more area on the flow regime map as the rolling period decreases.

  3. Remediation of PAH contaminated soils: application of a solid-liquid two-phase partitioning bioreactor.

    Science.gov (United States)

    Rehmann, Lars; Prpich, George P; Daugulis, Andrew J

    2008-10-01

    The feasibility of a two-step treatment process has been assessed at laboratory scale for the remediation of soil contaminated with a model mixture of polycyclic aromatic hydrocarbons (PAHs) (phenanthrene, pyrene, and fluoranthene). The initial step of the process involved contacting contaminated soil with thermoplastic, polymeric pellets (polyurethane). The ability of three different mobilizing agents (water, surfactant (Biosolve) and isopropyl alcohol) to enhance recovery of PAHs from soil was investigated and the results were compared to the recovery of PAHs from dry soil. The presence of isopropyl alcohol had the greatest impact on PAH recovery with approximately 80% of the original mass of PAHs in the soil being absorbed by the polymer pellets in 48 h. The second stage of the suggested treatment involved regeneration of the PAH loaded polymers via PAH biodegradation, which was carried out in a solid-liquid two-phase partitioning bioreactor. In addition to the PAH containing polymer pellets, the bioreactor contained a microbial consortium that was pre-selected for its ability to degrade the model PAHs and after a 14 d period approximately 78%, 62% and 36% of phenanthrene, pyrene, and fluoranthene, respectively, had been desorbed from the polymer and degraded. The rate of phenanthrene degradation was shown to be limited by mass transfer of phenanthrene from the polymer pellets. In case of pyrene and fluoranthene a combination of mass transfer and biodegradation rate might have been limiting.

  4. Selective separation of protein and saccharides by ionic liquids aqueous two-phase systems

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    In the present work,it was found that aqueous solution of a hydrophilic ionic liquid (IL),1-butyl-3-methylimidazolium dicyanamide ([C4mim][N(CN)2]),could be separated into an aqueous two-phase system (ATPS) by inorganic salts such as K2HPO4 and K3PO4.The top phase is IL-rich,while the bottom phase is phosphate-rich.It was shown that 82.7%-100% bovine serum albumin (BSA) could be enriched into the top phase and almost quantitative saccharides (arabinose,glucose,sucrose,raffinose or dextran) were preferentially extracted into the bottom phase in a single-step extraction by [C4mim][N(CN)2] + K2HPO4 ATPS.The extraction efficiency of BSA from the aqueous saccharide solutions was influenced by the molecular structure of saccharides.The conductivity,dynamic light scattering (DLS) and transmission electron microscopy (TEM) were combined to investigate the microstructure of the IL-rich top phase and the possible mechanism for the selective separation.It is suggested that the formation of the IL aggregate and the IL aggregate-BSA complex plays a significant role in the separation of BSA from aqueous saccharide solutions.This is the first example for the selective separation by ILs-based ATPSs.It is expected that these findings would have potential applications in bio-analysis,separation,and IL recycle.

  5. Review:Liquid film dryout model for predicting critical heat flux in annular two-phase flow

    Institute of Scientific and Technical Information of China (English)

    Bo JIAO; Li-min QIU; Jun-liang LU; Zhi-hua GAN

    2009-01-01

    Gas-liquid two-phase flow and heat transfer can be encountered in numerous fields, such as chemical engineering, refrigeration, nuclear power reactor, metallurgical industry, spaceflight. Its critical heat flux (CHF) is one of the most important factors for the system security of engineering applications. Since annular flow is the most common flow pattern in gas-liquid two-phase flow, predicting CHF of annular two-phase flow is more significant. Many studies have shown that the liquid film dryout model is successful for that prediction, and determining the following parameters will exert predominant effects on the accuracy of this model: onset of annular flow, inception criterion for droplets entrainment, entrainment fraction, droplets deposi-tion and entrainment rates. The main theoretical results achieved on the above five parameters are reviewed; also, limitations in the existing studies and problems for further research are discussed.

  6. A new contactless impedance sensor for void fraction measurement of gas-liquid two-phase flow

    Science.gov (United States)

    Ji, Haifeng; Chang, Ya; Huang, Zhiyao; Wang, Baoliang; Li, Haiqing

    2016-12-01

    With impedance elimination principle and phase sensitive demodulation (PSD) technique, this work aims to develop a new contactless impedance sensor, which is suitable for the void fraction measurement of gas-liquid two-phase flow. The impedance elimination principle is used to overcome the unfavorable influences of the coupling capacitances, i.e. the capacitive reactances of the coupling capacitances are eliminated by the inductive reactance of an introduced inductor. PSD technique is used to implement the impedance measurement. Unlike the conventional conductance/impedance sensors which use the equivalent conductance (the real part of the impedance) or the amplitude of the impedance of gas-liquid two-phase flow, the new contactless impedance sensor makes full use of the total impedance information of gas-liquid two-phase flow (including the amplitude, the real part and the imaginary part of the impedance, especially the imaginary part) to implement the void fraction measurement. As a preliminary study, to verify the effectiveness of the new contactless impedance sensor, two prototypes (with different inner diameters of 17.0 mm and 22.0 mm) are developed and experiments are carried out. Two typical flow patterns (bubble flow and stratified flow) of gas-liquid two-phase flow are investigated. The experimental results show that the new contactless impedance sensor is successful and effective. Compared with the conventional conductance/impedance sensors, the new contactless impedance sensor can avoid polarization effect and electrochemical erosion effect. The total impedance information is used and the void fraction measurement performance of the new sensor is satisfactory. The experimental results also indicate that the imaginary part of the impedance of gas-liquid two-phase flow is very useful for the void fraction measurement. Making full use of the total impedance information of gas-liquid two-phase flow can effectively improve the void fraction measurement

  7. Korea advanced liquid metal reactor development - Development of measuring techniques of the sodium two-phase flow

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Moo Hwan; Cha, Jae Eun [Pohang University of Science and Technology, Pohang (Korea)

    2000-04-01

    The technology which models and measures the behavior of bubble in liquid sodium is very important to insure the safety of the liquid metal reactor. In this research, we designed/ manufactured each part and loop of experimental facility for sodium two phase flow, and applied a few possible methods, measured characteristic of two phase flow such as bubbly flow. A air-water loop similar to sodium loop on each measuring condition was designed/manufactured. This air-water loop was utilized to acquire many informations which were necessary in designing the two phase flow of sodium and manufacturing experimental facility. Before the manufacture of a electromagnetic flow meter for sodium, the experiment using each electromagnetic flow mete was developed and the air-water loop was performed to understand flow characteristics. Experiments for observing the signal characteristics of flow were performed by flowing two phase mixture into the electromagnetic flow mete. From these experiments, the electromagnetic flow meter was designed and constructed by virtual electrode, its signal processing circuit and micro electro magnet. It was developed to be applicable to low conductivity fluid very successfully. By this experiment with the electromagnetic flow meter, we observed that the flow signal was very different according to void fraction in two phase flow and that probability density function which was made by statistical signal treatment is also different according to flow patterns. From this result, we confirmed that the electromagnetic flow meter could be used to understand the parameters of two phase flow of sodium. By this study, the experimental facility for two phase flow of sodium was constricted. Also the new electromagnetic flow meter was designed/manufactured, and experimental apparatus for two phase flow of air-water. Finally, this study will be a basic tool for measurement of two phase flow of sodium. As the fundamental technique for the applications of sodium at

  8. LIQUID PHASE FLOW ESTIMATION IN GAS-LIQUID TWO-PHASE FLOW USING INVERSE ANALYSIS AND PARTICLE TRACKING VELOCIMETRY

    Institute of Scientific and Technical Information of China (English)

    CHENG Wen; MURAI Yuichi; SASAKI Toshio; YAMAMOTO Fujio

    2004-01-01

    An inverse analysis algorithm is proposed for estimating liquid phase flow field from measurement data of bubble motion. This kind of technology will be applied in future for various estimation of fluid flow in rivers, lakes, sea surface flow, and also microscopic channel flow as the problem-handling in civil, mechanical, electronic, and chemical engineering. The relationship between the dispersion motion and the carrier phase flow is governed and expressed by the translational motion equation of spherical dispersion. The equation consists of all the force components including inertia, added inertia, drag, lift, pressure gradient force and gravity force. Using this equation enables us to estimate the carrier phase flow structure using only the data of the dispersion motion. Whole field liquid flow structure is also estimated using spatial or temporal interpolation method. In order to verify this principle, the Taylor-Green vortex flow, and the Karman vortex shedding from a square cylinder have been chosen. The results show that the combination of the inverse analysis and Particle Tracking Velocimetry (PTV) with the spatio-temporal post-processing algorithm could reconstruct well the carrier phase flow of the gas-liquid two-phase flow.

  9. SIMULATION OF THE TWO PHASE FLOW OF DROPLET IMPINGEMENT ON LIQUID FILM BY THE LATTICE BOLTZMANN METHOD

    Institute of Scientific and Technical Information of China (English)

    GUO Jia-hong; WANG Xiao-yong

    2012-01-01

    A Lattice Boltzmann Method (LBM) with two-distribution functions is employed for simulating the two-phase flow induced by a liquid droplet impinging onto the film of the same liquid on solid surface.The model is suitable for solution of twophase flow problem at high density and viscosity ratios of liquid to vapor and phase transition between liquid and its vapor.The roles of the vapor flow,the density ratio of liquid to vapor and the surface tension of the droplet in the splashing formation are discussed.It is concluded that the vapour flow induced by the droplet fall and splash in the whole impinging process may affect remarkably the splash behaviour.For the case of large density ratio of liquid to vapor a crown may engender after the droplet collides with the film.However,for the case of small density ratio of liquid to vapor a “bell” like splash may be observed.

  10. Fundamental Studies on Two-Phase Gas-Liquid Flows Through Packed Beds in Microgravity

    Science.gov (United States)

    Balakotaiah, Vemuri; McCready, Mark J.; Motil, Brian J.

    2002-01-01

    In the typical operation of a packed-bed reactor, gas and liquid flow simultaneously through a fixed bed of solid particles. Depending on the application, the particles can be of various shapes and sizes and provide for intimate contact and high rates of transport between the phases needed to sustain chemical or biological reactions. The packing may also serve as either a catalyst or as a support for growing biological material. NASA has flown two of these packed-bed systems in a microgravity environment with limited or no success. The goal of this research is to develop models (with scale-up capability) needed for the design of the physicochemical equipment to carry out these unit operations in microgravity. New insight will also lead to improvements in normal gravity operations. Our initial experiment was flown using an existing KC-135 two-phase flow rig with a modified test section. The test section is a clear polycarbonate rectangular column with a depth of 2.54 cm, a width of 5.08 cm, and 60 cm long. The column was randomly packed with spherical glass beads by slowly dropping the beads into the bed. Even though care was taken in handling the column after it was filled with packing, the alternating high and low gravity cycles with each parabola created a slightly tighter packed bed than is typically reported for this type. By the usual method of comparing the weight difference of a completely dry column versus a column filled with water, the void fraction was found to be .345 for both sizes of beads used. Five flush mounted differential pressure transducers are spaced at even intervals with the first location 4 cm from the inlet port and the subsequent pressure transducers spaced at 13 cm intervals along the column. Differential pressure data was acquired at 1000 Hz to adequately observe pulse formation and characteristics. Visual images of the flow were recorded using a high-speed SVHS system at 500 frames per second. Over 250 different test conditions were

  11. Measurment of gas-liquid two-phase slug flow with a Venturi meter based on blind source separation☆

    Institute of Scientific and Technical Information of China (English)

    Weiwei Wang; Xiao Liang; Mingzhu Zhang

    2015-01-01

    We propose a novel flow measurement method for gas–liquid two-phase slug flow by using the blind source sep-aration technique. The flow measurement model is established based on the fluctuation characteristics of differ-ential pressure (DP) signals measured from a Venturi meter. It is demonstrated that DP signals of two-phase flow are a linear mixture of DP signals of single phase fluids. The measurement model is a combination of throttle re-lationship and blind source separation model. In addition, we estimate the mixture matrix using the independent component analysis (ICA) technique. The mixture matrix could be described using the variances of two DP sig-nals acquired from two Venturi meters. The validity of the proposed model was tested in the gas–liquid two-phase flow loop facility. Experimental results showed that for most slug flow the relative error is within 10%. We also find that the mixture matrix is beneficial to investigate the flow mechanism of gas–liquid two-phase flow.

  12. Numerical simulation of three-dimensional gas/liquid two-phase flow in a proton exchange membrane fuel cell

    Institute of Scientific and Technical Information of China (English)

    ZHUGE Weilin; ZHANG Yangjun; MING Pingwen; LAO Xingsheng; CHEN Xiao

    2007-01-01

    Investigation into the formation and transport of liquid water in proton exchange membrane fuel cells (PEMFCs) is the key to fuel cell water management.A threedimensional gas/liquid two-phase flow and heat transfer model is developed based on the multiphase mixture theory.The reactant gas flow,diffusion,and chemical reaction as well as the liquid water transport and phase change process are modeled.Numerical simulations on liquid water distribution and its effects on the performance of a PEMFC are conducted.Results show that liquid water distributes mostly in the cathode,and predicted cell performance decreases quickly at high current density due to the obstruction of liquid water to oxygen diffusion.The simulation results agree well with experimental data.

  13. A comprehensive neural network model for predicting two-phase liquid holdup under various angles of pipe inclinations

    Energy Technology Data Exchange (ETDEWEB)

    Mohammadi, M. [Petroleum Univ. of Technology, Ahwaz (Iran, Islamic Republic of). Gas Engineering Dept.

    2006-07-01

    Liquid holdup in pipelines refers to the fraction of pipe that is occupied by liquid. Accurate prediction of liquid holdup associated with multiphase flow is important for the design and operation of modern petroleum production systems. Multiphase flow refers to the concurrent flow of 2 or more phases, liquid, solid or gas, where motion affects the interface between the phases. The ability to predict liquid holdup makes it possible to calculate a pressure gradient based on a two-phase friction factor. However, this approach is dependent on the accuracy of flow pattern predictions and is subject to discontinuities in predictions made across flow pattern transition boundaries. Artificial neural networks (ANN) are computing tools that can recognize complex patterns within available data. ANN has been used successfully to solve many difficult engineering problems including multiphase flow problems that involve pressure drop, flow pattern identification and liquid holdup. This study used a 3-layer backpropagation ANN model for predicting the liquid holdup in gas-liquid two-phase flow at all ranges of pipe inclinations. Five independent sets of experimental data were used, covering a wide range of variables such as inclination from horizontal, pipe diameter, gas and liquid superficial velocity, liquid viscosity, density and surface tension. The model is independent of flow pattern determination and uses an individual method for all conditions. Experimental results have shown that the newly developed model can accurately predict liquid holdup in terms of the lowest absolute average percent error, the lowest standard deviation and the highest correlation coefficient. This study confirmed the power of ANN models in solving complicated engineering problems. 28 refs., 5 tabs., 4 figs., 1 appendix.

  14. The Development of a Gas-Liquid Two-Phase Flow Sensor Applicable to CBM Wellbore Annulus.

    Science.gov (United States)

    Wu, Chuan; Wen, Guojun; Han, Lei; Wu, Xiaoming

    2016-11-18

    The measurement of wellbore annulus gas-liquid two-phase flow in CBM (coalbed methane) wells is of great significance for reasonably developing gas drainage and extraction processes, estimating CBM output, judging the operating conditions of CBM wells and analyzing stratum conditions. Hence, a specially designed sensor is urgently needed for real-time measurement of gas-liquid two-phase flow in CBM wellbore annulus. Existing flow sensors fail to meet the requirements of the operating conditions of CBM wellbore annulus due to such factors as an inapplicable measurement principle, larger size, poor sealability, high installation accuracy, and higher requirements for fluid media. Therefore, based on the principle of a target flowmeter, this paper designs a new two-phase flow sensor that can identify and automatically calibrate different flow patterns of two-phase flows. Upon the successful development of the new flow sensor, lab and field tests were carried out, and the results show that the newly designed sensor, with a measurement accuracy of ±2.5%, can adapt to the operating conditions of CBM wells and is reliable for long-term work.

  15. A New Void Fraction Measurement Method for Gas-Liquid Two-Phase Flow in Small Channels.

    Science.gov (United States)

    Li, Huajun; Ji, Haifeng; Huang, Zhiyao; Wang, Baoliang; Li, Haiqing; Wu, Guohua

    2016-01-27

    Based on a laser diode, a 12 × 6 photodiode array sensor, and machine learning techniques, a new void fraction measurement method for gas-liquid two-phase flow in small channels is proposed. To overcome the influence of flow pattern on the void fraction measurement, the flow pattern of the two-phase flow is firstly identified by Fisher Discriminant Analysis (FDA). Then, according to the identification result, a relevant void fraction measurement model which is developed by Support Vector Machine (SVM) is selected to implement the void fraction measurement. A void fraction measurement system for the two-phase flow is developed and experiments are carried out in four different small channels. Four typical flow patterns (including bubble flow, slug flow, stratified flow and annular flow) are investigated. The experimental results show that the development of the measurement system is successful. The proposed void fraction measurement method is effective and the void fraction measurement accuracy is satisfactory. Compared with the conventional laser measurement systems using standard laser sources, the developed measurement system has the advantages of low cost and simple structure. Compared with the conventional void fraction measurement methods, the proposed method overcomes the influence of flow pattern on the void fraction measurement. This work also provides a good example of using low-cost laser diode as a competent replacement of the expensive standard laser source and hence implementing the parameter measurement of gas-liquid two-phase flow. The research results can be a useful reference for other researchers' works.

  16. Studies of Two-Phase Gas-Liquid Flow in Microgravity. Ph.D. Thesis, Dec. 1994

    Science.gov (United States)

    Bousman, William Scott

    1995-01-01

    Two-phase gas-liquid flows are expected to occur in many future space operations. Due to a lack of buoyancy in the microgravity environment, two-phase flows are known to behave differently than those in earth gravity. Despite these concerns, little research has been conducted on microgravity two-phase flow and the current understanding is poor. This dissertation describes an experimental and modeling study of the characteristics of two-phase flows in microgravity. An experiment was operated onboard NASA aircraft capable of producing short periods of microgravity. In addition to high speed photographs of the flows, electronic measurements of void fraction, liquid film thickness, bubble and wave velocity, pressure drop and wall shear stress were made for a wide range of liquid and gas flow rates. The effects of liquid viscosity, surface tension and tube diameter on the behavior of these flows were also assessed. From the data collected, maps showing the occurrence of various flow patterns as a function of gas and liquid flow rates were constructed. Earth gravity two-phase flow models were compared to the results of the microgravity experiments and in some cases modified. Models were developed to predict the transitions on the flow pattern maps. Three flow patterns, bubble, slug and annular flow, were observed in microgravity. These patterns were found to occur in distinct regions of the gas-liquid flow rate parameter space. The effect of liquid viscosity, surface tension and tube diameter on the location of the boundaries of these regions was small. Void fraction and Weber number transition criteria both produced reasonable transition models. Void fraction and bubble velocity for bubble and slug flows were found to be well described by the Drift-Flux model used to describe such flows in earth gravity. Pressure drop modeling by the homogeneous flow model was inconclusive for bubble and slug flows. Annular flows were found to be complex systems of ring-like waves and a

  17. Liquid holdup measurement with double helix capacitance sensor in horizontal oil-water two-phase flow pipes

    Institute of Scientific and Technical Information of China (English)

    Lusheng Zhai; Ningde Jin; Zhongke Gao; Zhenya Wang

    2015-01-01

    This paper presents the characteristics of a double helix capacitance sensor for measurement of the liquid holdup in horizontal oil–water two-phase flow. The finite element method is used to calculate the sensitivity field of the sensor in a pipe with 20 mm inner diameter and the effect of sensor geometry on the distribution of sensitivity field is presented. Then, a horizontal oil–water two-phase flow experiment is carried out to measure the response of the double helix capacitance sensor, in which a novel method is proposed to calibrate the liquid holdup based on three pairs of paral el-wire capacitance probes. The performance of the sensor is analyzed in terms of the flow structures detected by mini-conductance array probes.

  18. Two-phase Flow of Liquid-gas in Diesel Fuel Injection System and Their Effect on Engine Performances

    Institute of Scientific and Technical Information of China (English)

    Yongling He; Zhihe Zhao; Jianxin Liu; Huiyong Du; Min Li; Yongping Zong

    2001-01-01

    In this paper, by using high-speed camera, CCD camera, signal and graph acquisition system, and other experimental instruments, investigation on liquid-gas two-phase flow in diesel fuel injection system and their effect on engine performances were made. Emerging and bursting of cavitation in the cavity above pump delivery valve, in injection pipe, and in fuel trough of injector of the fuel injection system were observed and mechanism of cavitation were discussed. Effects of liquid-gas two-phase flow on propagation velocity of pressure wave of the system and on irregular injection were analyzed. Two types of cavitation, long living time cavitation and short living time cavitation, in the cavity above pump delivery valve of diesel fuel injection system were observed.

  19. Velocity measurements in the liquid metal flow driven by a two-phase inductor

    CERN Document Server

    Pedcenko, A; Priede, J; Gerbeth, G; Hermann, R

    2013-01-01

    We present the results of velocity measurements obtained by ultrasonic Doppler velocimetry and local potential probes in the flow of GaInSn eutectic melt driven by a two-phase inductor in a cylindrical container. This type of flow is expected in a recent modification to the floating zone technique for the growth of small-diameter single intermetallic compound crystals. We show that the flow structure can be changed from the typical two toroidal vortices to a single vortex by increasing the phase shift between the currents in the two coils from 0 to 90 degrees. The latter configuration is thought to be favourable for the growth of single crystals. The flow is also computed numerically and a reasonable agreement with the experimental results is found. The obtained results may be useful for the design of combined two-phase electromagnetic stirrers and induction heaters for metal or semiconductor melts.

  20. Multi-Scale Morphological Analysis of Conductance Signals in Vertical Upward Gas-Liquid Two-Phase Flow

    Science.gov (United States)

    Lian, Enyang; Ren, Yingyu; Han, Yunfeng; Liu, Weixin; Jin, Ningde; Zhao, Junying

    2016-11-01

    The multi-scale analysis is an important method for detecting nonlinear systems. In this study, we carry out experiments and measure the fluctuation signals from a rotating electric field conductance sensor with eight electrodes. We first use a recurrence plot to recognise flow patterns in vertical upward gas-liquid two-phase pipe flow from measured signals. Then we apply a multi-scale morphological analysis based on the first-order difference scatter plot to investigate the signals captured from the vertical upward gas-liquid two-phase flow loop test. We find that the invariant scaling exponent extracted from the multi-scale first-order difference scatter plot with the bisector of the second-fourth quadrant as the reference line is sensitive to the inhomogeneous distribution characteristics of the flow structure, and the variation trend of the exponent is helpful to understand the process of breakup and coalescence of the gas phase. In addition, we explore the dynamic mechanism influencing the inhomogeneous distribution of the gas phase in terms of adaptive optimal kernel time-frequency representation. The research indicates that the system energy is a factor influencing the distribution of the gas phase and the multi-scale morphological analysis based on the first-order difference scatter plot is an effective method for indicating the inhomogeneous distribution of the gas phase in gas-liquid two-phase flow.

  1. Free energy based melting point prediction by NVT simulation with solid-liquid two-phase configuration

    Science.gov (United States)

    Inagaki, Taichi; Ishida, Toyokazu

    2016-10-01

    We propose a method for computing a melting point on the basis of the Gibbs free energy difference between the solid and liquid phases. The free energy difference is calculated from the average pressure obtained by performing a standard NVT simulation with a solid-liquid two-phase configuration. The method is validated by the melting point calculations of argon and benzene systems. In addition, the method is applied to a mannitol system, and the more reliable melting point than the previous estimate is successfully predicted. These results demonstrate that this method is very simple and useful to calculate melting points.

  2. Numerical simulation and analysis of solid-liquid two-phase three-dimensional unsteady flow in centrifugal slurry pump

    Institute of Scientific and Technical Information of China (English)

    吴波; 汪西力; 徐海良

    2015-01-01

    Based on RNGk-ε turbulence model and sliding grid technique, solid−liquid two-phase three-dimensional (3-D) unsteady turbulence of full passage in slurry pump was simulated by means of Fluent software. The effects of unsteady flow characteristics on solid−liquid two-phase flow and pump performance were researched under design condition. The results show that clocking effect has a significant influence on the flow in pump, and the fluctuation of flow velocity and pressure is obvious, particularly near the volute tongue, at the position of small sections of volute and within diffuser. Clocking effect has a more influence on liquid-phase than on solid-phase, and the wake-jet structure of relative velocity of solid-phase is less obvious than liquid-phase near the volute tongue and the impeller passage outlet. The fluctuation of relative velocity of solid-phase flow is 7.6% smaller than liquid-phase flow at the impeller outlet on circular path. Head and radial forces of the impeller are 8.1% and 85.7% of fluctuation, respectively. The results provide a theoretical basis for further research for turbulence, improving efficient, reducing the hydraulic losses and wear. Finally, field tests were carried out to verify the operation and wear of slurry pump.

  3. Stability of Wavy Films in Gas-Liquid Two-Phase Flows at Normal and Microgravity Conditions

    Science.gov (United States)

    Balakotaiah, V.; Jayawardena, S. S.

    1996-01-01

    For flow rates of technological interest, most gas-liquid flows in pipes are in the annular flow regime, in which, the liquid moves along the pipe wall in a thin, wavy film and the gas flows in the core region. The waves appearing on the liquid film have a profound influence on the transfer rates, and hence on the design of these systems. We have recently proposed and analyzed two boundary layer models that describe the characteristics of laminar wavy films at high Reynolds numbers (300-1200). Comparison of model predictions to 1-g experimental data showed good agreement. The goal of our present work is to understand through a combined program of experimental and modeling studies the characteristics of wavy films in annular two-phase gas-liquid flows under normal as well as microgravity conditions in the developed and entry regions.

  4. Liquid - liquid equilibria of the water + butyric acid + decanol ternary system

    Directory of Open Access Journals (Sweden)

    S.I. Kirbaslar

    2006-09-01

    Full Text Available Liquid-liquid equilibrium (LLE data for the water + butyric acid + decanol ternary system were determined experimentally at temperatures of 298.15, 308.15 and 318.15 K. Complete phase diagrams were obtained by determining the solubility curve and the tie lines. The reliability of the experimental tie line data was confirmed with the Othmer-Tobias correlation. The UNIFAC method was used to predict the phase equilibrium of the system using the interaction parameters for groups CH3, CH2, COOH, OH and H2O determined experimentally. Distribution coefficients and separation factors were evaluated for the immiscibility region.

  5. Liquid-liquid equilibrium of water + PEG 8000 + magnesium sulfate or sodium sulfate aqueous two-phase systems at 35°C: experimental determination and thermodynamic modeling

    Directory of Open Access Journals (Sweden)

    B. D. Castro

    2005-09-01

    Full Text Available Liquid-liquid extraction using aqueous two-phase systems is a highly efficient technique for separation and purification of biomolecules due to the mild properties of both liquid phases. Reliable data on the phase behavior of these systems are essential for the design and operation of new separation processes; several authors reported phase diagrams for polymer-polymer systems, but data on polymer-salt systems are still relatively scarce. In this work, experimental liquid-liquid equilibrium data on water + polyethylene glycol 8000 + magnesium sulfate and water + polyethylene glycol 8000 + sodium sulfate aqueous two-phase systems were obtained at 35°C. Both equilibrium phases were analyzed by lyophilization and ashing. Experimental results were correlated with a mass-fraction-based NRTL activity coefficient model. New interaction parameters were estimated with the Simplex method. The mean deviations between the experimental and calculated compositions in both equilibrium phases is about 2%.

  6. Relative hydrophobicity between the phases and partition of cytochrome-c in glycine ionic liquids aqueous two-phase systems.

    Science.gov (United States)

    Wu, Changzeng; Wang, Jianji; Li, Zhiyong; Jing, Jun; Wang, Huiyong

    2013-08-30

    In this work, glycine ionic liquids tetramethylammonium glycine ([N1111][Gly]), tetraethylammonium glycine ([N2222][Gly]), tetra-n-butylammonium glycine ([N4444][Gly]), tetra-n-butylphosphonium glycine ([P4444][Gly]) and tetra-n-pentylammonium glycine ([N5555][Gly]) were synthesized and used to prepare aqueous two-phase systems (ATPSs) in the presence of K2HPO4. Binodal curves of such ATPSs and partition coefficients of a series of dinitrophenylated (DNP) amino acids in these ATPSs were determined at 298.15K to understand the effect of cationic structure of the ionic liquids on the phase-forming ability of glycine ionic liquids, relative hydrophobicity between the phases in the ionic liquids ATPSs, and polarity of the ionic liquids-rich phases. With the attempt to correlate the relative hydrophobicity of the phases in the ATPSs with their extraction capability for proteins, partition coefficients of cytochrome-c in the ATPSs were also determined. It was shown that partition coefficients of cytochrome-c were in the range from 2.83 to 20.7 under the studied pH conditions. Then, hydrophobic interactions between cytochrome-c and the ionic liquid are suggested to be the main driving force for the preferential partition of cytochrome-c in the glycine ionic liquid-rich phases of the ATPSs. Result derived from polarity of the ionic liquids-rich phases supports this mechanism.

  7. Optical Readout of a Two Phase Liquid Argon TPC using CCD Camera and TGEMs

    CERN Document Server

    Mavrokoridis, K; Carroll, J; Lazos, M; McCormick, K J; Smith, N A; Touramanis, C; Walker, J

    2014-01-01

    This paper presents a preliminary study into the use of CCDs to image secondary scintillation light generated by Thick Gas Electron Multipliers (TGEMs) in a two phase LAr TPC. A Sony ICX285AL CCD chip was mounted above a double TGEM in the gas phase of a 40 litre two-phase LAr TPC with the majority of the camera electronics positioned externally via a feedthrough. An Am-241 source was mounted on a rotatable motion feedthrough allowing the positioning of the alpha source either inside or outside of the field cage. Developed for and incorporated into the TPC design was a novel high voltage feedthrough featuring LAr insulation. Furthermore, a range of webcams were tested for operation in cryogenics as an internal detector monitoring tool. Of the range of webcams tested the Microsoft HD-3000 (model no:1456) webcam was found to be superior in terms of noise and lowest operating temperature. In ambient temperature and atmospheric pressure 1 ppm pure argon gas, the TGEM gain was approximately 1000 and using a 1 msec...

  8. Design of functional guanidinium ionic liquid aqueous two-phase systems for the efficient purification of protein

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Xueqin; Wang, Yuzhi, E-mail: wyzss@hnu.edu.cn; Zeng, Qun; Chen, Jing; Huang, Yanhua; Xu, Kaijia

    2014-03-01

    Graphical abstract: - Highlights: • A series of novel cationic functional hexaalkylguanidinium ionic liquids and anionic functional tetraalkylguanidinium ionic liquids have been synthesized. • Functional guanidinium ionic liquid aqueous two-phase systems have been first designed for the purification of protein. • Mechanisms and performances of the process were researched. • Simple, green, safety and presents better purified ability than ordinary process. • A potential efficient platform for protein purification and related studies. - Abstract: A series of novel cationic functional hexaalkylguanidinium ionic liquids and anionic functional tetraalkylguanidinium ionic liquids have been devised and synthesized based on 1,1,3,3-tetramethylguanidine. The structures of the ionic liquids (ILs) were confirmed by {sup 1}H nuclear magnetic resonance ({sup 1}H NMR) and 13C nuclear magnetic resonance (13C NMR) and the production yields were all above 90%. Functional guanidinium ionic liquid aqueous two-phase systems (FGIL-ATPSs) have been first designed with these functional guanidinium ILs and phosphate solution for the purification of protein. After phase separation, proteins had transferred into the IL-rich phase and the concentrations of proteins were determined by measuring the absorbance at 278 nm using an ultra violet visible (UV–vis) spectrophotometer. The advantages of FGIL-ATPSs were compared with ordinary ionic liquid aqueous two-phase systems (IL-ATPSs). The proposed FGIL-ATPS has been applied to purify lysozyme, trypsin, ovalbumin and bovine serum albumin. Single factor experiments were used to research the effects of the process, such as the amount of ionic liquid (IL), the concentration of salt solution, temperature and the amount of protein. The purification efficiency reaches to 97.05%. The secondary structure of protein during the experimental process was observed upon investigation using UV–vis spectrophotometer, Fourier-transform infrared

  9. Characterizing the correlations between local phase fractions of gas-liquid two-phase flow with wire-mesh sensor.

    Science.gov (United States)

    Tan, C; Liu, W L; Dong, F

    2016-06-28

    Understanding of flow patterns and their transitions is significant to uncover the flow mechanics of two-phase flow. The local phase distribution and its fluctuations contain rich information regarding the flow structures. A wire-mesh sensor (WMS) was used to study the local phase fluctuations of horizontal gas-liquid two-phase flow, which was verified through comparing the reconstructed three-dimensional flow structure with photographs taken during the experiments. Each crossing point of the WMS is treated as a node, so the measurement on each node is the phase fraction in this local area. An undirected and unweighted flow pattern network was established based on connections that are formed by cross-correlating the time series of each node under different flow patterns. The structure of the flow pattern network reveals the relationship of the phase fluctuations at each node during flow pattern transition, which is then quantified by introducing the topological index of the complex network. The proposed analysis method using the WMS not only provides three-dimensional visualizations of the gas-liquid two-phase flow, but is also a thorough analysis for the structure of flow patterns and the characteristics of flow pattern transition. This article is part of the themed issue 'Supersensing through industrial process tomography'.

  10. Gas-Liquid Two-Phase Axial Backmixing Through Structured Packing at Elevated Pressure

    Institute of Scientific and Technical Information of China (English)

    张鹏; 刘春江; 唐忠利; 袁希钢; 余国琮

    2003-01-01

    An experimental study of the extent of axial backmixing in both gas and liquid phases was conducted in a 150 mm ID column packed with Mellapak 250Y corrugated structured packing. The column was operated at pressures ranging from 0.3 MPa to 2.0 MPa with nitrogen and water flowing countercurrently through the packing.The amount of axial backmixing was experimentally evaluated by the pulse response techniques using hydrogen in gas phase and an aqueous solution of NaC1 in liquid phase as inert tracers. The response of the tracer was monitored by means of thermal conductivity in the gas phase and electrical conductance in the liquid phase. The experimentally determined residence time distribution (RTD) curves were interpreted in terms of the diffusion-type model. The results indicated that the axial backmixing in the gas increased notably with gas flowrate and slightly with operating pressure and liquid flowrate. The liquid-phase axial backmixing was an increasing function of both gas and liquid flowrates and insensitive to pressure. Various correlations were developed for reproducing the experimental mixing data. The agreement between experimental and correlated data appeared to be acceptable and within ±20% of difference.

  11. Branch Quality Control of Gas-Liquid Two-Phase Flow Using a Novel T-Junction Type Distributor

    Institute of Scientific and Technical Information of China (English)

    FaChun Liang; Jing Chen; JinLong Wang; Hao Yu

    2014-01-01

    In order to eliminate mal-distribution and ensure the side arm to produce desirable gas quality a special distributor is proposed. The experimental distributor mainly consists of a straight through section, a gas extraction line, a liquid extraction line and a side arm branch. A gas orifice and a liquid orifice are mounted at the gas and liquid extraction line respectively to control the outlet gas quality. The diameter of the liquid orifice was set to 2�50 mm and three gas orifices with different size ( dG = 2�65, 5�00, 10�00 mm) were tested. The experiments were carried out at an air-water two-phase flow loop. The gas superficial velocity ranged from 6�0 to 20�0 m/s and the liquid superficial velocity was in the range of 0�02-0�18 m/s. Flow patterns such as wave flow, slug flow and annular flow were observed. The gas quality of the side arm branch was found mainly determined by the flow area ratio of the gas orifice to the liquid orifice and independent of gas and liquid superficial velocity, flow patterns and extraction flux.

  12. A New Void Fraction Measurement Method for Gas-Liquid Two-Phase Flow in Small Channels

    Directory of Open Access Journals (Sweden)

    Huajun Li

    2016-01-01

    Full Text Available Based on a laser diode, a 12 × 6 photodiode array sensor, and machine learning techniques, a new void fraction measurement method for gas-liquid two-phase flow in small channels is proposed. To overcome the influence of flow pattern on the void fraction measurement, the flow pattern of the two-phase flow is firstly identified by Fisher Discriminant Analysis (FDA. Then, according to the identification result, a relevant void fraction measurement model which is developed by Support Vector Machine (SVM is selected to implement the void fraction measurement. A void fraction measurement system for the two-phase flow is developed and experiments are carried out in four different small channels. Four typical flow patterns (including bubble flow, slug flow, stratified flow and annular flow are investigated. The experimental results show that the development of the measurement system is successful. The proposed void fraction measurement method is effective and the void fraction measurement accuracy is satisfactory. Compared with the conventional laser measurement systems using standard laser sources, the developed measurement system has the advantages of low cost and simple structure. Compared with the conventional void fraction measurement methods, the proposed method overcomes the influence of flow pattern on the void fraction measurement. This work also provides a good example of using low-cost laser diode as a competent replacement of the expensive standard laser source and hence implementing the parameter measurement of gas-liquid two-phase flow. The research results can be a useful reference for other researchers’ works.

  13. A Simple Approach to Characterize Gas-Aqueous Liquid Two-phase Flow Configuration Based on Discrete Solid-Liquid Contact Electrification.

    Science.gov (United States)

    Choi, Dongwhi; Lee, Donghyeon; Kim, Dong Sung

    2015-10-14

    In this study, we first suggest a simple approach to characterize configuration of gas-aqueous liquid two-phase flow based on discrete solid-liquid contact electrification, which is a newly defined concept as a sequential process of solid-liquid contact and successive detachment of the contact liquid from the solid surface. This approach exhibits several advantages such as simple operation, precise measurement, and cost-effectiveness. By using electric potential that is spontaneously generated by discrete solid-liquid contact electrification, the configurations of the gas-aqueous liquid two-phase flow such as size of a gas slug and flow rate are precisely characterized. According to the experimental and numerical analyses on parameters that affect electric potential, gas slugs have been verified to behave similarly to point electric charges when the measuring point of the electric potential is far enough from the gas slug. In addition, the configuration of the gas-aqueous liquid two-phase microfluidic system with multiple gas slugs is also characterized by using the presented approach. For a proof-of-concept demonstration of using the proposed approach in a self-triggered sensor, a gas slug detector with a counter system is developed to show its practicality and applicability.

  14. Design of functional guanidinium ionic liquid aqueous two-phase systems for the efficient purification of protein.

    Science.gov (United States)

    Ding, Xueqin; Wang, Yuzhi; Zeng, Qun; Chen, Jing; Huang, Yanhua; Xu, Kaijia

    2014-03-07

    A series of novel cationic functional hexaalkylguanidinium ionic liquids and anionic functional tetraalkylguanidinium ionic liquids have been devised and synthesized based on 1,1,3,3-tetramethylguanidine. The structures of the ionic liquids (ILs) were confirmed by (1)H nuclear magnetic resonance ((1)H NMR) and 13C nuclear magnetic resonance (13C NMR) and the production yields were all above 90%. Functional guanidinium ionic liquid aqueous two-phase systems (FGIL-ATPSs) have been first designed with these functional guanidinium ILs and phosphate solution for the purification of protein. After phase separation, proteins had transferred into the IL-rich phase and the concentrations of proteins were determined by measuring the absorbance at 278 nm using an ultra violet visible (UV-vis) spectrophotometer. The advantages of FGIL-ATPSs were compared with ordinary ionic liquid aqueous two-phase systems (IL-ATPSs). The proposed FGIL-ATPS has been applied to purify lysozyme, trypsin, ovalbumin and bovine serum albumin. Single factor experiments were used to research the effects of the process, such as the amount of ionic liquid (IL), the concentration of salt solution, temperature and the amount of protein. The purification efficiency reaches to 97.05%. The secondary structure of protein during the experimental process was observed upon investigation using UV-vis spectrophotometer, Fourier-transform infrared spectroscopy (FT-IR) and circular dichroism spectrum (CD spectrum). The precision, stability and repeatability of the process were investigated. The mechanisms of purification were researched by dynamic light scattering (DLS), determination of the conductivity and transmission electron microscopy (TEM). It was suggested that aggregation and embrace phenomenon play a significant role in the purification of proteins. All the results show that FGIL-ATPSs have huge potential to offer new possibility in the purification of proteins.

  15. Phase distribution in horizontal gas-liquid two-phase bubbly flow

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    An investigation on phase distribution in air-water two-phaseflow in horizontal circular channel was conducted by using the double-sensor resistivity probe. The variations of phase distribution with variations ofgas and liquid volumetric fluxes were analyzed and the present data werecompared with some of other researcher's data and existing models. It wasfound there exists more complicated phase distribution pattern in horizontalflow system than in vertical flow. The radial local void fraction profilesare similar at the same measurement angle with various gas and liquid flowrates. However, an asymmetric profile can be observed at a given slice ofthe pipe cross-section.

  16. (Ternary liquid + liquid) equilibria for (water + acetone + {alpha}-pinene, or {beta}-pinene, or limonene) mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Li Xiaoli [Department of Chemistry and Chemical Engineering, Division of Material Sciences, Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-machi, Kanazawa 920-1192 (Japan); Tamura, Kazuhiro, E-mail: tamura@t.kanazawa-u.ac.j [Department of Chemistry and Chemical Engineering, Division of Material Sciences, Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-machi, Kanazawa 920-1192 (Japan)

    2010-11-15

    (Ternary liquid + liquid) equilibria (tie-lines) of (water + acetone + {alpha}-pinene) at T = (288.15, 298.15, and 308.15) K and (water + acetone + {beta}-pinene, or limonene) at T = 298.15 K have been measured. The experimental (ternary liquid + liquid) equilibrium data have been correlated successfully by the original UNIQUAC and modified UNIQUAC models. The modified UNIQUAC model reproduced accurately the experimental results for the (water + acetone + {alpha}-pinene) system at all the temperatures but fairly agreed with the experimental data for the (water + acetone + {beta}-pinene, or limonene) systems.

  17. Transformation of ferulic acid to vanillin using a fed-batch solid-liquid two-phase partitioning bioreactor.

    Science.gov (United States)

    Ma, Xiao-kui; Daugulis, Andrew J

    2014-01-01

    Amycolatopsis sp. ATCC 39116 (formerly Streptomyces setonii) has shown promising results in converting ferulic acid (trans-4-hydroxy-3-methoxycinnamic acid; substrate), which can be derived from natural plant wastes, to vanillin (4-hydroxy-3-methoxybenzaldehyde). After exploring the influence of adding vanillin at different times during the growth cycle on cell growth and transformation performance of this strain and demonstrating the inhibitory effect of vanillin, a solid-liquid two-phase partitioning bioreactor (TPPB) system was used as an in situ product removal technique to enhance transformation productivity by this strain. The thermoplastic polymer Hytrel(®) G4078W was found to have superior partitioning capacity for vanillin with a partition coefficient of 12 and a low affinity for the substrate. A 3-L working volume solid-liquid fed-batch TPPB mode, using 300 g Hytrel G4078W as the sequestering phase, produced a final vanillin concentration of 19.5 g/L. The overall productivity of this reactor system was 450 mg/L. h, among the highest reported in literature. Vanillin was easily and quantitatively recovered from the polymers mostly by single stage extraction into methanol or other organic solvents used in food industry, simultaneously regenerating polymer beads for reuse. A polymer-liquid two phase bioreactor was again confirmed to easily outperform single phase systems that feature inhibitory or easily further degraded substrates/products. This enhancement strategy might reasonably be expected in the production of other flavor and fragrance compounds obtained by biotransformations.

  18. Numerical Simulation for Natural State of Two-Phase Liquid Dominated Geothermal Reservoir with Steam Cap Underlying Brine Reservoir

    Science.gov (United States)

    Pratama, Heru Berian; Miryani Saptadji, Nenny

    2016-09-01

    Hydrothermal reservoir which liquid-dominated hydrothermal reservoir is a type of geothermal reservoir that most widely used for power plant. The exploitation of mass and heat from the geothermal fluid will decrease the pressure in the reservoir over time. Therefore the pressure drop in the reservoir will have an impact on the formation of boiling zones or boiling will increase. The impacts are an increase in the fraction of steam, dryness, in the reservoir and with good vertical permeability will form a steam cap underlying the brine reservoir. The two- phase liquid dominated reservoir is sensitive to the porosity and difficult to assign average properties of the entire reservoir when there is boiling zone in some area of the reservoir. These paper showed successful development of two-phase liquid dominated geothermal reservoir and discussed the formation of steam cap above brine reservoir through numerical simulation for state natural conditions. The natural state modeling in steam cap shows a match with the conceptual model of the vapor-dominated developed. These paper also proofed the presence of transition zone, boiling zone, between steam cap and brine reservoir.

  19. Temporal and spatial evolution characteristics of gas-liquid two-phase flow pattern based on image texture spectrum descriptor

    Institute of Scientific and Technical Information of China (English)

    ZHOU Xi-guo; JIN Ning-de; WANG Zhen-ya; ZHANG Wen-yin

    2009-01-01

    The dynamic image information of typical gas-liquid two-phase flow patterns in vertical upward pipe is captured by a high-speed dynamic camera. The texture spectrum descriptor is used to describe the texture characteristics of the processed images whose content is represented in the form of texture spectrum histogram, and four time-varying characteristic param-eter indexes which represent image texture structure of different flow patterns are extracted. The study results show that the amplitude fluctuation of texture characteristic parameter indexes of bubble flow is lowest and shows very random complex dynamic behavior; the amplitude fluctuation of slug flow is higher and shows intermittent motion behavior between gas slug and liquid slug, and the amplitude fluctuation of churn flow is the highest and shows better periodicity; the amplitude fluctuation of bubble-slug flow is from low to high and oscillating frequence is higher than that of slug flow, and includes the features of both slug flow and bubble flow; the slug-churn flow loses the periodicity of slug flow and churn flow, and the amplitude fluctuation is high. The results indicate that the image texture characteristic parameter indexes of different flow pattern can reflect the flow characteristics of gas-liquid two-phase flow, which provides a new approach to tmderstand the temporal and spatial evolution of flow pattern dynamics.

  20. Two-phase flow equations for a dilute dispersion of gas bubbles in liquid

    NARCIS (Netherlands)

    Biesheuvel, A.; Wijngaarden, van L.

    1984-01-01

    Equations of motion correct to the first order of the gas concentration by volume are derived for a dispersion of gas bubbles in liquid through systematic averaging of the equations on the microlevel. First, by ensemble averaging, an expression for the average stress tensor is obtained, which is non

  1. Entrainment phenomenon in gas–liquid two-phase flow: A review

    Indian Academy of Sciences (India)

    R K Bagul; D S Pilkhwal; P K Vijayan; J B Joshi

    2013-12-01

    The gas–liquid separation equipments are aimed to be designed for maximum efficiency of phase separation. In order to maximize their capacity the flow rates are required to be optimized for the capital cost of equipment. This leads to the situation where the gas phase leaves the separation interface with high velocities and carry liquid phase along with it in the form of droplets reducing the equipment efficiency. This is known as entrainment or carryover. Depending on the nature of the separation interface i.e., turbulence intensity, bubble dynamics, the size and velocity distribution of liquid fragments, droplets at the separation interface varies. This is the main source of empiricism involved in the analysis of such equipments. The mechanics of motion of the dispersed liquid phase in bulk of gas is relatively well studied. In the present paper the various experimental, analytical and numerical investigations carried out to address the issues of entrainment/carryover are carefully analyzed. Further, a critical review has been presented for bringing out a coherent theme and a current status of the subject under reference.

  2. Interfacial wave patterns and their transitions in gas-liquid two-phase flow through horizontal ducts

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    The interfacial wave patterns and their transition characteristics in gas-liquid two-phase flow through rectangular and circular horizontal conduits are investigated.The interfacial waves were traced and recorded by using conductance probes.With the experimental observation and the analysis,some kinds of different interfacial waves were distinguished and dfined,and then the interfacial wave patterns were given,which were compared with previous results.The interfacial wave transition mechanism between each interfacial wave pattern was discussed and a set of transition equations were presented to predict the interfacial wave pattern transitions.The repdictive results are in good agreement with the experimental data.

  3. FORCES ON PARTICLES AND THEIR EFFECTS ON VERTICAL SEDIMENT SORTING IN SOLID-LIQUID TWO-PHASE FLOWS

    Institute of Scientific and Technical Information of China (English)

    NI Jinren; MENG Xiaogang

    2001-01-01

    Vertical motion of particles was simulated by the Lagrangian method in one-dimensional solid-liquid two-phase flow. The conventional equation was modified by inserting a particle-particle interaction term,which was identified by Bagnold's experimental results. Effects of various forces have been examined under different particle concentrations. The results showed that the vertical sorting patterns are primarily determined by the joint action of inter-particle force and effective gravitational force, whereas the pace towards the steady sorting pattern was affected by Basset force and additional mass force.

  4. (Liquid + liquid) equilibria of {l_brace}heptane + xylene + N-formylmorpholine{r_brace} ternary system

    Energy Technology Data Exchange (ETDEWEB)

    Chen Dongchu [College of Chemistry and Chemical Engineering, Central South University, ChangSha 410083 (China)], E-mail: dcchen@hnust.edu.cn; Ye Hongqi; Hao Wu [College of Chemistry and Chemical Engineering, Central South University, ChangSha 410083 (China)

    2007-12-15

    (Liquid + liquid) equilibrium (LLE) data for ternary system {l_brace}heptane (1) + m-xylene (2) + N-formylmorpholine (3){r_brace} have been determined experimentally at temperatures ranging from 298.15 K to 353.15 K. Complete phase diagrams were obtained by determining solubility and tie-line data. Tie-line compositions were correlated by Othmer-Tobias and Bachman methods. The universal quasichemical activity coefficient (UNIQUAC) and The non-random two liquids equation (NRTL) were used to correlate the phase equilibrium in the system using the interaction parameters determined from experimental data. It is found that UNIQUAC and NRTL used for LLE could provide a good correlation. Distribution coefficients, separation factors, and selectivity were evaluated for the immiscibility region.

  5. PREDICTION ON THE THERMODYNAMIC PROPERTIES OF TERNARY LIQUID ALLOYS BY MODIFIED COORDINATION EQUATION

    Institute of Scientific and Technical Information of China (English)

    D.P.Tao

    2001-01-01

    The coordination numbers in the Molecular Interaction Volume Model can be calcu-lated from the common physical quantities of pure matters.A significant advantage ofthe model lies in its ability to predict the thermodynamic properties of ternary liqmdalloys using only the binary infinite dilute activity coefficients,and the predicted values are in good agreement with the experimental data of ternary liquid alloys,whichshows that the model is reliable,convenient and economic.

  6. Liquid-Liquid Equilibria of Ternary Systems cis-1,2-Dimethylcyclohexane+Toluene+Sulfolane☆

    Institute of Scientific and Technical Information of China (English)

    Xiaoyan Sun; Shuguang Xiang

    2014-01-01

    Liquid–Liquid Equilibrium (LLE) data for three Ternary Systems comprising cis-1,2-dimethylcyclohexane+toluene+sulfolane were measured at 298.15, 313.15 and 328.15 K under atmospheric pressure. The phase di-agrams for the ternary systems were presented. The reliability of the experiment data was tested using the Othmer–Tobias correlation. The LLE data were then correlated with the universal functional activity coefficient for liquid–liquid systems (UNIF-LL) and non-random two liquid using dataset 2 (NRTL/2) activity coefficient models to obtain the binary interaction parameters as programmed by the Aspen Plus simulation. The results showed that the experimental data were satisfactorily represented by both the UNIF-LL and the NRTL/2 models as revealed from the very smal values of the root mean square error and the absolute deviation in composition. © 2014 The Chemical Industry and Engineering Society of China, and Chemical Industry Press. Al rights reserved.

  7. Treatment technologies of liquid and solid wastes from two-phase olive oil mills

    Directory of Open Access Journals (Sweden)

    Rincón, Bárbara

    2006-03-01

    Full Text Available Over the last 10 years the manufacture of olive oil has undergone important evolutionary changes in the equipment used for the separation of olive oil from the remaining components. The latest development has been the introduction of a two-phase centrifugation process in which a horizontally-mounted centrifuge is used for a primary separation of the olive oil fraction from the vegetable solid material and vegetation water. Therefore, the new two-phase olive oil mills produce three identifiable and separate waste streams. These are: 1 the wash waters from the initial cleansing of the fruit; 2 the wash waters from the secondary centrifuge and 3 the aqueous solid residues from the primary centrifugation. As well as offering process advantages they also reduce the water consumption of the mill. The introduction of this technology was carried out in 90% of Spanish olive oil factories. Therefore, the new twophase olive mill effluents (TPOME are made up of the mixture of effluents (1 and (2, the total volume of TPOME generated being around 0.25 l/kg of olives processed. In addition, the solid residue (two-phase olive pomace, TPOP has a high organic matter concentration giving an elevated polluting load and it cannot be easily handled by traditional technology which deals with the conventional three-phase olive cake.So, this paper aims to report the main features and characteristics of TPOME, and of TPOP, as compared to the classical olive mill wastewater (OMW and olive cake derived from the three-phase manufacturing process. The advantages and disadvantages of the two-phase decanting process will be summarized. Among the treatments reported for TPOME, aerobic processes in completely mixed and activated sludge reactor showed high COD removal efficiencies. Kinetic constants of the aerobic processes were also compared at different operational conditions. The report also includes the following findings: assays of anaerobic digestion of wastewaters from the

  8. Experimental study on two-phase gas-liquid flow patterns at normal and reduced gravity conditions

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Experimental studies have been performed for horizontal two-phase air-water flows at nor-mal and reduced gravity conditions in a square cross-section channel. The experiments at reducedgravity are conducted on board the Russian IL-76 reduced gravity airplane. Four flow patterns, namelybubble, slug, slug-annular transition and annular flows, are observed depending on the liquid and gassuperficial velocities at both conditions. Semi-theoretical Weber number model is developed to includethe shape influence on the slug-annular transition. It is shown that its prediction is in reasonable agree-ment with the experimental slug-annular transition under both conditions. For the case of two-phasegas-liquid flow with large value of the Froude number, the drift-flux model can predict well the observedboundary between bubble and slug flows.

  9. Determination of Sudan I-IV in candy using ionic liquid/anionic surfactant aqueous two-phase extraction coupled with high-performance liquid chromatography.

    Science.gov (United States)

    Yu, Wei; Liu, Zhongling; Li, Qiang; Zhang, Hanqi; Yu, Yong

    2015-04-15

    Ionic liquid/anionic surfactant aqueous two-phase system was developed and applied for the extraction of Sudan I-IV. High-performance liquid chromatography was applied to the determination of the analytes. The aqueous two-phase system (ATPS) was formed in the present of C4[MIM]BF4, sodium dodecyl benzene sulphonate and (NH4)2SO4. The parameters affecting the extraction efficiency, such as volume of ionic liquid, amount of sodium dodecyl benzene sulphonate, ionic strength, pH value of system, extraction time and temperature were investigated. The limits of detection for Sudan I, II, III and IV were 5.45, 4.66, 3.68, 4.20 μg kg(-1), respectively. When the present method was applied to the analysis of candy samples, the recoveries of the analytes ranged from 82.3% to 112.1% and relative standard deviations were lower than 7.41%.

  10. Flooding characteristics of gas-liquid two-phase flow in a horizontal U bend pipe

    Energy Technology Data Exchange (ETDEWEB)

    Sakaguchi, T.; Hosokawa, S.; Fujii, Y. [Kobe Univ. (Japan)] [and others

    1995-09-01

    For next-generation nuclear reactors, hybrid safety systems which consist of active and passive safety systems have been planned. Steam generators with horizontal U bend pipelines will be used as one of the passive safety systems. It is required to clarify flow characteristics, especially the onset of flooding, in the horizontal U bend pipelines in order to examine their safety. Flooding in vertical pipes has been studied extensively. However, there is little study on flooding in the horizontal U bend pipelines. It is supposed that the onset of flooding in the horizontal U bend pipelines is different from that in vertical pipes. On the other hand, liquid is generated due to condensation of steam in pipes of the horizontal steam generators at the loss of coolant accident because the steam generators will be used as a condenser of a cooling system of steam from the reactor. It is necessary to simulate this situation by the supply of water at the middle of horizontal pipe. In the present paper, experiments were carried out using a horizontal U bend pipeline with a liquid supply section in the midway of pipeline. The onset of flooding in the horizontal U bend pipeline was measured. Effects of the length of horizontal pipe and the radius of U bend on the onset of flooding were discussed.

  11. Numerical Thermodynamic Analysis of Two-Phase Solid-Liquid Abrasive Flow Polishing in U-Type Tube

    Directory of Open Access Journals (Sweden)

    Junye Li

    2014-08-01

    Full Text Available U-type tubes are widely used in military and civilian fields and the quality of the internal surface of their channel often determines the merits and performance of a machine in which they are incorporated. Abrasive flow polishing is an effective method for improving the channel surface quality of a U-type tube. Using the results of a numerical analysis of the thermodynamic energy balance equation of a two-phase solid-liquid flow, we carried out numerical simulations of the heat transfer and surface processing characteristics of a two-phase solid-liquid abrasive flow polishing of a U-type tube. The distribution cloud of the changes in the inlet turbulent kinetic energy, turbulence intensity, turbulent viscosity, and dynamic pressure near the wall of the tube were obtained. The relationships between the temperature and the turbulent kinetic energy, between the turbulent kinetic energy and the velocity, and between the temperature and the processing velocity were also determined to develop a theoretical basis for controlling the quality of abrasive flow polishing.

  12. A resolution approach of racemic phenylalanine with aqueous two-phase systems of chiral tropine ionic liquids.

    Science.gov (United States)

    Wu, Haoran; Yao, Shun; Qian, Guofei; Yao, Tian; Song, Hang

    2015-10-30

    Aqueous two-phase systems (ATPS) based on tropine type chiral ionic liquids and inorganic salt solution were designed and prepared for the enantiomeric separation of racemic phenylalanine. The phase behavior of IL-based ATPS was comprehensive investigated, and phase equilibrium data were correlated by Merchuk equation. Various factors were also systematically investigated for their influence on separation efficiency. Under the appropriate conditions (0.13g/g [C8Tropine]pro, 35mg/g Cu(Ac)2, 20mg/g d,l-phenylalanine, 0.51g/g H2O and 0.30g/g K2HPO4), the enantiomeric excess value of phenylalanine in solid phase (mainly containing l-enantiomer) was 65%. Finally, the interaction mechanism was studied via 1D and 2D NMR. The results indicate that d-enantiomer of phenylalanine interacts more strongly with chiral ILs and Cu(2+) based on the chiral ion-pairs space coordination mechanism, which makes it tend to remain in the top IL-rich phase. By contrast, l-enantiomer is transferred into the solid phase. Above chiral ionic liquids aqueous two-phase systems have demonstrated obvious resolution to racemic phenylalanine and could be promising alterative resolution approach for racemic amino acids in aqueous circumstance.

  13. Numerical simulation on the performance of the vortex pump for transporting solid-liquid two-phase with light particles

    Science.gov (United States)

    Mao, W. Y.; Song, P. Y.; Deng, Q. G.; Xu, H. J.

    2016-05-01

    With the purpose of studying performance of the vortex pump for transporting solid-liquid two-phase with light particles whose relative density smaller than 1, the numerical simulation of solid-liquid two phase flowing in the whole channel of a vortex pump with the particle diameter being 0.5 mm, 1 mm, 2 mm, 3 mm and the initial solid phase volume concentrations being 10%, 20% and 30% are respectively carried out by using the commercial software ANSYS Fluent by adopting RNG κ-ɛ turbulent flow model, Eulerian-Eulerian multi-phase flow model and SIMPLEC algorithm. The simulation results show that in the impeller region, the particles concentrate on the non-working surface of the blades, and the particles are rare on the working surface of the blades. As the initial solid phase volume concentration and particle diameter increase, the pump delivery head of vortex pump decrease. The pump delivery head of vortex pump with different initial solid phase concentrations and different particle diameters are predicted and compared with those obtained by an empirical formula, and they shows good agreement.

  14. Slug flow transitions in horizontal gas/liquid two-phase flows. Dependence on channel height and system pressure for air/water and steam/water two-phase flows

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Hideo [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1996-05-01

    The slug flow transitions and related phenomena for horizontal two-phase flows were studied for a better prediction of two-phase flows that typically appear during the reactor loss-of-coolant accidents (LOCAs). For better representation of the flow conditions experimentally, two large-scaled facility: TPTF for high-pressure steam/water two-phase flows and large duct test facility for air/water two-phase flows, were used. The visual observation of the flow using a video-probe was performed in the TPTF experiments for good understanding of the phenomena. The currently-used models and correlations based mostly on the small-scale low-pressure experiments were reviewed and improved based on these experimental results. The modified Taitel-Dukler model for prediction of transition into slug flow from wavy flow and the modified Steen-Wallis correlation for prediction of onset of liquid entrainment from the interfacial waves were obtained. An empirical correlation for the gas-liquid interfacial friction factor was obtained further for prediction of liquid levels at wavy flow. The region of slug flow regime that is generally under influences of the channel height and system pressure was predicted well when these models and correlations were applied together. (author). 90 refs.

  15. Numerical simulation of the effect of void fraction and inlet velocity on two-phase turbulence in bubble-liquid flows

    Institute of Scientific and Technical Information of China (English)

    Lixing Zhou; Rongxian Li; Ruxu Du

    2006-01-01

    There are contradicted opinions on whether bubbles enhance or reduce the liquid turbulence. In this paper, the effect of void fraction and inlet velocity on the bubble-liquid two-phase turbulence of the multiple bubble-liquid jets in a two-dimensional channel is studied by using the two-phase second-order moment turbulence model. The results confirm the phenomena observed in experiments and reported in references that at a low void fraction and low inlet velocities the bubbles enhance the liquid turbulence, whereas at a high void fraction and high inlet velocities the bubbles reduce the liquid turbulence.

  16. A New Method for Ultrasound Detection of Interfacial Position in Gas-Liquid Two-Phase Flow

    Directory of Open Access Journals (Sweden)

    Fábio Rizental Coutinho

    2014-05-01

    Full Text Available Ultrasonic measurement techniques for velocity estimation are currently widely used in fluid flow studies and applications. An accurate determination of interfacial position in gas-liquid two-phase flows is still an open problem. The quality of this information directly reflects on the accuracy of void fraction measurement, and it provides a means of discriminating velocity information of both phases. The algorithm known as Velocity Matched Spectrum (VM Spectrum is a velocity estimator that stands out from other methods by returning a spectrum of velocities for each interrogated volume sample. Interface detection of free-rising bubbles in quiescent liquid presents some difficulties for interface detection due to abrupt changes in interface inclination. In this work a method based on velocity spectrum curve shape is used to generate a spatial-temporal mapping, which, after spatial filtering, yields an accurate contour of the air-water interface. It is shown that the proposed technique yields a RMS error between 1.71 and 3.39 and a probability of detection failure and false detection between 0.89% and 11.9% in determining the spatial-temporal gas-liquid interface position in the flow of free rising bubbles in stagnant liquid. This result is valid for both free path and with transducer emitting through a metallic plate or a Plexiglas pipe.

  17. Gamma-ray attenuation technique for measuring void fraction in horizontal gas-liquid two-phase flow

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The measurement of void fraction is of importance to the oil industry and chemical industry. In this article,the principle and mathematical method of determining the void fraction of horizontal gas-liquid flow by using a single-energy γ-ray system is described. The γ-ray source is the radioactive isotope of 241Am with γ-ray energy of 59.5 keV. The time-averaged value of the void fraction in a 50.0-mm i.d. transparent horizontal pipeline is measured under various combinations of the liquid flow and gas flow. It is found that increasing the gas flow rate at a fixed liquid flow rate would increase the void fraction. Test data are compared with the predictions of the correlations and a good agreement is found. The result shows that the designed γ-ray system can be used for measuring the void fraction in a horizontal gas-liquid two-phase flow with high accuracy.

  18. [CFD numerical simulation onto the gas-liquid two-phase flow behavior during vehicle refueling process].

    Science.gov (United States)

    Chen, Jia-Qing; Zhang, Nan; Wang, Jin-Hui; Zhu, Ling; Shang, Chao

    2011-12-01

    With the gradual improvement of environmental regulations, more and more attentions are attracted to the vapor emissions during the process of vehicle refueling. Research onto the vehicle refueling process by means of numerical simulation has been executed abroad since 1990s, while as it has never been involved so far domestically. Through reasonable simplification about the physical system of "Nozzle + filler pipe + gasoline storage tank + vent pipe" for vehicle refueling, and by means of volume of fluid (VOF) model for gas-liquid two-phase flow and Re-Normalization Group kappa-epsilon turbulence flow model provided in commercial computational fluid dynamics (CFD) software Fluent, this paper determined the proper mesh discretization scheme and applied the proper boundary conditions based on the Gambit software, then established the reasonable numerical simulation model for the gas-liquid two-phase flow during the refueling process. Through discussing the influence of refueling velocity on the static pressure of vent space in gasoline tank, the back-flowing phenomenon has been revealed in this paper. It has been demonstrated that, the more the flow rate and the refueling velocity of refueling nozzle is, the higher the gross static pressure in the vent space of gasoline tank. In the meanwhile, the variation of static pressure in the vent space of gasoline tank can be categorized into three obvious stages. When the refueling flow rate becomes higher, the back-flowing phenomenon of liquid gasoline can sometimes be induced in the head section of filler pipe, thus making the gasoline nozzle pre-shut-off. Totally speaking, the theoretical work accomplished in this paper laid some solid foundation for self-researching and self-developing the technology and apparatus for the vehicle refueling and refueling emissions control domestically.

  19. Liquefaction and methanization of solid and liquid coffee wastes by two phase anaerobic digestion process.

    Science.gov (United States)

    Houbron, E; Larrinaga, A; Rustrian, E

    2003-01-01

    This study attempted to investigate the feasibility of volatile fatty acid (VFA) production from coffee pulp hydrolyse, and further to determine the potential of methanization of both the pre-acidified effluent and the coffee wastewater. The experiments were carried out in 2 completely mixed reactors, each one with a working volume of 4 litres. Coffee pulp was used as substrate in the acidogenic reactor and different mixtures of pulper and wash-water and pre-acidified effluent in the methanogenic one. The acidogenic and methanogenic reactors were operated at an organic loading rate of 5 COD g x l(-1) x d(-1) and 0.5 COD g x l(-1) x d(-1). The total, soluble and VFA's effluent COD concentrations of the acidogenic reactor present average values of 57.75, 17.00 and 13.92 g x l(-1) respectively. Under these experimental conditions, 23% (COD based) of coffee pulp was hydrolysed with a rate of 1.32 gCOD x l(-1) x d(-1) and the soluble fraction was transformed to VFA's with an acidification efficiency of 82%. Total VFA's concentration reached a value of 13.9 gCOD x l(-1), and acetate, propionate, butyrate and valerate represented 52%, 28%, 9% and 11% respectively of the liquid phase COD. In the methanogenic reactor, COD removal and methanization of fresh coffee wastewater, pre-acidified effluent and both combined occur with an efficiency of 85% to 95% respectively, with a characteristic biogas composition of 80% CH4 and 20% CO2. These results show that a humid coffee "Beneficio" processing daily 23 tons of cherry coffee (fresh fruit), equipped with a two stage anaerobic digestion process could generate at least 1,886 CH4 m3 x d(-1). This represents an increase in methane production by a factor 3 to 5 compared to a "Beneficio" using anaerobic digestion only for the treatment of its wastewater.

  20. Liquefaction and methanization of solid and liquid coffee wastes by two phase anaerobic digestion process

    Energy Technology Data Exchange (ETDEWEB)

    Houbron, E.; Rustrian, E. [Universidad Veracruzana, Orizaba, Ver. (Mexico). Facultad de Ciencias Quimicas; Larrinaga, A. [Instituto tecnologico de Orizaba, Ver. (Mexico)

    2003-07-01

    This study attempted to investigate the feasibility of volatile fatty acid (VFA) production from coffee pulp hydrolyse, and further to determine the potential of methanization of both the pre-acidified effluent and the coffee wastewater. The experiments were carried out in 2 completely mixed reactors, each one with working volume of 4 litres. Coffee pulp was used as substrate in the acidogenic reactor and different mixtures of pulper and wash-water and pre-acidified effluent in the methanogenic one. The acidogenic and methanogenic reactors were operated at an organic loading rate of 5 COD g.l{sup -1}.d{sup -1} and 0.5 COD g.l{sup -1}.d{sup -1}. The total, soluble and VFA's effluent COD concentrations of the acidogenic reactor present average values of 57.75, 17.00 and 13.92 g.l{sup -1} respectively. Under these experimental conditions, 23% (COD based) of coffee pulp was hydrolysed with a rate of 1.32 gCOD.l{sup -1}.d{sup -1} and the soluble fraction was transformed to VFA's with an acidification efficiency of 82%. Total VFA's concentration reached a value of 13.9 gCOD.l{sup -1}, and acetate, propionate, butyrate and valerate represented 52%, 28%, 9% and 11% respectively of the liquid phase COD. In the methanogenic reactor, COD removal and methanization of fresh coffee wastewater, pre-acidified effluent and both combined occur with an efficiency of 85% to 95% respectively, with a characteristic biogas composition of 80% CH{sub 4} and 20% CO{sub 2}. These results show that a humid coffee 'Beneficio' processing daily 23 tons of cherry coffee (fresh fruit), equipped with a two stage anaerobic digestion process could generate at least 1,886 CH{sub 4} m{sup 3}.d{sup -1}. This represents an increase in methane production by a factor 3 to 5 compared to a 'Beneficio' using anaerobic digestion only for the treatment of its wastewater. (author)

  1. High resolution of racemic phenylalanine with dication imidazolium-based chiral ionic liquids in a solid-liquid two-phase system.

    Science.gov (United States)

    Huang, Xiaoxia; Wu, Haoran; Wang, Zhixia; Luo, Yingjie; Song, Hang

    2017-01-06

    A novel solid-liquid two-phase system was developed for the chiral separation of racemic phenylalanine with new dication imidazolium-based chiral ionic liquids. Preliminary experiments showed distinct enantioselectivity in amino acid extraction with the novel solid-liquid two-phase system, more L-enantiomer of amino acid cooperatively interacted with ionic liquids and copper ions to be the solid phase. Various factors, including the alkyl chain length of cations of ionic liquids, the amount of copper acetate, the ratio of n(ILs)/n(Cu(2+)), the amount of water and racemic phenylalanine, the resolution time together with the resolution temperature, were systematically investigated for their influence on resolution efficiency. The results showed that, under a certain condition, the enantiomeric excess value and the yield of phenylalanine in liquid phase (mainly containing D-enantiomer) were 67.8% and 96.5%, the enantiomeric excess value and the yield of phenylalanine in solid phase (mainly containing L-enantiomer) were 99.2% and 85.2%. Finally, 2D NMR technology, infrared spectroscopy and molecular simulation method were used to study the interaction mechanism. The results indicated that L-enantiomer of phenylalanine interacts more strongly with chiral ILs and Cu(2+). The novel system has characteristics of free-organic solvent, simple operation, fast separation process and very high resolution efficiency for racemic phenylalanine. This work could provide a new and alternative resolution approach for other chiral separations.

  2. Two-phase and three-phase liquid-phase microextraction of hydrochlorothiazide and triamterene in urine samples.

    Science.gov (United States)

    Ahmad Panahi, Homayon; Ejlali, Maryam; Chabouk, Monireh

    2016-07-01

    This paper reports the applicability of two-phase and three-phase hollow fiber based liquid-phase microextraction (HF-LPME) for the extraction of hydrochlorothiazide (HYD) and triamterene (TRM) from human urine. The HYD in two-phase HF-LPME is extracted from 24 mL of the aqueous sample into an organic phase with microliter volume located inside the pores and lumen of a polypropylene hollow fiber as acceptor phase, but the TRM in three-phase HF-LPME is extracted from aqueous donor phase to organic phase and then back-extracted to the aqueous acceptor phase, which can be directly injected into HPLC for analysis. Under optimized conditions preconcentration factors of HYD and TRM were obtained as 128 and 239, respectively. The calibration curves were linear (R(2)  ≥ 0.995) in the concentration range of 1.0-100 µg/L for HYD and 2.0-100 µg/L for TRM. The limits of detection for HYD and TRM were 0.5 µg/L. The intra-day and inter-day RSD based on four replicates were obtained as ≤5.8 and ≤9.3%, respectively. The methods were successfully applied for determining the concentration of the drugs in urine samples. Copyright © 2015 John Wiley & Sons, Ltd.

  3. Correlations between the two-phase gas/liquid spray atomization and the Stokes/aerodynamic Weber numbers

    Science.gov (United States)

    Rahman, Mohammad A.; Heidrick, Ted; Fleck, Brian A.

    2009-02-01

    The The effects of air-to-liquid ratio (β) and void fraction (α) on Sauter mean diameter (SMD or D32), arithmetic mean diameter (D10), surface mean diameter (D20), volume mean diameter (VMD or D20), and radial velocity profiles were experimentally investigated for a two-phase gas/liquid (TPGL) nozzle with a hybrid design of classical twin-fluid and effervescent nozzles. Radial spray profiles were measured using a Phase-Doppler-Particle-Anemometer (PDPA) system on 15Dn, 30Dn, 60Dn, 120Dn;(Dn represents nozzle diameter = 3.10,mm) axial distances. In addition, the effects of spray break-up patterns were analyzed with changing axial distances. The average void fraction in the feeding conduit (FC) was measured by a pneumatic controlled quick-closing-valve (QCV). The experiments were performed using mixtures of air with water at water flow rates of 1.50 to 7.50 kg/min and air-to-liquid mass ratios (β) of 0.30 to 10;%. The length and diameter of the FC was 36.8,cm and 6.35,mm, respectively. Result indicates that as the St number reaches the value of one, no more break-up continues, thus the droplets start to coalesce each other forming bigger droplets (higher D10 values) with increasing radial distances. Knowledge from this study will provide better understanding that ensures an increase in plant efficiency and product yield in oil sands bitumen upgrading.

  4. Liquid-phase turbulence measurements in air-water two-phase flows over a wide range of void fractions

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Xinquan [Nuclear Engineering Program, Department of Mechanical and Aerospace Engineering, The Ohio State University, 201 W. 19th Ave., Columbus, OH 43210 (United States); Sun, Xiaodong, E-mail: sun.200@osu.edu [Nuclear Engineering Program, Department of Mechanical and Aerospace Engineering, The Ohio State University, 201 W. 19th Ave., Columbus, OH 43210 (United States); Liu, Yang [Nuclear Engineering Program, Department of Mechanical Engineering, Virginia Tech, 635 Prices Fork Road, Blacksburg, VA 24061 (United States)

    2016-12-15

    This paper focuses on liquid-phase turbulence measurements in air-water two-phase flows over a wide range of void fractions and flow regimes, spanning from bubbly, cap-bubbly, slug, to churn-turbulent flows. The measurements have been conducted in two test facilities, the first one with a circular test section and the second one with a rectangular test section. A particle image velocimetry-planar laser-induced fluorescence (PIV-PLIF) system was used to acquire local liquid-phase turbulence information, including the time-averaged velocity and velocity fluctuations in the streamwise and spanwise directions, and Reynolds stress. An optical phase separation method using fluorescent particles and optical filtration technique was adopted to extract the liquid-phase velocity information. An image pre-processing scheme was imposed on the raw PIV images acquired to remove noise due to the presence of bubble residuals and optically distorted particles in the raw PIV images. Four-sensor conductivity probes and high-speed images were also used to acquire the gas-phase information, which was aimed to understand the flow interfacial structure. The highest area-averaged void fraction covered in the measurements for the circular and rectangular test sections was about 40%.

  5. Separation of curcuminoids using ionic liquid based aqueous two-phase system coupled with in situ dispersive liquid-liquid microextraction.

    Science.gov (United States)

    Shu, Yang; Gao, Mingcen; Wang, Xueying; Song, Rusheng; Lu, Jun; Chen, Xuwei

    2016-01-01

    An aqueous two-phase extraction system (ATPS) combined with an in situ dispersive liquid-liquid microextraction (DLLME) method using imidazolium ionic liquids (ILs) for the separation of curcuminoids is developed. The influence of structure of IL, the type of metathesis reagents, and the back extraction agents on the extraction efficiency is investigated. 2.0mg of curcuminoids are extracted by an IL ATPS composed of 0.4g 1,3-diethylimidazolium iodine (EeimI), 0.6g potassium hydrogen phosphate, 1.0g water. Then the bis[(trifluoromethyl)sulfonyl]imide lithium (LiNTf2) aqueous solution is added to the EeimI-rich phase of the ATPS. The water-immiscible ionic liquids, 1,3-diethylimidazole bis[(trifluoromethyl)sulfonyl]imide (EeimNTf2), forms by the metathesis reaction. The in situ DLLME is triggered simultaneously and further purifies the curcuminoids. 92% of EeimI transforms into EeimNTf2 and thus the Eeim(+) cation is used for twice in this method. Finally, 0.1mol/L NaOH aqueous solution is used as the back extraction reagent. The curcuminoids precipitate is achieved with 93% of recovery when the aqueous solution is adjusted to pH 3.0. This ATPS-DLLME method is successfully applied to the separation of curcuminoids from Curcuma Longa (0.96±0.02% of extraction yield, a purity of >51% with respect to the total dry mass of the product).

  6. Microstructure-property relationships in digitally generated three-dimensional, two-phase, liquid phase sintered materials

    Science.gov (United States)

    Lee, Sukbin

    complete wetting of particles by matrix and the constraint that the site exchange for diffusion of voxels is allowed only for neighboring particle-matrix voxel pairs in the Monte Carlo Potts model, this model can also be used for modeling isotropic coarsening of solid particles during liquid phase sintering. Kinetic Monte Carlo simulation is used to probe the coarsening dynamics and to obtain the characteristics of the solid particles, including the volume of critical nuclei and the distribution of particle size as a function of time. It is found that the average particle volume increases linearly with time and that the particle size distributions are consistent with those obtained experimentally, as in liquid phase sintered W-Ni-Fe and Sn-Pb systems. In obtaining these results, careful consideration is given to the role of initial microstructural conditions in the subsequent evolution of the system. The other objective of this project is to explore the effect of individual microstructural parameters in the hypothetical two-phase microstructures, including ones from the proposed Monte Carlo coarsening simulation, on stress and strain rate fields when uniaxial tension is applied. Using those two-phase digital microstructures as inputs, the microstructure-property relationship study is performed using a viscoplastic simulation based on the Fast Fourier Transform (FFT) algorithm. In the simulations, the dispersed phase consists of hard BCC particles with random spatial orientations while the matrix phase is either (1) a single soft FCC crystal with a fixed spatial orientation or (2)a soft FCC polycrystalline structure with random spatial orientations. A systematic parametric study, varying selected microstructural parameters such as the volume fraction of phases, contiguity of particles and spatial distribution of particles, is employed in order to explore the mechanical response of the hypothetical microstructures under uniaxial tension. It is found that the contiguity of

  7. Characterization of aqueous two phase systems by combining lab-on-a-chip technology with robotic liquid handling stations.

    Science.gov (United States)

    Amrhein, Sven; Schwab, Marie-Luise; Hoffmann, Marc; Hubbuch, Jürgen

    2014-11-07

    Over the last decade, the use of design of experiment approaches in combination with fully automated high throughput (HTP) compatible screenings supported by robotic liquid handling stations (LHS), adequate fast analytics and data processing has been developed in the biopharmaceutical industry into a strategy of high throughput process development (HTPD) resulting in lower experimental effort, sample reduction and an overall higher degree of process optimization. Apart from HTP technologies, lab-on-a-chip technology has experienced an enormous growth in the last years and allows further reduction of sample consumption. A combination of LHS and lab-on-a-chip technology is highly desirable and realized in the present work to characterize aqueous two phase systems with respect to tie lines. In particular, a new high throughput compatible approach for the characterization of aqueous two phase systems regarding tie lines by exploiting differences in phase densities is presented. Densities were measured by a standalone micro fluidic liquid density sensor, which was integrated into a liquid handling station by means of a developed generic Tip2World interface. This combination of liquid handling stations and lab-on-a-chip technology enables fast, fully automated, and highly accurate density measurements. The presented approach was used to determine the phase diagram of ATPSs composed of potassium phosphate (pH 7) and polyethylene glycol (PEG) with a molecular weight of 300, 400, 600 and 1000 Da respectively in the presence and in the absence of 3% (w/w) sodium chloride. Considering the whole ATPS characterization process, two complete ATPSs could be characterized within 24h, including four runs per ATPS for binodal curve determination (less than 45 min/run), and tie line determination (less than 45 min/run for ATPS preparation and 8h for density determination), which can be performed fully automated over night without requiring man power. The presented methodology provides

  8. Comparison of a Full Second-Order Moment Model and an Algebraic Stress Two-Phase Turbulence Model for Simulating Bubble-Liquid Flows in a Bubble Column

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A full second-order moment (FSM) model and an algebraic stress (ASM) two-phase turbulence modelare proposed and applied to predict turbulent bubble-liquid flows in a 2D rectangular bubble column. Predictiongives the bubble and liquid velocities, bubble volume fraction, bubble and liquid Reynolds stresses and bubble-liquidvelocity correlation. For predicted two-phase velocities and bubble volume fraction there is only slight differencebetween these two models, and the simulation results using both two models are in good agreement with the particleimage velocimetry (PIV) measurements. Although the predicted two-phase Reynolds stresses using the FSM are insomewhat better agreement with the PIV measurements than those predicted using the ASM, the Reynolds stressespredicted using both two models are in general agreement with the experiments. Therefore, it is suggested to usethe ASM two-phase turbulence model in engineering application for saving the computation time.

  9. Statistical thermodynamics of liquid-liquid phase separation in ternary systems during complex coacervation

    Science.gov (United States)

    Pawar, Nisha; Bohidar, H. B.

    2010-09-01

    Liquid-liquid phase separation leading to complex coacervation in a ternary system (oppositely charged polyion and macroion in a solvent) is discussed within the framework of a statistical thermodynamics model. The polyion and the macroion in the ternary system interact to form soluble aggregates (complexes) in the solvent, which undergoes liquid-liquid phase separation. Four necessary conditions are shown to drive the phase separation: (i) (σ23)3r/Φ23c≥((64)/(9α2))(χ23Φ3)2 , (ii) r≥[(64(χ23Φ3)2)/(9α2σ233)]1/2 , (iii) χ23≥((2χ231-1))/(Φ23cΦ3) , and (iv) (σ23)2/I≥(8)/(3α)(2χ231-1) (where σ23 is the surface charge on the complex formed due to binding of the polyelectrolyte and macroion, Φ23c is the critical volume fraction of the complex, χ23 is the Flory interaction parameter between polyelectrolyte and macroion, χ231 is the same between solvent and the complex, Φ3 is the volume fraction of the macroions, I is the ionic strength of the solution, α is electrostatic interaction parameter and r is typically of the order of molecular weight of the polyions). It has been shown that coacervation always requires a hydrated medium. In the case of a colloidal macroion and polyelectrolyte coacervation, molecular weight of polyelectrolyte must satisfy the condition r≥103Da to exhibit liquid-liquid phase separation. This model has been successfully applied to study the coacervation phenomenon observed in aqueous Laponite (macroion)-gelatin (polyion) system where it was found that the coacervate volume fraction, δΦ23˜χ2312 (where δΦ23 is the volume fraction of coacervates formed during phase separation). The free energy and entropy of this process have been evaluated, and a free-energy landscape has been drawn for this system that maps the pathway leading to phase separation.

  10. (Liquid + liquid) and (liquid + solid) equilibrium of aqueous two-phase systems containing poly ethylene glycol di-methyl ether 2000 and di-sodium hydrogen phosphate

    Energy Technology Data Exchange (ETDEWEB)

    Zafarani-Moattar, Mohammed Taghi, E-mail: zafarani47@yahoo.co [Physical Chemistry Department, University of Tabriz, Tabriz 51664 (Iran, Islamic Republic of); Nasiri, Saeed [Physical Chemistry Department, University of Tabriz, Tabriz 51664 (Iran, Islamic Republic of)

    2010-09-15

    (Liquid + liquid) equilibrium (LLE) for the {l_brace}poly ethylene glycol di-methyl ether 2000 (PEGDME{sub 2000}) + Na{sub 2}HPO{sub 4} + H{sub 2}O{r_brace} system have been determined experimentally at T = (298.15, 308.15, 313.15, and 318.15) K. The effects of temperature on the binodals and tie-lines for the investigated aqueous two-phase system (ATPS) have been studied. An empirical non-linear expression developed by Merchuk was used for reproducing the experimental binodal data. In this work, the three fitting parameters of the Merchuk equation were obtained with the temperature dependence expressed in the linear form with (T - T{sub 0}) K as a variable. Furthermore, the modified local composition segment-based NRTL and Wilson models and also osmotic virial equation were used to describe the LLE data of the studied system. Also, the effects of the type of salt on LLE are discussed. In addition, the effects of end groups of the polymers PEGDME{sub 2000} and poly ethylene glycol 2000 on phase forming ability were studied. The complete phase diagram for the poly ethylene {l_brace}glycol di-methyl ether 2000 (PEGDME{sub 2000}) + Na{sub 2}HPO{sub 4} + H{sub 2}O{r_brace} system has also been determined at T = 298.15 K.

  11. Isolation of natural red colorants from fermented broth using ionic liquid-based aqueous two-phase systems.

    Science.gov (United States)

    Ventura, Sónia P M; Santos-Ebinuma, Valéria C; Pereira, Jorge F B; Teixeira, Maria F S; Pessoa, Adalberto; Coutinho, João A P

    2013-05-01

    There is a growing demand for natural colorants. This is prompting the search for new alternative and "benign" separation systems allowing higher recoveries, extraction yields, and selectivities. This work investigates the use of aqueous two-phase systems (ATPS) based on ionic liquids as extraction processes for the recovery of red colorants from the fermented broth of Penicillium purpurogenum DPUA 1275. Several ATPS based on quaternary ammonium and imidazolium were studied in this work aiming at separating the red colorants produced from the remaining colorants and contaminant proteins present in the fermented broth. The results suggest that the red colorants can be isolated by an appropriate manipulation of some of the process conditions, such as the use of quaternary ammonium with short alkyl chains, alkaline media, and short tie-line lengths (extraction point systems with lower concentrations of ionic liquid). These conditions allow large partition coefficients for the red colorants (K red = 24.4 ± 2.3), high protein removal (60.7 ± 2.8 %) and selectivity parameters (S red/prot = 10.05).

  12. Visualization of two-phase gas-liquid flow regimes in horizontal and slightly-inclined circular tubes

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Livia Alves [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil); Nuclear Engineering Institute (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)], E-mail: livia@lasme.coppe.ufrj.br; Cunha Filho, Jurandyr; Su, Jian [Coordenacao dos Programas de Pos-Graduacao de Engenharia (COPPE/UFRJ), RJ (Brazil). Nuclear Engineering Program], Emails: cunhafilho@lasme.coppe.ufrj.br, sujian@lasme.coppe.ufrj.br; Faccini, Jose Luiz Horacio [Nuclear Engineering Institute (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)], E-mail: faccini@ien.gov.br

    2010-07-01

    In this paper a flow visualization study was performed for two-phase gas-liquid flow in horizontal and slightly inclined tubes. The test section consists of a 2.54 cm inner diameter stainless steel circular tube, followed by a transparent acrylic tube with the same inner diameter. The working fluids were air and water, with liquid superficial velocities ranging from 0:11 to 3:28 m/s and gas superficial velocities ranging from 0:27 to 5:48 m/s. Flow visualization was executed for upward flow at 5 deg and 10 deg and downward flow at 2:5 deg, 5 deg and 10 deg, as well as for horizontal flow. The visualization technique consists of a high-speed digital camera that records images at rates of 125 and 250 frames per second of a concurrent air-water mixture through a transparent part of the tube. From the obtained images, the flow regimes were identified (except for annular flow), observing the effect of inclination angles on flow regime transition boundaries. Finally, the experimental results were compared with empirical and theoretical flow pattern maps available in literature. (author)

  13. Formation and characteristics of aqueous two-phase systems formed by a cationic surfactant and a series of ionic liquids.

    Science.gov (United States)

    Wei, Xi-Lian; Wang, Xiu-Hong; Ping, A-Li; Du, Pan-Pan; Sun, De-Zhi; Zhang, Qing-Fu; Liu, Jie

    2013-11-15

    Aqueous two-phase systems (ATPS) were obtained in the aqueous mixtures of a cationic surfactant and a series of ionic liquids (ILs). The effects of IL structure, temperature and additives on the phase separation were systematically investigated. The microstructures of some ATPS were observed by freeze-fracture replication technique. Lyotropic liquid crystal was found in the bottom phase besides micelles under different conditions. Remarkably, both IL structure and additives profoundly affected the formation and properties of the ATPSs. The phase separation can be attributed to the existence of different aggregates and the cation-π interactions of the cationic surfactant with the ILs, which has a significant role in the formation of ATPS. The extraction capacity of the studied ATPS was also evaluated through their application in the extraction of two biosubstances. The results indicate that the ILs with BF4(-) as anion show much better extraction efficiencies than the corresponding ILs with Br(-) as anion do under the same conditions. l-Tryptophan was mainly distributed into the NPTAB-rich phase, while methylene blue and capsochrome were mainly in the IL-rich phase.

  14. Isothermal (liquid + liquid) equilibrium data at T = 313.15 K and isobaric (vapor + liquid + liquid) equilibrium data at 101.3 kPa for the ternary system (water + 1-butanol + p-xylene)

    OpenAIRE

    Gomis Yagües, Vicente; Font Escamilla, Alicia; Saquete Ferrándiz, María Dolores; García Cano, Jorge

    2014-01-01

    The (vapor + liquid), (liquid + liquid) and (vapor + liquid + liquid) equilibria of the ternary system (water + 1-butanol + p-xylene) have been determined. (Water + 1-butanol + p-xylene) is a type 2 heterogeneous ternary system with partially miscible (water + 1-butanol) and (water + p-xylene) pairs. By contrast, (1-butanol + p-xylene) is totally miscible under atmospheric conditions. This paper examines the (vapor + liquid) equilibrium in both heterogeneous and homogeneous regions at 101.3 k...

  15. Experimental investigation of the liquid volumetric mass transfer coefficient for upward gas-liquid two-phase flow in rectangular microchannels

    Directory of Open Access Journals (Sweden)

    X. Y. Ji

    2010-12-01

    Full Text Available The gas-liquid two-phase mass transfer process in microchannels is complicated due to the special dynamical characteristics. In this work, a novel method was explored to measure the liquid side volumetric mass transfer coefficient kLa. Pressure transducers were utilized to measure the pressure variation of upward gas-liquid two-phase flow in three vertical rectangular microchannels and the liquid side volumetric mass transfer coefficient kLa was calculated through the Pressure-Volume-Temperature correlation of the gas phase. Carbon dioxide-water, carbon dioxide-ethanol and carbon dioxide-n-propanol were used as working fluids, respectively. The dimensions of the microchannels were 40 µm×240 µm (depth×width, 100 µm×800 µm and 100 µm×2000 µm, respectively. Results showed that the channel diameter and the capillary number influence kLa remarkably and that the maximum value of kLa occurs in the annular flow regime. A new correlation of kLa was proposed based on the Sherwood number, Schmidt number and the capillary number. The predicted values of kLa agreed well with the experimental data.

  16. Prediction of liquid-liquid equilibria for polyethylene glycol based aqueous two-phase system by ASOG and UNIFAC method

    Directory of Open Access Journals (Sweden)

    M. Perumalsamy

    2009-03-01

    Full Text Available Liquid-Liquid equilibrium data were obtained for the polyethylene glycol2000(PEG2000-sodium citrate-water system at 298.15, 308.15 and 318.15 K. The effect of temperature on binodal and tie line data was studied and published in a previous article (Murugesan and Perumalsamy, 2005. The interaction parameters of ASOG and UNIFAC models were estimated using the LLE data of PEG2000-sodium citrate-water system and are used to predict the LLE data for PEG6000-sodium citrate-water system at 298.15, 308.15 and 318.15 K (literature data. The predicted LLE data by both ASOG and UNIFAC models showed good agreement with the experimental and literature data.

  17. Synthesis and toxicity evaluation of hydrophobic ionic liquids for volatile organic compounds biodegradation in a two-phase partitioning bioreactor

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Castillo, Alfredo Santiago [Ecole Nationale Supérieure de Chimie de Rennes, CNRS, UMR 6226, 11 Allée de Beaulieu, CS 50837, 35708 Rennes Cedex 7 (France); Université européenne de Bretagne (France); Guihéneuf, Solène, E-mail: solene.guiheneuf@wanadoo.fr [Université européenne de Bretagne, Université de Rennes 1, Sciences Chimiques de Rennes, UMR, CNRS 6226, Groupe Ingénierie Chimique & Molécules Pour le Vivant (ICMV), Bât. 10A, Campus de Beaulieu, Avenue du Général Leclerc, CS 74205, 35042 Rennes cedex (France); Le Guével, Rémy [Plate-forme ImPACcell Structure Fédérative de Recherche BIOSIT Université de Rennes 1, Bat. 8, Campus de Villejean, 2 Avenue du Pr. Leon Bernard, CS 34317, 35043 Rennes Cedex (France); Biard, Pierre-François [Ecole Nationale Supérieure de Chimie de Rennes, CNRS, UMR 6226, 11 Allée de Beaulieu, CS 50837, 35708 Rennes Cedex 7 (France); Université européenne de Bretagne (France); and others

    2016-04-15

    Highlights: • Description of a VOC depollution system suitable with industrial processes, TPPB. • Novel association of TPPB and hydrophobic ionic liquids. • Synthesis of several hydrophobic ionic liquids designed to fit desired properties. • Toxicity evaluation of these ILs towards cells, animals and bacteria. - Abstract: Synthesis of several hydrophobic ionic liquids (ILs), which might be selected as good candidates for degradation of hydrophobic volatile organic compounds in a two-phase partitioning bioreactor (TPPB), were carried out. Several bioassays were also realized, such as toxicity evaluation on activated sludge and zebrafish, cytotoxicity, fluoride release in aqueous phase and biodegradability in order to verify their possible effects in case of discharge in the aquatic environment and/or human contact during industrial manipulation. The synthesized compounds consist of alkylimidazoliums, functionalized imidazoliums, isoqinoliniums, triazoliums, sulfoniums, pyrrolidiniums and morpholiniums and various counter-ions such as: PF{sub 6}{sup −}, NTf{sub 2}{sup −} and NfO{sup −}. Toxicity evaluation on activated sludge of each compound (5% v/v of IL) was assessed by using a glucose uptake inhibition test. Toxicity against zebrafish and cytotoxicity were evaluated by the ImPACCell platform of Rennes (France). Fluoride release in water was estimated by regular measurements using ion chromatography equipment. IL biodegradability was determined by measuring BOD{sub 28} of aqueous samples (compound concentration,1 mM). All ILs tested were not biodegradable; while some of them were toxic toward activated sludge. Isoquinolinium ILs were toxic to human cancerous cell lines. Nevertheless no toxicity was found against zebrafish Danio rerio. Only one IL released fluoride after long-time agitation.

  18. Drag reduction by polymer addition in single and two-phase gas-liquid flows in pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Bizotto, Vanessa Cristina; Paes, Diogo Melo; Franca, Fernando de Almeida [Universidade Estadual de Campinas, SP (Brazil). Centro de Estudos de Petroleo. LabPetro]. E-mails: vanessa@cepetro.unicamp.br; diogopaes10@hotmail.com; Sabadini, Edvaldo [Universidade Estadual de Campinas, SP (Brazil). Inst. de Quimica]. E-mails: sabadini@iqm.unicamp.br; ffranca@fem.unicamp.br

    2008-07-01

    Turbulence mechanisms, as the eddies formation frequency and size, promote energy dissipation that appears as pressure drop in pipe flows. Adding minute amounts of polymers - ppm - of high molecular weight to the solution can lead to the reduction of the viscous dissipation. The formed macromolecules interact with the eddies, cause the eddies coherence breakdown, damp the energy transport and reduces the pressure drop. This phenomenon is known as the hydrodynamic drag reduction (DR, for short). Thus, for a given pipe flow rate there is decrease in pressure head, which is a desired operating strategy when transporting liquids. Studies on the hydrodynamic drag reduction in polymeric systems have been carried out in collaboration by the Chemistry Institute and the Petroleum Laboratory - LabPetro, UNICAMP. These studies have allowed microscopic approaches to the engineering scales, tackling the most usual processes - single phase flows, as well as gas-liquid two-phase flows in pipelines, which are quite common in the chemical and the petroleum industries. Tests conducted in the Chemistry Institute comprised over-the-bench experimentations made with a rotational double-gap type rheometer. These quick performed tests used small amount of polymers, and provided information on the additive concentration, the drag reduction and the solution mechanical stability along a turbulent shearing process. The results indicated that 17% is the limiting drag reduction achieved when a 2 ppm aqueous solution of polyacrylamide - PAM - was tested. These tests, besides giving preliminary estimations, are limited in terms of engineering application due to the low shearing rates applied by the viscometer. The tests performed at LabPetro comprised pressure drop measurements in actual pipe flows, both water single and air-water two-phase flows, using the previous knowledge acquired with the viscometer tests. In the former case, the Prandtl-von Karman map has been drawn to show the %DR in terms

  19. Gas-liquid countercurrent two-phase flow in a PWR hot leg: A comprehensive research review

    Energy Technology Data Exchange (ETDEWEB)

    Deendarlianto, E-mail: deendarlianto@ugm.ac.id [Helmholtz-Zentrum Dresden-Rossendorf e.V., Institute of Safety Research, P.O. Box 510 119, D-01314 Dresden (Germany); Department of Mechanical and Industrial Engineering, Faculty of Engineering, Gadjah Mada University, Jalan Grafika No. 2, Yogyakarta 55281 (Indonesia); Hoehne, Thomas; Lucas, Dirk [Helmholtz-Zentrum Dresden-Rossendorf e.V., Institute of Safety Research, P.O. Box 510 119, D-01314 Dresden (Germany); Vierow, Karen [Department of Nuclear Engineering Texas A and M University, 129 Zachry Engineering Center, 3133 TAMU College Station, TX 77843-3133 (United States)

    2012-02-15

    Highlights: Black-Right-Pointing-Pointer We review the scientific progress on the CCFL in a PWR hot leg. Black-Right-Pointing-Pointer It includes the experimental data, one-dimensional and CFD models in the open literatures. Black-Right-Pointing-Pointer The weak and strong points of the published works were clarified. Black-Right-Pointing-Pointer The research directions in this field were proposed. - Abstract: Research into gas-liquid countercurrent two-phase flow in a model of pressurized water reactor (PWR) hot leg has been carried out over the last several decades. An extensive experimental data base has been accumulated from these studies, leading to the development of phenomenological correlations and scaling parameters of the countercurrent flow limitation (CCFL). However, most of the proposed correlations apply under a relatively narrow range of conditions, generally limited to the test section conditions and/or geometry. Moreover the development of mechanistic models based on the underlying physical processes has been limited. In contrast to this mechanistic form of modelling, the implementation of computational fluid dynamics (CFD) techniques has also been pursued, but the considerable robust three-dimensional (3D) closure relations for this application remain an unachieved goal due to lack of detailed phenomenological knowledge and consequent application of empirical one-dimensional experimental correlations to the multidimensional problem. This paper presents a comprehensive review of research work on countercurrent gas-liquid two-phase flow in a PWR hot leg and provides direction regarding future research on this topic. In the introductory section, the problems facing current research are described. In the following sections, recent experimental as well as theoretical research achievements are overviewed. In the last section, the problems that remain unsolved are discussed, along with some concluding remarks. It was found that only limited theoretical

  20. Progress of experimental studies on gas-liquid (liquid-liquid) two-phase flow in microchannels%微通道内气液(液液)二相流的实验研究进展

    Institute of Scientific and Technical Information of China (English)

    付涛涛; 马友光; 朱春英

    2011-01-01

    The characteristics of gas-liquid (liquid-liquid) two-phase flow in microchannels were reviewed. The flow patterns of gas-liquid two-phase flow in microchannels include bubbly flow, slug flow, annular flow and churn flow; the flow patterns of liquid-liquid two-phase flow are categorized into droplet flow, plug flow, parallel flow and annular flow. The parameters influencing the behaviors of gasdiquid (liquid-liquid) two-phase flow in microchannels were analyzed. The flow pattern maps for gas-liquid (liquid-liquid) two-phase flow in microchannels were introduced, and the flow patterns widely used in literature such as slug, droplet and plug flow were particularly introduced. The difficulties encountered in the investigation of gas-liquid (liquid-liquid) two-phase flow in microchannels were pointed out, and the developing prospects of gas-liquid (liquid-liquid) two-phase flow in microchannels were expected.%综述了微通道内气液(液液)二相流的流型特征.微通道内气液二相流常见的流型为泡状流、弹状流、环状流和翻腾流;液液二相流常见的流型为液滴流、塞状流、平行流及环状流.分析了不同操作条件对气液(液液)二相流行为的影响.介绍了微通道内气液(液液)二相流流型判别谱图,对常用的弹状流、液滴流和塞状流进行了重点介绍.指出了微通道内气液(液液)二相流的研究难点,并对该领域今后的主要研究方向进行了展望.

  1. Enthalpies of mixing of the liquid phase in the ternary system Ag-Au-Bi

    Energy Technology Data Exchange (ETDEWEB)

    Zoro, E. [Laboratoire de Chimie Physique Minerale et Bioinorganique, EA401, Fac. Pharm., Universite de Paris XI, 5 rue JB Clement, 92296 Chatenay Malabry (France) and Laboratoire de Physico-Chimie de l' Etat Solide, UMR 8648, Bat 410-415, 91405 Orsay Cedex (France)]. E-mail: zoroe@netcourrier.com; Boa, D. [Laboratoire de Thermodynamique et de Physico-Chimie du Milieu, Universite d' Abobo-Adjame, UFR-SFA, 02 BP801 Abidjan 02, Cote d' Ivoire, Africa (Ivory Coast); Servant, C. [Laboratoire de Physico-Chimie de l' Etat Solide, UMR 8648, Bat 410-415, 91405 Orsay Cedex (France); Legendre, B. [Laboratoire de Chimie Physique Minerale et Bioinorganique, EA401, Fac. Pharm., Universite de Paris XI, 5 rue JB Clement, 92296 Chatenay Malabry (France)

    2005-08-02

    The enthalpies of mixing of the liquid phase of the Ag-Au-Bi ternary alloys along the sections Ag {sub x}Bi{sub 1-x}-Au (x = 0.11, 0.10 and 0.24) and Au {sub x}Bi{sub 1-x}-Ag (x = 0.11 and 0.27) have been determined at 673 and 773 K. We used a SETARAM devised heat flow calorimeter of Tian-Calvet type. The values obtained are almost compatible with estimations from Scientific Group of Thermodata Europe (SGTE) binary database without adding ternary thermodynamic excess parameters. However, slight discrepancies are observed. The result of this study is useful tools for the Ag-Au-Bi ternary system thermodynamic computer optimization in process by the authors.

  2. Numerical modelling of the impact of a liquid drop on the surface of a two-phase fluid system

    Science.gov (United States)

    Sochan, Agata; Lamorski, Krzysztof; Bieganowski, Andrzej; Ryżak, Magdalena

    2014-05-01

    The aim of the study was validation of a numerical model of the impact of a liquid drop on the surface of a two-phase system of immiscible fluids. The drop impact phenomenon was recorded using a high-speed camera (Vision Research MIRO M310) and the data were recorded at 2000 frames per second. The numerical calculations were performed with the Finite Volume Method (FVM) solving the three-dimensional Navier-Stokes equations for three phases: air and two selected immiscible fluids. The Volume of Fluid (VOF) technique was employed for modelling of the boundaries between the phases. Numerical modelling was done with the Finite Volume Method using an available OpenFOAM software. The experiment was based on three variables: • the height from which the drop of the selected fluids fell (the speed of the drop), • the thickness of the layers of the two selected immiscible fluids (a thin layer of the fluid with a lower density was spread over the higher-density fluid), • the size of the fluid droplet. The velocity and radius of the falling drop was calculated based on the recorded images. The used parameters allowed adequate projection of the impact of fluid droplets on a system of two immiscible liquids. Development of the numerical model of splash may further have practical applications in environmental protection (spraying of hazardous fluids, spread of fuels and other hazardous substances as a result of disasters, spraying (water cooling) of hot surfaces), and in agriculture (prevention of soil erosion). The study was partially funded from the National Science Centre (Poland) based on the decision no. DEC-2012/07/N/ST10/03280.

  3. Gas-liquid Two Phase Flow Modelling of Incompressible Fluid and Experimental Validation Studies in Vertical Centrifugal Casting

    Science.gov (United States)

    Zhou, J. X.; Shen, X.; Yin, Y. J.; Guo, Z.; Wang, H.

    2015-06-01

    In this paper, Gas-liquid two phase flow mathematic models of incompressible fluid were proposed to explore the feature of fluid under certain centrifugal force in vertical centrifugal casting (VCC). Modified projection-level-set method was introduced to solve the mathematic models. To validate the simulation results, two methods were used in this study. In the first method, the simulation result of basic VCC flow process was compared with its analytic solution. The relationship between the numerical solution and deterministic analytic solution was presented to verify the correctness of numerical algorithms. In the second method, systematic water simulation experiments were developed. In this initial experiment, special experimental vertical centrifugal device and casting shapes were designed to describe typical mold-filling processes in VCC. High speed camera system and data collection devices were used to capture flow shape during the mold-filling process. Moreover, fluid characteristic at different rotation speed (from 40rpm, 60rpmand 80rpm) was discussed to provide comparative resource for simulation results. As compared with the simulation results, the proposed mathematical models could be proven and the experimental design could help us advance the accuracy of simulation and further studies for VCC.

  4. Numerical simulation of predicting and reducing solid particle erosion of solid-liquid two-phase flow in a choke

    Institute of Scientific and Technical Information of China (English)

    Li Guomei; Wang Yueshe; He Renyang; Cao Xuewen; Lin Changzhi; Meng Tao

    2009-01-01

    Chokes are one of the most important components of downhole flow-control equipment. The particle erosion mathematical model, which considers particle-particle interaction, was established and used to simulate solid particle movement as well as particle erosion characteristics of the solid-liquid two-phase flow in a choke. The corresponding erosion reduction approach by setting ribs on the inner wall of the choke was advanced. This mathematical model includes three parts: the flow field simulation of the continuous carrier fluid by an Eulerian approach, the particle interaction simulation using the discrete particle hard sphere model by a Lagrangian approach and calculation of erosion rate using semi-empirical correlations. The results show that particles accumulated in a narrow region from inlet to outlet of the choke and the dominating factor affecting particle motion is the fluid drag force. As a result, the optimization of rib geometrical parameters indicates that good anti-erosion performance can be achieved by four ribs, each of them with a height (H) of 3 mm and a width (B) of 5 mm equaling the interval between ribs (L).

  5. Modeling of the anode of a liquid-feed DMFC: Inhomogeneous compression effects and two-phase transport phenomena

    Science.gov (United States)

    García-Salaberri, Pablo A.; Vera, Marcos; Iglesias, Immaculada

    2014-01-01

    An isothermal two-phase 2D/1D across-the-channel model for the anode of a liquid-feed Direct Methanol Fuel Cell (DMFC) is presented. The model takes into account the effects of the inhomogeneous assembly compression of the Gas Diffusion Layer (GDL), including the spatial variations of porosity, diffusivity, permeability, capillary pressure, and electrical conductivity. The effective anisotropic properties of the GDL are evaluated from empirical data reported in the literature corresponding to Toray carbon paper TGP-H series. Multiphase transport is modeled according to the classical theory of porous media (two-fluid model), considering the effect of non-equilibrium evaporation and condensation of methanol and water. The numerical results evidence that the hydrophobic Leverett J-function approach is physically inconsistent to describe capillary transport in the anode of a DMFC when assembly compression effects are considered. In contrast, more realistic results are obtained when GDL-specific capillary pressure curves reflecting the mixed-wettability characteristics of GDLs are taken into account. The gas coverage factor at the GDL/channel interface also exhibits a strong influence on the gas-void fraction distribution in the GDL, which in turn depends on the relative importance between the capillary resistance induced by the inhomogeneous compression, Rc(∝ ∂pc / ∂ ε) , and the capillary diffusivity, Dbarc(∝ ∂pc / ∂ s) .

  6. Extraction and purification of wheat-esterase using aqueous two-phase systems of ionic liquid and salt.

    Science.gov (United States)

    Jiang, Bin; Feng, Zhibiao; Liu, Chunhong; Xu, Yingcao; Li, Dongmei; Ji, Guo

    2015-05-01

    To explore a new and simple rapid extraction and purification technique for wheat-esterase, an ionic liquids (ILs)-based aqueous two-phase system (ATPS) was developed for the purification of wheat-esterase from wheat extracts. Effects of various process parameters such as the concentrations of [Bmim]BF4, the types and concentrations of phase-forming salt, the system pH and the temperature on partitioning of wheat-esterase were evaluated. The obtained data indicated that wheat-esterase was preferentially partitioned into the ILs-rich phase and the ATPS composed of 20 % [Bmim]BF4 (w/w) and 25 % (w/w) NaH2PO4(pH = 4.8) showed good selectivity on wheat-esterase. Under the optimum conditions, wheat-esterase was purified with an acceptable yield (88.93 %), but produced wheat-esterase was 4.23 times as pure. It was obvious that temperature shows little influence on the purification between 10 and 50 °C. Sephadex G-150FF revealed that the band intensity of contaminating proteins in ATPS fraction almost disappeared. Therefore, ILs-based ATPS was an effective method for partitioning and recovery of wheat-esterase from wheat crude extracts.

  7. Development of tropine-salt aqueous two-phase systems and removal of hydrophilic ionic liquids from aqueous solution.

    Science.gov (United States)

    Wu, Haoran; Yao, Shun; Qian, Guofei; Song, Hang

    2016-08-26

    A novel aqueous two-phase systems (ATPS) composed of a small molecule organic compound tropine and an organic or inorganic salt aqueous solution has been developed for the first time. The phase behavior of tropine-salt ATPS was systemically investigated and the phase equilibrium data were measured in different temperatures and concentrations and correlated by the Merchuk equation with satisfactory results. The detection of the conductivity and particle size proved the formation of micelle in the process of forming tropine-salt ATPS. The separation application of the ATPS was assessed with the removal of hydrophilic benzothiazolium-based ionic liquids (ILs) from aqueous solution. The result showed that ILs were effectively extracted into the top tropine-rich phase. Finally, ILs in the top tropine-rich phase were further separated by the means of adsorption-desorption with DM301 macroporous resin and ethanol. The method of novel tropine-salt ATPS combined with adsorption-desorption is demonstrated a promising alternative thought and approach for the removal or recovery of hydrophilic compounds from aqueous media and also could provide a potential application for bio-separation.

  8. Synthesis and toxicity evaluation of hydrophobic ionic liquids for volatile organic compounds biodegradation in a two-phase partitioning bioreactor.

    Science.gov (United States)

    Rodriguez Castillo, Alfredo Santiago; Guihéneuf, Solène; Le Guével, Rémy; Biard, Pierre-François; Paquin, Ludovic; Amrane, Abdeltif; Couvert, Annabelle

    2016-04-15

    Synthesis of several hydrophobic ionic liquids (ILs), which might be selected as good candidates for degradation of hydrophobic volatile organic compounds in a two-phase partitioning bioreactor (TPPB), were carried out. Several bioassays were also realized, such as toxicity evaluation on activated sludge and zebrafish, cytotoxicity, fluoride release in aqueous phase and biodegradability in order to verify their possible effects in case of discharge in the aquatic environment and/or human contact during industrial manipulation. The synthesized compounds consist of alkylimidazoliums, functionalized imidazoliums, isoqinoliniums, triazoliums, sulfoniums, pyrrolidiniums and morpholiniums and various counter-ions such as: PF6(-), NTf2(-) and NfO(-). Toxicity evaluation on activated sludge of each compound (5% v/v of IL) was assessed by using a glucose uptake inhibition test. Toxicity against zebrafish and cytotoxicity were evaluated by the ImPACCell platform of Rennes (France). Fluoride release in water was estimated by regular measurements using ion chromatography equipment. IL biodegradability was determined by measuring BOD28 of aqueous samples (compound concentration,1mM). All ILs tested were not biodegradable; while some of them were toxic toward activated sludge. Isoquinolinium ILs were toxic to human cancerous cell lines. Nevertheless no toxicity was found against zebrafish Danio rerio. Only one IL released fluoride after long-time agitation. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Ternary System of Fe-based Ionic Liquid, Ethanol and Water for Wet Flue Gas Desulfurization

    Institute of Scientific and Technical Information of China (English)

    解美莹; 李沛沛; 郭惠锋; 高丽霞; 余江

    2012-01-01

    Fe-based ionic liquid (Fe-IL) was synthesized by mixing FeCl3·6H2O and 1-butyl-3-methylimidazolium chloride [Bmim]C1 in this paper. The phase diagram of a ternary Fe-IL, ethanol and water system was investigated to construct a ternary desulfurization solution for wet flue gas desulfurization. The effects of flow rate and concentration of SO2, reaction temperature, pH and Fe-IL fraction in aqueous desulfurization solution on the desulfiariza- tion efficiency were investigated. The results shows that the best composition of ternary desulfurization solution of Fe-IL, ethanol and water is 1 : 1.5 : 3 by volume ratio, and pH should be controlled at 2.0. Under such conditions, a desulfurization rate greater than 90% could be obtained. The product of sulfuric acid had inhibition effect on the wet desulfurization process. With applying this new ternary desulfurization solution, not only the catalyst Fe-IL can be recycled and reused, but also the product sulfuric acid can be separated directly from the ternary desulfurization system.

  10. Carbon dioxide corrosion inhibition of N80 carbon steel in single liquid phase and liquid/particle two-phase flow by hydroxyethyl imidazoline derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Liu, X. [State Key Laboratory for Corrosion and Protection, Institute of Metal Research, Chinese Academy of Sciences, 62 Wencui Road, Shenyang 110016, Liaoning Province (China); Department of Applied Chemistry, Shenyang Institute of Chemical Technology, Shenyang 110142 (China); Zheng, Y.G. [State Key Laboratory for Corrosion and Protection, Institute of Metal Research, Chinese Academy of Sciences, 62 Wencui Road, Shenyang 110016, Liaoning Province (China); Okafor, P.C. [State Key Laboratory for Corrosion and Protection, Institute of Metal Research, Chinese Academy of Sciences, 62 Wencui Road, Shenyang 110016, Liaoning Province (China); Department of Pure and Applied Chemistry, University of Calabar, Calabar (Nigeria)

    2009-07-15

    CO{sub 2} corrosion inhibition of N80 steel in liquid single-phase and liquid/particle two-phase flow by 2-undecyl-1-hydroxyethyl imidazoline (HEI-11) and 2-undecyl-1-hydroxyethyl-1-hydroxyethyl quaternary imidazoline (HQI-11) was investigated using weight loss, potentiodynamic polarization, EIS, and scanning electron microscope (SEM) techniques. The results show that the corrosion rate in the absence and presence of the imidazolines is strongly dependent on the flow condition and presence of entrained sand particles. The imidazolines function via a mixed-type corrosion inhibition mechanism. The inhibition efficiencies of the imidazolines followed the trend HQI-11 > HEI-11 in all the systems studied. Inhibition mechanism has been discussed in relation to the polycentric adsorption sites on the imidazoline molecules. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  11. Determination of sunset yellow and tartrazine in food samples by combining ionic liquid-based aqueous two-phase system with high performance liquid chromatography.

    Science.gov (United States)

    Sha, Ou; Zhu, Xiashi; Feng, Yanli; Ma, Weixing

    2014-01-01

    We proposed a simple and effective method, by coupling ionic liquid-based aqueous two-phase systems (IL-ATPSs) with high performance liquid chromatography (HPLC), for the analysis of determining tartrazine and sunset yellow in food samples. Under the optimized conditions, IL-ATPSs generated an extraction efficiency of 99% for both analytes, which could then be directly analyzed by HPLC without further treatment. Calibration plots were linear in the range of 0.01-50.0 μg/mL for both Ta and SY. The limits of detection were 5.2 ng/mL for Ta and 6.9 ng/mL for SY. This method proves successful for the separation/analysis of tartrazine and sunset yellow in soft drink sample, candy sample, and instant powder drink and leads to consistent results as obtained from the Chinese national standard method.

  12. Determination of Sunset Yellow and Tartrazine in Food Samples by Combining Ionic Liquid-Based Aqueous Two-Phase System with High Performance Liquid Chromatography

    Directory of Open Access Journals (Sweden)

    Ou Sha

    2014-01-01

    Full Text Available We proposed a simple and effective method, by coupling ionic liquid-based aqueous two-phase systems (IL-ATPSs with high performance liquid chromatography (HPLC, for the analysis of determining tartrazine and sunset yellow in food samples. Under the optimized conditions, IL-ATPSs generated an extraction efficiency of 99% for both analytes, which could then be directly analyzed by HPLC without further treatment. Calibration plots were linear in the range of 0.01–50.0 μg/mL for both Ta and SY. The limits of detection were 5.2 ng/mL for Ta and 6.9 ng/mL for SY. This method proves successful for the separation/analysis of tartrazine and sunset yellow in soft drink sample, candy sample, and instant powder drink and leads to consistent results as obtained from the Chinese national standard method.

  13. PEG-salt aqueous two-phase systems: an attractive and versatile liquid-liquid extraction technology for the downstream processing of proteins and enzymes.

    Science.gov (United States)

    Glyk, Anna; Scheper, Thomas; Beutel, Sascha

    2015-08-01

    Nowadays, there is an increasing demand to establish new feasible, efficient downstream processing (DSP) techniques in biotechnology and related fields. Although several conventional DSP technologies have been widely employed, they are usually expensive and time-consuming and often provide only low recovery yields. Hence, the DSP is one major bottleneck for the commercialization of biological products. In this context, polyethylene glycol (PEG)-salt aqueous two-phase systems (ATPS) represent a promising, efficient liquid-liquid extraction technology for the DSP of various biomolecules, such as proteins and enzymes. Furthermore, ATPS can overcome the limitations of traditional DSP techniques and have gained importance for applications in several fields of biotechnology due to versatile advantages over conventional DSP methods, such as biocompatibility, technical simplicity, and easy scale-up potential. In the present review, various practical applications of PEG-salt ATPS are presented to highlight their feasibility to operate as an attractive and versatile liquid-liquid extraction technology for the DSP of proteins and enzymes, thus facilitating the approach of new researchers to this technique. Thereby, single- and multi-stage extraction, several process integration methods, as well as large-scale extraction and purification of proteins regarding technical aspects, scale-up, recycling of process chemicals, and economic aspects are discussed.

  14. Design and development of single stage purification of papain using Ionic Liquid based aqueous two phase extraction system and its Partition coefficient studies

    Directory of Open Access Journals (Sweden)

    Senthilkumar Rathnasamy

    2013-04-01

    Full Text Available As an emerging trend in bioseparation, aqueous two phase extractions based on phosponium ionic liquid have been utilized in this work to extract papain from Carica papaya fruit latex and the same wascompared with conventional aqueous two phase extraction system. Factors affecting the partition coefficient of papain such as ionic liquid concentration, pH of the extraction system and temperature have been investigated. The optimization studies show that ionic liquid concentrations and pH are majorly influencing the phaseformations and papain partitioning. It reveals the importance of electrostatic and hydrophobic interactions in the papain partitioning. Purification studies performed on Gel Filtration Chromatography shows that 96% of the papain enzyme could be extracted with the phosponium based ionic liquid in a single stage extraction. The final fraction containing papain enzyme was confirmed by SDS Page analysis.

  15. GLOBAL EXISTENCE OF CLASSICAL SOLUTION FOR A VISCOUS LIQUID-GAS TWO-PHASE MODEL WITH MASS-DEPENDENT VISCOSITY AND VACUUM

    Institute of Scientific and Technical Information of China (English)

    Zhen WANG; Hui ZHANG

    2014-01-01

    In this work, we obtain the global existence and uniqueness of classical solu-tions to a viscous liquid-gas two-phase model with mass-dependent viscosity and vacuum in one dimension, where the initial vacuum is allowed. We get the upper and lower bounds of gas and liquid masses n and m by the continuity methods which we use to study the compressible Navier-Stokes equations.

  16. Empirical Correlations and CFD Simulations of Vertical Two-Phase Gas-Liquid (Newtonian and Non-Newtonian) Slug Flow Compared Against Experimental Data of Void Fraction

    DEFF Research Database (Denmark)

    Ratkovich, Nicolas Rios; Majumder, S.K.; Bentzen, Thomas Ruby

    2013-01-01

    Gas-Newtonian liquid two-phase flows (TPFs) are presented in several industrial processes (e.g. oil-gas industry). In spite of the common occurrence of these TPFs, the understanding of them is limited compared to single-phase flows. Various studies on TPF focus on developing empirical correlation...

  17. The measurement of gas-liquid two-phase flows in a small diameter pipe using a dual-sensor multi-electrode conductance probe

    Science.gov (United States)

    Zhai, Lu-Sheng; Bian, Peng; Han, Yun-Feng; Gao, Zhong-Ke; Jin, Ning-De

    2016-04-01

    We design a dual-sensor multi-electrode conductance probe to measure the flow parameters of gas-liquid two-phase flows in a vertical pipe with an inner diameter of 20 mm. The designed conductance probe consists of a phase volume fraction sensor (PVFS) and a cross-correlation velocity sensor (CCVS). Through inserting an insulated flow deflector in the central part of the pipe, the gas-liquid two-phase flows are forced to pass through an annual space. The multiple electrodes of the PVFS and the CCVS are flush-mounted on the inside of the pipe wall and the outside of the flow deflector, respectively. The geometry dimension of the PVFS is optimized based on the distribution characteristics of the sensor sensitivity field. In the flow loop test of vertical upward gas-liquid two-phase flows, the output signals from the dual-sensor multi-electrode conductance probe are collected by a data acquisition device from the National Instruments (NI) Corporation. The information transferring characteristics of local flow structures in the annular space are investigated using the transfer entropy theory. Additionally, the kinematic wave velocity is measured based on the drift velocity model to investigate the propagation behavior of the stable kinematic wave in the annular space. Finally, according to the motion characteristics of the gas-liquid two-phase flows, the drift velocity model based on the flow patterns is constructed to measure the individual phase flow rate with higher accuracy.

  18. Stability of clavulanic acid in PEG/citrate and liquid–liquid extraction in aqueous two-phase system

    OpenAIRE

    Carneiro-da-Cunha, M. N.; Souza, K. P. S.; Mota, A; J.A. Teixeira; Porto, C S; Porto, Tatiana Souza; Porto, Ana L. F.

    2014-01-01

    β-Lactamases are enzymes responsible for the hydrolysis of β-lactam antibiotics, being produced by several pathogenic bacteria. Clavulanic acid is a commercially and clinically important β-lactamase inhibitor, its extraction being possible by the application of aqueous two-phase system. In this study, clavulanic acid stability was investigated at different molar mass PEG (400, 1 000 and 20 000 g mol−1) and at different citrate concentrations (5 and 20%) PEG/citrate aqueous-two phase systems (...

  19. (Liquid + liquid) equilibria in ternary aqueous mixtures of phosphoric acid with organic solvents at T = 298.2 K

    Energy Technology Data Exchange (ETDEWEB)

    Ghanadzadeh, H., E-mail: hggilani@guilan.ac.i [Department of Chemistry, Faculty of Science, University of Guilan, Rasht (Iran, Islamic Republic of); Department of Chemical Engineering, University of Guilan, Rasht (Iran, Islamic Republic of); Ghanadzadeh, A., E-mail: aggilani@guilan.ac.i [Department of Chemistry, Faculty of Science, University of Guilan, Rasht (Iran, Islamic Republic of); Aghajani, Z.; Abbasnejad, S.; Shekarsaraee, S. [Department of Chemistry, Faculty of Science, University of Guilan, Rasht (Iran, Islamic Republic of)

    2010-06-15

    (Liquid + liquid) equilibrium (LLE) data for the ternary mixtures of left bracewater (1) + phosphoric acid (2) + organic solvents (3)right brace were determined at T = 298.2 K and atmospheric pressure. The organic solvents were cyclohexane, 2-methyl-2-butanol (tert-amyl alcohol), and isobutyl acetate. All the investigated systems exhibit Type-1 behaviour of LLE. The immiscibility region was found to be larger for the (water + phosphoric acid + cyclohexane) ternary system. The experimental LLE results were correlated with the NRTL model, and the binary interaction parameters were obtained. The reliability of the experimental tie-line results was tested through the Othmer-Tobias and Bachman correlation equations. Distribution coefficients and separation factors were evaluated over the immiscibility regions and a comparison of the extracting capabilities of the solvents was made with respect to these factors. The experimental results indicate the superiority of cyclohexane as the preferred solvent for the extraction of phosphoric acid from its aqueous solutions.

  20. The accurate estimation of physicochemical properties of ternary mixtures containing ionic liquids via artificial neural networks.

    Science.gov (United States)

    Cancilla, John C; Díaz-Rodríguez, Pablo; Matute, Gemma; Torrecilla, José S

    2015-02-14

    The estimation of the density and refractive index of ternary mixtures comprising the ionic liquid (IL) 1-butyl-3-methylimidazolium tetrafluoroborate, 2-propanol, and water at a fixed temperature of 298.15 K has been attempted through artificial neural networks. The obtained results indicate that the selection of this mathematical approach was a well-suited option. The mean prediction errors obtained, after simulating with a dataset never involved in the training process of the model, were 0.050% and 0.227% for refractive index and density estimation, respectively. These accurate results, which have been attained only using the composition of the dissolutions (mass fractions), imply that, most likely, ternary mixtures similar to the one analyzed, can be easily evaluated utilizing this algorithmic tool. In addition, different chemical processes involving ILs can be monitored precisely, and furthermore, the purity of the compounds in the studied mixtures can be indirectly assessed thanks to the high accuracy of the model.

  1. Ecoulements diphasiques gaz-liquide à poches et à bouchons en conduites Two-Phase Gas-Liquid Slug Flow in Pipes

    Directory of Open Access Journals (Sweden)

    Ferschneider G.

    2006-11-01

    Full Text Available Les écoulements diphasiques gaz-liquide ont été étudiés afin de contribuer à développer des modèles de calculs prédictifs des pertes de charge dans les conduites de production des bruts pétroliers. Les expériences nécessaires ont été réalisées sur la boucle diphasique de Boussens dans les conditions suivantes représentatives des conditions industrielles : diamètre 6 , longueur 120 m, disposition de la conduite horizontale ou faiblement ascendante, couple de fluide gaz naturel-huile légère. Le gradient de pression, le contenu global, et la distribution locale des phases ont été mesurés. Le traitement des équations de conservation phasique intégrées sur la section par différents types de moyennes a permis de développer un modèle cellulaire qui inclue un nombre limité d'équations constitutives nécessaires à sa fermeture. Ce modèle prédétermine convenablement le gradient de pression, le contenu gaz global et la longueur des poches et des bouchons. Two-phase gas-liquid flows were analyzed so as to develop models for prediction of pressure drops in crude-oil production lines. The experiments were performed on the two-phase loop at Boussens under the following representative industrial conditions: 6 diameter, 120 m length, horizontal or slightly rising pipe, couple of fluids natural gas and light oil. The pressure gradient, average content and local phase distribution were measured. Conservation phase equations integrated along the cross-section were processed by different time-averaged operators so as to develop a cellular model including a limited number of constitutive equations required for its closure. This model suitably predetermines the pressure gradient, the average gas content and the length of gas and liquid slug.

  2. Ionic Liquid-salt Aqueous Two-phase System, a Novel System for the Extraction of Abused Drugs

    Institute of Scientific and Technical Information of China (English)

    She Hong LI; Chi Yang HE; Hu Wei LIU; Ke An LI; Feng LIU

    2005-01-01

    A 1-butyl-3-methylimidazolium chloride-salt aqueous two-phase system was studied on extraction of abused drugs. The effects of sorts of salts, temperature, concentration of salt and drugs on system were investigated systematically. A satisfactory extraction efficiency of 93%was obtained for papaverine while that of morphine was 65%. The extraction mechanism was primarily discussed.

  3. Magnetic ionic liquid aqueous two-phase system coupled with high performance liquid chromatography: A rapid approach for determination of chloramphenicol in water environment.

    Science.gov (United States)

    Yao, Tian; Yao, Shun

    2017-01-20

    A novel organic magnetic ionic liquid based on guanidinium cation was synthesized and characterized. A new method of magnetic ionic liquid aqueous two-phase system (MILATPs) coupled with high-performance liquid chromatography (HPLC) was established to preconcentrate and determine trace amount of chloramphenicol (CAP) in water environment for the first time. In the absence of volatile organic solvents, MILATPs not only has the excellent properties of rapid extraction, but also exhibits a response to an external magnetic field which can be applied to assist phase separation. The phase behavior of MILATPs was investigated and phase equilibrium data were correlated by Merchuk equation. Various influencing factors on CAP recovery were systematically investigated and optimized. Under the optimal conditions, the preconcentration factor was 147.2 with the precision values (RSD%) of 2.42% and 4.45% for intra-day (n=6) and inter-day (n=6), respectively. The limit of detection (LOD) and limit of quantitation (LOQ) were 0.14ngmL(-1) and 0.42ngmL(-1), respectively. Fine linear range of 12.25ngmL(-1)-2200ngmL(-1) was obtained. Finally, the validated method was successfully applied for the analysis of CAP in some environmental waters with the recoveries for the spiked samples in the acceptable range of 94.6%-99.72%. Hopefully, MILATPs is showing great potential to promote new development in the field of extraction, separation and pretreatment of various biochemical samples. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Simulation of two-phase liquid-vapor flows using a high-order compact finite-difference lattice Boltzmann method.

    Science.gov (United States)

    Hejranfar, Kazem; Ezzatneshan, Eslam

    2015-11-01

    A high-order compact finite-difference lattice Boltzmann method (CFDLBM) is extended and applied to accurately simulate two-phase liquid-vapor flows with high density ratios. Herein, the He-Shan-Doolen-type lattice Boltzmann multiphase model is used and the spatial derivatives in the resulting equations are discretized by using the fourth-order compact finite-difference scheme and the temporal term is discretized with the fourth-order Runge-Kutta scheme to provide an accurate and efficient two-phase flow solver. A high-order spectral-type low-pass compact nonlinear filter is used to regularize the numerical solution and remove spurious waves generated by flow nonlinearities in smooth regions and at the same time to remove the numerical oscillations in the interfacial region between the two phases. Three discontinuity-detecting sensors for properly switching between a second-order and a higher-order filter are applied and assessed. It is shown that the filtering technique used can be conveniently adopted to reduce the spurious numerical effects and improve the numerical stability of the CFDLBM implemented. A sensitivity study is also conducted to evaluate the effects of grid size and the filtering procedure implemented on the accuracy and performance of the solution. The accuracy and efficiency of the proposed solution procedure based on the compact finite-difference LBM are examined by solving different two-phase systems. Five test cases considered herein for validating the results of the two-phase flows are an equilibrium state of a planar interface in a liquid-vapor system, a droplet suspended in the gaseous phase, a liquid droplet located between two parallel wettable surfaces, the coalescence of two droplets, and a phase separation in a liquid-vapor system at different conditions. Numerical results are also presented for the coexistence curve and the verification of the Laplace law. Results obtained are in good agreement with the analytical solutions and also

  5. Optimized Enzymatic Synthesis of Hesperidin Fatty Acid Esters in a Two-Phase System Containing Ionic Liquid

    Directory of Open Access Journals (Sweden)

    Yollanda Edwirges Moreira Franco

    2011-08-01

    Full Text Available Response surface methodology (RSM based on a five-level, three-variable central composite design (CCD was employed for modeling and optimizing the conversion yield of the enzymatic acylation of hesperidin with decanoic acid using immobilized Candida antarctica lipase B (CALB in a two-phase system containing [bmim]BF4. The three variables studied (molar ratio of hesperidin to decanoic acid, [bmim]BF4/acetone ratio and lipase concentration significantly affected the conversion yield of acylated hesperidin derivative. Verification experiments confirmed the validity of the predicted model. The lipase showed higher conversion degree in a two-phase system using [bmim]BF4 and acetone compared to that in pure acetone. Under the optimal reaction conditions carried out in a single-step biocatalytic process when the water content was kept lower than 200 ppm, the maximum acylation yield was 53.6%.

  6. The influence of interfacial properties on the two-phase liquid flow of organic contaminants in groundwater. Final report, July 1, 1989--June 30, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Demond, A.H.; Desai, F.N.; Hayes, K.F.

    1992-12-31

    DOE`s waste sites are contaminated with a variety of organic liquids. Because of their low solubility in water, organic liquids such as these will persist as separate liquid phases and be transported as such in the subsurface. Thus, an improved understanding of the factors influencing the movement of a separate organic liquid phase in the subsurface is important to DOE`s efforts to control groundwater contamination. Wettability is sometimes cited as the most important factor influencing two-phase flow in porous media. The wetting phase migrates preferentially through the smaller pores, whereas the nonwetting phase is concentrated in the larger pores. Typically, aquifers are thought of as strongly water-wet, implying that the organic liquid preferentially occupies the larger pores. But in fact, that state depends on the properties of the three interfaces of the system: between the organic liquid and water, water and the solid, and the organic liquid and the solid. Characteristics of the system which affect the interfacial properties also impact the wettability, such as the nature of the aquifer solids` surfaces, the composition of the goundwater and the properties of the organic contaminant. The alteration of wettability at DOE waste sites may be dominated by the presence of co-contaminants such as organic acids and bases which behave as surface-active agents or surfactants. Because of their physicochemical nature, surfactants will sorb preferentially at the interfaces of the system, thereby impacting the wettability and the distribution of the liquids in the porous medium. The over-all objective of this research was to determine how changes in interfacial properties affect two-phase flow. Specifically, the objective was to examine the effect of surfactant sorption on capillary pressure relationships by correlating measurements of sorption, zeta potential, interfacial tension and contact angle, with changes in the capillary pressure-saturation relationships.

  7. Aqueous two-phase based on ionic liquid liquid-liquid microextraction for simultaneous determination of five synthetic food colourants in different food samples by high-performance liquid chromatography.

    Science.gov (United States)

    Sha, Ou; Zhu, Xiashi; Feng, Yanli; Ma, Weixing

    2015-05-01

    A rapid and effective method of aqueous two-phase systems based on ionic liquid microextraction for the simultaneous determination of five synthetic food colourants (tartrazine, sunset yellow, amaranth, ponceau 4R and brilliant blue) in food samples was established. High-performance liquid chromatography coupled with an ultraviolet detector of variable wavelength was used for the determinations. 1-alkyl-3-methylimidazolium bromide was selected as the extraction reagent. The extraction efficiency of the five colourants in the proposed system is influenced by the types of salts, concentrations of salt and [CnMIM]Br, as well as the extracting time. Under the optimal conditions, the extraction efficiencies for these five colourants were above 95%. The phase behaviours of aqueous two-phase system and extraction mechanism were investigated by UV-vis spectroscopy. This method was applied to the analysis of the five colourants in real food samples with the detection limit of 0.051-0.074 ng/mL. Good spiked recoveries from 93.2% to 98.9% were obtained.

  8. Mathematical methods for restricted domain ternary liquid mixture free energy determination using light scattering.

    Science.gov (United States)

    Wahle, Chris W; Ross, David S; Thurston, George M

    2013-09-28

    We extend methods of solution of a light scattering partial differential equation for the free energy of mixing to apply to connected, isotropic ternary liquid composition domains that do not touch all three binary axes. To do so we mathematically analyze the problem of inferring needed Dirichlet boundary data, and solving for the free energy, with use of hypothetical static light scattering measurements that correspond to dielectric composition gradient vectors that have distinct directions. The physical idea behind the technique is that contrasting absorption properties of mixture components can result in such distinctly directed dielectric composition gradient vectors, due to their differing wavelength dependences of dielectric response. At suitably chosen wavelengths, contrasting light scattering efficiency patterns in the ternary composition triangle can then correspond to the same underlying free energy, and enlarge the scope of available information about the free energy, as shown here. We show how to use distinctly directed dielectric gradients to measure the free energy on both straight lines and curves within the ternary composition triangle, so as to provide needed Dirichlet conditions for light scattering partial differential equation solution. With use of Monte Carlo simulations of noisy light scattering data, we provide estimates of the overall system measurement time and sample spacing needed to determine the free energy to a desired degree of accuracy, for various angles between the assumed dielectric gradient vectors, and indicate how the measurement time depends on instrumental throughput parameters. The present analysis methods provide a way to use static light scattering to measure, directly, mixing free energies of many systems that contain such restricted liquid domains, including aqueous solutions of biological macromolecules, micellar mixtures and microemulsions, and many small molecule systems that are important in separation technology.

  9. Experimental Study of the Interfacial Waves in Horizontal Stratified Gas-liquid Two-phase Flows by Using the Developed Image Processing Technique

    CERN Document Server

    Kuntoro, Hadiyan Yusuf; Dinaryanto, Okto; Deendarlianto,; Indarto,

    2015-01-01

    Experimental series of stratified gas-liquid two-phase flows had been carried out in a 26 mm i.d. transparent acrylic horizontal pipe. The study was aimed to determine the interfacial wave characteristics of the flow and to develop a high quality database of it. The longitudinal section of the pipe was used as the reference section of image recording. Air and water were used as the test fluids, flowing co-currently inside the pipe. The flow behavior was recorded by using a high-speed video camera around 5 m in axial distance from the inlet pipe to ensure the fully-developed stratified gas-liquid two-phase flow. To correct the refraction due to the acrylic pipe, a correction box was employed in the visualization test section. The group of stratified smooth and wavy two-phase flows were successfully recorded and classified on the basis of the visualization study from 24 couples of test condition of superficial water and air velocities. Digital image processing technique was then used to perform quantitative ana...

  10. Phase equilibrium calculations of ternary liquid mixtures with binary interaction parameters and molecular size parameters determined from molecular dynamics.

    Science.gov (United States)

    Oh, Suk Yung; Bae, Young Chan

    2010-07-15

    The method presented in this paper was developed to predict liquid-liquid equilibria in ternary liquid mixtures by using a combination of a thermodynamic model and molecular dynamics simulations. In general, common classical thermodynamic models have many parameters which are determined by fitting a model with experimental data. This proposed method, however, provides a simple procedure for calculating liquid-liquid equilibria utilizing binary interaction parameters and molecular size parameters determined from molecular dynamics simulations. This method was applied to mixtures containing water, hydrocarbons, alcohols, chlorides, ketones, acids, and other organic liquids over various temperature ranges. The predicted results agree well with the experimental data without the use of adjustable parameters.

  11. Separation of four flavonol glycosides from Solanum rostratum Dunal using aqueous two-phase flotation followed by preparative high-performance liquid chromatography.

    Science.gov (United States)

    Chang, Lin; Shao, Qian; Xi, Xingjun; Chu, Qiao; Wei, Yun

    2017-02-01

    Aqueous two-phase flotation followed by preparative high-performance liquid chromatography was used to separate four flavonol glycosides from Solanum rostratum Dunal. In the aqueous two-phase flotation section, the effects of sublation solvent, solution pH, (NH4 )2 SO4 concentration in aqueous solution, cosolvent, N2 flow rate, flotation time, and volumes of the polyethylene glycol phase on the recovery were investigated in detail, and the optimal conditions were selected: 50 wt% polyethylene glycol 1000 ethanol solvent as the flotation solvent, pH 4, 350 g/L of (NH4 )2 SO4 concentration in aqueous phase, 40 mL/min of N2 flow rate, 30 min of flotation time, 10.0 mL of flotation solvent volume, and two times. After aqueous two-phase flotation concentration, the flotation products were purified by preparative high-performance liquid chromatography. The purities of the final products A and B were 98.1 and 99.0%. Product B was the mixture of three compounds based on the analysis of high-performance liquid chromatography at the temperature of 10°C, while product A was hyperoside after the identification by nuclear magnetic resonance. Astragalin, 3'-O-methylquercetin 3-O-β-d-galactopyranoside, and 3'-O-methylquercetin 3-O-β-d-glucopyranoside were obtained with the purity of 93.8, 97.1, and 99.2%, respectively, after the further separation of product B using preparative high-performance liquid chromatography.

  12. Treatment of substituted phenol mixtures in single phase and two-phase solid-liquid partitioning bioreactors

    Energy Technology Data Exchange (ETDEWEB)

    Tomei, M. Concetta, E-mail: tomei@irsa.cnr.it [Water Research Institute, C.N.R., Via Salaria km 29.300, 00015 Monterotondo Scalo (Rome) (Italy); Rita, Sara; Angelucci, Domenica Mosca [Water Research Institute, C.N.R., Via Salaria km 29.300, 00015 Monterotondo Scalo (Rome) (Italy); Annesini, M. Cristina [Department of Chemical Engineering Materials and Environment, Sapienza University of Rome, Via Eudossiana 18, 00184 Rome (Italy); Daugulis, Andrew J. [Department of Chemical Engineering, Queen' s University, Kingston, Ontario, K7L 3N6 (Canada)

    2011-07-15

    Highlights: {yields} We investigate the biodegradation of a phenolic mixture (2,4-dimethylphenol and 4-nitrophenol). {yields} We identify an effective polymer to absorb these substrates. {yields} We utilize the polymer in a Two Phase Partitioning Bioreactor (TPPB) to overcome cytotoxicity. {yields} The polymer-based TPPB significantly out-performs a single phase system. {yields} The re-release of the substrates at differing rates (based on the partition coefficients) affects the process kinetics. - Abstract: The biological treatment of phenolics is constrained by the inherent cytotoxicity of these compounds. One method to alleviate such toxicity is to add a sequestering phase to absorb, and subsequently release, the substrate(s) to the micro-organisms; such a system is termed a Two Phase Partitioning Bioreactor. Here we have compared the performance of a TPPB, relative to single phase operation, in which a small volume (5%, v/v) of beads of the polymer Hytrel 8206 was used to treat aqueous mixtures of 2,4-dimethylphenol and 4-nitrophenol. Hytrel 8206 was selected from a range of polymers that were tested for their partition coefficients (PCs) for the target molecules, with the more hydrophobic compound (2,4-dimethylphenol) having a higher PC value (201) than 4-nitrophenol (143). Significantly increased removal rates for both substrates were demonstrated in TPPB mode relative to single phase operation. Additionally, the differential release of the compounds to the aqueous phase and their distinct PC values changed the kinetic pattern of the biotreatment system, smoothing out the cellular oxygen demand. Release of the substrates by the polymer over 60 operating cycles was virtually complete (>97%) demonstrating the reusability and robustness of the use of polymers in overcoming cytotoxicity of phenolic substrates.

  13. Liquid-liquid equilibria for binary and ternary systems containing glycols, aromatic hydrocarbons, and water: Experimental measurements and modeling with the CPA EoS

    DEFF Research Database (Denmark)

    Folas, Georgios; Kontogeorgis, Georgios; Michelsen, Michael Locht;

    2006-01-01

    Liquid-liquid equilibrium data of four binary glycol + aromatic hydrocarbon systems and three ternary systems containing water have been measured at atmospheric pressure. The measured systems are monoethylene glycol (MEG) + benzene or toluene, triethylene glycol (TEG) + benzene or toluene, MEG + ...

  14. Calculation of liquid-liquid phase separation in a ternary system of a polymer in a mixture of a solvent and a nonsolvent

    NARCIS (Netherlands)

    Altena, Frank W.; Smolders, C.A.

    1982-01-01

    A numerical method for the calculation of the binodal of liquid-liquid phase separation in a ternary system is described. The Flory-Huggins theory for three-component systems is used. Binodals are calculated for polymer/solvent/nonsolvent systems which are used in the preparation of asymmetric ultra

  15. Direct Measurement of the Metastable Liquid Miscibility Gap in Fe-Co-Cu Ternary Alloy System

    Institute of Scientific and Technical Information of China (English)

    CAO Chong-De; Georg P.G(O)RLER

    2005-01-01

    @@ The metastable liquid-liquid phase separation in undercooled Fe-Co-Cu ternary alloy melts (XCu = 0.10-0.84;XCo:XFe = 1:3,1:1 and 3:1) is investigated by differential thermal analysis in combination with glass fluxing technique. In almost every case, the undercooling of the homogeneous alloy melt was sufficient to reach the boundary line of the submerged miscibility gap. The differential-thermal-analysis signals indicate that this separation into a (Fe, Co)-rich liquid phase L1 and a Cu-rich liquid L2 is exothermic and proceeds until the rapid solidification of the L1 phase occurs. At a given Cu concentration and with the increase of Co content, the phase separation temperatures decrease monotonically between the corresponding values of the boundary systems Fe-Cu and Co-Cu. The boundary lines of the miscibility gap, which are determined for the three quasi-binary cross-sections of the (Fe, Co)-Cu alloy system, show remarkably flat domes. The occurrence of the liquid phase separation shows an evident influence on the subsequent γ-Fe(Co, Cu)→α-Fe(Co, Cu) solid phase transformation.

  16. The Impact of Photon Flight Path on S1 Pulse Shape Analysis in Liquid Xenon Two-phase Detectors

    CERN Document Server

    Moongweluwan, M

    2015-01-01

    The LUX dark matter search experiment is a 350 kg dual-phase xenon time projection chamber located at the 4850 ft level of the Sanford Underground Research Facility in Lead, SD. The success of two-phase xenon detectors for dark matter searches relies on their ability to distinguish electron recoil (ER) background events from nuclear recoil (NR) signal events. Typically, the NR-ER discrimination is obtained from the ratio of the electroluminescence light (S2) to the prompt scintillation light (S1). Analysis of the S1 pulse shape is an additional discrimination technique that can be used to distinguish NR from ER. Pulse-shape NR-ER discrimination can be achieved based on the ratio of the de-excitation processes from singlet and triplet states that generate the S1. The NR S1 is dominated by the de-excitation process from singlet states with a time constant of about 3 ns while the ER S1 is dominated by the de-excitation process from triplet states with a time constant of about 24 ns. As the size of the detectors ...

  17. Structure of low-head two-phase flow in flat nozzlesduring outflow of the liquid into rarefied medium

    Institute of Scientific and Technical Information of China (English)

    Kochenkov A G; Tonkonog V G

    2011-01-01

    Outcomes of experimental researches of the low-pressure adiabatic flow of the boiling liquid through two-dimensional Laval nozzles in a vacuum atmosphere were adduced.Requirements of critical conditions of flow were determined.Structural forms of a stream were investigated and their connection with crisis of flow was shown.It was established periodic non-stationary macrostructures of a stream which was stipulated by the rotational gear of origin of a vapor phase.

  18. Partitioning of Cephalexin in Ionic Liquid Aqueous Two-Phase System Composed of 1-Butyl-3-Methylimidazolium Tetrafluoroborate and ZnSO4

    Directory of Open Access Journals (Sweden)

    Yan Fang Li

    2013-01-01

    Full Text Available Ionic liquid aqueous two-phase system (ILATPS was applied in the extraction and separation of hydrosoluble antibiotics. The partitioning behavior of cephalexin (CEX in 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim]BF4-ZnSO4 aqueous two-phase system was studied by the partitioning parameter of the extraction efficiency. The effect of the volume of [Bmim]BF4, the concentration of ZnSO4, temperature, pH, and the volume of ZnSO4 solution was discussed concretely. When the volume of [Bmim]BF4 was 2 mL and the concentration of ZnSO4 was 35%, the extraction efficiency of CEX could reach 92.64% with pH unadjusted. The effect of the volume of [Bmim]BF4 on the extraction efficiency was higher than that of the concentration of ZnSO4. The temperature influenced not only the formation of aqueous two-phase system but also the extraction efficiency of CEX. The target was found to be preferentially extracted to the [Bmim]BF4-rich phase at the pH below 4.3. The partition of CEX to the top phase was enhanced by increasing the volume of [Bmim]BF4, the concentration of ZnSO4, and temperature; however, the partition of CEX to the top phase increased by decreasing the pH.

  19. First Demonstration of Imaging Cosmic Muons in a Two-Phase Liquid Argon TPC using an EMCCD Camera and a THGEM

    CERN Document Server

    Mavrokoridis, K; McCormick, K J; Paudyal, P; Roberts, A; Smith, N A; Touramanis, C

    2015-01-01

    Colossal two-phase Liquid Argon Time Projection Chambers (LAr TPCs) are a proposed option for future long-baseline neutrino experiments. This study illustrates the feasibility of using an EMCCD camera to capture light induced by single cosmic events in a two-phase LAr TPC employing a THGEM. An Andor iXon Ultra 897 EMCCD camera was externally mounted via a borosilicate glass viewport on the Liverpool two-phase LAr TPC. The camera successfully captured the secondary scintillation light produced at the THGEM holes that had been induced by cosmic events. The light collection capability of the camera for various EMCCD gains was assessed. For a THGEM gain of 64 and an EMCCD gain of 1000, clear images were captured with an average signal-to-noise ratio of 6. Preliminary 3D reconstruction of straight cosmic muon tracks has been performed by combining the camera images, PMT signals and THGEM charge data. Reconstructed cosmic muon tracks were used to determine THGEM gain and to calibrate the intensity levels of the EMC...

  20. ETHANOL, ACETIC ACID, AND WATER ADSORPTION FROM BINARY AND TERNARY LIQUID MIXTURES ON HIGH-SILICA ZEOLITES

    Science.gov (United States)

    Adsorption isotherms were measured for ethanol, acetic acid, and water adsorbed on high-silica ZSM-5 zeolite powder from binary and ternary liquid mixtures at room temperature. Ethanol and water adsorption on two high-silica ZSM-5 zeolites with different aluminum contents and a h...

  1. Modeling and simulation of a pseudo-two-phase gas-liquid column reactor for thermal hydrocracking of petroleum heavy fractions

    Directory of Open Access Journals (Sweden)

    E.M. Matos

    2002-07-01

    Full Text Available This work presents a model to predict the behavior of velocity, gas holdup and local concentration fields in a pseudo-two-phase gas-liquid column reactor applied for thermal hydrocracking of petroleum heavy fractions. The model is based on the momentum and mass balances for the system, using an Eulerian-Eulerian approach. Using the k-epsilon model,fluid dynamics accounts for both laminar and turbulent flows, with discrete small bubbles (hydrogen flowing in a continuous pseudohomogeneous liquid phase (oil and catalyst particles. The petroleum is assumed to be a mixture of pseudocomponents, grouped by similar chemical structural properties, and the thermal hydrocracking is taken into account using a kinetic network based on these pseudocomponents.

  2. Measurement of Gas and Liquid Velocities in an Air-Water Two-Phase Flow using Cross-Correlation of Signals from a Double Senor Hot-Film Probe

    Energy Technology Data Exchange (ETDEWEB)

    B. Gurau; P. Vassalo; K. Keller

    2002-02-19

    Local gas and liquid velocities are measured by cross-correlating signals from a double sensor hot-film anemometer probe in pure water flow and air water two-phase flow. The gas phase velocity measured in two-phase flow agrees with velocity data obtained using high-speed video to within +/-5%. A turbulent structure, present in the liquid phase, allows a correlation to be taken, which is consistent with the expected velocity profiles in pure liquid flow. This turbulent structure is also present in the liquid phase of a two-phase flow system. Therefore, a similar technique can be applied to measure the local liquid velocity in a two-phase system, when conditions permit.

  3. Light Yield in DarkSide-10: a Prototype Two-phase Liquid Argon TPC for Dark Matter Searches

    CERN Document Server

    Akimov, D; Alton, D; Arisaka, K; Back, H O; Beltrame, P; Benziger, J; Bolozdynya, A; Bonfini, G; Brigatti, A; Brodsky, J; Cadonati, L; Calaprice, F; Candela, A; Cao, H; Cavalcante, P; Chavarria, A; Chepurnov, A; Chidzik, S; Cline, D; Cocco, A G; Condon, C; D'Angelo, D; Davini, S; De Haas, E; Derbin, A; Di Pietro, G; Dratchnev, I; Durben, D; Empl, A; Etenko, A; Fan, A; Fiorillo, G; Fomenko, K; Gabriele, F; Galbiati, C; Gazzana, S; Ghag, C; Ghiano, C; Goretti, A; Grandi, L; Gromov, M; Guan, M; Guo, C; Guray, G; Hungerford, E V; Ianni, Al; Ianni, An; Kayunov, A; Keeter, K; Kendziora, C; Kidner, S; Kobychev, V; Koh, G; Korablev, D; Korga, G; Shields, E; Li, P; Loer, B; Lombardi, P; Love, C; Ludhova, L; Lukyanchenko, L; Lund, A; Lung, K; Ma, Y; Machulin, I; Maricic, J; Martoff, C J; Meng, Y; Meroni, E; Meyers, P D; Mohayai, T; Montanari, D; Montuschi, M; Mosteiro, P; Mount, B; Muratova, V; Nelson, A; Nemtzow, A; Nurakhov, N; Orsini, M; Ortica, F; Pallavicini, M; Pantic, E; Parmeggiano, S; Parsells, R; Pelliccia, N; Perasso, L; Perfetto, F; Pinsky, L; Pocar, A; Pordes, S; Ranucci, G; Razeto, A; Romani, A; Rossi, N; Saggese, P; Saldanha, R; Salvo, C; Sands, W; Seigar, M; Semenov, D; Skorokhvatov, M; Smirnov, O; Sotnikov, A; Sukhotin, S; Suvorov, Y; Tartaglia, R; Tatarowicz, J; Testera, G; Teymourian, A; Thompson, J; Unzhakov, E; Vogelaar, R B; Wang, H; Westerdale, S; Wojcik, M; Wright, A; Xu, J; Yang, C; Zavatarelli, S; Zehfus, M; Zhong, W; Zuzel, G

    2012-01-01

    As part of the DarkSide program of direct dark matter searches using liquid argon TPCs, a prototype detector with an active volume containing 10 kg of liquid argon, DarkSide-10, was built and operated underground in the Gran Sasso National Laboratory in Italy. A critically important parameter for such devices is the scintillation light yield, as photon statistics limits the rejection of electron-recoil backgrounds by pulse shape discrimination. We have measured the light yield of DarkSide-10 using the readily-identifiable full-absorption peaks from gamma ray sources combined with single-photoelectron calibrations using low-occupancy laser pulses. For gamma lines of energies in the range 122-1275 keV, we get consistent light yields averaging 8.887\\pm0.003(stat)\\pm0.444(sys) p.e./keV_ee. With additional purification, the light yield measured at 511 keV increased to 9.142\\pm0.006(stat) p.e./keV_ee.

  4. Ternary liquid–liquid equilibria for mixtures of toluene + n-heptane + an ionic liquid

    NARCIS (Netherlands)

    Meindersma, G. Wytze; Podt, Anita J.G.; Haan, de André B.

    2006-01-01

    This research has been focused on a study of sulfolane and four ionic liquids as solvents in liquid–liquid extraction. Liquid–liquid equilibria data were obtained for mixtures of (sulfolane or 4-methyl-N-butylpyridinium tetrafluoroborate ([mebupy]BF4) or 1-ethyl-3-methylimidazolium ethylsulfate ([em

  5. Extraction of Theanine from Waste Liquid of Tea Polyphenol Production in Aqueous Two-phase Systems with Cationic and Anionic Surfactants

    Institute of Scientific and Technical Information of China (English)

    ZHANG Junwei; WANG Yan; PENG Qijun

    2013-01-01

    Extraction of theanine from waste liquid of tea polyphenol production was studied in aqueous surfactant two-phase system (ASTP) with cationic suffactant (CTAB) and anionic surfactant (SDS).Results indicate that the region of ASTP is narrow and there is only a two-phase region of cationic surfactant.The increase in concentrations of NaBr and Na2SO4 are beneficial to the formation of ASTP.Theanine concentration in the bottom phase increases with increasing concentration of theanine,whereas the partition coefficient and extraction rate only change a little when the concentration of theanine is above 0.2 g· L-1.With the increase of SDS concentration,the phase ratio and the partition coefficient decrease,while the extraction efficiency of theanine increases and the concentration of theaninc changes a little in the range from 2.4/7.5 to 2.8/7.2 for SDS/CTAB ratio.The temperature has a notable effect on the concentration of theanine in the bottom phase,partition coefficient and extraction rate of theanine.The increase of waste liquid decreases the phase ratio,increases the concentration and extraction rate of theanine in the bottom phase,since the protein and the saccharide enter the bottom phase with theanine.

  6. Solid—Liquid Equilibria of Several Binary and Ternary Systems Containing Meleic Anhydride

    Institute of Scientific and Technical Information of China (English)

    MAPeisheng; CHENMingming; 等

    2002-01-01

    Solid-liquid equilibria(SLE) of three binary systems and seven ternary systems containing maleic anhydride(MA) are measured by visual method. The experimental data are compared with the calculated ones with modified universal quasichemical functional group activity coefficient(UNIFAC) method in which the interaction parameters between groups come from two sources,dortmund data bank (DDB), if there′s any,and correlations based on our former presented experimental SLE data of twenty binary systems.New groups of MA,ACCOO group,COO group,>C=O group and cy-CH2 group are defined and the SLE data of maleic anhydride in isopropyl acetate in literature are cited in order to assess the new interaction parameters,correlated with Wilson equation and the λh equation.The modified UNIFAC method with these new regressed interaction parameters is also used to predict other three binary systems containing maleic anhydride.

  7. Atomic mobility in a ternary liquid Ga-In-Sn alloy of the eutectic composition

    Science.gov (United States)

    Nefedov, D. Yu.; Antonenko, A. O.; Podorozhkin, D. Yu.; Uskov, A. V.; Charnaya, E. V.; Lee, M. K.; Chang, J. L.; Haase, J.; Michel, D.; Kumzerov, Yu. A.; Fokin, A. V.; Samoilovich, M. I.; Bugaev, A. S.

    2017-02-01

    The nuclear spin-lattice relaxation and Knight shift of 71Ga, 69Ga, and 115In nuclei in a ternary liquid gallium-indium-tin alloy of the eutectic composition, which was introduced into pores of an opal matrix and porous glasses with pore sizes of 18 and 7 nm, have been investigated and compared with those for the bulk melt. It has been found that longitudinal relaxation is accelerated and the Knight shift is decreased, depending on the size of pores. The correlation time of the atomic motion has been calculated for the nanostructured melt in porous matrices. It has been shown that the atomic mobility in the melt decreases with decreasing size of pores in the glasses.

  8. Study of Co-Current and Counter-Current Gas-Liquid Two-Phase Flow Through Packed Bed in Microgravity

    Science.gov (United States)

    Revankar, Shripad T.

    2002-11-01

    The main goal of the project is to obtain new experimental data and development of models on the co-current and counter-current gas-liquid two-phase flow through a packed bed in microgravity and characterize the flow regime transition, pressure drop, void and interfacial area distribution, and liquid hold up. Experimental data will be obtained for earth gravity and microgravity conditions. Models will be developed for the prediction of flow regime transition, void fraction distribution and interfacial area concentration, which are key parameters to characterize the packed bed performance. Thus the specific objectives of the proposed research are to: (1) Develop experiments for the study of the gas liquid two-phase flow through the packed bed with three different flow combinations: co-current down flow, co-current upflow and counter current flow. (2) Develop pore scale and bed scale two-phase instrumentation for measurement of flow regime transition, void distribution and gas-liquid interfacial area concentration in the packed bed. (3) Obtain database on flow regime transition, pressure drop, void distribution, interfacial area concentration and liquid hold up as a function of bed characteristics such as bed particle size, porosity, and liquid properties such as viscosity and surface tension. (4) Develop mathematical model for flow regime transition, void fraction distribution and interfacial area concentration for co-current gas-liquid flow through the porous bed in gravity and micro gravity conditions.(4) Develop mathematical model for the flooding phenomena in counter-current gas-liquid flow through the porous bed in gravity and micro gravity conditions. The present proposal addresses the most important topic of HEDS-specific microgravity fluid physics research identified by NASA 's one of the strategic enterprises, OBPR Enterprise. The proposed project is well defined and makes efficient use of the ground-based parabolic flight research aircraft facility. The

  9. Cooling the dark energy camera CCD array using a closed-loop two-phase liquid nitrogen system

    Science.gov (United States)

    Cease, H.; DePoy, D.; Derylo, G.; Diehl, H. T.; Estrada, J.; Flaugher, B.; Kuk, K.; Kuhlmann, S.; Lathrop, A.; Schultz, K.; Reinert, R. J.; Schmitt, R. L.; Stefanik, A.; Zhao, A.

    2010-07-01

    The Dark Energy Camera (DECam) is the new wide field prime-focus imager for the Blanco 4m telescope at CTIO. This instrument is a 3 sq. deg. camera with a 45 cm diameter focal plane consisting of 62 2k × 4k CCDs and 12 2k × 2k CCDs and was developed for the Dark Energy Survey that will start operations at CTIO in 2011. The DECam CCD array is inside the imager vessel. The focal plate is cooled using a closed loop liquid nitrogen system. As part of the development of the mechanical and cooling design, a full scale prototype imager vessel has been constructed and is now being used for Multi-CCD readout tests. The cryogenic cooling system and thermal controls are described along with cooling results from the prototype camera. The cooling system layout on the Blanco telescope in Chile is described.

  10. Experimental measurements of vapor-liquid equilibria of the H2O + CO2 + CH4 ternary system

    Science.gov (United States)

    Qin, J.; Rosenbauer, R.J.; Duan, Zhenhao

    2008-01-01

    Reported are the experimental measurements on vapor-liquid equilibria in the H2O + CO2 + CH4 ternary system at temperatures from (324 to 375) K and pressures from (10 to 50) MPa. The results indicate that the CH4 solubility in the ternary mixture is about 10 % to 40 % more than that calculated by interpolation from the Henry's law constants of the binary system, H2O + CH4, and the solubility of CO2 is 6 % to 20 % more than what is calculated by the interpolation from the Henry's law constants of the binary mixture, H 2O + CO2. ?? 2008 American Chemical Society.

  11. Ternary liquid-liquid equilibria for the phenolic compounds extraction from artificial textile industrial waste

    Science.gov (United States)

    Fardhyanti, Dewi Selvia; Prasetiawan, Haniif; Hermawan, Sari, Lelita Sakina

    2017-03-01

    Liquid waste in textile industry contains large amounts of dyes and chemicals which are capable of harming the environment and human health. It is due to liquid waste characteristics which have high BOD, COD, temperature, dissolved and suspended solid. One of chemical compound which might be harmful for environment when disposed in high concentration is phenol. Currently, Phenol compound in textile industrial waste has reached 10 ppm meanwhile maximum allowable phenol concentration is not more than 0.2 ppm. Otherwise, Phenol also has economic value as feedstock of plastic, pharmaceutical and cosmetic industry. Furthermore, suitable method to separate phenol from waste water is needed. In this research, liquid - liquid extraction method was used with extraction time for 70 minutes. Waste water sample was then separated into two layers which are extract and raffinate. Thereafter, extract and raffinate were then tested by using UV-Vis Spectrophotometer to obtained liquid - liquid equilibrium data. Aim of this research is to study the effect of temperature, stirring speed and type of solvent to obtain distribution coefficient (Kd), phenol yield and correlation of Three-Suffix Margules model for the liquid - liquid extraction data equilibrium. The highest extraction yield at 80.43 % was found by using 70% methanol as solvent at extraction temperature 50 °C with stirring speed 300 rpm, coefficient distribution was found 216.334. From this research it can be concluded that Three-Suffix Margules Model is suitable to predict liquid - liquid equilibrium data for phenol system.

  12. Phase separation and rapid solidification of liquid Cu60Fe30Co10 ternary peritectic alloy

    Institute of Scientific and Technical Information of China (English)

    DAI FuPing; CAO ChongDe; WEI BingBo

    2007-01-01

    The metastable liquid phase separation and rapid solidification of Cu60Fe30Co10 ternary peritectic alloy were investigated by using the drop tube technique and the differential scanning calorimetry method. It was found that the critical temperature of metastable liquid phase separation in this alloy is 1623.5 K, and the two separated liquid phases solidify as Cu(Fe,Co) and Fe(Cu,Co) solid solutions, respectively. The undercooling and cooling rate of droplets processed in the drop tube increase with the decrease of their diameters. During the drop tube processing, the structural morphologies of undercooled droplets are strongly dependent on the cooling rate. With the increase of the cooling rate, Fe(Cu,Co) spheres are refined greatly and become uniformly dispersed in the Cu-rich matrix. The calculations of Marangoni migration velocity (VM) and Stokes motion velocity (VS) of Fe(Cu,Co) droplets indicated that Marangoni migration contributes more to the coarsening and congregation of the minor phase during free fall. At the same undercooling, the VM/VS ratio increases drastically as Fe(Cu,Co) droplet size decreases. On the other hand, a larger undercooling tends to increase the VM/VS value for Fe(Cu,Co) droplets with the same size.

  13. Phase separation and rapid solidification of liquid Cu60Fe30Co10 ternary peritectic alloy

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The metastable liquid phase separation and rapid solidification of Cu60Fe30Co10 ternary peritectic alloy were investigated by using the drop tube technique and the differential scanning calorimetry method. It was found that the critical temperature of metastable liquid phase separation in this alloy is 1623.5 K, and the two sepa- rated liquid phases solidify as Cu(Fe,Co) and Fe(Cu,Co) solid solutions, respec- tively. The undercooling and cooling rate of droplets processed in the drop tube increase with the decrease of their diameters. During the drop tube processing, the structural morphologies of undercooled droplets are strongly dependent on the cooling rate. With the increase of the cooling rate, Fe(Cu,Co) spheres are refined greatly and become uniformly dispersed in the Cu-rich matrix. The calculations of Marangoni migration velocity (VM) and Stokes motion velocity (VS) of Fe(Cu,Co) droplets indicated that Marangoni migration contributes more to the coarsening and congregation of the minor phase during free fall. At the same undercooling, the VM/VS ratio increases drastically as Fe(Cu,Co) droplet size decreases. On the other hand, a larger undercooling tends to increase the VM/VS value for Fe(Cu,Co) drop- lets with the same size.

  14. Non-invasive classification of gas-liquid two-phase horizontal flow regimes using an ultrasonic Doppler sensor and a neural network

    Science.gov (United States)

    Musa Abbagoni, Baba; Yeung, Hoi

    2016-08-01

    The identification of flow pattern is a key issue in multiphase flow which is encountered in the petrochemical industry. It is difficult to identify the gas-liquid flow regimes objectively with the gas-liquid two-phase flow. This paper presents the feasibility of a clamp-on instrument for an objective flow regime classification of two-phase flow using an ultrasonic Doppler sensor and an artificial neural network, which records and processes the ultrasonic signals reflected from the two-phase flow. Experimental data is obtained on a horizontal test rig with a total pipe length of 21 m and 5.08 cm internal diameter carrying air-water two-phase flow under slug, elongated bubble, stratified-wavy and, stratified flow regimes. Multilayer perceptron neural networks (MLPNNs) are used to develop the classification model. The classifier requires features as an input which is representative of the signals. Ultrasound signal features are extracted by applying both power spectral density (PSD) and discrete wavelet transform (DWT) methods to the flow signals. A classification scheme of ‘1-of-C coding method for classification’ was adopted to classify features extracted into one of four flow regime categories. To improve the performance of the flow regime classifier network, a second level neural network was incorporated by using the output of a first level networks feature as an input feature. The addition of the two network models provided a combined neural network model which has achieved a higher accuracy than single neural network models. Classification accuracies are evaluated in the form of both the PSD and DWT features. The success rates of the two models are: (1) using PSD features, the classifier missed 3 datasets out of 24 test datasets of the classification and scored 87.5% accuracy; (2) with the DWT features, the network misclassified only one data point and it was able to classify the flow patterns up to 95.8% accuracy. This approach has demonstrated the

  15. Preparation of aqueous two-phase systems composed of two pH-response polymers and liquid-liquid extraction of demeclocycline.

    Science.gov (United States)

    Yan, Bo; Cao, Xuejun

    2012-07-06

    Aqueous two-phase systems have potential applications for separation and purification of bioproducts in bio-industry. However, a key problem is the recovery of the polymers forming aqueous two-phase systems. In this study, two novel random copolymers (P(ADB) and P(ADBA)) were synthesized using acrylic acid, dimethylamino-ethyl methacrylate, butyl methacrylate and allyl alcohol as monomers and used to form pH response aqueous two-phase systems. The recoveries of P(ADB) and P(ADBA) are 97.18% and 98.87% and the pI of P(ADB) and P(ADBA) are 2.79 and 4.01, respectively. Demeclocycline was partitioned in the P(ADB)/P(ADBA) aqueous two-phase systems and the partition coefficient reached 0.085, in the presence of MgSO₄ (60 mmol/L) at pH 5.28. Copyright © 2012 Elsevier B.V. All rights reserved.

  16. Application of Two Phase (Liquid/Gas) Xenon Gamma-Camera for the Detection of Special Nuclear Material and PET Medical Imaging

    Energy Technology Data Exchange (ETDEWEB)

    McKinsey, Daniel Nicholas [Yale University

    2013-08-27

    The McKinsey group at Yale has been awarded a grant from DTRA for the building of a Liquid Xenon Gamma Ray Color Camera (LXe-GRCC), which combines state-of-the-art detection of LXe scintillation light and time projection chamber (TPC) charge readout. The DTRA application requires a movable detector and hence only a single phase (liquid) xenon detector can be considered in this case. We propose to extend the DTRA project to applications that allow a two phase (liquid/gas) xenon TPC. This entails additional (yet minimal) hardware and extension of the research effort funded by DTRA. The two phase detector will have better energy and angular resolution. Such detectors will be useful for PET medical imaging and detection of special nuclear material in stationary applications (e.g. port of entry). The expertise of the UConn group in gas phase TPCs will enhance the capabilities of the Yale group and the synergy between the two groups will be very beneficial for this research project as well as the education and research projects of the two universities. The LXe technology to be used in this project has matured rapidly over the past few years, developed for use in detectors for nuclear physics and astrophysics. This technology may now be applied in a straightforward way to the imaging of gamma rays. According to detailed Monte Carlo simulations recently performed at Yale University, energy resolution of 1% and angular resolution of 3 degrees may be obtained for 1.0 MeV gamma rays, using existing technology. With further research and development, energy resolution of 0.5% and angular resolution of 1.3 degrees will be possible at 1.0 MeV. Because liquid xenon is a high density, high Z material, it is highly efficient for scattering and capturing gamma rays. In addition, this technology scales elegantly to large detector areas, with several square meter apertures possible. The Yale research group is highly experienced in the development and use of noble liquid detectors for

  17. Ionic liquid-impregnated agarose film two-phase micro-electrodriven membrane extraction (IL-AF-μ-EME) for the analysis of antidepressants in water samples.

    Science.gov (United States)

    Mohamad Hanapi, Nor Suhaila; Sanagi, Mohd Marsin; Ismail, Abd Khamim; Wan Ibrahim, Wan Aini; Saim, Nor'ashikin; Wan Ibrahim, Wan Nazihah

    2017-03-01

    The aim of this study was to investigate and apply supported ionic liquid membrane (SILM) in two-phase micro-electrodriven membrane extraction combined with high performance liquid chromatography-ultraviolet detection (HPLC-UV) for pre-concentration and determination of three selected antidepressant drugs in water samples. A thin agarose film impregnated with 1-hexyl-3-methylimidazolium hexafluorophosphate, [C6MIM] [PF6], was prepared and used as supported ionic liquid membrane between aqueous sample solution and acceptor phase for extraction of imipramine, amitriptyline and chlorpromazine. Under the optimized extraction conditions, the method provided good linearity in the range of 1.0-1000μgL(-1), good coefficients of determination (r(2)=0.9974-0.9992) and low limits of detection (0.1-0.4μgL(-1)). The method showed high enrichment factors in the range of 110-150 and high relative recoveries in the range of 88.2-111.4% and 90.9-107.0%, for river water and tap water samples, respectively with RSDs of ≤7.6 (n=3). This method was successfully applied to the determination of the drugs in river and tap water samples. It is envisaged that the SILM improved the perm-selectivity by providing a pathway for targeted analytes which resulted in rapid extraction with high degree of selectivity and high enrichment factor.

  18. Ionic Liquid-Based Ultrasonic-Assisted Extraction of Secoisolariciresinol Diglucoside from Flaxseed (Linum usitatissimum L.) with Further Purification by an Aqueous Two-Phase System.

    Science.gov (United States)

    Tan, Zhi-Jian; Wang, Chao-Yun; Yang, Zi-Zhen; Yi, Yong-Jian; Wang, Hong-Ying; Zhou, Wan-Lai; Li, Fen-Fang

    2015-09-30

    In this work, a two-step extraction methodology of ionic liquid-based ultrasonic-assisted extraction (IL-UAE) and ionic liquid-based aqueous two-phase system (IL-ATPS) was developed for the extraction and purification of secoisolariciresinol diglucoside (SDG) from flaxseed. In the IL-UAE step, several kinds of ILs were investigated as the extractants, to identify the IL that affords the optimum extraction yield. The extraction conditions such as IL concentration, ultrasonic irradiation time, and liquid-solid ratio were optimized using response surface methodology (RSM). In the IL-ATPS step, ATPS formed by adding kosmotropic salts to the IL extract was used for further separation and purification of SDG. The most influential parameters (type and concentration of salt, temperature, and pH) were investigated to obtain the optimum extraction efficiency. The maximum extraction efficiency was 93.35% under the optimal conditions of 45.86% (w/w) IL and 8.27% (w/w) Na₂SO₄ at 22 °C and pH 11.0. Thus, the combination of IL-UAE and IL-ATPS makes up a simple and effective methodology for the extraction and purification of SDG. This process is also expected to be highly useful for the extraction and purification of bioactive compounds from other important medicinal plants.

  19. Separation, concentration and determination of chloramphenicol in environment and food using an ionic liquid/salt aqueous two-phase flotation system coupled with high-performance liquid chromatography.

    Science.gov (United States)

    Han, Juan; Wang, Yun; Yu, Cuilan; Li, Chunxiang; Yan, Yongsheng; Liu, Yan; Wang, Liang

    2011-01-31

    Ionic liquid-salt aqueous two-phase flotation (ILATPF) is a novel, green, non-toxic and sensitive samples pretreatment technique. ILATPF coupled with high-performance liquid chromatography (HPLC) was developed for the analysis of chloramphenicol, which combines ionic liquid aqueous two-phase system (ILATPS) based on imidazolium ionic liquid (1-butyl-3-methylimidazolium chloride, [C(4)mim]Cl) and inorganic salt (K(2)HPO(4)) with solvent sublation. In ILATPF systems, phase behaviors of the ILATPF were studied for different types of ionic liquids and salts. The sublation efficiency of chloramphenicol in [C(4)mim]Cl-K(2)HPO(4) ILATPF was influenced by the types of salts, concentration of K(2)HPO(4) in aqueous solution, solution pH, nitrogen flow rate, sublation time and the amount of [C(4)mim]Cl. Under the optimum conditions, the average sublation efficiency is up to 98.5%. The mechanism of ILATPF contains two principal processes. One is the mechanism of IL-salt ILATPS formation, the other is solvent sublation. This method was practical when applied to the analysis of chloramphenicol in lake water, feed water, milk, and honey samples with the linear range of 0.5-500 ng mL(-1). The method yielded limit of detection (LOD) of 0.1 ng mL(-1) and limit of quantification (LOQ) of 0.3 ng mL(-1). The recovery of CAP was 97.1-101.9% from aqueous samples of environmental and food samples by the proposed method. Compared with liquid-liquid extraction, solvent sublation and ionic liquid aqueous two-phase extraction, ILATPF can not only separate and concentrate chloramphenicol with high sublation efficiency, but also efficiently reduce the wastage of IL. This novel technique is much simpler and more environmentally friendly and is suggested to have important applications for the concentration and separation of other small biomolecules.

  20. Prediction of Activities in Fe-Based Ternary Liquid Alloys by Hoch-Arpshofen Model

    Institute of Scientific and Technical Information of China (English)

    YANGHong—wei; LIANChao; TAODong—ping

    2012-01-01

    Thermodynamic properties for an alloy system play an important role in the materials science and engineer- ing. Therefore, theoretical calculations having the flexibility to deal with complexity are very useful and have scien- tific meaning. The Hoch-Arpshofen model was deduced from physical principles and is applicable to binary, ternary and larger system using its binary interaction parameters only. Calculations of the activities of Fe-based liquid alloys are calculated using Hoch-Arpshofen model from data on the binary subsystems. Results for the activities for Fe-Au- Ni, Fe-Cr-Ni, Fe-Co-Cr and Fe-Co-Ni systems at required temperature are presented by Hoch-Arpshofen model. The average relative errors of prediction are 7.8%, 4.5%, 4.9~ and 2.7%, respectively. It shows that the calcu- lated results are in good agreement with the experimental data except Fe-Au-Ni system, which exhibits strong inter- action between unlike atoms. The model provides a simple, reliable and general method for calculating the activities for Fe-based liquid alloys.

  1. The micro-flow reaction system featured the liquid-liquid interface created with ternary mixed carrier solvents in a capillary tube.

    Science.gov (United States)

    Masuhara, Yuji; Jinno, Naoya; Hashimoto, Masahiko; Tsukagoshi, Kazuhiko

    2012-01-01

    A micro-flow reaction system was developed in which liquid-liquid interface was created based on the tube radial distribution of ternary mixed carrier solvents. The system was constructed from double capillary tubes having different inner diameters (100 and 250 µm i.d.). The smaller tube was inserted into the larger one through a T-type joint. The reaction of a protein with a fluorescence derivatizing reagent was adopted as a model. A water-acetonitrile mixture (3:1 volume ratio) including bovine serum albumin (hydrophilic) was delivered into the large tube from the inside through the small tube and an acetonitrile-ethyl acetate mixture (7:4 volume ratio) containing fluorescamine (hydrophobic) as a derivatizing reagent was delivered from the outside through the joint. Solutions were mixed through the double capillary tubes to promote ternary mixed carrier solvents (water-acetonitrile-ethyl acetate; 1:2:1 volume ratio). The liquid-liquid interface was created based on the tube radial distribution of ternary solvents in the larger tube. The derivatization reaction was performed in the larger, or reaction, tube in the micro-flow system. The fluorescence intensity of the fluorescamine-derivatized bovine serum albumin obtained by the system, which specifically included the kinetic liquid-liquid interface in the tube, was greater than that obtained through a batch reaction using a homogeneous solution of water-acetonitrile (1:2 volume ratio).

  2. Optimization and application of homogeneous liquid-liquid extraction in preconcentration of copper (II) in a ternary solvent system

    Energy Technology Data Exchange (ETDEWEB)

    Farajzadeh, Mir Ali [Department of Analytical Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz (Iran, Islamic Republic of)], E-mail: farajzade@yahoo.com; Bahram, Morteza [Department of Chemistry, Faculty of Science, Urmia University, Urmia (Iran, Islamic Republic of); Zorita, Saioa [Department of Analytical Chemistry, University of Lund, P.O. Box 124, 221 00 Lund (Sweden); Mehr, Behzad Ghorbani [Department of Chemistry, Faculty of Science, Urmia University, Urmia (Iran, Islamic Republic of)

    2009-01-30

    In this study a homogeneous liquid-liquid extraction based on the Ph-dependent phase-separation process was investigated using a ternary solvent system (water-acetic acid-chloroform) for the preconcentration of Cu{sup 2+} ions. 8-Hydroxy quinoline was used as the chelating agent prior to its extraction. Flame atomic absorption spectrophotometry using acetylene-air flame was used for the quantitation of analyte after preconcentration. The effect of various experimental parameters in extraction step was investigated using two optimization methods, one variable at a time and central composite design. The experimental design was done at five levels of operating parameters. Nearly the same optimized results were obtained using both methods: sample size, 5 mL; volume of NaOH 10 M, 2 mL; chloroform volume, 300 {mu}L; 8-hydroxy quinoline concentration more than 0.01 M and salt amount did not affect the extraction significantly. Under the optimum conditions the calibration graph was linear over the range 10-2000 {mu}g L{sup -1}. The relative standard deviation was 7.6% for six repeated determinations (C = 500 {mu}g L{sup -1}). Furthermore, the limit of detection (S/N = 3) and limit of quantification (S/N = 10) of the method were obtained as 1.74 and 6 {mu}g L{sup -1}, respectively.

  3. Liquid-liquid equilibrium and partitioning features of bovine trypsin in Ucon 50 HB5100 /sodium citrate aqueous two phase systems

    OpenAIRE

    Tubío, Gisela; Venâncio, Armando; Teixeira, J. A.; Nerli, Bibiana B.; Picó, Guillermo A.

    2008-01-01

    The phase diagrams of Ucon 50-HB-5100, a non-ionic random copolymer of ethylene oxide and propylene oxide (EOPO) and sodium citrate aqueous two-phase systems were determined at different pHs (5.20 and 8.20) and temperatures (5, 20 and 40º C). The binodal curves were determined by refractive index and enzymatic assay of the solution and described using a four-parameter sigmoidal equation, the reliability of the measured tie line compositions was ascertained by correlation equations...

  4. Two-phase flow characteristics of liquid nitrogen in vertically upward 0.5 and 1.0 mm micro-tubes: Visualization studies

    Science.gov (United States)

    Zhang, P.; Fu, X.

    2009-10-01

    Application of liquid nitrogen to cooling is widely employed in many fields, such as cooling of the high temperature superconducting devices, cryosurgery and so on, in which liquid nitrogen is generally forced to flow inside very small passages to maintain good thermal performance and stability. In order to have a full understanding of the flow and heat transfer characteristics of liquid nitrogen in micro-tube, high-speed digital photography was employed to acquire the typical two-phase flow patterns of liquid nitrogen in vertically upward micro-tubes of 0.531 and 1.042 mm inner diameters. It was found from the experimental results that the flow patterns were mainly bubbly flow, slug flow, churn flow and annular flow. And the confined bubble flow, mist flow, bubble condensation and flow oscillation were also observed. These flow patterns were characterized in different types of flow regime maps. The surface tension force and the size of the diameter were revealed to be the major factors affecting the flow pattern transitions. It was found that the transition boundaries of the slug/churn flow and churn/annular flow of the present experiment shifted to lower superficial vapor velocity; while the transition boundary of the bubbly/slug flow shifted to higher superficial vapor velocity compared to the results of the room-temperature fluids in the tubes with the similar hydraulic diameters. The corresponding transition boundaries moved to lower superficial velocity when reducing the inner diameter of the micro-tubes. Time-averaged void fraction and heat transfer characteristics for individual flow patterns were presented and special attention was paid to the effect of the diameter on the variation of void fraction.

  5. CFD studies on the phenomena around counter-current flow limitations of gas/liquid two-phase flow in a model of a PWR hot leg

    Energy Technology Data Exchange (ETDEWEB)

    Deendarlianto, E-mail: deendarlianto@ugm.ac.id [Helmholtz-Zentrum Dresden-Rossendorf e.V., Institute of Safety Research, P.O. Box 510 119, D-01314 Dresden (Germany); Department of Mechanical and Industrial Engineering, Faculty of Engineering, Gadjah Mada University, Jalan Grafika No. 2, Yogyakarta 55281 (Indonesia); Hoehne, Thomas; Lucas, Dirk; Vallee, Christophe [Helmholtz-Zentrum Dresden-Rossendorf e.V., Institute of Safety Research, P.O. Box 510 119, D-01314 Dresden (Germany); Zabala, Gustavo Adolfo Montoya [Department of Chemical Engineering, Simon Bolivar University, Valle of Sartenejas, Caracas 1080 (Venezuela, Bolivarian Republic of)

    2011-12-15

    Highlights: Black-Right-Pointing-Pointer We modelled CCFL in a PWR hot leg using Algebraic Interfacial Area Density model. Black-Right-Pointing-Pointer The model is able to distinguish the local flow morphologies. Black-Right-Pointing-Pointer Test fluids are air-water and steam-water. Black-Right-Pointing-Pointer Calculated CCFL and water level are in good agreement with experimental data. - Abstract: In order to improve the understanding of counter-current two-phase flow and to validate new physical models, CFD simulations of a 1/3rd scale model of the hot leg of a German Konvoi pressurized water reactor (PWR) with rectangular cross section were performed. Selected counter-current flow limitation (CCFL) experiments conducted at Helmholtz-Zentrum Dresden-Rossendorf (HZDR) were calculated with ANSYS CFX using the multi-fluid Euler-Euler modelling approach. The transient calculations were carried out using a gas/liquid inhomogeneous multiphase flow model coupled with a shear stress transport (SST) turbulence model. In the simulation, the drag law was approached by a newly developed correlation of the drag coefficient in the Algebraic Interfacial Area Density (AIAD) model. The model can distinguish the bubbles, droplets and the free surface using the local liquid phase volume fraction value. A comparison with the high-speed video observations shows a good qualitative agreement. The results indicate also a quantitative agreement between calculations and experimental data for the CCFL characteristics and the water level inside the hot leg channel.

  6. Ionic liquid-based ultrasound-assisted extraction and aqueous two-phase system for analysis of caffeoylquinic acids from Flos Lonicerae Japonicae.

    Science.gov (United States)

    Tan, Ting; Lai, Chang-Jiang-Sheng; OuYang, Hui; He, Ming-Zhen; Feng, Yulin

    2016-02-20

    In this work, an ionic liquid-based ultrasonic-assisted extraction (ILUAE) method was developed to extract caffeoylquinic acids (CQAs) from Flos Lonicerae Japonicae (FLJ). ILUAE parameters were optimized by response surface methodology, including IL concentration, ultrasonic time, and liquid-solid ratio. Optimized ILUAE approach gained the highest extraction yields of 28.53, 18.21, 3.84mg/g for 3-O-caffeoylquinic acid (C1), 3,5-di-O-caffeoylquinic acid (C2), 3,4-di-O-caffeoylquinic acid (C3), respectively. C1-C3 are the three most abundant CQAs compounds in FLJ. The method showed comparable extraction yield and shorter extraction time compared with conventional extraction techniques. Subsequently, an aqueous two-phase system (ATPS) was applied in extraction solutions. Two trace CQAs, 5-O-caffeoylquinic acid (C4) and 4,5-di-O-caffeoylquinic acid (C5), were significantly enriched with signal to noise values increasing from less than 10 to higher than 1475. The results indicated that ILUAE and ATPS are efficient and environmentally-friendly sample extraction and enrichment techniques for CQAs from herbal medicines.

  7. Determining the effect of solid and liquid vectors on the gaseous interfacial area and oxygen transfer rates in two-phase partitioning bioreactors

    Energy Technology Data Exchange (ETDEWEB)

    Quijano, Guillermo [Departmento de Ingenieria Quimica y Tecnologia del Medio Ambiente, Universidad de Valladolid, Paseo del Prado de la Magdalena, s/n, 47005 Valladolid (Spain); Departamento de Biotecnologia y Bioingenieria, Centro de Investigacion y de Estudios, Avanzados del IPN (Cinvestav), Apdo. Postal 14-740, 07360 Mexico, D.F. (Mexico); Rocha-Rios, Jose [Departmento de Ingenieria Quimica y Tecnologia del Medio Ambiente, Universidad de Valladolid, Paseo del Prado de la Magdalena, s/n, 47005 Valladolid (Spain); Departamento de Ingenieria de Procesos e Hidraulica (IPH), Universidad Autonoma Metropolitana-Iztapalapa, Av. San Rafael Atlixco No. 186, 09340 Mexico, D.F. (Mexico); Hernandez, Maria; Villaverde, Santiago [Departmento de Ingenieria Quimica y Tecnologia del Medio Ambiente, Universidad de Valladolid, Paseo del Prado de la Magdalena, s/n, 47005 Valladolid (Spain); Revah, Sergio [Departamento de Procesos y Tecnologia, Universidad Autonoma Metropolitana-Cuajimalpa, c/o IPH, UAM-Iztapalapa, Av. San Rafael Atlixco No. 186, 09340 Mexico, D.F. (Mexico); Munoz, Raul, E-mail: mutora@iq.uva.es [Departmento de Ingenieria Quimica y Tecnologia del Medio Ambiente, Universidad de Valladolid, Paseo del Prado de la Magdalena, s/n, 47005 Valladolid (Spain); Thalasso, Frederic [Departamento de Biotecnologia y Bioingenieria, Centro de Investigacion y de Estudios, Avanzados del IPN (Cinvestav), Apdo. Postal 14-740, 07360 Mexico, D.F. (Mexico)

    2010-03-15

    The effect of liquid and solid transfer vectors (silicone oil and Desmopan, respectively) on the gaseous interfacial area (a{sub g}) was evaluated in a two-phase partitioning bioreactor (TPPB) using fresh mineral salt medium and the cultivation broth of a toluene degradation culture (Pseudomonas putida DOT-T1E cultures continuously cultivated with and without silicone oil at low toluene loading rates). Higher values of a{sub g} were recorded in the presence of both silicone oil and Desmopan compared to the values obtained in the absence of a vector, regardless of the aqueous medium tested (1.6 and 3 times higher, respectively, using fresh mineral salt medium). These improvements in a{sub g} were well correlated to the oxygen mass transfer enhancements supported by the vectors (1.3 and 2.5 for liquid and solid vectors, respectively, using fresh medium). In this context, oxygen transfer rates of 2.5 g O{sub 2} L{sup -1} h{sup -1} and 1.3 g O{sub 2} L{sup -1} h{sup -1} were recorded in the presence of Desmopan and silicone oil, respectively, which are in agreement with previously reported values in literature. These results suggest that mass transfer enhancements in TPPBs might correspond to an increase in a{sub g} rather than to the establishment of a high-performance gas/vector/water transfer pathway.

  8. Ternary (liquid + liquid) equilibria of (diethyl carbonate + ethanol or 1-propanol + water) systems at 303.15 K under atmospheric pressure

    Science.gov (United States)

    Ginting, Rizqy Romadhona; Mustain, Asalil; Gunardi, Ignatius; Wibawa, Gede

    2017-01-01

    Ternary (liquid + liquid) equilibria data of diethyl carbonate (DEC) + ethanol or 1-propanol + water systems were accurately determined at 303.15 K using jacketed equilibrium cell under atmospheric pressure. The reliability of experimental tie-line data were checked by using Bachman-Brown correlation giving an r-squared value of 0.9933 and 0.9996, respectively. Both systems studied in this work exhibit Treybal's Type I ternary phase behavior. The experimental tie-line data were correlated well using the Non-Random Two Liquid (NRTL) and Universal Quasi-Chemical (UNIQUAC) activity coefficient models giving root-mean-square deviation (RMSD) of 0.95 and 1.18% for DEC + ethanol + water system.,While DEC + 1-propanol + water system gives RMSD value of 0.30 and 0.37%, respectively. The effect of carbon chain length of alcohol to the phase boundary of both systems was observed and discussed in detail.

  9. A comparative study of solid and liquid non-aqueous phases for the biodegradation of hexane in two-phase partitioning bioreactors.

    Science.gov (United States)

    Hernández, María; Quijano, Guillermo; Thalasso, Frédéric; Daugulis, Andrew J; Villaverde, Santiago; Muñoz, Raúl

    2010-08-01

    A comparative study of the performance of solid and liquid non-aqueous phases (NAPs) to enhance the mass transfer and biodegradation of hexane by Pseudomonas aeruginosa in two-phase partitioning bioreactors (TPPBs) was undertaken. A preliminary NAP screening was thus carried out among the most common solid and liquid NAPs used in pollutant biodegradation. The polymer Kraton G1657 (solid) and the liquid silicone oils SO20 and SO200 were selected from this screening based on their biocompatibility, resistance to microbial attack, non-volatility and high affinity for hexane (low partition coefficient: K = C(g)/C(NAP), where C(g) and C(NAP) represent the pollutant concentration in the gas phase and NAP, respectively). Despite the three NAPs exhibited a similar affinity for hexane (K approximately 0.0058), SO200 and SO20 showed a superior performance to Kraton G1657 in terms of hexane mass transfer and biodegradation enhancement. The enhanced performance of SO200 and SO20 could be explained by both the low interfacial area of this solid polymer (as a result of the large size of commercial beads) and by the interference of water on hexane transfer (observed in this work). When Kraton G1657 (20%) was tested in a TPPB inoculated with P. aeruginosa, steady state elimination capacities (ECs) of 5.6 +/- 0.6 g m(-3) h(-1) were achieved. These values were similar to those obtained in the absence of a NAP but lower compared to the ECs recorded in the presence of 20% of SO200 (10.6 +/- 0.9 g m(-3) h(-1)). Finally, this study showed that the enhancement in the transfer of hexane supported by SO200 was attenuated by limitations in microbial activity, as shown by the fact that the ECs in biotic systems were far lower than the maximum hexane transfer capacity recorded under abiotic conditions.

  10. Ionic liquid and aqueous two-phase extraction based on salting-out coupled with high-performance liquid chromatography for the determination of seven rare ginsenosides in Xue-Sai-Tong injection.

    Science.gov (United States)

    Li, Lan-Jie; Jin, Yong-Ri; Wang, Xiao-Zhong; Liu, Ying; Wu, Qian; Shi, Xiao-Lei; Li, Xu-Wen

    2015-09-01

    A method of ionic liquid salt aqueous two-phase extraction coupled with high-performance liquid chromatography has been developed for the analysis of seven rare ginsenosides including Rg6 , F4 , 20(S)-Rg3 , 20(R)-Rg3 , Rk3 , Rk1 , and Rg5 in Xue-Sai-Tong injection. The injection was mixed with ionic liquid 1-butyl-3-methylimidazolium bromide aqueous solution, and a mixture was obtained. With the addition of sodium dodecyl sulfate and dipotassium phosphate into the mixture, the aqueous two-phase mixture was formed after ultrasonic treatment and centrifuged. Rare ginsenosides were extracted into the upper phase. To obtain a high extraction factors, various influences were considered systematically, such as the volume of ionic liquid, the category and amount of salts, the amount of sodium dodecyl sulfate, the pH value of system, and the time of ultrasonic treatment. Under the optimal condition, rare ginsenosides in Xue-Sai-Tong injection were enriched and detected, the recoveries of seven rare ginsenosides ranged from 90.05 to 112.55%, while relative standard deviations were lower than 2.50%. The developed method was reliable, rapid and sensitive for the determination of seven rare ginsenosides in the injections.

  11. A three-dimensional solid-liquid two-phase turbulence model with the effect of vegetation in non-orthogonal curvilinear coordinates

    Institute of Scientific and Technical Information of China (English)

    LIU Cheng; SHEN YongMing

    2009-01-01

    A three-dimensional k-ε-Ap solid-liquid two-phase two-fluid model with the effect of vegetation Is solved numerically with a finite-volume method on an adaptive grid to study water-sediment movements and bed evolution in vegetated channels. The additional drag force and additional turbulence generation due to vegetation are added to the relevant control equations for simulating the interaction between vegetation and flow. The flow structure and the bed-topography changes in a 60° partly vegetated channel bend are calculated by the model. The numerical results agree well with the measured ones. Calculated and measured results show that the primary flow velocity reduces much in the vegetation zone and increases in the non-vegetation zone, the secondary flow velocity weakens in the vegetation zone and strengthens in the non-vegetation zone, the sediment movement and bed-topography change also weaken in the vegetation zone and strengthen in the non-vegetation zone, a well-planed vegetation arrangement can improve bank stabilization program, and the k-ε-Ap model can deal with bed-load transport with a more reasonable method than the one-fluid model.

  12. A three-dimensional solid-liquid two-phase turbulence model with the effect of vegetation in non-orthogonal curvilinear coordinates

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    A three-dimensional k-ε-Ap solid-liquid two-phase two-fluid model with the effect of vegetation is solved numerically with a finite-volume method on an adaptive grid to study water-sediment movements and bed evolution in vegetated channels. The additional drag force and additional turbulence generation due to vegetation are added to the relevant control equations for simulating the interaction between vegetation and flow. The flow structure and the bed-topography changes in a 60° partly vegetated channel bend are calculated by the model. The numerical results agree well with the measured ones. Calculated and measured results show that the primary flow velocity reduces much in the vegetation zone and increases in the non-vegetation zone, the secondary flow velocity weakens in the vegetation zone and strengthens in the non-vegetation zone, the sediment movement and bed-topography change also weaken in the vegetation zone and strengthen in the non-vegetation zone, a well-planed vegetation arrangement can improve bank stabilization program, and the k-ε-Ap model can deal with bed-load transport with a more reasonable method than the one-fluid model.

  13. Online polar two phase countercurrent chromatography×high performance liquid chromatography for preparative isolation of polar polyphenols from tea extract in a single step.

    Science.gov (United States)

    Chen, Wei-Bin; Li, Shu-Qi; Chen, Long-Jiang; Fang, Mei-Juan; Chen, Quan-Cheng; Wu, Zhen; Wu, Yun-Long; Qiu, Ying-Kun

    2015-08-01

    Herein, we report an on-line two-dimensional system constructed by counter-current chromatography (CCC) coupling with preparative high-performance liquid chromatography (prep-HPLC) for the separation and purification of polar natural products. The CCC was used as the first dimensional isolation column, where an environmental friendly polar two-phase solvent system of isopropanol and 16% sodium chloride aqueous solution (1:1.2, v/v) was introduced for low toxicity and favorable resolution. In addition, by applying the stop-and-go flow technique, effluents pre-fractionated by CCC was further purified by a preparative column packed with octadecyl silane (ODS) as the second dimension. The interface between the two dimensions was comprised of a 6-port switching valve and an electronically controlled 2-position 10-port switching valve connected with two equivalent holding columns. To be highlighted here, this rationally designed interface for the purpose of smooth desalination, absorption and desorption, successfully solved the solvent compatibility problem between the two dimensional separation systems. The present integrated system was successfully applied in a one-step preparative separation and identification of 10 pure compounds from the water extracts of Tieguanyin tea (Chinese oolong tea). In short, all the results demonstrated that the on-line 2D CCC×LC method is an efficient and green approach for harvesting polar targets in a single step, which showed great promise in drug discovery. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. CFD Simulation of Effect of Interphase Forces and Turbulence Models on Gas-Liquid Two-Phase Flows in Non-Industrial Aluminum Electrolysis Cells

    Science.gov (United States)

    Zhan, Shuiqing; Yang, Jianhong; Wang, Zhentao; Zhao, Ruijie; Zheng, Jun; Wang, Junfeng

    2017-09-01

    Numerical simulations of gas-liquid two-phase flows in aluminum electrolysis cells using the Euler-Euler approach were presented. The attempt was made to assess the performance and applicability of different interphase forces (drag, lift, wall lubrication, and turbulent dispersion forces) and turbulence models (standard k- ɛ, renormalization group k- ɛ, standard k- ω, shear stress transport k- ω, and Reynolds stress models). Moreover, three different bubble-induced turbulence models have been also analyzed. The simulated electrolyte velocity profiles were discussed by comparing with each other and against published experimental data. Based on the results of the validation of different interphase forces and turbulence models, a set consisting of the dispersed standard k- ɛ model, Grace drag coefficient model, Simonin turbulent dispersion force model, and Sato et al.'s bubble-induced effective viscosity model was found to provide the best agreement with the experimental data. The prediction results showed that the contributions of the lift force and the wall lubrication force can be neglected for the present bubbly flows.

  15. CFD Simulation of Effect of Interphase Forces and Turbulence Models on Gas-Liquid Two-Phase Flows in Non-Industrial Aluminum Electrolysis Cells

    Science.gov (United States)

    Zhan, Shuiqing; Yang, Jianhong; Wang, Zhentao; Zhao, Ruijie; Zheng, Jun; Wang, Junfeng

    2017-03-01

    Numerical simulations of gas-liquid two-phase flows in aluminum electrolysis cells using the Euler-Euler approach were presented. The attempt was made to assess the performance and applicability of different interphase forces (drag, lift, wall lubrication, and turbulent dispersion forces) and turbulence models (standard k-ɛ, renormalization group k-ɛ, standard k-ω, shear stress transport k-ω, and Reynolds stress models). Moreover, three different bubble-induced turbulence models have been also analyzed. The simulated electrolyte velocity profiles were discussed by comparing with each other and against published experimental data. Based on the results of the validation of different interphase forces and turbulence models, a set consisting of the dispersed standard k-ɛ model, Grace drag coefficient model, Simonin turbulent dispersion force model, and Sato et al.'s bubble-induced effective viscosity model was found to provide the best agreement with the experimental data. The prediction results showed that the contributions of the lift force and the wall lubrication force can be neglected for the present bubbly flows.

  16. Numerical Simulation of the vortex shedding from two side-by-side square cylinders in gas-liquid two-phase flow

    Science.gov (United States)

    Zhou, Y. L.; Deng, D.

    2010-03-01

    Considering the turbulence deduced by shearing stress and air bubble, and based on two-fluid model, gas-liquid two-phase flow around two square cylinders in side-by-side arrangement in vertical tube with different void fraction different spacing ratio is numerically simulated by using the finite volume method in this paper. It is found that the gap flow with the spacing ratio smaller than 2.0 is not only biased to one side, resulting in the formation of a narrower wake behind one cylinder and a wider wake behind the other, but also not-biased to neither of them; vortex shedding from the two cylinders with the spacing ratio larger than or equal to 2.0 is synchronized. But when the spacing ratio is equal to 2.0, In-phase mode is the predominant mode while anti-phase mode predominates when the spacing ratio is 2.5, 3.0, 5.0. In bias pattern, the cylinder with wide wake has smaller resistance, the cylinder with narrow wake has larger resistance, and the cylinders with middle wake have equality resistance. Meanwhile the spacing ratio has tremendous influence on pulsating lift, amplitude spectrum and so on. The volume of void fraction in the incident flow influence the vortex production, falling off & development heavily. When the volume of void fraction increases to 0.12, the stable vortex street does not produce.

  17. The BLOW-3A: A theoretical model to describe transient two phase flow conditions in Liquid Metal Fast Breeder Reactor (LMFBR) coolant channels

    Science.gov (United States)

    Bottoni, M.; Struwe, D.

    The theoretical background of the BLOW-3A program is reported, including the basic equations used to determine temperature fields in the fuel, clad, coolant and structure material as well as the coolant dynamics in single and two-phase flow conditions. The two-phase flow model assumes an annular flow regime. Special aspects to calculate two-phase pressure drops for these conditions are discussed. Examples of the experimental validation of the program are given.

  18. Ternary and quaternary (liquid + liquid) equilibria for (water + ethanol + {alpha}-pinene, +{beta}-pinene, or +limonene) and (water + ethanol + {alpha}-pinene + limonene) at the temperature 298.15 K

    Energy Technology Data Exchange (ETDEWEB)

    Li Hengde [Department of Chemistry and Chemical Engineering, Division of Material Engineering and Material Sciences, Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-machi, Kanazawa 920-1192 (Japan); Tamura, Kazuhiro [Department of Chemistry and Chemical Engineering, Division of Material Engineering and Material Sciences, Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-machi, Kanazawa 920-1192 (Japan)]. E-mail: tamura@t.kanazawa-u.ac.jp

    2006-08-15

    (Liquid + liquid) equilibria and tie-lines for the ternary (water + ethanol + {alpha}-pinene, or {beta}-pinene or limonene) and quaternary (water + ethanol + {alpha}-pinene + limonene) mixtures have been measured at T = 298.15 K. The experimental multicomponent (liquid + liquid) equilibrium data have been successfully represented in terms of the modified UNIQUAC model with binary parameters.

  19. Two phase sampling

    CERN Document Server

    Ahmad, Zahoor; Hanif, Muhammad

    2013-01-01

    The development of estimators of population parameters based on two-phase sampling schemes has seen a dramatic increase in the past decade. Various authors have developed estimators of population using either one or two auxiliary variables. The present volume is a comprehensive collection of estimators available in single and two phase sampling. The book covers estimators which utilize information on single, two and multiple auxiliary variables of both quantitative and qualitative nature. Th...

  20. (Vapour + liquid) equilibrium and excess Gibbs functions of ternary mixtures containing 1-butanol or 2-butanol, n-hexane, and 1-chlorobutane at T = 298.15 K

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, S.; Bandres, I.; Ballesteros, L.M.; Lafuente, C. [Departamento de Quimica Organica-Quimica Fisica, Facultad de Ciencias, Universidad de Zaragoza, 50009 Zaragoza (Spain); Gascon, I. [Departamento de Quimica Organica-Quimica Fisica, Facultad de Ciencias, Universidad de Zaragoza, 50009 Zaragoza (Spain)], E-mail: igascon@unizar.es

    2009-09-15

    Isothermal (vapour + liquid) equilibrium data for the ternary mixtures 1-butanol + n-hexane + 1-chlorobutane and 2-butanol + n-hexane + 1-chlorobutane have been studied with a recirculating still at T = 298.15 K. The experimental data were satisfactorily checked for thermodynamic consistency using the method of van Ness. Activity coefficients and excess Gibbs function have been correlated with the Wilson equation. The G{sup E} values obtained for the two ternary systems are very similar.

  1. Ebulliometric determination and prediction of (vapor + liquid) equilibria for binary and ternary mixtures containing alcohols (C{sub 1}-C{sub 4}) and dimethyl carbonate

    Energy Technology Data Exchange (ETDEWEB)

    Matsuda, Hiroyuki, E-mail: matsuda@chem.cst.nihon-u.ac.jp [Department of Materials and Applied Chemistry, Nihon University, 1-8 Kanda Surugadai, Chiyoda-ku, Tokyo 101-8308 (Japan); Fukano, Makoto; Kikkawa, Shinichiro [Department of Materials and Applied Chemistry, Nihon University, 1-8 Kanda Surugadai, Chiyoda-ku, Tokyo 101-8308 (Japan); Constantinescu, Dana [Carl von Ossietzky Universitaet Oldenburg, Technische Chemie, D-26111 Oldenburg (Germany); Kurihara, Kiyofumi; Tochigi, Katsumi; Ochi, Kenji [Department of Materials and Applied Chemistry, Nihon University, 1-8 Kanda Surugadai, Chiyoda-ku, Tokyo 101-8308 (Japan); Gmehling, Juergen [Carl von Ossietzky Universitaet Oldenburg, Technische Chemie, D-26111 Oldenburg (Germany)

    2012-01-15

    Highlights: > The VLE behavior of systems containing dimethyl carbonate (DMC) was investigated. > VLE data for ternary and binary mixtures containing alcohol and DMC were measured. > Several activity coefficient models were used for data reduction or prediction. > Valley line, i.e., distillation boundary, was observed for the ternary mixture. > Residue curves were calculated to investigate composition profile for distillation. - Abstract: (Vapor + liquid) equilibrium (VLE) data for a ternary mixture, namely {l_brace}methanol + propan-1-ol + dimethyl carbonate (DMC){r_brace}, and four binary mixtures, namely an {l_brace}alcohol (C{sub 3} or C{sub 4}) + DMC{r_brace}, containing the binary constituent mixtures of the ternary mixture, were measured at p = (40.00 to 93.32) kPa using a modified Swietoslawski-type ebulliometer. The experimental data for the binary systems were correlated using the Wilson model. The Wilson model was also applied to the ternary system to predict the VLE behavior using parameters from the binary mixtures. The modified UNIFAC (Dortmund) model was also tested for the predictions of the VLE behavior of the binary and ternary mixtures. In addition, the experimental VLE data for the ternary and constituent binary mixtures were correlated using the extended Redlich-Kister (ERK) model, which can completely represent the azeotropic points. For the ternary system, a comparison of the experimental and the predicted or correlated boiling points obtained using the Wilson and ERK models showed that the ERK model is more accurate. The valley line, i.e., the curve which divides the patterns of vapor-liquid tie lines, was found in the (methanol + propan-1-ol + DMC) system. This valley line could be represented by the ERK model. Finally, the composition profile for simple distillation of this ternary mixture was obtained by analysis of the residue curves from the estimated Wilson parameters of the constituent binary mixtures.

  2. Speeds of sound and isothermal compressibility of ternary liquid systems: Application of Flory's statistical theory and hard sphere models

    Indian Academy of Sciences (India)

    Vimla Vyas

    2008-04-01

    Speeds of sound and densities of three ternary liquid systems namely, toluene + -heptane + -hexane (I), cyclohexane + -heptane + -hexane (II) and -hexane + - heptane + -decane (III) have been measured as a function of the composition at 298.15 K at atmospheric pressure. The experimental isothermal compressibility has been evaluated from measured values of speeds of sound and density. The isothermal compressibility of these mixtures has also been computed theoretically using different models for hard sphere equations of state and Flory's statistical theory. Computed values of isothermal compressibility have been compared with experimental findings. A satisfactory agreement has been observed. The superiority of Flory's statistical theory has been established quite reasonably over hard sphere models.

  3. Thermodynamic Properties of Ternary Liquid Mixtures of 2-Pyrrolidinone with Aromatic Hydrocarbons

    Science.gov (United States)

    Yadav, Jaibir S.; Sharma, Dimple; Sharma, Vinod Kumar

    2010-02-01

    Molar excess volumes, {V^E_{ijk}}, and speeds of sound, u ijk , of 2-pyrrolidinone (2-Py) ( i) + toluene ( j) + o-xylene or p-xylene ( k) ternary mixtures have been determined by using a dilatometer and interferometer as a function of composition at 308.15 K. The speeds of sound of ternary mixtures have been utilized to predict their excess isentropic compressibilities. The Redlich-Kister equation has been fitted to the molar excess volumes, {V^E_{ijk}}, and excess isentropic compressibilities, {left( {kappa _S^E}right)_{ijk}}, to predict ternary adjustable parameters and standard deviations. The observed data have been analyzed in terms of the Flory theory and the Sanchez and Lacombe theory.

  4. Empirical Correlations and CFD Simulations of Vertical Two-Phase Gas-Liquid (Newtonian and Non-Newtonian) Flow Compared Against Experimental Data of Void Fraction and Pressure Drop

    DEFF Research Database (Denmark)

    Ratkovich, Nicolas Rios; Bentzen, Thomas Ruby; Majumder, S.K.

    2012-01-01

    Gas-Newtonian liquid two-phase flows (TPFs) are presented in several industrial processes (i.e. oil-gas industry). In spite of the common occurrence of these TPFs, their understanding is limited compared to single-phase flows. Different studies on TPF have focus on developing empirical correlatio...

  5. [bmim][PF6]-DMF-水三元体系的液液相平衡测定%Determination of Liquid-Liquid Phase Equilibrium for the Ternary System of [bmim] [PF6]-DMF-Water

    Institute of Scientific and Technical Information of China (English)

    郭斌; 高亮; 段二红; 任爱玲; 刘振伟

    2012-01-01

    为得到含N,N-二甲基甲酰胺(DMF)废水中萃取回收DMF工艺所需的基础数据,用液液平衡釜常压下测定了1-丁基-3-甲基咪唑六氟磷酸盐([bmim][PF6)离子液体-DMF-H2O三元体系在283.15~323.15 K下的液液分层曲线和液液相平衡数据.在此基础上,考察了三元体系中DMF和[bmim][PF6]离子液体的含量以及温度对[bmim][PF6]的选择性系数的影响.实验结果表明,液液平衡相图中两相区面积随温度升高而减小;相同温度下,[bmim][PF6]的选择性系数随着三元体系中DMF的含量增加而减小,随着离子液体用量增加而增大;溶液组成一定时,[bmim][PF6]的选择性系数随着温度升高而减小;当DMF的含量大于10%时,温度对选择性系数影响不大;283.15 K,三元体系中DMF的质量分数为2.04%时,选择性系数可达33.62,[bmim][PF6]用于萃取分离水中的DMF可行.%In order to obtain the basic data for the recovery of N,N-dimethylformamide (DMF) from wastewater by extraction, the liquid-liquid delamination curves and liquid-liquid phase equilibrium data of the 1 -butyl-3-methylimidazoHum hexafluorophosphate ([bmimJfPFg]) ionic liquid-DMF-H2O ternary system were determined by using an equilibrium autoclave at 283.15 to 323.15 K and atmospheric pressure. The effects of the contents of DMF and [bmim][PF6] in the ternary system and the temperature on the selectivity coefficient of [bmim][PF6] were investigated. The results show that the area of two-phase in the liquid-liquid equilibrium phase diagram decreases with the increase of the temperature. The selectivity coefficient of [bmim] [PF6] decreases with the increase of the content of DMF in the ternary system and increases with the increase of the amount of ionic liquid at the same temperature. And when the composition of the solution keeps unchanged, the selectivity coefficient of [bmim] [PF6] decreases with the increase of temperature. However, the temperature has little effect on

  6. Extraction and isolation of lithospermic acid B from Salvia miltiorrhiza Bunge using aqueous two-phase extraction followed by high-performance liquid chromatography.

    Science.gov (United States)

    Guo, Yong Xue; Shi, Chang Zhi; Zhang, Lei; Lv, Lin; Zhang, Yue Yong

    2016-09-01

    A rapid and effective method integrating separation and purification of lithospermic acid B from Salvia miltiorrhiza Bunge was developed by combining an aqueous two-phase system extraction with preparative chromatography. An aqueous two-phase system of n-butyl alcohol/KH2 PO4 was chosen from seven systems. The influence of parameters including concentration of KH2 PO4 , n-butyl alcohol concentration, pH, and the ratio of an aqueous two-phase system to crude extract were investigated using a single factor design. Response surface methodology was subsequently used to find the optimal compositions of an aqueous two-phase system. Keeping a solvent-to-solid ratio of 10, the final optimized composition of an aqueous two-phase system was 39.1% w/w n-butyl alcohol and 22.6% w/w KH2 PO4 . Under these conditions a recovery yield of 99.8% and a high partition coefficient of 310.4 were obtained. In a pilot-scale experiment using optimized conditions, 18.79 g of lithospermic acid B with a purity of 70.5% and in a yield of 99.8% was separated from 0.5 kg of crude extract. Subsequently, 9.94 g lithospermic acid B with a purity of 99.3% and recovery yield of 70.3% was obtained with a preparative chromatographic process, and the two-step total recovery was 70.1%.

  7. 新型复合T型管对液液二相流的分离%Phase separation of liquid-liquid two-phase flow by multi-tube T-junction separator

    Institute of Scientific and Technical Information of China (English)

    杨利民; 赵振莹; 沈小明; 赵立立

    2012-01-01

    T-junction separator is a novel type of two-phase flow separator with the advantages of compact, continuous, simple, economical and safe operations as well as being easy for installation, replacement and maintenance, but its separation efficiency of the simple T-junction separator is low for separating the two-phase flow. The multi-tube T-junction separator combines several T-junctions in one unit for improving the separation efficiency of the two-phase flow. With kerosene and water as working fluids, the separation experiments were carried out by using the simple T and the multi-tube T-junction units with main pipe in horizontal and branch in vertically upward under the flow patterns of stratified flow and the stratified flow with mixing at interface. The results show that under these two patterns the separation efficiencies of the two phases for the multi-tube T-junctions are much higher than those of the simple T-junction. Increasing the number of connecting tubes in the multi-tube T-junction unit can improve the separation efficiency. Generally, for the stratified flow,the complete separation of two phases can be achieved by a multi-tube T-junction separator with 5 or more connecting tubes; increasing the mixedness of the inlet flow will cause the drop of the separation efficiency peak; the effect of water volume fraction on the separation efficiency is associated with the flow pattern. The phase separation of liquid-liquid two-phase flow by using the multi-tube T-junction separator is a promising technique for industrial application.%T型管分离器是一类新型的二相流分离器,具有集约、连续、简单、经济、安全以及安装、更新、维护方便等优点,缺点是简单T型管作为分离器在分离二相流时的分离效率往往不高,只能起到部分分离的作用.新型复合T型管是对简单T型管的一种改进,以期能提高二相流的分离效率.以煤油和水为液液二相工作介质,用主管水平,侧支管垂

  8. Ternary liquid-liquid equilibria of dimethyl carbonate + 2-propanol + water system at 303.15 and 313.15 K

    Science.gov (United States)

    Ginting, Rizqy Romadhona; Mustain, Asalil; Tetrisyanda, Rizki; Gunardi, Ignatius; Wibawa, Gede

    2015-12-01

    In this work, liquid-liquid equilibria data of dimethyl carbonate (DMC) + 2-propanol + water system were accurately determined at 303.15 and 313.15 K using stirred and jacketed equilibrium cell under atmospheric pressure. The reliabilities of the experimental data were confirmed using Bachman-Brown correlation giving r-squared value of 0.9993 and 0.9983 at 303.15 and 313.15 K, respectively. Experimental data obtained in this work exhibit Treybal's Type I ternary phase behavior. The selectivity and distribution coefficient of DMC increases with addition of DMC concentration in the organic phase. On the other hand, the effect of temperature to phase boundary was found to be not significant. The data were correlated well using the Non-Random Two Liquid (NRTL) and Universal Quasi-Chemical (UNIQUAC) activity coefficient models with root-mean-square deviation of 1.5% and 1.3%, respectively.

  9. Resolution of Ternary Mixture of Aspirin, Atorvastatin, and Clopidogrel by Chemometric-Assisted UV Spectroscopic and Liquid Chromatography Methods

    Directory of Open Access Journals (Sweden)

    Mahmoud Mohamed Issa

    2013-01-01

    Full Text Available Two chemometrics-assisted UV spectrophotometric methods were proposed for the resolution of ternary mixtures without any chemical pretreatment. The first method is based on modification of H-point standard addition method which permits simultaneous analysis of three species from a unique calibration set by making the simultaneous addition of the three analytes. Quotient between the spectra of aspirin, atorvastatin, and clopidogrel was obtained and the results showed that simultaneous determination of aspirin, atorvastatin, and clopidogrel can be obeyed in the linear range 2.5–20 μg mL−1 of aspirin, 2.5–17.5 μg mL−1 of atorvastatin, and 2.5–20 μg mL−1 of clopidogrel in ternary mixture. The second method is based on the combination of the first derivative spectra and Cramer's matrix rule. In the matrix calculation, clopidogrel has zero crossing point at 316.8 and 212 nm, while for atorvastatin the zero crossing point at 250 nm where the matrix is greatly simplified and easily solved. The linear concentration ranges were 2.5–20 μg mL−1 aspirin, 2.5–17.5 μg mL−1 atorvastatin and 2.5–20 μg mL−1 clopidogrel in ternary mixtures. The results proved that the simultaneous determination of aspirin, atorvastatin, and clopidogrel could be obeyed. Both methods were applied for capsules containing the three ingredients and results were in good concordance with alternative liquid chromatography.

  10. Vapor-Liquid Equilibrium Measurements and Modeling for Ternary System Water + Ethanol + 1-Butyl-3-methylimidazolium Acetate

    Institute of Scientific and Technical Information of China (English)

    D.ENG Dongshun; WANG Rufa; ZHANG Lianzhong; GE Yun; JI Jianbing

    2011-01-01

    Vapor-liquid equilibrium(VLE) data were measured for ternary system water + ethanol + 1-butyl-3methylimidazolium acetate([bmim][OAc]),in a relatively wide range of ionic liquid(IL) mass fractions up to 0.8.Six sets of complete T-x-y data were obtained,in which the mole fraction of ethanol on IL-free basis was fixed separately at 0.1,0.2,0.4,0.6,0.8,and approximate 0.98.The non-random-two-liquid(NRTL) and electrolyte non-random-two-liquid(eNRTL) equations were used for correlation,showing similar deviations.The ternary VLE was also modeled with the correlation from two data sets,with the mole fractions of ethanol on IL-free basis being 0.1 and approximate 0.98.The VLE data were also reproduced satisfactorily.With the eNRTL model,the root-mean-square deviation for temperature is 0.79K and that for vapor-phase mole fraction is 0.0094.The calculations are in good agreement with experimental data.The effect of the IL on the VLE behavior of the volatile components is also illustrated.

  11. Study on constant-pressure specific heat of non-equi- librium phase change process in gas-liquid two-phase flow system

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In this paper, the air-water vapor-water system is taken as an example, and the formula of constantpressure specific heat during non-equilibrium phase change process in the two-phase flow system is deduced using the theory of two-phase flow and thermophysics. The constant-pressure specific heat of non-equilibrium phase change process is calculated with the corresponding numerical model, and the numerical results are compared to those of the equilibrium phase change process. It is shown that in evaporation process, the variational rate of the non-equilibrium specific heat increases with increasing initial fluid temperature and particle mass fraction. The smaller particle radius is, the faster the variational rate is. Meanwhile, the constant-pressure specific heat of equilibrium process is higher than that of the non-equilibrium process all the time.

  12. Aqueous Two-Phase Systems formed by Biocompatible and Biodegradable Polysaccharides and Acetonitrile.

    Science.gov (United States)

    de Brito Cardoso, Gustavo; Souza, Isabela Nascimento; Pereira, Matheus M; Freire, Mara G; Soares, Cleide Mara Faria; Lima, Álvaro Silva

    2014-11-05

    In this work, it is shown that novel aqueous two-phase systems can be formed by the combination of acetonitrile and polysaccharides, namely dextran. Several ternary phase diagrams were determined at 25 °C for the systems composed of water + acetonitrile + dextran. The effect of the dextran molecular weight (6,000, 40,000 and 100,000 g.mol(-1)) was ascertained toward their ability to undergo liquid-liquid demixing. An increase in the dextran molecular weight favors the phase separation. Furthermore, the effect of temperature (25, 35 and 45 °C) was evaluated for the system constituted by the dextran of higher molecular weight. Lower temperatures are favorable for phase separation since lower amounts of dextran and acetonitrile are required for the creation of aqueous two-phase systems. In general, acetonitrile is enriched in the top phase while dextran is majorly concentrated in the bottom phase. The applicability of this new type of two-phase systems as liquid-liquid extraction approaches was also evaluated by the study of the partition behavior of a well-known antioxidant - vanillin - and used here as a model biomolecule. The optimized conditions led to an extraction efficiency of vanillin of 95% at the acetonitrile-rich phase.

  13. An improved algorithm of image processing technique for film thickness measurement in a horizontal stratified gas-liquid two-phase flow

    Energy Technology Data Exchange (ETDEWEB)

    Kuntoro, Hadiyan Yusuf, E-mail: hadiyan.y.kuntoro@mail.ugm.ac.id; Majid, Akmal Irfan; Deendarlianto, E-mail: deendarlianto@ugm.ac.id [Center for Energy Studies, Gadjah Mada University, Sekip K-1A Kampus UGM, Yogyakarta 55281 (Indonesia); Department of Mechanical and Industrial Engineering, Faculty of Engineering, Gadjah Mada University, Jalan Grafika 2, Yogyakarta 55281 (Indonesia); Hudaya, Akhmad Zidni; Dinaryanto, Okto [Department of Mechanical and Industrial Engineering, Faculty of Engineering, Gadjah Mada University, Jalan Grafika 2, Yogyakarta 55281 (Indonesia)

    2016-06-03

    Due to the importance of the two-phase flow researches for the industrial safety analysis, many researchers developed various methods and techniques to study the two-phase flow phenomena on the industrial cases, such as in the chemical, petroleum and nuclear industries cases. One of the developing methods and techniques is image processing technique. This technique is widely used in the two-phase flow researches due to the non-intrusive capability to process a lot of visualization data which are contain many complexities. Moreover, this technique allows to capture direct-visual information data of the flow which are difficult to be captured by other methods and techniques. The main objective of this paper is to present an improved algorithm of image processing technique from the preceding algorithm for the stratified flow cases. The present algorithm can measure the film thickness (h{sub L}) of stratified flow as well as the geometrical properties of the interfacial waves with lower processing time and random-access memory (RAM) usage than the preceding algorithm. Also, the measurement results are aimed to develop a high quality database of stratified flow which is scanty. In the present work, the measurement results had a satisfactory agreement with the previous works.

  14. An improved algorithm of image processing technique for film thickness measurement in a horizontal stratified gas-liquid two-phase flow

    Science.gov (United States)

    Kuntoro, Hadiyan Yusuf; Hudaya, Akhmad Zidni; Dinaryanto, Okto; Majid, Akmal Irfan; Deendarlianto

    2016-06-01

    Due to the importance of the two-phase flow researches for the industrial safety analysis, many researchers developed various methods and techniques to study the two-phase flow phenomena on the industrial cases, such as in the chemical, petroleum and nuclear industries cases. One of the developing methods and techniques is image processing technique. This technique is widely used in the two-phase flow researches due to the non-intrusive capability to process a lot of visualization data which are contain many complexities. Moreover, this technique allows to capture direct-visual information data of the flow which are difficult to be captured by other methods and techniques. The main objective of this paper is to present an improved algorithm of image processing technique from the preceding algorithm for the stratified flow cases. The present algorithm can measure the film thickness (hL) of stratified flow as well as the geometrical properties of the interfacial waves with lower processing time and random-access memory (RAM) usage than the preceding algorithm. Also, the measurement results are aimed to develop a high quality database of stratified flow which is scanty. In the present work, the measurement results had a satisfactory agreement with the previous works.

  15. Study on Calculation Method of Liquid Holdup of Gas-Liquid Two-phase Flow in Inclined Tube Column%倾斜管柱气液两相流持液率计算方法研究

    Institute of Scientific and Technical Information of China (English)

    曾祥柱; 罗威; 刘政轩; 张瑞尧

    2016-01-01

    The calculation method of liquid holdup of gas-liquid two-phase flow in inclined tube column plays an important role in petroleum industry. In this paper, Beggs-Brill correlation, Mukherjee-Brill correlation, Eaton correlation and Dukler II correlation formula were used to calculate liquid holdup. Through experiments, the liquid holdup in inclined tube column with different angles under the same gas liquid volume flow rate was tested, and the accuracies of the four formulas were analyzed. The results showed that Beggs-Brill correlation was more accurate. The Beggs Brill correlation were analyzed. It's found that when the other conditions are the same, the calculated liquid holdup has symmetry with the tube column tilting angle, symmetry axis is 50 degrees, calculated liquid holdups of tilt angle of 90 degrees and 10 degrees are equal. Combined with the measured experimental data, the drawn curve shows that liquid holdup between 45 and 60 degrees inclination angle is the maximum, and the liquid holdup of 90 degree is close to the liquid holdup of 10 degrees, on the whole, the liquid holdup has a certain symmetry with the change of the angle.%倾斜管柱气液两相流持液率的计算方法在石油工业中具有重要地位。采用 Beggs-Brill 相关式、Mukherjee-Brill 相关式、Eaton 相关式和杜克勒Ⅱ相关式计算了倾斜管柱的持液率,通过实验手段测量相同气液体积流量下,不同角度的持液率数据,分析了上述4种计算式的准确性,发现 Beggs-Brill 相关式比较准确。对Beggs-Brill 相关式进行了分析,发现当其他条件一定时,其计算的持液率关于管柱倾斜角度具有一定的对称性,对称轴为50°,倾斜角度为90°时和10°时计算的持液率相等,结合所测量的实验数据,做出曲线发现在倾斜角度在45°到60°之间持液率最大,倾斜角度为90°的持液率与为10°的持液率比较接近,同时持液率随角度的变化具有一定的对称性。

  16. Measurement and Modeling of Vapor-Liquid Equilibrium for Ternary System Water+2-Propanol+1-Butyl-3-methylimidazolium Chloride

    Institute of Scientific and Technical Information of China (English)

    邓东顺; 乔玉珍; 姬登祥; 葛筠; 章连众

    2014-01-01

    Vapor-liquid equilibrium (VLE) data for water+2-propanol+1-butyl-3-methylimidazolium chloride ([bmim]Cl) were measured. Six sets of complete T, x, y data are reported, in which the 2-propanol mole fraction on IL-free basis is fixed separately at 0.1, 0.2, 0.4, 0.6, 0.8, and approximate 0.98, while the IL mass fraction is varied from 0.1 to 0.8, in an interval of 0.1. The non-random-two-liquid (NRTL) and electrolyte non-random-two-liquid (eNRTL) equations are used to correlate the experimental data with satisfactory results. The ternary VLE behavior is also modeled with the parameters obtained by correlating two data sets, in which the mole fraction of 2-propanol on IL-free basis is approximately 0.1 and 0.98. In this way, the six sets of data are reproduced satisfactorily. With the eNRTL model, the root-mean-square deviation for temperature is 0.82 K and that for vapor-phase mole fraction is 0.0078. The influences of IL on activity coefficients and relative volatility of the volatile components are also graphically illustrated.

  17. Phase Behavior at High Pressure of the Ternary System: CO2, Ionic Liquid and Disperse Dye

    Directory of Open Access Journals (Sweden)

    Helen R. Mazzer

    2012-01-01

    Full Text Available High pressure phase behavior experimental data have been measured for the systems carbon dioxide (CO2 + 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim] [PF6] and carbon dioxide (CO2 + 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim] [PF6] + 1-amino-2-phenoxy-4-hydroxyanthraquinone (C.I. Disperse Red 60. Measurements were performed in the pressure up to 18 MPa and at the temperature (323 to 353 K. As reported in the literature, at higher concentrations of carbon dioxide the phase transition pressure increased very steeply. The experimental data for the binary and ternary systems were correlated with good agreement using the Peng-Robinson equation of state. The amount of water in phase behavior of the systems was evaluated.

  18. Solid-liquid two-phase partitioning bioreactors (TPPBs) operated with waste polymers. Case study: 2,4-dichlorophenol biodegradation with used automobile tires as the partitioning phase.

    Science.gov (United States)

    Tomei, M Concetta; Annesini, M Cristina; Daugulis, Andrew J

    2012-11-01

    Used automobile tire pieces were tested for their suitability as the sequestering phase in a two-phase partitioning bioreactor to treat 2,4-dichlorophenol (DCP). Abiotic sorption tests and equilibrium partitioning tests confirmed that tire "crumble" possesses very favourable properties for this application with DCP diffusivity (4.8 × 10(-8) cm(2)/s) and partition coefficient (31) values comparable to those of commercially available polymers. Biodegradation tests further validated the effectiveness of using waste tires to detoxify a DCP solution, and allow for enhanced biodegradation compared to conventional single-phase operation. These results establish the potential of using a low-cost waste material to assist in the bioremediation of a toxic aqueous contaminant.

  19. SIMULTANEOUS PIV/PTV MEASUREMENTS OF BUBBLE AND PARTICLE PHASES IN GAS-LIQUID TWO-PHASE FLOW BASED ON IMAGE SEPARATION AND RECONSTRUCTION

    Institute of Scientific and Technical Information of China (English)

    QU Jian-wu; MURAI Yuichi; YAMAMOTO Fujio

    2004-01-01

    A Particle Image Velocimetry (PIV) method based on the image separation and reconstruction with the median filter and triangular Bézier patch was proposed to measure multiple velocity fields from single-camera images in the present study. The method was examined on synthetic PIV images with the Green-Taylor two-phase vortex flows and the test results showed high accuracy and highly correct tracking percent compared with the exact solution. An experiment of the bubbly jet flow was also conducted as a practical demonstration of the present method. As a result, it is confirmed from the simulation image examination and the experimental measurement that the proposed method shows a good performance in the measurement of bubble and particle phases.

  20. Computation of Isobaric Vapor-Liquid Equilibrium Data for Binary and Ternary Mixtures of Methanol, Water, and Ethanoic Acid from T, p, x, and HmE Measurements

    Directory of Open Access Journals (Sweden)

    Daming Gao

    2012-01-01

    Full Text Available Vapor-liquid equilibrium (VLE data for the strongly associated ternary system methanol + water + ethanoic acid and the three constituent binary systems have been determined by the total pressure-temperature-liquid-phase composition-molar excess enthalpy of mixing of the liquid phase (p, T, x, HmE for the binary systems using a novel pump ebulliometer at 101.325 kPa. The vapor-phase compositions of these binary systems had been calculated from Tpx and HmE based on the Q function of molar excess Gibbs energy through an indirect method. Moreover, the experimental T, x data are used to estimate nonrandom two-liquid (NRTL, Wilson, Margules, and van Laar model parameters, and these parameters in turn are used to calculate vapor-phase compositions. The activity coefficients of the solution were correlated with NRTL, Wilson, Margules, and van Laar models through fitting by least-squares method. The VLE data of the ternary system were well predicted from these binary interaction parameters of NRTL, Wilson, Margules, and van Laar model parameters without any additional adjustment to build the thermodynamic model of VLE for the ternary system and obtain the vapor-phase compositions and the calculated bubble points.

  1. Determination of Hydrodynamic Parameters on Two--Phase Flow Gas - Liquid in Pipes with Different Inclination Angles Using Image Processing Algorithm

    Science.gov (United States)

    Montoya, Gustavo; Valecillos, María; Romero, Carlos; Gonzáles, Dosinda

    2009-11-01

    In the present research a digital image processing-based automated algorithm was developed in order to determine the phase's height, hold up, and statistical distribution of the drop size in a two-phase system water-air using pipes with 0 , 10 , and 90 of inclination. Digital images were acquired with a high speed camera (up to 4500fps), using an equipment that consist of a system with three acrylic pipes with diameters of 1.905, 3.175, and 4.445 cm. Each pipe is arranged in two sections of 8 m of length. Various flow patterns were visualized for different superficial velocities of water and air. Finally, using the image processing program designed in Matlab/Simulink^, the captured images were processed to establish the parameters previously mentioned. The image processing algorithm is based in the frequency domain analysis of the source pictures, which allows to find the phase as the edge between the water and air, through a Sobel filter that extracts the high frequency components of the image. The drop size was found using the calculation of the Feret diameter. Three flow patterns were observed: Annular, ST, and ST&MI.

  2. Binary, ternary and quaternary liquid-liquid equilibria in 1-butanol, oleic acid, water and n-heptane mixtures

    NARCIS (Netherlands)

    Winkelman, J. G. M.; Kraai, G. N.; Heeres, H. J.

    2009-01-01

    This work reports on liquid-liquid equilibria in the system 1-butanol, oleic acid, water and n-heptane used for biphasic, lipase catalysed esterifications. The literature was studied on the mutual solubility in binary systems of water and each of the organic components. Experimental results were obt

  3. Ternary mixtures of ionic liquids for better salt solubility, conductivity and cation transference number improvement

    Science.gov (United States)

    Karpierz, E.; Niedzicki, L.; Trzeciak, T.; Zawadzki, M.; Dranka, M.; Zachara, J.; Żukowska, G. Z.; Bitner-Michalska, A.; Wieczorek, W.

    2016-10-01

    We hereby present the new class of ionic liquid systems in which lithium salt is introduced into the solution as a lithium cation-glyme solvate. This modification leads to the reorganisation of solution structure, which entails release of free mobile lithium cation solvate and hence leads to the significant enhancement of ionic conductivity and lithium cation transference numbers. This new approach in composing electrolytes also enables even three-fold increase of salt concentration in ionic liquids.

  4. Ternary mixtures of ionic liquids for better salt solubility, conductivity and cation transference number improvement

    Science.gov (United States)

    Karpierz, E.; Niedzicki, L.; Trzeciak, T.; Zawadzki, M.; Dranka, M.; Zachara, J.; Żukowska, G. Z.; Bitner-Michalska, A.; Wieczorek, W.

    2016-01-01

    We hereby present the new class of ionic liquid systems in which lithium salt is introduced into the solution as a lithium cation−glyme solvate. This modification leads to the reorganisation of solution structure, which entails release of free mobile lithium cation solvate and hence leads to the significant enhancement of ionic conductivity and lithium cation transference numbers. This new approach in composing electrolytes also enables even three-fold increase of salt concentration in ionic liquids. PMID:27767069

  5. Recovery of lignin peroxidase from submerged liquid fermentation of Amauroderma rugosum (Blume & T. Nees) Torrend using polyethylene glycol/salt aqueous two-phase system.

    Science.gov (United States)

    Jong, Wan Yng Linda; Show, Pau Loke; Ling, Tau Chuan; Tan, Yee Shin

    2017-07-01

    Amauroderma rugosum is a wild mushroom species widely distributed in tropics and is classified under the class of Basidiomycetes. Basidiomycetes are well-known for their abilities of producing lignocellulolytic enzymes such as lignin peroxidase (LiP), laccase (Lac) and manganese peroxidase (MnP). Different factors such as nutrient sources, incubation period and agitation affect the production of lignocellulolytic enzymes. The A. rugosum produced LiP in the medium supplemented with potato dextrose broth (PDB), 0.5% yeast and 1.0% saw dust at 26.70±3.31 U/mL. However, the LiP activity was increased to 106.32±5.32 U/mL when supplemented with 150 μm of copper (CuSO4). The aqueous two-phase system (ATPS) is a simple, rapid and low cost method for primary extraction and recovery of LiP. A total of 25 systems made from five different molecular weights of polyethylene glycol (PEG)/dipotassium hydrogen phosphate (K2HPO4) were tested. PEG 600 produced the highest top phase purification factor (PFT) of 1.33±0.62 with yield of 72.18±8.50%. The optimization of the ATPS parameters, such as volume ratio VR, pH and crude enzyme loading are the factors controlling the phase partition. Our results showed that significant improvement (PFT of 6.26±2.87 with yield of 87.31±3.14%) of LiP recovery can be achieved by optimized the parameters. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  6. Ternary fission

    Indian Academy of Sciences (India)

    M Balasubramaniam; K R Vijayaraghavan; C Karthikraj

    2015-09-01

    We present the ternary fission of 252Cf and 236U within a three-cluster model as well as in a level density approach. The competition between collinear and equatorial geometry is studied by calculating the ternary fragmentation potential as a function of the angle between the lines joining the stationary middle fragment and the two end fragments. The obtained results for the 16O accompanying ternary fission indicate that collinear configuration is preferred to equatorial configuration. Further, for all the possible third fragments, the potential energy surface (PES) is calculated corresponding to an arrangement in which the heaviest and the lightest fragments are considered at the end in a collinear configuration. The PES reveals several possible ternary modes including true ternary modes where the three fragments are of similar size. The complete mass distributions of Si and Ca which accompanied ternary fission of 236U is studied within a level density picture. The obtained results favour several possible ternary combinations.

  7. The Behavior and Characteristics of the Interfacial Waves in Gas-Liquid Two-Phase Separated Flow Thorugh Downward Inclined Rectangular Channel

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    An Experimental investigation on the behavior and characteristics of interfacial waves in downward inclined rectangular channel was conducted.The interfacial waves were traced and measured by using conductance technique.The wave patterns were distingushed and defined.The characteristics of the interfacial waves.such as time-averaged film thickness,wave height,wave propagation speed,wavelength and wave frequency,were systematically examined in terms of gas and liquid superficial volumetric fluxes.The effect of the inclination and flow channel geometry of the test section on the interfacial wave was also investigated.

  8. Advances in Simulation of Liquid-Liquid Two-phase Flow in Extraction Columns with CFD-PBM%萃取柱内液-液两相流CFD-PBM模拟研究进展

    Institute of Scientific and Technical Information of China (English)

    李少伟; 景山; 张琦; 吴秋林

    2012-01-01

    对萃取柱内CFD-PBM模拟研究进行了较详细的综述,包括其基本理论、不同的求解方法及模拟研究现状等.CFD-PBM模拟的基本方程包括流动方程和群体平衡方程,其相互耦合,群体平衡方程涉及破碎与聚并2个关键模型.群体平衡模型的求解方法包括直接离散化方法、矩量法、正交矩量法、直接正交矩量法、分段正交矩量法等,对这些方法的原理、优点和缺点进行了综述.目前国际上关于萃取柱内CFD模拟采用较多的是简单的欧拉-欧拉两相流模拟,考虑液滴尺寸分布和进一步的浓度分布的群体平衡模型应用较少.完善伴随传质的液-液分散体系的群体平衡模型,并将其应用于不同类型的萃取柱中,是萃取分离学科的重要任务.%A detailed review on the CFD-PBM research in the extraction columns is presented, including the fundamental theory, different solution methods, and status of the simulation research. The basic equations in the CFD-PBM simulation contain the flow equations and the population balance equation, which are coupled with each other. Coalescence and break-up models are two important models in the population equation. The methods to solve the population balance equation include the class method, the method of moments, the quadrature method of moments, the direct quadrature method of moments, and the sectional quadrature method of moments. The fundamental, advantages and disadvantaged of these methods were reviewed. The Eulerian-Eulerian method is mainly used in the CFD simulation of the two-phase flow in extraction columns to date. The PBM which considers the droplet size distribution and further the concentration distribution is relatively less used in extraction columns. To improve the PBM in a liquid-liquid dispersion system with mass transfer and to use the model in different types of extraction columns are important issues for extraction research.

  9. Characteristics of the entrained droplets in gas-liquid two-phase annular flow%气液两相环状流中夹带液滴特性研究

    Institute of Scientific and Technical Information of China (English)

    樊文娟; 彭颖

    2016-01-01

    气液两相环状流中液体薄膜沿着管壁流动而速度较大的气核在管中心流动,通常速度较大的气核会夹带部分液滴。液滴夹带来源于沿着管壁流动的液体层的雾化速率和液滴沉积速率之间的平衡过程。目前大多数环状两相流的研究主要集中在对主要夹带现象的分析上。文中主要从夹带液滴直径、液滴速度分布和夹带分数3个方面进行夹带液滴特性研究。%The liquid film flows along the pipe wall and the gas nucleus of higher speed flows in the center of the pipe flow in the gas-liquid two-phase annular flow,usually the high speed gas nucleus entrains some droplets. The droplet entrainment is derived from a balance between the rate of atomization of the liquid layer flowing along the pipe wall and the rate of deposition of droplets. When gas flow rate is low,gravity sedimentation controls the deposition rate,and when the gas phase is at high flow velocity,droplet turbulence controls the deposition rate. At present,most of the annular two-phase flow research focuses on the analysis of the main entrainment phenomenon. This article mainly discussed the entrained droplets from the gas liquid interface,because the entrained droplets play an important role in a lot of flow parameters. Therefore, this article made the droplet entrainment characteristics research mainly from the three aspects,namely droplet diameter, droplet velocity distribution and entrainment fraction.

  10. A Hydrodynamic Model for Slug Frequency in Horizontal Gas-Liquid Two-Phase Flow%水平管气液两相弹状流液弹频率的水动力学新模型

    Institute of Scientific and Technical Information of China (English)

    刘磊; 孙贺东; 胡志华; 周芳德

    2003-01-01

    The prediction of slug frequency has important significance on gas-liquid two-phase flow. A hydrodynamic model was put forward to evaluate slug frequency for horizontal two-phase flow, based on the dependence of slug frequency on the frequency of unstable interfacial wave. Using air and water, experimental verification of the model was carried out in a large range of flow parameters. Six electrical probes were installed at different positions of a horizontal plexiglass pipe to detect slug frequency development. The pipe is 30 m long and its inner diameter is 24 mm. It is observed experimentally that the interfacial wave frequency at the inlet is about 1 to 3 times the frequency of stable slug. The slug frequencies predicted by the model fit well with Tronconi (1990) model and the experimental data. The combination of the hydrodynamic model and the experimental data results in a conclusion that the frequency of equilibrium liquid slug is approximately half the minimum frequency of interfacial wave.

  11. Study on the Structure of Gas-Liquid Two-Phase Flow Based on Particle Image Velocimetry%粒子图像测速在气液两相流动结构研究中的应用

    Institute of Scientific and Technical Information of China (English)

    周云龙; 李洪伟; 刘旭

    2012-01-01

    文章应用DPIV方法对气液两相流在管道中不同位置分布情况进行了计算,分别从不同流型,不同气相流量两种情况下对轴向平均速度、轴向速度均方根、径向速度均方根以及雷诺应力四个参数进行计算分析,通过不同角度计算分析,得到结论:气液两相界面波对流动影响较大,气泡分布散落状态对流动影响较大,雷诺应力在相界面与管壁附近有明显峰值。%The paper computed the distribution of different position of gas-liquid two-phase flow pipe based on the DPIV method. And calculated the four parameters (axial average speed, axial speed mean square root, radial velocity mean square root and Reynolds stress) from the different flow pattern and different gas phase flow. The conclusion is that: the flow are influenced mainly by the wave of the interface of gas-liquid two phase and the distribution state of bubbles. Reynolds stress have an obvious peak in the interface and the near wall.

  12. Liquid–liquid equilibria in the quinary aqueous two-phase system of poly(ethylene glycol) 6000 + sodium sulfate + water in the presence of glucose and ethanol: Experimental investigation and thermodynamic modeling

    Energy Technology Data Exchange (ETDEWEB)

    Hekayati, Javad; Roosta, Aliakbar, E-mail: aa.roosta@sutech.ac.ir; Javanmardi, Jafar

    2016-02-10

    Highlights: • Quinary LLE phase equilibria involving PEG 6000 + Na{sub 2}SO{sub 4} + H{sub 2}O + glucose + ethanol. • Favorable partition coefficients of ethanol and glucose. • Satisfactory correlation of the LLE experimental data with the original NRTL model. • Root mean squared deviations (RMSDs) of less than 0.6%. - Abstract: Extractive fermentation processes involving aqueous two-phase systems (ATPSs) are considered as viable means of overcoming the problems associated with product inhibition. Practical development of these processes requires accurate knowledge of the liquid–liquid equilibrium (LLE) of the ATPS forming components alongside the substrate and product of the fermentation process. In this work, the quinary aqueous two-phase LLE of poly(ethylene glycol) 6000 + sodium sulfate + water in the presence of glucose and ethanol have been experimentally determined at 298.15 K using spectrophotometric methods. The resulting LLE data were then satisfactorily correlated by the non-random two-liquid (NRTL) activity coefficient model based on mass fractions. In doing so, the binary energy interaction parameters of the NRTL activity coefficient model were obtained and reported. Calculated RMS deviations below 0.6% demonstrate that the original NRTL activity coefficient model can accurately correlate the LLE data of the quinary aqueous biphasic system of interest.

  13. Simultaneous determination of diclofenac potassium and methocarbamol in ternary mixture with guaifenesin by reversed phase liquid chromatography.

    Science.gov (United States)

    Elkady, Ehab F

    2010-09-15

    New, simple, rapid and precise reversed phase liquid chromatographic (RP-LC) method has been developed for the simultaneous determination of diclofenac potassium (DP) and methocarbamol (MT) in ternary mixture with guaifenesin (GF), degradation product of methocarbamol. Chromatographic separation was achieved on a Symmetry Waters C18 column (150 mm x 4. 6mm, 5 microm). Gradient elution based on phosphate buffer pH (8)-acetonitrile at a flow rate of 1 mL min(-1) was applied. The UV detector was operated at 282 nm for DP and 274 nm for MT and GF. Linearity, accuracy and precision were found to be acceptable over the concentration ranges of 0.05-16, 0.5-160 and 0.5-160 microg mL(-1) for DP, MT and GF, respectively. The optimized method proved to be specific, robust and accurate for the quality control of the cited drugs in pharmaceutical preparation. Copyright (c) 2010 Elsevier B.V. All rights reserved.

  14. An experimental study of the size effect on adiabatic gas-liquid two-phase flow patterns and void fraction in microchannels

    Science.gov (United States)

    Xiong, Renqiang; Chung, J. N.

    2007-03-01

    Adiabatic gas-liquid flow patterns and void fractions in microchannels were experimentally investigated. Using nitrogen and water, experiments were conducted in rectangular microchannels with hydraulic diameters of 0.209mm, 0.412mm and 0.622mm, respectively. Gas and liquid superficial velocities were varied from 0.06-72.3m/s and 0.02-7.13m/s, respectively. The main objective is focused on the effects of microscale channel sizes on the flow regime map and void fraction. The instability of flow patterns was observed. Four groups of flow patterns including bubbly slug flow, slug-ring flow, dispersed-churn flow, and annular flow were observed in microchannels of 0.412mm and, 0.622mm. In the microchannel of 0.209mm, the bubbly slug flow became the slug flow and the dispersed-churn flow disappeared. The current flow regime maps showed the transition lines shifted to higher gas superficial velocity due to a dominant surface tension effect as the channel size was reduced. The regime maps presented by other authors for minichannels were found to not be applicable for microchannels. Time-averaged void fractions were measured by analyzing 8000 high speed video images for each flow condition. The void fractions hold a nonlinear relationship with the homogeneous void fraction as opposed to the relatively linear trend for the minichannels. A new correlation was developed to predict the nonlinear relationship that fits most of the current experimental data and those of the 0.1mm diameter tube reported by Kawahara et al. [Int. J. Multiphase Flow 28, 1411 (2002)] within ±15%.

  15. Calculation of liquid-vapor and liquid-liquid equilibrium in multicomponent systems using correlations of equilibrium data

    OpenAIRE

    Reyes Labarta, Juan Antonio; Olaya López, María del Mar; Gómez Siurana, Amparo; Marcilla Gomis, Antonio

    1999-01-01

    Póster presentado en el congreso EQUIFASE 99 (Vigo, del 20 al 24 de Junio de 1999). Resumen publicado en el libro de actas del Congreso An algebraic correlation method to calculate equilibrium data for ternary vapor-liquid equilibrium and quaternary liquid-liquid equilibrium has been proposed. The proposed method allows the calculation of the conjugated phase in equilibrium with a given phase, and the calculation of the two phases in equilibrium from the composition of a heterogeneous glob...

  16. Analysis of the turbulence anisotropy characteristic in the interface of gas-liquid two phase flow in horizontal tubes%水平管内气液两相流界面湍流各向异性分析

    Institute of Scientific and Technical Information of China (English)

    邱国栋; 蔡伟华; 姜益强

    2016-01-01

    In order to explore how to choose the turbulence model of the gas-liquid two phase flow in a horizontal pipe, the guess that the turbulence of the interface of the gas-liquid two phase flow in a horizontal pipe is anisotropic was put forward. The emergence and development mechanism of the turbulence anisotropy in the interface was analyzed. It points out that the turbulence inertial force generated by the turbulence anisotropy in the interface is an important reason for the formation of annular flow in a horizontal tube, which was verified by comparing the simulation results of using the two-equation model and Reynolds stress model ( RSM) to simulate the same working condition of annular flow in a horizontal tube. On such basis, the basis of selecting turbulence model in gas-liquid two phase flow was discussed. The results show that the RSM model is adaptive for large gas-liquid shear stress in a horizontal pipe, while the two-equation model and RSM model are both adaptive for other conditions.%为探讨水平管内气液两相流湍流模型如何选择,提出水平管内气液两相流界面湍流为各向异性的猜想,分析了该界面湍流各向异性产生和发展的机理,指出界面湍流各向异性产生的湍流惯性力是水平管环状流形成的重要原因.通过比较二方程模型和雷诺应力模型( RSM)模拟同一个水平管环状流工况的结果来验证分析的正确性,在此基础上探讨了气液两相流湍流模型的选择依据.结果表明当水平管内气液剪切力较大时适合选用RSM模型,其他情况二方程模型和RSM模型均适用.

  17. 管道充气排液工况下气液两相流数值模拟研究%Mathematic Simulation on Gas-liquid Two-phase Flow of Pipe Pigging by Gas Condition

    Institute of Scientific and Technical Information of China (English)

    姜俊泽; 张伟明; 李正阳

    2013-01-01

    Based on the deeply analyzing the simulation method, VOF model was employed to research gas-liquid two-phase flow of the pipe pigging process, taking surface tension, wall adhesion, the viscosity of the liquid, the wall's roughness and the gas compressibility into consideration. The simulation took unobstructed mesh and mesh decipherment technology to trace the gas-liquid interface and the gas-liquid interface mixture and variation processes were obtained. Then, The pressure distribution, gas volume percentage, two-phase flow friction and the energy transformation at different moment were analyzed.The results show that VOF model could be used to the numerical simulation of non-free surface two phase flow.%为了获得管道充气排液过程的两相流动状态,采用VOF模型对管道充气排液工况进行了数值模拟研究.模型考虑了液体表面张力、壁面粘附力,流体粘度,管壁粗糙度以及气体可压缩性效应,并采用结构化网格和自适应网格加密技术,对两相界面进行了跟踪,观察了这一工况下的气液两相混合及界面变化过程,分析了充气过程中不同时刻的管道内压力分布、气相体积分数、管流摩阻和能量交换情况,得到了这一工况下气液两相的流动特征.模拟结果也表明,在进行适当的网格划分和参数设置,VOF模型可以用于非自由表面的有压流动的数值模拟.

  18. Determination of solid-liquid interfacial energies in the In-Bi-Sn ternary alloy

    Energy Technology Data Exchange (ETDEWEB)

    Akbulut, S; Ocak, Y [Department of Physics, Institute of Science and Technology, Erciyes University, Kayseri, 38039 (Turkey); Marasli, N; Keslioglu, K [Department of Physics, Faculty of Arts and Sciences, Erciyes University, Kayseri, 38039 (Turkey); Kaya, H [Department of Science Education, Education Faculty, Erciyes University, Kayseri, 38039 (Turkey); Cadirli, E [Department of Physics, Faculty of Arts and Sciences, Nigde University, Nigde (Turkey)], E-mail: marasli@erciyes.edu.tr

    2008-09-07

    The equilibrated grain boundary groove shapes of solid In{sub 2}Bi solution in equilibrium with the In-Bi-Sn eutectic liquid were observed from a quenched sample at 59 {sup 0}C. The Gibbs-Thomson coefficient, solid-liquid interfacial energy and grain boundary energy of the solid In{sub 2}Bi solution have been determined to be (1.42 {+-} 0.07) x 10{sup -7} K m, (49.6 {+-} 5.0) x 10{sup -3} J m{sup -2} and (97.1 {+-} 10.7) x 10{sup -3} J m{sup -2}, respectively, from the observed grain boundary groove shapes. The thermal conductivities of the solid phases for In-21.23 at% Bi-19.04 at% Sn and In-30.5 at% Bi-3 at% Sn alloys and the thermal conductivity ratio of the liquid phase to the solid phase for In-21.23 at% Bi-19.04 at% Sn have also been measured with a radial heat flow apparatus and a Bridgman type growth apparatus, respectively, at their melting temperature.

  19. Thermodynamic modeling of ternary and quaternary (liquid + liquid) systems containing water, FeCl3, HCl and diisopropyl ether

    NARCIS (Netherlands)

    Milosevic, M.; Hendriks, I.; Smits, R.E.R.; Schuur, Boelo; de Haan, A.B.

    2013-01-01

    Liquid–liquid extraction using ethers as solvents is a potentially energy saving alternative for the concentration of aqueous ferric chloride solutions. Adequate thermodynamic models that describe the behavior of the resulting quaternary systems (FeCl3, ether, acid and water) are not available in

  20. Use of hydrophilic ionic liquids in a two-phase system to improve Mung bean epoxide hydrolases-mediated asymmetric hydrolysis of styrene oxide.

    Science.gov (United States)

    Chen, Wen-Jing; Lou, Wen-Yong; Yu, Chun-Yang; Wu, Hong; Zong, Min-Hua; Smith, Thomas J

    2012-12-31

    A comparative study was made of Mung bean epoxide hydrolases-catalyzed asymmetric hydrolysis of styrene oxide to (R)-1-phenyl-1,2-ethanediol in an n-hexane/buffer biphasic system containing various hydrophilic ionic liquids (ILs). Compared to the n-hexane/buffer biphasic system alone, addition of a small amount of hydrophilic ILs reduced the amount of non-enzymatic hydrolysis, and improved the reaction rate by up to 22%. The ILs with cation containing an alkanol group, namely [C(2)OHMIM][BF(4)] and [C(2)OHMIM][TfO], and the choline amino acid ILs [Ch][Arg] and [Ch][Pro] were found to be the most suitable co-solvents for the reaction, owing to their good biocompatibility with the enzyme, which led to high initial rates (0.99-1.25 μmol/min) and high product e.e.s (95%). When substrate concentration was around 30 mM, where optimal performance was observed with the IL-containing systems, the product e.e. was improved from 90% without ILs to ≥95% in the presence of ILs.

  1. A study on the effect of gas flow rate on the wave characteristics in two-phase gas-liquid annular flow

    Energy Technology Data Exchange (ETDEWEB)

    Han Huawei [Faculty of Engineering and Applied Science, University of Ontario Institute of Technology, Oshawa, Ont., L1H 7K4 (Canada)]. E-mail: colin.han@uoit.ca; Zhu Zhenfeng [Department of Mechanical Engineering, University of Saskatchewan, Saskatoon, Sask., S7N 5A9 (Canada)]. E-mail: zhz752@mail.usask.ca; Gabriel, Kamiel [University of Ontario Institute of Technology, Oshawa, Ont., L1H 7K4 (Canada)]. E-mail: kamiel.gabriel@uoit.ca

    2006-12-15

    Interfacial waves play a very important role in the mass, momentum and energy transport phenomena in annular flow. In this paper, film thickness time-trace measurements for air-water annular flow were collected in a small vertical tube using a parallel wire probe. Using the data, a typical disturbance wave shape was obtained and wave properties (e.g., width, height, speed and roughness) were presented. The liquid mass flux ranged from 100 to 200 kg/m{sup 2} s and the gas mass flux ranged from 18 to 47 kg/m{sup 2} s. Disturbance wave characteristics were defined and the effects of changing the gas flow rate on the wave spacing, wave width, wave peak height and wave base height were studied. An average velocity model for the wave and base regions has been developed to determine the wave velocity. The investigation method could be further extended to annular-mist flow which frequently occurs in boiling water reactors.

  2. Visually Experimental Investigation on Flow Patterns of GAS-liquid Two-phase Through Packed Channel With Spheres%球床反应堆气-液两相流流型可视化实验研究

    Institute of Scientific and Technical Information of China (English)

    赵忠南

    2016-01-01

    在新概念核反应堆堆型的研究、碎片床的冷却、石油和化学工业中的反应床中都涉及球床气液两相流。气-液两相流流型研究的首要问题是流型的观测,只有解决了这个问题,后续的流型分类、流型识别、流型与阻力特性的关系等一系列问题才能得以展开。因此,本文研究内容由可视化研究开始,通过可视化研究得到的结果来指导球床空气-水两相流流型的相关研究。本章详细叙述了流型可视化研究的目的、方法和内容,给出了CaCl2溶液的基本物性参数以及可视化研究的结果,为进一步研究球床空气-水两相流流型等相关方面的研究扫清障碍。%In the research of new-concept nuclear reactor, debris bed cooling, and chemical industry, gas-liquid two-phase flow in porous media are involved. Type gas-liquid two phase flow study is the first problem of flow pattern observation, only solved the problem, the subsequent flow pattern classification, the flow pattern identification, the relationship between the resistance to flow pattern and a series of problems, such as can be. Therefore, this article research content by the visualization study began, through visualization research results to guide the pebble bed type air-water two phase flow of related research. Is described in detail in this chapter flow pattern visualization study purpose, method and content, the basic physical parameters of CaCl2 solution is given and visual results, for the further study on the air bed - water two phase flow and other related research.

  3. 矩形通道内两相脉动流平均摩擦压降实验研究%Experimental Study on Average Frictional Pressure Drop of Gas-liquid Two-phase Pulsatile Flow

    Institute of Scientific and Technical Information of China (English)

    周豹; 高璞珍; 谭思超; 田竞达; 张虹

    2013-01-01

    通过对截面为40 mm ×3 mm窄矩形通道内不同正弦脉动周期、振幅、平均流量工况下氮气-水两相流(平均分液相雷诺数 Rel<10000,平均分气相雷诺数 Reg <800)进行实验研究,发现两相脉动流与单相水脉动流的规律不同,平均压差对脉动周期、振幅不敏感。应用各经验公式计算的脉动工况下平均摩擦压降的偏差与稳态工况的计算偏差在数值和分布上均无明显差异,且计算值分布在测量值两侧、相对偏差基本小于20%。其中,Mishima-Hibiki方法和Lee-Lee方法的计算结果与测量结果吻合良好,相对偏差在10%以内,说明两相流摩擦压降经验公式同样适用于脉动工况下平均摩擦压降的计算。%The gas-liquid two-phase pulsatile flow was studied in a rectangular channel with 40 mm × 3 mm cross section under different periods ,flow rate amplitudes and its mean values (mean Rel < 10 000 ,mean Reg < 800) .There was difference between the single phase pulsatile flow and the gas-liquid two-phase pulsatile flow ,and pulsation period and amplitude were not sensitive for the average frictional pressure drop .There was no significant difference on the values and distribution between the calculation deviations in pulsatile flow and the calculation deviations in steady flow by using different empirical formulas .Almost all of the relative deviations were less than 20% , and the relative deviations of Mishima-Hibiki method and Lee-Lee method were less than 10% .The results show that the empirical formulas for the two-phase steady flow frictional pressure drop are also suitable for the calculation of the average value of two-phase pulsatile flow .

  4. Study of Water Turbine′s Gas-Liquid Two-Phase Flow Based Numerical Simulation%基于气液两相流模型的水轮机数值模拟研究进展

    Institute of Scientific and Technical Information of China (English)

    冯俊; 郑源

    2012-01-01

    随着水电站机组容量不断增大和计算机技术的飞速发展,传统的数值模拟手段已不能满足人们对深入分析水轮机性能的要求,因此更贴近实际、结果更准确的基于气液两相流模型的数值模拟越来越受到人们的关注。介绍了气液两相流动的主要计算模型,概述近年来国内外水轮机气液两相流数值模拟进展,重点阐述在其应用于水轮机空化性能、尾水管压力脉动等方面的研究成果和应用前景,并对需要进一步深入研究的问题及研究中应遵循的一些原则作出初步探讨。%With the development of water turbines′ capacity and computer technology,people start to focus on the need for accurate numerical simulation to analyse turbines′ internal flow.The Gas-Liquid two-phase flow model which is closer to actual is now drawing more and more attention from people.This article will be followed by a brief instruction of main Gas-Liquid two-phase flow models and an overview of latest international progress of water turbine′s Gas-Liquid flow based numerical simulation.Details on applications in water turbines′ cavitation and draft tube′s pressure pulsation are described in later sections.Finally,it shows a discussion on problems and methods to solve them.

  5. Time-Resolved Soft X-ray Diffraction Reveals Transient Structural Distortions of Ternary Liquid Crystals

    Directory of Open Access Journals (Sweden)

    Klaus Mann

    2009-11-01

    Full Text Available Home-based soft X-ray time-resolved scattering experiments with nanosecond time resolution (10 ns and nanometer spatial resolution were carried out at a table top soft X-ray plasma source (2.2–5.2 nm. The investigated system was the lyotropic liquid crystal C16E7/paraffin/glycerol/formamide/IR 5. Usually, major changes in physical, chemical, and/or optical properties of the sample occur as a result of structural changes and shrinking morphology. Here, these effects occur as a consequence of the energy absorption in the sample upon optical laser excitation in the IR regime. The liquid crystal shows changes in the structural response within few hundred nanoseconds showing a time decay of 182 ns. A decrease of the Bragg peak diffracted intensity of 30% and a coherent macroscopic movement of the Bragg reflection are found as a response to the optical pump. The Bragg reflection movement is established to be isotropic and diffusion controlled (1 μs. Structural processes are analyzed in the Patterson analysis framework of the time-varying diffraction peaks revealing that the inter-lamellar distance increases by 2.7 Å resulting in an elongation of the coherently expanding lamella crystallite. The present studies emphasize the possibility of applying TR-SXRD techniques for studying the mechanical dynamics of nanosystems.

  6. Time-resolved soft X-ray diffraction reveals transient structural distortions of ternary liquid crystals.

    Science.gov (United States)

    Quevedo, Wilson; Peth, Christian; Busse, Gerhard; Scholz, Mirko; Mann, Klaus; Techert, Simone

    2009-11-04

    Home-based soft X-ray time-resolved scattering experiments with nanosecond time resolution (10 ns) and nanometer spatial resolution were carried out at a table top soft X-ray plasma source (2.2-5.2 nm). The investigated system was the lyotropic liquid crystal C(16)E(7)/paraffin/glycerol/formamide/IR 5. Usually, major changes in physical, chemical, and/or optical properties of the sample occur as a result of structural changes and shrinking morphology. Here, these effects occur as a consequence of the energy absorption in the sample upon optical laser excitation in the IR regime. The liquid crystal shows changes in the structural response within few hundred nanoseconds showing a time decay of 182 ns. A decrease of the Bragg peak diffracted intensity of 30% and a coherent macroscopic movement of the Bragg reflection are found as a response to the optical pump. The Bragg reflection movement is established to be isotropic and diffusion controlled (1 micros). Structural processes are analyzed in the Patterson analysis framework of the time-varying diffraction peaks revealing that the inter-lamellar distance increases by 2.7 A resulting in an elongation of the coherently expanding lamella crystallite. The present studies emphasize the possibility of applying TR-SXRD techniques for studying the mechanical dynamics of nanosystems.

  7. 密闭容器内两相液体的液位测量%Level detection of two-phase liquid in sealed container

    Institute of Scientific and Technical Information of China (English)

    王萍; 刘尧; 万凯

    2015-01-01

    Liquid level of oil and water in sealed container as detecting object , an ultrasonic level measurement system based on the cross-correlation algorithm is designed. Taking C8051F120 as control kernel , the hardware architecture is mainly composed of ultrasonic transmitting and receiving circuit , weak echo signal conditioning circuit and so on. The echo signal is extracted from strong noise by cross-correlation algorithm. Oil and water level are measured through calculating time of flight in accordance with the peak of cross-correlated function. In the upper computer, the dynamic link library of Matlab is called by Visual Basic interface to realize the pocessing of noise interference and improve the recognition rate of useful signal. The experimental results show that the measurement accuracy of the system can be controlled at around 1%, and the system has the characteristics of simple realization, high stability, good repeatablity, etc.%以密闭容器内油、水液位为检测对象,设计一种基于互相关算法的超声波液位测量系统。以C8051F120为系统的控制核心,硬件架构主要包括超声波收发电路、回波信号调理电路等。采用互相关算法从强噪声中提取回波信号,计算出互相关函数峰值所对应的渡越时间,从而测出油、水液位。在上位机,通过Visual Basic界面调用Matlab的动态链接库来实现互相关函数处理噪声干扰,提高有用信号的识别率。实验结果表明:该系统的测量精度控制在1%左右,并且具有实现简单、稳定性较高、重复性好等特点。

  8. 基于COMSOL与MATLAB的气液两相流空隙率研究%Research on void fraction of gas-liquid two-phase flow based on COMSOL and MATLAB

    Institute of Scientific and Technical Information of China (English)

    苏亮; 宋志平; 王宝寿; 丁力

    2013-01-01

      文章利用电阻层析成像技术进行了空隙率的静态测试,并将测试数据、COMSOL计算数据与MATLAB编程数据进行了比较。在验证了所编MATLAB程序的正确性后,将其应用于气液两相流空隙率测试。为了避免电阻层析成像技术在气液两相流空隙率测试中图像处理的难题,文中针对三种典型的气液两相流流型,建立了各自流型下的空隙率与截面平均电导率之间的函数关系。具体试验时,可将试验测试数据导入所编MATLAB程序中,得到截面平均电导率,并将此值代入对应流型下的空隙率与截面平均电导率之间的函数关系式中,进而得到空隙率值。该文提出的方法能够解决气液两相流空隙率测试的难点,具有较大的工程应用价值。%The void fraction is measured by electrical resistance tomography technology and the data mea-sured by experiment is compared with calculating data by COMSOL and simulating data by MATLAB. The MATLAB program is used to measure the void fraction of gas-liquid two-phase flow after it is proved true. The functional equation between void fraction and sectional average conductivity is established according to three different types of flow pattern in order to avoid the difficulity in image processing of gas-liquid two-phase flow. For one experiment, the measured data is imported into MATLAB program to obtain the val-ue of sectional average conductivity and then plug the value of sectional average conductivity into the func-tional equation above, the value of void fraction is obtained. The method proposed in this paper can solve the problem in void fraction measurement of gas-liquid two-phase flow and is of great engineering value.

  9. Extraction of Doxycycline Hydrochloride Using Alcohol and Ionic Liquid Binary Aqueous Two Phase System%醇与离子液体二元双水相体系萃取盐酸多西环素

    Institute of Scientific and Technical Information of China (English)

    关卫省; 黎文娟; 韩娟

    2012-01-01

    Based on the molecular alcohol aqueous two-phase system and the ionic liquid aqueous two-phase system, the new method of using n-propanol and hydrophilic ionic liquid(1-butyl-3-methylimidazolium tetrafluoroborate, [Bmim]BF4) with (NH4)2SO4 binary aqueous two phase system for the extraction of doxycycline hydrochloride was developed. The influence factors on partition behaviors of doxycycline hydrochloride were studied, including concentration of (NH4)2SO4, n-propanol con-sumption, pH value, concentration of ionic liquid and doxycycline hydrochloride. The results showed that when using pH value of 4. 0 - 5. 0, (NH4) 2SO4 concentration of 34% and doxycycline hydrochloride concentration between 25 -95 mg/L, the extraction rate and distribution coefficient of doxycycline hydrochloride will be up to 90. 26% -95. 71% and 62. 452 - 149. 401, respectively.%基于小分子醇双水相体系和离子液体双水相体系,建立了正丙醇与亲水性离子液体1-丁基-3-甲基咪唑四氟硼酸[ Bmim]BF4和(NH4 )2SO4形成的二元双水相体系萃取盐酸多西环素的新方法.考察了(NH4)2SO4含量、正丙醇用量、pH值、离子液体含量以及盐酸多西环素含量对盐酸多西环素分配行为的影响.结果表明:当醇和离子液体二元双水相体系的pH值在4.0~5.0范围内,(NH4)2SO4含量为34%,且盐酸多西环素的质量浓度在25 ~ 95 mg/L之间时,该体系对盐酸多西环素的萃取率可达90.26% ~95.71%,分配系数可达62.452 ~ 149.401.

  10. 气液两相流方法对络合-超滤膜组件污染的清洗%Cleaning for Fouled Membrane Module in Complexation-Ultrafiltration Processes with Gas/Liquid Two-Phase Flow Method

    Institute of Scientific and Technical Information of China (English)

    乔玉柏; 邵嘉慧; 何义亮

    2012-01-01

    Ultrafiltiation (UF) membrane technology has become one of the most promising high-techs in water treatment. However, its applications are significantly limited because of membrane fouling. A gas/liquid two-phase flow cleaning method was put forward and its performance on cleaning membrane modules fouled in the complexation-ultrafiltration process was studied. Effects of cleaning methods (gas flushing, water backflushing, chemical backflushing and gas-liquid two-phase flow with either water or chemical as cleaning solution) on the flux recovery were compared. Results show that the gas/liquid two-phase flow method can recover the membrane flux most with the minimum cleaning time. Effects of gas pulse time (tc), gas pulse interval (ti), velocity ratio of gas to liquid (Rs/t) on gas/liquid two-phase flow performance were investigated. When ti is 10 s and Rg/1 is 20:1, the flux was recovered most with tc of 15 s and 25 s. When tc is 15 s and Rg/1 is 20:1, the flux is recovered most with 20 s ti. When tc is 15 s and ti is 10 s, the two-phase flow cleaning method with water as cleaning solution can recover the flux most with Rg/t = 80:l and the two-phase flow cleaning method with HC1 as cleaning solution can recover the flux most with Rg/1=40:1. Results indicate that the gas/liquid two-phase flow cleaning method can effectively remove UF membrane foulants in the complexation-ultrafiltration process and can be called a green membrane cleaning method.%超滤膜法是目前最有发展前途的水处理技术之一,但使用过程中不可避免的污染问题很大程度上限制了该技术的推广.该文提出特定的气液两相流清洗方法并针对络合-超滤膜组件污染清洗进行研究,比较了气体冲洗、水力反冲洗、化学试剂反冲洗和气液两相流清洗(分别以水和HCl作为清洗液)络合-超滤污染膜组件的效果.结果显示气液两相流方法的清洗效果最好,且用时最短.考察了通气时间tc、气停时间ti和

  11. Liquid chromatographic determination of sitagliptin either alone or in ternary mixture with metformin and sitagliptin degradation product.

    Science.gov (United States)

    El-Bagary, Ramzia I; Elkady, Ehab F; Ayoub, Bassam M

    2011-07-15

    Two reversed-phase liquid chromatographic (RP-LC) methods have been developed for the determination of sitagliptin phosphate monohydrate (STG). The first method comprised the determination of STG alone in bulk and plasma; and in its pharmaceutical preparation. This method was based on isocratic elution of STG using a mobile phase consisting of potassium dihydrogen phosphate buffer pH (7.8)-acetonitrile (70:30, v/v) at a flow rate of 1 mL min(-1) with flourometric detection. The flourometric detector was operated at 267 nm for excitation and 575 nm for emission. In the second method, the simultaneous determination of STG and metformin (MET) in the presence of sitagliptin alkaline degradation product (SDP) has been developed. In this method, the ternary mixture of STG, MET and SDP was separated using a mobile phase consisting of potassium dihydrogen phosphate buffer pH (4.6)-acetonitrile-methanol (30:50:20, v/v/v) at a flow rate of 1 mL min(-1) with UV detection at 220 nm. Chromatographic separation in the two methods was achieved on a Symmetry(®) Waters C18 column (150 mm×4.6 mm, 5 μm). Linearity, accuracy and precision were found to be acceptable over the concentration ranges of 0.25-200 μg mL(-1) for STG with the first method and 5-160 μg mL(-1), 25-800 μg mL(-1) for STG and MET, respectively with the second method. The optimized methods were validated and proved to be specific, robust and accurate for the quality control of the cited drugs in pharmaceutical preparations.

  12. Solid-liquid equilibria in the ternary system NaBr-KBr-H2O at 398 K

    Science.gov (United States)

    Cui, Rui-Zhi; Zhang, Ting-Ting; Wang, Wei; Sang, Shi-Hua

    2017-09-01

    The solubilities of the ternary system NaBr-KBr-H2O were investigated by isothermal method at 398 K. On the basis of the experimental data, the phase diagram was plotted. In the phase diagram of ternary system NaBr-KBr-H2O at 398 K, no complex salt or solid solution was found. It belongs to simple co-saturation type. There are only one invariant point, two univariant curves, and two crystallization fields corresponding to NaBr and KBr. Using the equilibrium solubilities data of the ternary system at 398 K, mixing ioninteraction parameter ΨNa,K,Br of Pitzer's equation was fitted by multiple linear regression method. Based on the Pitzer model and its extended Harvie-Weare (HW) model, the solubilities of phase equilibrium in the ternary system NaBr-KBr-H2O at 398 K were calculated. The phase diagram of the ternary system was plotted. The results show that calculated values have a good agreement with measured experimental data. It can demonstrate the accuracy of the experimental data, and it also shows that reasonable parameters of the Pitzer model can be used in ternary system NaBr-KBr-H2O at 398 K.

  13. Research on the dynamic characteristics of gas-liquid two phase flow measurement with different throttle devices%不同节流装置测量气液两相流的动态特性研究

    Institute of Scientific and Technical Information of China (English)

    陈飞; 孙斌; 王二朋; 白宏震

    2012-01-01

    为了研究文丘里管、多孔孔板和V型内锥3种功能节流式流量计测量得到的气液两相流动态特性,采用高频差压传感器获取不同流型下的动态差压信号,利用AOK时频谱对差压信号进行分析,通过时频谱图研究不同流型下信号的时变特征.通过对典型的泡状流、弹状流、塞状流信号的实验分析表明:文丘里管在塞泡流存在较强的噪声信号,V型内锥在泡状流存在较强的噪声信号.多孔孔板具有很好的降噪效果,且多孔孔板能均衡信号的能量,信号能量分布较均衡.3种节流仪表均能很好地描述两相流定态特性,能够用于两相流流型识别及其它参数测量.%In this paper, the dynamic characteristics in the measurement of gas-liquid two-phase flow with different throttle flow-meters including Venturi tube, multi-hole orifices plate and V-shaped inner conical were studied. Firstly, high-frequency pressure sensor is adopted to get the dynamic differential pressure signal under different flow patterns. Secondly, the AOK spectrum is introduced and used in the analysis of the dynamic differential pressure signal. Then, the time-varying characteristic of dynamic differential pressure signal in different flow patterns is studied by estimating the time-frequency spectrum. It is indicated by experiments with the typical bubbly flow, slug flow and plug flow signals that Venturi tube has strong noise component at plug flow, and V-shaped inner cone has strong noise component at bubbly flow, multi-hole orifices plate is good at restraining noise. Furthermore, the multi-hole orifices plate can perform fine rectifying function and balance the energy of signals, which makes the energy distribution of signals more proportionate. The three kinds of throttling flow-meter can well describe the dynamic characteristics of gas-liquid two-phase flow, which can be used in the two-phase flow pattern I-dentification and characteristic variables

  14. Molecular thermodynamic analysis for assessing the relationship between reentrant swelling behavior and ternary liquid-liquid equilibrium for poly(N-isopropylacrylamide) nanometer-sized gel particles in a water-tetrahydrofuran cosolvent system.

    Science.gov (United States)

    Jung, Sang Chul; Bae, Young Chan

    2012-02-23

    The influence of phase separation on swelling behavior was investigated based on the thermodynamic framework of reswelling phenomena. The cloud-point for a ternary system of water(1)-tetrahydrofuran (THF)(2)-poly(N-isopropylacrylamide)(3) was examined by thermo-optical analysis (TOA). Nanometer-sized N-isopropylacrylamide (NIPA) gel particles were prepared by precipitation polymerization, and their swelling behaviors were determined using photon correlation spectroscopy (PCS). NIPA gel particles underwent reswelling when the ratio of water to THF was varied. First, the modified double lattice model (MDL) was employed to determine ternary interaction energy parameters for the liquid-liquid equilibrium (LLE) of linear poly-NIPA in a water-THF cosolvent system. The reentrant swelling equilibria of the NIPA gel in the water-THF system were then calculated using the interaction energy parameters. © 2012 American Chemical Society

  15. (Liquid + liquid) equilibrium of (NaNO{sub 3} + PEG 4000 + H{sub 2}O) ternary system at different temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez, Yecid P. [Departamento de Ingenieria Quimica, Universidad de Antofagasta, CICITEM (Chile); Galleguillos, Hector R., E-mail: hgalleguillos@uantof.cl [Departamento de Ingenieria Quimica, Universidad de Antofagasta, CICITEM (Chile)

    2011-11-15

    Highlights: > LLE data for the ATPS NaNO{sub 3} + PEG 4000 were determined at T = (288.15 and 308.15) K. > The experimental data shown that the temperature increases as STL and biphasic area increase. > The Chen-NRTL, modified Wilson and UNIQUAC models were used to correlate the experimental tie-line data. > The results show that the quality of fitting is better with the UNIQUAC model. - Abstract: Phase diagram and (liquid + liquid) equilibrium (LLE) data for the (NaNO{sub 3} + polyethylene glycol 4000 (PEG 4000) + H{sub 2}O) system have been determined experimentally at T = (288.15 and 308.15) K. The effects of temperature on the binodal curves and tie-lines have been studied and it was found that an increasing in temperature caused the expansion of two-phase region. The Chen-NRTL, modified Wilson and UNIQUAC models were used to correlate the experimental tie-line data. The results show that the quality of fitting is better with the UNIQUAC model.

  16. Response of two-phase droplets to intense electromagnetic radiation

    Science.gov (United States)

    Spann, James F.; Maloney, Daniel J.; Lawson, William F.; Casleton, Kent H.

    1993-04-01

    The behavior of two-phase droplets subjected to high intensity radiation pulses is studied. Droplets are highly absorbing solids in weakly absorbing liquid medium. The objective of the study was to define heating thresholds required for causing explosive boiling and secondary atomization of the fuel droplet. The results point to mechanisms for energy storage and transport in two-phase systems.

  17. 自吸泵启动过程气液两相流动的数值模拟%Numerical simulation on gas-liquid two-phase flow of self-priming pump during starting period

    Institute of Scientific and Technical Information of China (English)

    李红; 徐德怀; 涂琴; 成军; 李磊

    2013-01-01

    Self-priming pump is a kind of special centrifugal pump, which is widely used in irrigation and drainage, construction, mine drainage, city fire fighting, military, petrochemical industry, food industry and so on. The self-priming pumps produced in China have some problems such as complex structure, large size, difficulty for casting, low suction height, long self-priming time, and the design methods of the self-priming pump have still stayed in the semi-empirical theories stage, which can not meet the demand of predicting properties and the requirement of new products design. In order to know the flow rule, it becomes very important to research the inner flow of the self–priming pump. The self-priming transient process in self-priming pump is complex gas-liquid two-phase flow, gas-liquid mixing and separation performances play a crucial role during self-priming process. The self-priming pump typed 65ZB-40C was chosen as the numerical model. The three-dimensional model was generated in Pro/E software, and the three-dimensional unstructured grid was adopted in meshing in ICEM software because of the complexity of the geometric model. The gas-liquid two-phase flow field in a self-priming pump was simulated in FLUENT software by using VOF multiphase model, sliding mesh, and combined with the rotational speed curve of the impeller and the pressure curve of the pump outlet from tests. The PISO algorithm was used to handle the pressure-velocity coupling, and governing equations were discrete with second order upstream scheme. The model was initialized before computing, set the lower part of the pump for water, and the rest of the pump for air. Gas-liquid mixing and separation phenomena were simulated and the air volume fraction curves during starting period were obtained from monitoring points on the gas-liquid separation chamber inlet, the reflux hole, the cross-sections of volute and impeller. Results show that a gas-liquid mixing layer appeared at the outer edge of

  18. 一种测量气--液两相流的线列阵传感器设计%A wire mesh sensor design for gas-liquid two phase flow measurement

    Institute of Scientific and Technical Information of China (English)

    王兴涛; 田芳; Eisemberg Jascha; Prasser H M

    2015-01-01

    针对气—液两相流研究对含气率测量的需求,基于线列阵测量技术原理,设计了一种可移动式线列阵两相流测量传感器,该传感器具有较高的空间分辨率(3 mm)和极高的时间分辨率(2500 Hz),设计了线列阵传感器标定和含气率算法,实现了瞬时二维局部含气率的测量。经过射流冲击试验验证表明:该线列阵传感器结构稳定,基于原始测量数据,采用标定和含气率求解算法,可计算气泡夹带现象在水平截面的平均含气率分布情况。%Aiming at gas fraction measurement needs of gas-liquid two-phase flow study,a movable wire mesh sensor( WMS)for two-phase flow measurement is designed based on principle of WMS measuring technology. The sensor has high spatial and temporal resolutions which are 3 mm and 2 500 Hz. The calibration and gas fraction algorithm are designed to calculate the instantaneous 2D local gas fraction. The plunging jet experiment verifies that the WMS is stable,and based on the original data,the average void fraction distributions of cross-section bubble entrainment phenomenon are calculated using calibration and void fraction algorithm.

  19. T型结构微通道气液两相流型的数值模拟%Numerical Simulation of Gas-Liquid Two Phase Flow Pattern in T-Junction Microchannel

    Institute of Scientific and Technical Information of China (English)

    袁希钢; 宋文琦

    2012-01-01

    针对T型微通道气液两相流型的数值模拟,建立了适用于微通道气液两相流的计算模型,在流体力学软件FLUENT求解器中数值求算,模拟出不同气液相表观流速下的流型并与实验对比验证模型合理性.模拟过程中通过改变液相组成,考察了黏度和表面张力对气液两相流型分布的影响,并与前人的实验结果进行对比.模拟研究表明:液相流体黏度的改变,对流型分布图的影响很小;而随着表面张力的减小,Taylor流的区域在逐渐减小,这说明表面张力对Taylor流的形成有较大的影响.%To simulate the gas-liquid two phase flow pattern in T-junction microchannel, the numerical model was established using the VOF in the FLUENT solver. According to the simulated results in different gas and liquid superficial velocity, the flow regime was formed to compare with the published experimental data. The simulated results make a good agreement with the existent flow patterns and flow regime. The different physical properties were used to investigate the influence of viscosity and surface tension on the flow regimes in the simulation. The comparison between simulated results and experimental data was carried out. It is found that the transitions remain almost unvaried when liquid viscosity changes. The smaller surface tension is, the smaller area of Taylor flow will be. The surface tension has a great impact on the form of Taylor flow in microchannel.

  20. Two-Phase Cavitating Flow in Turbomachines

    Directory of Open Access Journals (Sweden)

    Sandor I. Bernad

    2012-11-01

    Full Text Available Cavitating flows are notoriously complex because they are highly turbulent and unsteady flows involving two species (liquid/vapor with a large density difference. These features pose a unique challenge to numerical modeling works. The study briefly reviews the methodology curently employed for industrial cavitating flow simulations using the two-phase mixture model. The two-phase mixture model is evaluated and validated using benchmark problem where experimental data are available. A 3D cavitating flow computation is performed for the GAMM Francis runner. The model is able to qualitatively predict the location and extent of the 3D cavity on the blade, but further investigation are needed to quatitatively assess the accuracy for real turbomachinery cavitating flows.

  1. Studies of ternary surface complexes at liquid-solid interfaces in seawater. 3: Comparative studies of the E(%)-pH curves and the diffuse reflectance IR spectra of the {alpha}-FeOOH-Cu(II)-tryptophan system

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Zhengbin; Wang Wei; Liu Liansheng; Fu Youjun; Wu Zhijian [Ocean Univ. of Qingdao (China). Inst. of Marine Chemistry

    1997-06-01

    The E(%)-pH curves of the ternary surface complexes at liquid-solid interfaces in the simulated seawater system of {alpha}-FeOOH-Cu(II)-tryptophan were determined. The diffuse reflectance IR spectra of the species at the solid surfaces in the above ternary equilibration system were examined. The above two results were comparatively studied. It is shown that the coadsorption of Cu(II) and tryptophan on {alpha}0FeOOH surface results in the formation of the ternary surface complex. Cu(II) can promote the exchange adsorption of tryptophan on {alpha}-FeOOH surface. The diffuse reflectance IR spectra can give one some evidence for the structure of the ternary surface complex, and these results are in accordance with the results of the E(%)-pH curves.

  2. 磨料射流固液两相流场的数值模拟%Numerical simulation of liquid-solid two phase flow field for abrasive water jet

    Institute of Scientific and Technical Information of China (English)

    张永利; 于欢; 马玉林

    2011-01-01

    为了解决磨料射流固、液两相流场运动对割缝效果的影响问题,采用数值模拟的方法,通过建立磨料射流固、液两相流场的数学模型,研究了磨料两相射流割缝的速度场和流动场规律。结果表明:磨料射流中割缝速度可达100 m/s左右,有利于有效割缝;有效割缝需要入射压力至少达到25 Mpa;磨料射流割缝过程中会形成了一道“水墙,,阻止磨料射流全部高速射出。产生二次回流。虽然二次加速的效果有限,但二次循环的水和颗粒经过二次加速能够再一次对壁面形成高速打击,提高割缝效率。研究成果对磨料两相射流割缝提高油井采收率具有指导意义。%In order to understand the impact on abrasive hydraulic slotting by liquid-solid two phase flow field, this study has developed a mathematical model of liquid-solid two phase flow field for abrasive water jet, and investigated the velocity field and fluid field of abrasive hydraulic slotting. The study shows that the cutting speed using abrasive water jet can reach approaximately 100 m/s, which is benefical to slot cutting. The incident pressure for an effective slotting is at least 25Mpa. A "water wall" will be formed during the abrasive hydraulic slotting which arrests the high-speed abrasive granules, engender the secondary reverse current. Although the effect of the second acceleration were limited, the recirculate water and granules engender hypervelocity impact on wall face by the second acceleration, which can increase the efficiency of slotting. The findings in this study can provide a guide for improving oil recovery using abrasive hydraulic slotting.

  3. Turbulência induzida por jatos bifásicos do tipo gás-líquido em tanques de aeração Turbulence induced by two-phase gas-liquid jets in aeration tanks

    Directory of Open Access Journals (Sweden)

    Iran Eduardo Lima Neto

    2010-03-01

    Full Text Available Jatos bifásicos do tipo gás-líquido são bastante usados nas engenharias sanitária e ambiental para fins de aeração artificial e mistura turbulenta. O presente trabalho investiga a turbulência gerada por meio desses jatos em um tanque de água, utilizando velocimetria por imagem de partículas. As condições experimentais incluíram jatos bifásicos com frações volumétricas de ar de até 70% e números de Reynolds variando entre 10.600 e 17.700. Os resultados dos ensaios indicaram que a fração volumétrica de ar afeta consideravelmente as propriedades turbulentas da fase líquida, enquanto o número de Reynolds apresenta efeito secundário. Correlações adimensionais foram então obtidas para expressar a energia cinética turbulenta e a taxa de dissipação de energia em função desses dois parâmetros. Finalmente, são apresentadas possíveis aplicações dos resultados deste trabalho.Two-phase gas-liquid jets are widely used in the sanitary and environmental engineering field for artificial aeration and turbulent mixing. The present work investigates the turbulence generated by these jets in a water tank, using particle image velocimetry. The experimental conditions included two-phase jets with gas volume fractions of up to 70% and Reynolds numbers ranging from 10,600 to 17,700. The results indicated that the gas volume fraction affects significantly the turbulent properties of the liquid phase, while the Reynolds number presents a secondary effect. Dimensionless correlations were then obtained to express the turbulent kinetic energy and dissipation rate as a function of these two parameters. Finally, possible applications of the results obtained in this work are presented.

  4. Critical transport velocity in two-phase, horizontal pipe flow

    Energy Technology Data Exchange (ETDEWEB)

    Sommerville, D. (U.S. Army Chemical Research, Development and Engineering Center, Aberdeen Proving Grounds, MD (US))

    1991-02-01

    This paper reports on the suspension of solid particles or entrainment of liquid droplets in two- phase flow. Theoretical and empirical relationships have been derived for both instances without any consideration to the similarities between the two. However, a general relation for two-phase flow is desirable since there are systems that cannot be readily defined due to the dual (solid/liquid) nature of the transported material, such as colloids, pulp, slurries, and sludge. Using turbulence theory, one general equation can be derived to predict critical transport velocities for two-phase horizontal flow.

  5. New numerical algorithm of gas-liquid two-phase flow considering characteristics of liquid metal during mold filling%基于充型过程金属液流动特点的气-液两相流算法模型

    Institute of Scientific and Technical Information of China (English)

    牛晓峰; 方钊; 梁伟; 侯华; 王红霞

    2014-01-01

    A new program is developed for gas-liquid two-phase mold filling simulation in casting. The gas fluid, the superheated liquid metal and the liquid metal containing solid grains are assumed to be governed by Navier-Stokes equations and solved through Projection method. The Level set method is used to track the gas-liquid interface boundary. In order to demonstrate the correctness of this new program for simulation of gas-liquid two-phase mold filling in casting, a benchmark filling experiment is simulated (this benchmark test is designed by XU and the filling process is recorded by a 16-mm film camera). The simulated results agree very well with the experimental results, showing that this new program can be used to properly predicate the gas-liquid two-phase mold filling simulation in casting.%针对在铸件充型过程中,金属液表现出不同的流动特点,含有固体颗粒的金属液具有不可压缩非牛顿流的流动特性,而过热金属液具有不可压缩牛顿流的流动特点,采用 Projection 方法求解气体、过热金属液和含有固体颗粒的金属液的速度场,用Level set方法来追踪气-液界面边界。为了验证计算模型,将模拟结果与实验结果(采用16 mm摄像机记录充型过程)进行比对,从而证明计算模型的正确性。

  6. Partitioning behavior and structural characterization of papain in ionic liquid aqueous two-phase system%木瓜蛋白酶在离子液体双水相中的分配行为

    Institute of Scientific and Technical Information of China (English)

    王伟涛; 蒋志国; 张海德; 彭健; 许英豪; 董安华; 杨雪芳; 蒋欣欣

    2015-01-01

    Papain was extracted by ionic liquid aqueous two-phase system. Firstly,the influence of concentration, pH, and temperature of ionic liquid on the activity of papain was investigated. Secondly, the effects of different ionic liquid aqueous two-phase systems, alkyl chain lengths and concentrations of the ionic liquid, dosage of papain, pH, temperature on the partitioning behavior of papain were discussed. [C4mim]Cl and [C4mim]Br systems were better than [C4mim]BF4 system in extraction of papain, and it was disadvantageous to extract papain at a high temperature (60℃or higher). Activity recovery of enzyme reached 95.16%and purification factor reached 1.5 under the optimum conditions:[C4mim]Cl 0.25 g·ml−1, K2HPO4 0.35 g·ml−1, pH 8.0, enzyme addition 2.0 mg·ml−1, 30℃. The result laid the experimental basis for further scale-up research and commercial production.%采用离子液体双水相提取木瓜蛋白酶。首先考察不同浓度、pH、温度的离子液体对木瓜蛋白酶活性的影响,其次考察不同离子液体双水相体系、离子液体侧烷基链长度及浓度、酶添加量、pH、温度对木瓜蛋白酶分配行为的影响。结果表明:[C4mim]Cl 和[C4mim]Br 体系萃取木瓜蛋白酶的效果比[C4mim]BF4体系好;高温(≥60℃)对离子液体双水相体系萃取木瓜蛋白酶不利。离子液体双水相萃取木瓜蛋白酶的最佳工艺条件:0.25 g·ml−1的[C4mim]Cl,0.35 g·ml−1的K2HPO4,pH 8.0,酶添加量2.0 mg·ml−1,30℃。此条件下木瓜蛋白酶的酶活性回收率达到95.16%,纯化因子达到1.5。为今后进一步研究该体系的放大实验或规模化生产奠定了基础。

  7. Estudio y modelación del flujo bifásico líquido-gas para bajos valores de Reynolds//Study and modelation for low reynolds value of two phases flow liquid-gas

    Directory of Open Access Journals (Sweden)

    Annamaris Olmo Velázquez

    2015-01-01

    Full Text Available El flujo simultáneo de líquido y gas es una de las combinaciones más complejas de flujo bifásico. Para este estudio se seleccionaron como fluidos de trabajo Glicerina en solución con agua al 80 % y Gel industrial. Estos por sus viscosidades permiten establecer los sistemas deseados para el estudio, con valores de Reynolds menor a 15. Fueron desarrollados experimentos para la determinación de las propiedades hidrodinámicas del los fluidos y los parámetros que caracterizan este tipo de flujo en un canal vertical. Fue obtenido a partir del análisis físico matemático de losexperimentos realizados, un modelo teórico experimental capaz de evaluar las fuerzas y coeficientes de arrastre para una burbuja aislada y un tren de burbujas. Se realizaron modelaciones computacionales de los distintos regímenes de trabajo, validadas con los resultados experimentales. Obteniéndose simulaciones y resultados que permiten visualizar y analizar el comportamiento real del sistema.Palabras claves: flujo bifásico, número de Reynolds, burbuja aislada, tren de burbujas, coeficientes de arrastre, fuerzas de arrastre._________________________________________________________________________________AbstractThe study of simultaneous flow of liquid and gas over a conduit is two phases flow combinations more complex that exist. For the study we select fluid (glycerin in solution with water (80 % and industrial gel that establish flow models necessary for the investigation the desired systems. And is obtained from physical-mathematical analysis of obtained results made experiment for different configurations, a theorys experimental model have evaluate the drag coefficient and force acting on only bubble and train bubbles in job regimen for Reynolds value less and equal to 15. In the present study was performed computational modeling of different patterns, validated with experimental results.Simulations and results obtained for visualizing and analyzing the actual

  8. Solubility measurement and solid-liquid equilibrium model for the ternary system MgBr2 + MgSO4 + H2O at 288.15 K

    Directory of Open Access Journals (Sweden)

    Li Dan

    2014-06-01

    Full Text Available The solubility of magnesium minerals and the refractive index of the ternary system MgBr2 + MgSO4 + H2O at 288.15 K were investigated using an isothermal dissolution method. It was found that there are two invariant points in the phase diagram and the solubility isotherm of this ternary system consists of three branches, corresponding to equilibrium crystallization of Epsomite (MgSO4·7H2O, Eps, hexahydrite (MgSO4·6H2O, Hex and magnesium bromide hexahydrate (MgBr2·6H2O, Mb. Neither solid solutions nor double salts were found. The refractive indices calculated from empirical equation are in good agreement with the experimental data. Combining the results from solubility measurements with the single-salt parameters for MgBr2 and MgSO4, and the mixed ion-interaction parameter θBr,S0(4, the parameter ψMg,Br,S0(4 at 288.15 K was fitted using the Pitzer theory and Harvie-Weare (HW approach. In addition, the average equilibrium constants of the stable equilibrium solids at 288.15 K were obtained by a method using the activity product constant. A chemical model, which combined the Pitzer parameters and the average equilibrium constants, was constructed to calculate the solid + liquid equilibria in the ternary system MgBr2 + MgSO4 + H2O at 288.15 K. The model agreed well with the equilibrium solubility data for the magnesium salts.

  9. 离子液体双水相萃取山楂黄酮和多糖的研究%Study on the Extraction of Hawthorn Flavonoids and Polysaccharide in Ionic Liquid Aqueous Two-Phase System

    Institute of Scientific and Technical Information of China (English)

    巩育军; 牛盛童; 黄学锋; 王键

    2014-01-01

    Partition behaviors of hawthorn flavonoids and polysaccharide in ionic liquid aqueous two-phase system(ILATPS)were studied by spectrophotometry.Effects of concentration of ionic liquid and ammonium sulfate,dosage of hawthorn and ultrasonic time on the extraction rate of hawthorn flavonoids and polysaccharide were investigated.The optimal extraction conditions were as follows:concentration of ionic liquid [Bmim]BF4 was 0.26~0.30 g·mL-1,concentration of ammonium sulfate was 0.08~0.10 g·mL-1,dosage of hawthorn was 0.14~0.17 g,ultrasonic time was 15~20 min.Under these conditions,extraction rate of hawthorn fla-vonoids was 86.4%~96.0% in the up phase,and extraction rate of polysaccharide was 75.2%~76.0% in the down phase.%采用分光光度法研究了山楂黄酮和多糖在[Bmim]BF4/(NH4)2 SO4双水相体系的分配行为,探讨了离子液体浓度、(NH4)2 SO4浓度、山楂用量和超声时间等因素对山楂黄酮和多糖萃取率的影响。确定最佳萃取条件为:离子液体[Bmim]BF4浓度0.26~0.30 g·mL-1,(NH4)2 SO4浓度0.08~0.10 g·mL-1,山楂用量0.14~0.17 g,超声时间15~20 min,在此优化条件下,双水相上相中黄酮的萃取率为86.4%~96.0%、下相中多糖的萃取率为75.2%~76.0%。

  10. 多喷嘴汽-液两相喷射器的工作特性研究%Working Character of Multi Nozzle Steam-liquid Two-phase Ejectors

    Institute of Scientific and Technical Information of China (English)

    马昕霞; 袁益超; 黄鸣; 刘聿拯

    2012-01-01

    A one-dimensional theoretical model was built to calculate the performance data of multi-nozzle steam-water two-phase ejector by the equations of mass,energy and momentum conservation for calculation of mechanism of multi nozzle steam-liquid two-phase ejector with wet saturated steam as the working fluid.The critical velocity of the single steam nozzle was computed by homogeneous equilibrium model of two-phase critical flow and amended by the multi-steam nozzle speed coefficient,and then the exit velocity of the multi-steam nozzle was obtained,and the resistance of the mixing section was determined by integrating Cattadori's wall forces model and Howard's "throat" pressure loss theory.In order to verify the proposed model,a set of experimental facility was designed with wet saturated steam as the working fluid and a type of multi-nozzle ejector as the experimental unit.The results show that volume entrainment ratio decreases with the increasing of pressure ratio,that the increasing of cross section of the ejector can increase volume entrainment ratio but cut down the working range of the ejector,and that the volume entrainment ratio decreases with the increasing of the steam dryness and sub-cooled water temperature.The computational results of volume entrainment ratio agree well with the experimental data.%对以湿蒸汽为工作流体的多喷嘴汽–液喷射器机制进行研究,利用质量、能量及动量守恒方程建立了喷射器工作特性一维理论模型。模型求解过程中,采用两相临界流均相平衡模型计算单喷射蒸汽喷嘴的临界流速,并利用多喷射速度系数对其修正,得到多喷射蒸汽喷嘴的出口速度;综合考虑Cattadori的壁面力和Howard的喉部压损理论对流动的影响来确定混合室阻力。为验证模型的正确性,设计以湿蒸汽为工作蒸汽的实验台,并采用多喷嘴喷射器作为实验元件。研究结果表明:容积喷射系数随压力比的增大而减小,

  11. Dynamics of two-phase interfaces and surface tensions: A density-functional theory perspective

    Science.gov (United States)

    Yatsyshin, Petr; Sibley, David N.; Duran-Olivencia, Miguel A.; Kalliadasis, Serafim

    2016-11-01

    Classical density functional theory (DFT) is a statistical mechanical framework for the description of fluids at the nanoscale, where the inhomogeneity of the fluid structure needs to be carefully accounted for. By expressing the grand free-energy of the fluid as a functional of the one-body density, DFT offers a theoretically consistent and computationally accessible way to obtain two-phase interfaces and respective interfacial tensions in a ternary solid-liquid-gas system. The dynamic version of DFT (DDFT) can be rigorously derived from the Smoluchowsky picture of the dynamics of colloidal particles in a solvent. It is generally agreed that DDFT can capture the diffusion-driven evolution of many soft-matter systems. In this context, we use DDFT to investigate the dynamic behaviour of two-phase interfaces in both equilibrium and dynamic wetting and discuss the possibility of defining a time-dependent surface tension, which still remains in debate. We acknowledge financial support from the European Research Council via Advanced Grant No. 247031 and from the Engineering and Physical Sciences Research Council of the UK via Grants No. EP/L027186 and EP/L020564.

  12. SDS/[C_nmim]Br/H_2O体系的双水相性质%Aqueous Two-Phase System(ATPS) Containing Ionic Liquids [C_nmim]Br and SDS

    Institute of Scientific and Technical Information of China (English)

    陈婷; 马爱青; 王菲; 尚亚卓; 刘洪来

    2012-01-01

    研究了咪唑类离子液体[Cnmim]Br与传统阴离子表面活性剂SDS混合水溶液的性质,结果显示混合水溶液性质随咪唑阳离子上烷烃链长的变化而呈现出明显的不同。当离子液体取代烷基链的碳数大于或等于6时,混合体系可以自发地分为共存的两相,即双水相。共存的两相界面清晰、性能稳定且能有效萃取染料二甲酚橙,有望成为新型高效的分离体系,在生物活性物质的纯化、分离中发挥作用。混合体系中离子液体和传统表面活性剂相对含量的改变引起混合溶液中表面活性剂聚集体尺寸和形态的变化,最终导致双水相上、下两相表观现象的差异。此外,离子液体、SDS头基间库仑力作用、烷烃链的疏溶剂力以及离子液体与SDS的协同效应,是形成溶致液晶的重要驱动力,导致较低浓度下十字花纹理层状液晶(LC)的生成。%Properties of mixed aqueous solutions of ionic liquid(Br) and traditional surfactant(SDS) were studied.Results showed that the properties of the mixed systems varied with the chain length of substituted alkyl in ionic liquids.Only those systems containing ionic liquids with equal to or more than 6 carbon atoms in alkyl chains can form aqueous two phase system(ATPS).The ATPS containing ionic liquids and surfactant has obvious extraction ability to xylenol orange and the potential to separate and purify biomaterials.The difference in appearance of ATPS should be attributed to the various size and shape of the surfactants aggregates formed in mixed solutions.Furthermore,the electrostatic attractive interaction,the hydrophobic interaction in addition to the synergistic effect between ionic liquids and SDS further promote the surfactant assembly,which leads to the formation of liquid crystal at lower surfactant concentration.

  13. 基于图像多特征融合和支持向量机的气液两相流流型识别%Identification Method of Gas-Liquid Two-phase Flow Regime Based on Image Multi-feature Fusion and Support Vector Machine

    Institute of Scientific and Technical Information of China (English)

    周云龙; 陈飞; 孙斌

    2008-01-01

    The knowledge of flow regime is very important for quantifying the pressure drop, the stability and safety of two-phase flow systems. Based on image multi-feature fusion and support vector machine, a new method to identify flow regime in two-phase flow was presented. Firstly, gas-liquid two-phase flow images including bubbly flow, plug flow, slug flow, stratified flow, wavy flow, annular flow and mist flow were captured by digital high speed video systems in the horizontal tube. The image moment invariants and gray level co-occurrence matrix texture features were extracted using image processing techniques. To improve the performance of a multiple classifier system, the rough sets theory was used for reducing the inessential factors. Furthermore, the support vector machine was trained by using these eigenvectors to reduce the dimension as flow regime samples, and the flow regime intelligent identification was realized. The test results showed that image features which were reduced with the rough sets theory could excellently reflect the difference between seven typical flow regimes, and successful training the support vector machine could quickly and accurately identify seven typical flow regimes of gas-liquid two-phase flow in the horizontal tube. Image multi-feature fusion method provided a new way to identify the gas-liquid two-phase flow, and achieved higher identification ability than that of single characteristic. The overall identification accuracy was 100%, and an estimate of the image processing time was 8 ms for online flow regime identification.

  14. (Liquid + liquid) equilibria of three ternary systems: (heptane + benzene + N-formylmorpholine), (heptane + toluene + N-formylmorpholine), (heptane + xylene + N-formylmorpholine) from T = (298.15 to 353.15) K

    Energy Technology Data Exchange (ETDEWEB)

    Chen Dongchu [College of Chemistry and Chemical Engineering, Central South University, Changsha 411083 (China)]. E-mail: dcchen@hnust.edu.cn; Ye Hongqi [College of Chemistry and Chemical Engineering, Central South University, Changsha 411083 (China); Wu Hao [College of Chemistry and Chemical Engineering, Central South University, Changsha 411083 (China)

    2007-08-15

    (Liquid + liquid) equilibrium (LLE) data for ternary systems: (heptane + benzene + N-formylmorpholine), (heptane + toluene + N-formylmorpholine), and (heptane + xylene + N-formylmorpholine) have been determined experimentally at temperatures ranging from 298.15 K to 353.15 K. Complete phase diagrams were obtained by determining solubility and tie-line data. Tie-line compositions were correlated by Othmer-Tobias and Bachman methods. The universal quasichemical activity coefficient (UNIQUAC) and the non-random two liquids equation (NRTL) were used to predict the phase equilibrium in the system using the interaction parameters determined from experimental data. It is found that UNIQUAC and NRTL used for LLE could provide a good correlation. Distribution coefficients, separation factors, and selectivity were evaluated for the immiscibility region.

  15. Two-Phase Quality/Flow Meter

    Science.gov (United States)

    Moerk, J. Steven (Inventor); Youngquist, Robert C. (Inventor); Werlink, Rudy J. (Inventor)

    1999-01-01

    A quality and/or flow meter employs a capacitance probe assembly for measuring the dielectric constant of flow stream, particularly a two-phase flow stream including liquid and gas components.ne dielectric constant of the flow stream varies depending upon the volume ratios of its liquid and gas components, and capacitance measurements can therefore be employed to calculate the quality of the flow, which is defined as the volume ratio of liquid in the flow to the total volume ratio of gas and liquid in the flow. By using two spaced capacitance sensors, and cross-correlating the time varying capacitance values of each, the velocity of the flow stream can also be determined. A microcontroller-based processing circuit is employed to measure the capacitance of the probe sensors.The circuit employs high speed timer and counter circuits to provide a high resolution measurement of the time interval required to charge each capacitor in the probe assembly. In this manner, a high resolution, noise resistant, digital representation of each of capacitance value is obtained without the need for a high resolution A/D converter, or a high frequency oscillator circuit. One embodiment of the probe assembly employs a capacitor with two ground plates which provide symmetry to insure that accurate measurements are made thereby.

  16. Analytical and experimental investigations for dimensioning of safety valves for single-phase and two-phase flow with a high-viscosity liquid phase; Analytische und experimentelle Untersuchungen zur Bemessung von Sicherheitsventilen bei Einphasen- und bei Zweiphasenstroemung mit hochviskoser Fluessigphase

    Energy Technology Data Exchange (ETDEWEB)

    Wieczorek, Martin

    2010-07-01

    The widening of the relief diameter of safety valves in a stream of high-viscosity liquids as a rule is calculated using correction factors that have never been validated so far. Also, there is no generally accepted design method for two-phase flows consisting of a high-viscosity liquid and a gas. Using analytical investigations and measurements of commercial full-lift safety valves, the dissertation shows that it is possible to make comparatively accurate predictions for high-viscosity liquids and for two-phase flows of a high-viscosity liquid and air by using a new integrated model while retaining the established procedure. At the same time, preventive overdimensioning of the relief cross section is recommended. (orig.)

  17. 气升式陶瓷膜过滤过程的气液两相流模拟%Simulation of gas-liquid two-phase flow for airlift ceramic membrane filtration process

    Institute of Scientific and Technical Information of China (English)

    林进; 沈浩; 景文珩

    2016-01-01

    采用VOF双流体模型对19通道气升式陶瓷膜过滤装置进行气液两相流的流体动力学模拟,研究了曝气孔直径和曝气量对气升式陶瓷膜过滤装置的气含率、环流液速、膜面剪切力及膜管内湍流强度的影响,模拟结果与实验结果的误差在5%~10%之间。结果表明,气升管与降液管的气含率都随曝气量增大而增大,随曝气孔直径减小而增大;环流液速、膜面剪切力及膜管内的湍流强度都随曝气量增大先增大,当曝气量达到400 L·h−1时其增大趋势变缓。通过实验和模拟比较了3种不同孔径的曝气头,环流液速与曝气孔的直径关系不大,仅与曝气量相关,但曝气孔直径越小,其膜面剪切力越大,越有利于过滤过程的进行。%The influences of aerator aperture size and aeration rate on the gas hold-up, liquid circulation velocity, wall shear stress and turbulence intensity in a novel airlift ceramic membrane filtration equipment containing a 19-channel ceramic membrane was investigated by the CFD simulation. Further, the VOF model was adopted to simulate the flow state of the gas-liquid two-phase fluid and the mean error between experiment date and simulation date was 5%—10%. The results demonstrated that the gas hold-up increased with increasing aeration rate and decreasing aerator aperture size. The liquid circulation velocity, wall shear stress and turbulence intensity increased with increasing aeration rate, and the increasing trend became slow after the aeration rate reached 400 L·h−1. For the three aperture aerator with different size, the comparison of experiment and simulation results have indicated that the liquid circulation velocity was only related to the aeration rate, and had little to do with aerator aperture size. Decreasing of the aerator aperture size was conductive to the increasing of the wall shear stress and the filtration process.

  18. 基于红外热像的气液两相分层流液膜厚度非介入测量%Gas-liquid two phase stratified flow liquid film height non-invasive measurement based on infrared imaging technique

    Institute of Scientific and Technical Information of China (English)

    龚金海; 梁法春; 刘德绪; 燕慧

    2012-01-01

    Traditional invasive liquid film measurement method such as conductance probe technique is not suitable for the gas-liquid two-phase flow system with high pressure, flammable,combustible and corrosity medium. A novel method was proposed based on infrared imaging for gas-liquid two phase stratified flow liquid film height measurement. In order to improve the measurement accuracy, a heating belt was applied to improve the temperature difference between the gas and liquid,the film height was obtained using infrared imaging to distinguish gas-liquid interface. A VOF multiphase flow model was used to simulate the temperature distribution of the pipe section under constant heat flux,based on this,the experiments were carried out at an air-water two-phase flow loop and the infrared image were obtained using an infrared camera. The gas-liquid interface position was determined according to the temperature gradient characteristics. The measurement results were compared with capacitance probe method. It showed during the experimental range,the maximum measurement error was 8. 2% .%对于输送高压、易燃易爆、强腐蚀性介质的气液两相流管道,电导探针等传统的介入式液膜厚度测量方法不适用.针对这种情况,提出了通过红外热像测量气液两相分层流液膜厚度的新方法:在管道外壁敷设加热带,通过施加恒定热流密度来增加气液相温差,通过采集红外图像识别气液界面获得液膜高度.在建立VOF多相流模型模拟恒定热流密度条件下管截面上温度分布特征基础上,实验在气液两相流环道上进行,采用热像仪采集管壁红外图像,真实液膜厚度由介入式电容探针测量,在试验范围内红外方法液膜厚度测量最大误差8.2%.

  19. What types of investors generate the two-phase phenomenon?

    Science.gov (United States)

    Ryu, Doojin

    2013-12-01

    We examine the two-phase phenomenon described by Plerou, Gopikrishnan, and Stanley (2003) [1] in the KOSPI 200 options market, one of the most liquid options markets in the world. By analysing a unique intraday dataset that contains information about investor type for each trade and quote, we find that the two-phase phenomenon is generated primarily by domestic individual investors, who are generally considered to be uninformed and noisy traders. In contrast, our empirical results indicate that trades by foreign institutions, who are generally considered informed and sophisticated investors, do not exhibit two-phase behaviour.

  20. Two-phase viscoelastic jetting

    Energy Technology Data Exchange (ETDEWEB)

    Yu, J-D; Sakai, S.; Sethian, J.A.

    2008-12-10

    A coupled finite difference algorithm on rectangular grids is developed for viscoelastic ink ejection simulations. The ink is modeled by the Oldroyd-B viscoelastic fluid model. The coupled algorithm seamlessly incorporates several things: (1) a coupled level set-projection method for incompressible immiscible two-phase fluid flows; (2) a higher-order Godunov type algorithm for the convection terms in the momentum and level set equations; (3) a simple first-order upwind algorithm for the convection term in the viscoelastic stress equations; (4) central difference approximations for viscosity, surface tension, and upper-convected derivative terms; and (5) an equivalent circuit model to calculate the inflow pressure (or flow rate) from dynamic voltage.

  1. Research of Kick and Distribution Features of Gas-Liquid Two Phase Flow During Drilling%钻井气液两相流体溢流与分布特征研究

    Institute of Scientific and Technical Information of China (English)

    任美鹏; 李相方; 徐大融; 尹邦堂

    2012-01-01

    常规钻井返出管线敞口,钻井液在返出管线中流动为非满管流动,小气侵量时,泥浆池液面变化不明显,检测装置无法测量液面变化,钻井液返出流量无法测量或者测量误差较大,无法感知小流量差的变化。本文基于气液两相流理论建立了井筒气液两相流参数与井口溢流速度的关系模型,计算表明气侵速度越大,气泡运移距井口越近,井口溢流速度越大。并以空气和钻井液(非牛顿流体)为介质,基于VOF多相流模型,模拟了钻井液返出流量变化时气液界面变化情况,分析了纯钻井液和不同含气率钻井液在返出管线流动时液面变化特征,得出纯钻井液流动时喇叭口处液面变化最明显,优化液面检测装置安装在喇叭上,更能准确及时地检测液面变化早期发现溢流,进气速度影响返出管线钻井液液面稳定性。%Because of the opening of mud return pipe, the pipe is not full of drilling mud. When gas kick is little, the change of pit gain was indistinct, so the detection device would not be available to reflect fluid level. According the undetectable or incorrect disadvantages and default of kick detection, this paper has established the relationship between wellhead kick velocity and gas-liquid two phase flow in wellhole based on the theory of two phase flow, and the result shows that the greater of the velocity of kick, the greater of wellhead kick velocity, and the wellhead kick velocity becomes also greater with the upper movement of bubble. Based on air and mud (non-Newtonian fluids) medium and VOF method, this paper has analyzed characters of mud level of return pipe with pure mud and different void fraction. According to the results, the mud level is most obvious in the bell nipple when the fluid is pure mud. When the device is installed on the bell mouth, pit level change monitoring would be more accurate and without delay to detect early kick

  2. 闭式循环振荡热管内气液两相流数值模拟%Numerical simulation of vapor-liquid two-phase flow in closed loop oscillating heat pipe

    Institute of Scientific and Technical Information of China (English)

    刘向东; 郝英立

    2009-01-01

    A comprehensive mathematical model including the effects of vapor-liquid interface and surface tension is proposed to describe the vapor-liquid two-phase flow, heat and mass transfer, and the phase change process in oscillating heat pipe (OHP) . The VOF (volume of fluid) method is used for the vapor-liquid distribution and interface motion and the CSF (continuum surface force) model is used for the effect of surface tension. The initial operation of a typical closed loop OHP was simulated based on the proposed model. The results indicate that the initial distribution of working fluid, the complex flow pattern such as bubbly flow, slug flow, semi-annular/annular flow, back-flow and the flow pattern transition can be predicted by the model. The phenomenon of annular flow and slug flow in alternating vertical tubes at initial circulation stage was also simulated successfully. The results coincide well with the experimental observations. The flow and heat transfer of working fluid in two transition sections at initial operation stage were analyzed. It is shown that the changes of temperature, pressure and flow pattern are obvious in the transition section between adiabatic section and condensing section, where the transition of heat transfer conditions takes place.%建立了考虑气液界面存在及其表面张力影响的较全面描述振荡热管内气液两相流动、传热传质和相变过程的气液两相流数理模型.模型中气液分布及界面运动采用VOF方法,表面张力影响采用CSF模型,对一典型闭式循环振荡热管起始工作阶段进行数值模拟.结果表明:所建立的模型成功模拟了振荡热管初始气液分布,启动阶段管内的泡状流、柱塞流、环状/半环状流和壁面回流等复杂气液流动流型和转变,以及起始循环阶段环状流和柱塞流在竖直管段内交替出现的现象.结果与相关定性实验观测非常一致,进而分析了启动阶段2个过渡管段内工质的流动及

  3. 机动车加油过程中气液两相流动特性的CFD数值模拟%CFD Numerical Simulation onto the Gas-Liquid Two-Phase Flow Behavior During Vehicle Refueling Process

    Institute of Scientific and Technical Information of China (English)

    陈家庆; 张男; 王金惠; 朱玲; 尚超

    2011-01-01

    With the gradual improvement of environmental regulations,more and more attentions are attracted to the vapor emissions during the process of vehicle refueling.Research onto the vehicle refueling process by means of numerical simulation has been executed abroad since 1990s,while as it has never been involved so far domestically.Through reasonable simplification about the physical system of "Nozzle + filler pipe+ gasoline storage tank + vent pipe" for vehicle refueling,and by means of volume of fluid(VOF) model for gas-liquid two-phase flow and Re-Normalization Group k-ε turbulence flow model provided in commercial computational fluid dynamics(CFD) software Fluent,this paper determined the proper mesh discretization scheme and applied the proper boundary conditions based on the Gambit software,then established the reasonable numerical simulation model for the gas-liquid two-phase flow during the refueling process.Through discussing the influence of refueling velocity on the static pressure of vent space in gasoline tank,the back-flowing phenomenon has been revealed in this paper.It has been demonstrated that,the more the flow rate and the refueling velocity of refueling nozzle is,the higher the gross static pressure in the vent space of gasoline tank.In the meanwhile,the variation of static pressure in the vent space of gasoline tank can be categorized into three obvious stages.When the refueling flow rate becomes higher,the back-flowing phenomenon of liquid gasoline can sometimes be induced in the head section of filler pipe,thus making the gasoline nozzle pre-shut-off.Totally speaking,the theoretical work accomplished in this paper laid some solid foundation for self-researching and self-developing the technology and apparatus for the vehicle refueling and refueling emissions control domestically.%随着环保法规的不断完善,机动车加油过程中所产生的油气排放污染问题越来越受到重视.国外自20世纪90年代中后

  4. CALCULATION ON TWO-PHASE FLOW TRANSIENTS AND THEIR EXPERIMENTAL RESEARCH

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    From basic equations of gas-liquid, solid-liquid, solid-gas two-phase flow, the calculating method on flowtransients of two-phase flow is developed by means of characteristic method. As one example, a gas-liquid flow transientis calculated and it agrees well with the experimental result. It is shown that the method is satisfactory for engineeringdemand.

  5. 方柱体与圆柱体气液两相涡街特性的研究%Study of Gas-liquid Two-phase Vortex Street Characteristics of a Square Cylinder and a Circular One

    Institute of Scientific and Technical Information of China (English)

    周云龙; 刁成东; 曹茹

    2009-01-01

    When a gas-liquid two-phase fluid in a vertically ascending tube with a rectangular section transversely scours a horizontally arranged cylinder,under certain conditions,an alternating vortex shedding phenomenon will occur at the back of the cylinder.By adopting a tube-wall pressure-difference method to study the vortex shedding characteristics of the above flow transversely sweeping across a circular cylinder and a square one,the authors have identified the vortex street shedding frequency and the variation of Strouhal number.During the test,the Reynolds number ranges from 0.9×10~4 to 2.3×10~4 and the sectional gas content has a variation range of 0 to 0.2.The test results indicate that in a certain range of gas content,the vortex-street shedding frequency and Strouhal numbers of the two types of cylinders will increase with an increase of the sectional gas content.The increment gradient of the square cylinder Strouhal number is independent of the Reynolds number while that of the circular one is susceptible to the influence of the Reynolds number.%气液两相流体在垂直上升矩形截面管道内横向冲刷水平布置的柱体时,一定条件下会在柱体后面产生旋涡交替脱落现象.利用管壁压差法来研究气液两相流横掠圆柱体和方柱体时的旋涡脱落特性,得到了涡街的脱落频率和斯特罗哈数的变化情况.实验中雷诺数的范围为0.9×10~4~2.3×10~4,截面含气率的范围为0~0.2.实验结果表明:在一定的含气率范围内,两种柱体涡街的脱落频率与斯特罗哈数都随着截面含气率的增大而增大;方柱体斯特罗哈数增大的梯度与雷诺数无关,圆柱体斯特罗哈数增大的梯度受雷诺数的影响.

  6. For solid-liquid two phase softness abrasive flow embedded real-time monitoring and control system%面向固-液两相软性磨粒流嵌入式实时测控系统

    Institute of Scientific and Technical Information of China (English)

    计时鸣; 兰信鸿

    2012-01-01

    In order to solve the problems of flow pipe is to small to the conventional sensor for solid-liquid two phase softness abrasive flow,a monitoring method based on the vibration signal was proposed. Through the wavelet packet analysis of vibration signal, extraction signal characteristics were gotten. Using object-oriented technology, a kind of measurement and control software framework was developed, combined with finite state machine theory and embedded real-time operating system and programming methods of multitasking. Using Linux and DSP/BIOS RTOS, the double operating system signal processing technology was implemented,a multi-channel high speed data acquisition function was implemented on the intelligence embedded real-time measurement and control platform. The results indicate that it is easy to expand and interactive.%针对固-液两相软性磨粒流精密抛光方法中流道微小,无法采用常规直接信号传感器的问题,提出了一种基于二次信号-加速度振动信号的软性磨粒流监测方法.通过小波包分析提取了振动信号的特征.结合基于有限状态机理论与基于嵌入式实时操作系统的并发多任务的程序设计方法,采用面向对象技术开发了一种测控软件框架.采用Linux和DSP/BIOS RTOS实施了双操作系统信号处理技术,开发实现了一个面向软性磨粒流的,具有通用多通道高速数据采集功能的智能化嵌入式实时测控平台.研究结果表明,该系统具有易扩展与易交互的优点.

  7. Stochastic subspsace parameter identification and stability diagram of gas-liquid two-phase flow patterns%基于随机子空间结合稳定图的气液两相流型分析

    Institute of Scientific and Technical Information of China (English)

    李洪伟; 周云龙; 刘旭; 孙斌

    2012-01-01

    The characteristics of stability diagram of several typical flow patterns are studied,and the signals of flow patterns under 47 kinds of flowing conditions are identified with stochastic subspace parameter identification.The results show that the characteristic of a stability diagram can reflect the internal characteristics of complex time series,the characteristics of time series can be quantified by extracted straightness characteristics and the differences of characteristics of stability diagrams of three typical flow patterns.The characteristics of stability diagrams of bubble flow are the most confused and followed by Mist flows'.Slug flows' are the most regular.The extraction and recognition for characteristics of gray fluctuation sequence of gas-liquid two-phase images and the accurate classification for flow pattern samples provide a new path for the classification of multi-phase flow patterns.At the same time,the stability diagram analysis method provides a useful exploration for the further revelation of flowing mechanism of multi-phase flows.%研究了儿种典型气液两相干流流型的稳定图特征,并应用随机子空间方法对47种流动条件下的流型信号进行了识别.研究结果表明:稳定图特征能够反映出复杂时间序列的内部特征,利用其提取的直线度特征值可以对时间序列的特征进行量化分析,三种典型流型的稳定图特征差异较明显,泡状流的稳定图特征最为混乱.雾状流次之.段塞流量为规整.应用随机子空间方法对气液两相流图像灰度波动序列进行特征向量提取和辨识,通过幅值以及相角的分布特征能够对不同工况下的流型样本进行准确分类,为多相流的分类提供了一条新路径.同时基于稳定图的分析方法为进一步揭示多相流的流动机理提供有益的探索.

  8. Influence of gas-liquid two-phase flow on the anti-fouling performance of tubular membranes module for microfiltration%气液两相流下膜的抗污染性能研究

    Institute of Scientific and Technical Information of China (English)

    钱光磊; 周集体; 张劲松; 刘万涛

    2012-01-01

    Concentration polarization and cake layer formation on the surface of the membrane are two significant aspects resulting in membrane fouling. Aeration in tubular membrane module can form gas liquid two-phase flow, which can increase the shear force on the surface of tubular membrane and control the membrane fouling effectively. In this study, experiments were conducted under different gas flow rates in tubular membrane module. As it was shown, bubble rate and bubble frequency increased obviously as aeration increased yet membrane fouling rate decreased gradually so as to extend the membrane filtration operation time. It was found that the injected gas can increase turbulence on the surface of membrane to slow down transmembrane pressure rate and keep membrane fouling with a low flow rate, thus it can save the energy consumption and prolonging membrane service life.%膜表面浓差极化与滤饼层形成是膜污染的重要因素.通过管式膜曝气,使膜表面形成气液两相流,增大膜表面剪切力,能有效控制膜污染行为.实验通过微滤高岭土悬浊液,观察了不同曝气量下膜组件内气液流态,发现随着曝气量的增加,膜组件内气泡单元上升速率和频率加快,膜污染速率逐渐减小,延长了膜过滤运行时间.研究发现,气体的通入使膜表面湍流程度增大,有效减缓跨膜压力增长速率,并且实现了在较低流速下控制膜污染,节省了能耗成本,延长了膜使用寿命.

  9. 气液两相流波动信号多重分形去趋势波动分析%Multi-Fractal Detrended Fluctuation Analysis of Fluctuation Signal ofGas-Liquid Two-Phase Flow

    Institute of Scientific and Technical Information of China (English)

    孙斌; 许明飞; 周云龙

    2011-01-01

    为了研究不同流型压差波动信号的分形特征,本文首先讨论了多重分形去趋势波动分析对周期信号、随机信号和混沌信号的识别能力,然后运用多重分形去趋势波动分析方法对水平管内气-液两相流压差波动信号进行分析.通过计算广义Hurst指数、尺度函数,多重分形谱,细致量化了压差波动信号的局部及不同层次的波动奇异性.研究结果表明:压差波动信号具有长程相关性,而且足多重分形过程,多重分形谱参数可以反映不同流型的动力性特征.压差波动信号的多重分形分析有助于进一步理解流型转化的动力学特性.%In order to study the fractal feature of differential pressure fluctuation signal of the different flow regime, this paper discusses the recognition ability of periodic signals, random signals and chaotic signals first, and then analyzes the differential pressure fluctuation signal of the horizontal tube of gas-liquid two-phase flow based on the multi-fractal detrended fluctuation analysis method. Detailed quantification the volatility singularity of partial and different levels of thedifferential pressure fluctuation signal by calculating the generalized Hurst index, scaling function and multi-fractal spectrum. The results show that: the differential pressure fluctuation signal have long-range correlation, and is multi-fractal process. Multi-fractal spectrum parameters can reflect the dynamic characteristic of the different flow regime. Multi-fractal of differential pressure fiuctuation signal analysis can help to understand the dynamic characteristic of flow regime transition further.

  10. Liquid-Liquid Equilibria of the Water-Ethanol-Dimethyl Succinate Ternary System%水,乙醇和丁二酸二甲酯三元体系的液体平衡

    Institute of Scientific and Technical Information of China (English)

    ErolInce; IsmailKirbaslar

    2002-01-01

    Liquid-liquid equilibrium (LLE) data for the ternary system water-ethanol-dimethyl succinate havebeen determined experimentally at temperatures ranging from 298.15 to 318.15 K at 5 K intervals. Complete phasediagrams were obtained by determining solubility and the tie-line data. Tie-line compositions were correlated byOthmer-Tobias method. The universal quasichemical functional group activity coefficient (UNIFAC) and modifiedUNIFAC methods were used to predict the phase equilibrium in the system using the interaction parameters determined from experimental data between groups CH3, CH2, OH, CH3COO and H2O. It is found that UNIFAC andmodified UNIFAC group interaction parameters used for LLE could not provide a good prediction. Distributioncoefficients and separation factors were evaluated for the immiscibility region.

  11. Study of two-phase flows in reduced gravity

    Science.gov (United States)

    Roy, Tirthankar

    Study of gas-liquid two-phase flows under reduced gravity conditions is extremely important. One of the major applications of gas-liquid two-phase flows under reduced gravity conditions is in the design of active thermal control systems for future space applications. Previous space crafts were characterized by low heat generation within the spacecraft which needed to be redistributed within the craft or rejected to space. This task could easily have been accomplished by pumped single-phase loops or passive systems such as heat pipes and so on. However with increase in heat generation within the space craft as predicted for future missions, pumped boiling two-phase flows are being considered. This is because of higher heat transfer co-efficients associated with boiling heat transfer among other advantages. Two-phase flows under reduced gravity conditions also find important applications in space propulsion as in space nuclear power reactors as well as in many other life support systems of space crafts. Two-fluid model along with Interfacial Area Transport Equation (IATE) is a useful tool available to predict the behavior of gas-liquid two-phase flows under reduced gravity conditions. It should be noted that considerable differences exist between two-phase flows under reduced and normal gravity conditions especially for low inertia flows. This is because due to suppression of the gravity field the gas-liquid two-phase flows take a considerable time to develop under reduced gravity conditions as compared to normal gravity conditions. Hence other common methods of analysis applicable for fully developed gas-liquid two-phase flows under normal gravity conditions, like flow regimes and flow regime transition criteria, will not be applicable to gas-liquid two-phase flows under reduced gravity conditions. However the two-fluid model and the IATE need to be evaluated first against detailed experimental data obtained under reduced gravity conditions. Although lot of studies

  12. Collins Model and Phase Diagram of 2D Ternary System

    Institute of Scientific and Technical Information of China (English)

    XIE Chuan-Mei; CHEN Li-Rong

    2004-01-01

    The Collins model is introduced into the two-dimensional (2D) alternative ternary system having the Lennard-Jones (L-J) potential. The Gibbs free energy of this ternary system is calculated, and according to thermodynamic theory, a group of equations that determine the solid-liquid diagram of ternary system are derived, some isothermal sectional diagrams of the 2D ternary system are obtained. The results are quite similar to the behavior of three-dimensional substances.

  13. Multi-dimensional modeling of gas-liquid two-phase flows. Application to the simulation of ascending bubble flows in vertical ducts; Modelisation multidimensionnelle des ecoulements diphasiques gaz-liquide. Application a la simulation des ecoulements a bulles ascendants en conduite verticale

    Energy Technology Data Exchange (ETDEWEB)

    Morel, Ch

    1997-10-31

    The aim of this thesis is the 3-D modeling and numerical simulation of liquid/gas (water/vapor or water/air) two-phase flows in cooling circuits of nuclear power plants during normal and accidental situations. The development of a multidimensional dual-fluid model encounters two problems: the statistical effects of turbulence and the interface mass, momentum and energy transfers. The models developed in this study were introduced in the 3-D module of the CATHARE code developed by the CEA and the results were compared to experimental results available in the literature. The first chapter describes the equations of the local dual-fluid model for the 3-D description of two-phase flows. Closing relations adapted to dispersed flows with isothermal bubbles and without phase transformation are proposed and focus on the momentum transfer at the interfaces. The theoretical study of turbulence in the liquid phase of a bubble flow is modelled in chapter 2. Chapter 3 deals with the voluminal interface area used in the interface mass, momentum and energy transfers, and chapters 4 and 5 concern the application of the developed models to concrete situations. Chapter 4 describes in details the 3-D module of the CATHARE code while chapter 5 gives a comparison of numerical results obtained using the CATHARE code with other experimental results obtained at EdF. (J.S.) 109 refs.

  14. Z形狭缝内两种工质沸腾汽液两相特性分析%Study on Gas-liquid Two-phase Flow Characteristics of Two Kinds of Media in Z-shaped Channels

    Institute of Scientific and Technical Information of China (English)

    郭雷; 张树生; 程林

    2011-01-01

    为深入探索狭缝通道内沸腾换热机制,对2种不同液体在Z形狭缝通道内的沸腾汽液两相流动展开研究.利用数值模拟和自编程的方法分析汽泡生成、长大和脱离的过程,通过几何重构和界面追踪获取相界面移动和变化对系统内压降以及平均表面换热系数的影响,计算中考虑了重力、表面张力和黏性的作用.发现液体黏性的不同对汽泡生长方式和汽泡形态产生很大影响,黏性较小的液体产生汽泡的脱离直径较小,汽泡脱离频率高:表面张力和液体黏性对流动沸腾系统压降都具有较大影响;液体比热和沸点的不同导致换热系数有较大差别;结果与实验数据吻合良好,均表明水沸腾换热系数高于乙醇,Z形通道强化换热效果明显.%To explore the boiling heat transfer mechanism in narrow channels, gas-liquid two-phase flow in z-shaped narrow channels was studied with two different types of media. The bubble generation, growth and departure processes were analyzed using numerical simulation and self-programming. The influence of interface movements and changes on internal pressure difference and average surface heat transfer coefficient was investigated by using geometry reconstruction and interface tracking, taking into account gravity, surface tension and viscosity during calculation. The results show that the viscosity has great influence on generation modes and shapes of bubbles, that is, the lower the viscosity is, the smaller the diameter is when the bubble departs with a higher frequency. In addition, surface tension and viscosity significantly impact the pressure drop of boiling system, and different specific heat and boiling point values result in different heat transfer coefficients. The simulation results in this paper match well with the experimental data revealed in other sources, both show that the heat transfer coefficient of water is higher than that of ethanol and z-shaped channels have

  15. Numerical Simulation of Gas-Liquid Two-Phase Flow in Zinc Electrowinning%锌电解槽内气液两相流动的数值模拟

    Institute of Scientific and Technical Information of China (English)

    周萍; 李昊岚; 魏文武; 苏寅彪

    2015-01-01

    The gas-liquid two-phase flows in zinc electrolytic cells with single plate and multiple plates were respectively numerically simulated with the commercial software of FLUENT.Based on the mechanism of the generation and movement of oxygen bubbles,the rising velocity of a single bubble was calculated.The results indicate that the rising velocity is 0.017 m/s.With the effect of bubbles from the anode,the electrolyte near the anode flows upward and oppositely flows downward near the cathodes,forming a large recirculation zone in the cell.The average velocity of bubble cluster is 0.021 m/s,which is consistent with the experimental data from the literature. In practical operation,with the joint action of the differential pressure and the bubble drag force, the recirculation of electrolyte flow can be enhanced remarkably. The average velocity of interelectrode fluid is 1.5 times higher than that under the bubble-free condition. This phenomenon indicates that the bubble movement can promote the refreshing of zinc electrolyte and restrain the dilution of zinc ions.%应用FLUENT软件,分别对单组阴阳极、多组阴阳极锌电解槽中的电解液流动进行了数值模拟研究.针对单组阴阳极间的电解液,基于气泡产生及运动的机理计算出单个气泡在静止电解液中的上浮速度为0.017 m/s.气液两相流数值模拟结果表明:在气泡的作用下,电解液沿阳极板向上运动,沿阴极板向下运动,形成一个大的循环;而气泡群上浮的平均速度约为0.021 m/s,与文献实验数据相吻合.针对实际生产中多组阴阳极锌电解槽,气液两相流数值模拟结果表明:在气泡上浮曳力和电解液进出口压差驱动的共同作用下,电解液的运动态势与单组阴阳极仅考虑气泡曳力作用时的状况相同,极间电解液平均流速是无气泡作用时的1.5倍左右,这将有利于加快极板附近电解液的更新,延缓锌离子的贫化.

  16. Determination of stability constant of ternary surface complexes at liquid-solid interface in sea water by the rule of left-right shifts of S-shaped curve

    Institute of Scientific and Technical Information of China (English)

    张正斌; 刘莲生; 刘国盛; 俞志明

    1996-01-01

    A new method is suggested for determining the stability constant of ternary surface complexes (TSC) at liquid-solid interfaces in natural water. Its basic principle is based on the rule of left-right shift (RLRS) of S-shaped curve, from which the peak-type curve of E(%) with the concentration of organic matter is obtained. The peak-type curve is further used to obtain the (ksAM/kSM) values by using respectively the method of equality of E(%) when [H2A] = [H2A]0 (1) and the method of [H2A]max (2). From the known KSM,the stability constant KSAM of liquid-solid interfacial ternary surface complexes can be obtained.

  17. 喷雾接种生物颗粒两相流及其对菌种活性的影响%Solid-liquid two-phase flow of microbial particle spraying inoculation and its influence on microbial viability

    Institute of Scientific and Technical Information of China (English)

    李建华; 郑加强; 余果

    2014-01-01

    hermetic bioreactor. After sterilization, the nozzle of the inoculation spraying system can spray the microbial strain on the solid substrate, to realize sterilizing, cooling, inoculation, and fermentation inside one solid-state fermentation bioreactor. The microbial viability may be determined by the spraying system of the spraying inoculation of pure-culturing solid-state fermentation that could directly result in the death of the microorganisms. The solid-liquid two-phase flow of the microbial particle spray inoculation fluid system was analyzed. Fluid characteristics of the two-phase flow composed of microorganisms and sterile water was discussed, and the forced state of the microorganism particles was also analyzed. The energy component was deduced, and the theoretical basis, reliability, and practicability of the energy dissipation rate which could quantify the microbial particles’ damage within comprehensive hydrodynamic stresses were also discussed and analyzed. The effect of nozzle type and spraying parameters on the results of the spraying inoculation was studied by a simulation using FLUENT. A user-defined function was created in FLUENT to compute the energy dissipation rate from the flow field information. By setting reasonable boundary conditions and initial conditions, simulations of a hollow cone nozzle’s flow field of the pressure and energy dissipation rate were conducted for each size of the nozzle and the experimental inlet pressure. A set of spraying inoculation experimental flow devices was designed and manufactured. At the same time, an appropriate test method was determined. Microzyme was selected as the microbial particle in the spraying inoculation experimental system because it was easy to separate the living microzyme from the dead microzyme. It could be dyed with Loeffler basic methylene blue dye and the living microzyme with a strong reducing ability is colorless and the dead or weak dying microzyme is blue under microscope. Experimental

  18. Cathodic Deposition of Components in BiSbTe Ternary Compounds as Thermoelectric Films Using Choline-Chloride-Based Ionic Liquids

    Science.gov (United States)

    Golgovici, Florentina; Cojocaru, Anca; Nedelcu, Marin; Visan, Teodor

    2010-09-01

    This paper reports electrodeposition of BiTe, SbTe, and BiSbTe films using ionic liquids based on choline chloride (ChCl) and malonic acid mixtures (1:1 moles) at 80°C to 85°C. The electrolyte contained bismuth and/or antinomy species and tellurium species with 1.5 mM to 50 mM concentrations; Pt sheet, Pt mesh, and Pt wire were used for working, auxiliary, and quasireference electrodes, respectively. Cyclic voltammograms revealed the beginning and cathodic peak of pure Te deposition; at more negative potentials simultaneous codeposition of binary or ternary compounds as limiting currents or a series of peaks were observed. Correspondingly, two or three dissolution (stripping) anodic peaks were observed. Nyquist and Bode impedance spectra show differences in Pt behavior due to its polarization at various cathodic potentials. Equivalent-circuit components providing the best fit to the data were calculated. Deposition of BiSbTe films on copper plates was also performed by electrolysis at controlled potentials or current pulses. Some measurements of Seebeck coefficients of the obtained films were carried out.

  19. Dynamic Modeling of Phase Crossings in Two-Phase Flow

    DEFF Research Database (Denmark)

    Madsen, Søren; Veje, Christian; Willatzen, Morten

    2012-01-01

    of the variables and are usually very slow to evaluate. To overcome these challenges, we use an interpolation scheme with local refinement. The simulations show that the method handles crossing of the saturation lines for both liquid to two-phase and two-phase to gas regions. Furthermore, a novel result obtained...... in this work, the method is stable towards dynamic transitions of the inlet/outlet boundaries across the saturation lines. Results for these cases are presented along with a numerical demonstration of conservation of mass under dynamically varying boundary conditions. Finally we present results...

  20. Mathematical modeling of disperse two-phase flows

    CERN Document Server

    Morel, Christophe

    2015-01-01

    This book develops the theoretical foundations of disperse two-phase flows, which are characterized by the existence of bubbles, droplets or solid particles finely dispersed in a carrier fluid, which can be a liquid or a gas. Chapters clarify many difficult subjects, including modeling of the interfacial area concentration. Basic knowledge of the subjects treated in this book is essential to practitioners of Computational Fluid Dynamics for two-phase flows in a variety of industrial and environmental settings. The author provides a complete derivation of the basic equations, followed by more advanced subjects like turbulence equations for the two phases (continuous and disperse) and multi-size particulate flow modeling. As well as theoretical material, readers will discover chapters concerned with closure relations and numerical issues. Many physical models are presented, covering key subjects including heat and mass transfers between phases, interfacial forces and fluid particles coalescence and breakup, a...

  1. Design and Experimental Analyses of Small-flow High-head centrifugal-vortex Pump for Gas-Liquid Two-phase Mixture%小流量高扬程离心漩涡泵气液混输的设计和试验研究

    Institute of Scientific and Technical Information of China (English)

    朱祖超; 谢鹏; 偶国富; 崔宝玲; 李昳

    2008-01-01

    The design method of small-flow high-head centrifugal-vortex pump was presented.This pump,configured with 1nducer,complex-centrifulgal impeller and open-vortex impeller,was put torward to deliver gas-liquid two-phase mixture.An HTB-5/60 type sample pump was developed and tested on a closed-loop test rig.Experimental studies on perfbrmance and cavitation tests tor gas-hquid two-phase mixture were camed out compared With pure-water experimental results.Also the effect of gas phase on pump was analyzed and discussed.The experimental results show that performance and cavitation characteristics of the sample pump deteriorates progressively with increasing volume fraction of gas.When the total capacity QmiS between 4.5 m3·h-1and 6 m3·h-1 and the gas flow rate qg below 0.66 m3·h-1,or qg/Qm is lower than 15%,the characteristic curves are approximately parallel to those in pure water test,but the perforh~deteriorates sharply until an abrupt flow-cutting at a critical volume fraction of gas.This pump is found suitable for transporting gas-liquid two-phase mixture when working around rated capacity of 5 m3·h-1 with qg/Qm below 15%.

  2. Interaction of ionic liquid with water with variation of water content in 1-butyl-3-methyl-imidazolium hexafluorophosphate ([bmim][PF6])/TX-100/water ternary microemulsions monitored by solvent and rotational relaxation of coumarin 153 and coumarin 490.

    Science.gov (United States)

    Seth, Debabrata; Chakraborty, Anjan; Setua, Palash; Sarkar, Nilmoni

    2007-06-14

    The interaction of water with room temperature ionic liquid (RTIL) [bmim][PF6] has been studied in [bmim][PF6]/TX-100/water ternary microemulsions by solvent and rotational relaxation of coumarin 153 (C-153) and coumarin 490 (C-490). The rotational relaxation and average solvation time of C-153 and C-490 gradually decrease with increase in water content of the microemulsions. The gradual increase in the size of the microemulsion with increase in w0 (w0=[water]/[surfactant]) is evident from dynamic light scattering measurements. Consequently the mobility of the water molecules also increases. In comparison to pure water the retardation of solvation time in the RTIL containing ternary microemulsions is very less. The authors have also reported the solvation time of C-490 in neat [bmim][PF6]. The solvation time of C-490 in neat [bmim][PF6] is bimodal with time constants of 400 ps and 1.10 ns.

  3. 加压下规整填料塔内气液两相轴向返混实验研究%Gas-Liquid Two-Phase Axial Backmixing Through Structured Packing at Elevated Pressure

    Institute of Scientific and Technical Information of China (English)

    张鹏; 刘春江; 唐忠利; 袁希钢; 余国琮

    2003-01-01

    An experimental study of the extent of axial backmixing in both gas and liquid phases was conducted in a 150 mm ID column packed with Mellapak 250Y corrugated structured packing. The column was operated at pressures ranging from 0.3 MPa to 2.0 MPa with nitrogen and water flowing countercurrently through the packing.The amount of axial backmixing was experimentally evaluated by the pulse response techniques using hydrogen in gas phase and an aqueous solution of NaCl in liquid phase as inert tracers. The response of the tracer was monitored by means of thermal conductivity in the gas phase and electrical conductance in the liquid phase. The experimentally determined residence time distribution (RTD) curves were interpreted in terms of the diffusion-type model. The results indicated that the axial backmixing in the gas increased notably with gas flowrate and slightly with operating pressure and liquid flowrate. The liquid-phase axial backmixing was an increasing function of both gas and liquid flowrates and insensitive to pressure. Various correlations were developed for reproducing the experimental mixing data. The agreement between experimental and correlated data appeared to be acceptable and within +20% of difference.

  4. Vapor-liquid two phase flow simulation in porous media with Lattice-Boltzmann method%孔隙介质中汽液两相流数值模拟的Lattice-Boltzmann方法

    Institute of Scientific and Technical Information of China (English)

    张新明; 刘家琦; 刘克安

    2011-01-01

    A single component, two-phase flow simulator is developed to investigate the behavior of isothermal twophase fluid flow in porous media. The simulator is based on the Lattice-Boltzmann method and the Shan-Chen multiphase model of non-ideal fluids that allow coexistence of two phases of a single substance. Some different idealized situations (phase separation, surface tension, contact angle, pipe flow, and fluid droplet motion, et al) )in which the results are already known from theory or laboratory measurements are reproduced, and the validity of the implementation for the physical two-phase flow in porous media is shown. Application of the method to fluid intrusion in porous media is discussed and shows the effect of wettability on the fluid flow. The capability of reproducing critical flooding phenomena ( formation of advancing wetting film, snap off in throats and vapor condensation in pore) under strong wettability conditions is also proved.%基于格子波尔兹曼方法(Lattice-Boltzmann Method,LBM)和Shan-Chen单组分多相流模型,用单组分两相流LBM方法对孔隙介质中等温汽液两相流流动特性进行了研究.通过理想状态下流体特性(相分离、表面张力计算、流固接触角、管道两相流以及变形液滴运动)的研究验证了LBM应用于孔隙介质两相流的可行性,并进一步研究了孔隙介质中润湿相入侵非润湿相的流动特性和固体润湿性对于流体流动的影响,再现了孔隙介质中流体流动的狭长薄膜形成、狭窄孔道流体卡断和非润湿性相聚集等现象.

  5. Solvent relaxation of a room-temperature ionic liquid [bmim][PF6] confined in a ternary microemulsion

    Indian Academy of Sciences (India)

    Debabrata Seth; Palash Setua; Anjan Chakraborty; Nilmoni Sarkar

    2007-03-01

    In this paper we have reported the solvent and rotational relaxation of 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim][PF6]) confined in tween 20/([bmim][PF6]/water microemulsion using coumarin 153 (C-153) as probe. The most interesting feature of our experiment was that we observed an increase in solvent relaxation time with increase in ( = tween 20-to-[bmim][PF6] molar ratio). This is due to the fact that with increase in [bmim][PF6] content of the microemulsions, the microviscosity of the pool of the microemulsions increases, and motion of ions of [bmim][PF6] is hindered in the pool of microemulsions. Since motion of ions is responsible for solvation in room-temperature ionic liquids (RTILs), solvent-relaxation time increases with increase in .

  6. LIQUID-LIQUID EQUILIBRIUM FOR TERNARY SYSTEMS CONTAINING ETHYLIC BIODIESEL + ANHYDROUS ETHANOL + REFINED VEGETABLE OIL (SUNFLOWER OIL, CANOLA OIL AND PALM OIL: EXPERIMENTAL DATA AND THERMODYNAMIC MODELING

    Directory of Open Access Journals (Sweden)

    T. P. V. B. Dias

    2015-09-01

    Full Text Available AbstractPhase equilibria of the reaction components are essential data for the design and process operations of biodiesel production. Despite their importance for the production of ethylic biodiesel, the reaction mixture, reactant (oil and ethanol and the product (fatty acid ethyl esters up to now have received less attention than the corresponding systems formed during the separation and purification phases of biodiesel production using ethanol. In this work, new experimental measurements were performed for the liquid-liquid equilibrium (LLE of the system containing vegetable oil (sunflower oil and canola oil + ethylic biodiesel of refined vegetable oil + anhydrous ethanol at 303.15 and at 323.15 K and the system containing refined palm oil + ethylic biodiesel of refined palm oil + ethanol at 318.15 K. The experimental data were successfully correlated by the nonrandom two-liquid (NRTL model; the average deviations between calculated and experimental data were smaller than 1.00%.

  7. Thermodynamics of the ternary systems: (water + glycine, L-alanine and L-serine + di-ammonium hydrogen citrate) from volumetric, compressibility, and (vapour + liquid) equilibria measurements

    Energy Technology Data Exchange (ETDEWEB)

    Sadeghi, Rahmat, E-mail: rahsadeghi@yahoo.co [Department of Chemistry, University of Kurdistan, Sanandaj (Iran, Islamic Republic of); Gholamireza, Afsaneh [Department of Chemistry, University of Kurdistan, Sanandaj (Iran, Islamic Republic of)

    2011-02-15

    The apparent molar volumes and isentropic compressibility of glycine, L-alanine and L-serine in water and in aqueous solutions of (0.500 and 1.00) mol . kg{sup -1} di-ammonium hydrogen citrate {l_brace}(NH{sub 4}){sub 2}HCit{r_brace} and those of (NH{sub 4}){sub 2}HCit in water have been obtained over the (288.15 to 313.15) K temperature range at 5 K intervals at atmospheric pressure from measurements of density and ultrasonic velocity. The apparent molar volume and isentropic compressibility values at infinite dilution of the investigated amino acids have been obtained and their variations with temperature and their transfer properties from water to aqueous solutions of (NH{sub 4}){sub 2}HCit have also been obtained. The results have been interpreted in terms of the hydration of the amino acids. In the second part of this work, water activity measurements by the isopiestic method have been carried out on the aqueous solutions of {l_brace}glycine + (NH{sub 4}){sub 2}HCit{r_brace}, {l_brace}alanine + (NH{sub 4}){sub 2}HCit{r_brace}, and {l_brace}serine + (NH{sub 4}){sub 2}HCit{r_brace} at T = 298.15 K at atmospheric pressure. From these measurements, values of vapour pressure, osmotic coefficient, activity coefficient and Gibbs free energy were obtained. The effect of the type of amino acids on the (vapour + liquid) equilibrium of the systems investigated has been studied. The experimental water activities have been correlated successfully with the segment-based local composition Wilson model. Furthermore, the thermodynamic behaviour of the ternary solutions investigated has been studied by using the semi-ideal hydration model and the linear concentration relations have been tested by comparing with the isopiestic measurements for the studied systems at T = 298.15 K.

  8. 水-丁酸-壬醇三相系统的液液平衡%Liquid-Liquid Equilibria of Water + Butyric Acid + Nonanol Ternary System

    Institute of Scientific and Technical Information of China (English)

    S.üsmail K1rbaslar; Sema Yüksel; Erol ínce; ísmail Boz

    2004-01-01

    Liquid-liquid equilibrium (LLE) data for the water + butyric acid + nonanol system have been determined experimentally at the temperatures of 298.15 K, 308.15 K and 318.15 K. Tie-line compositions were correlated by Othmer-Tobias method. The universal quasichemical functional group activity coefficient (UNIFAC) and modified UNIFAC methods were used to predict the phase equilibrium in the system using the interaction parameters between CH3, CH2, COOH, OH and H2O functional groups. Distribution coefficients and separation factors were evaluated for the immiscibility region.

  9. Two-phase Flow Distribution in Heat Exchanger Manifolds

    OpenAIRE

    Vist, Sivert

    2004-01-01

    The current study has investigated two-phase refrigerant flow distribution in heat exchange manifolds. Experimental data have been acquired in a heat exchanger test rig specially made for measurement of mass flow rate and gas and liquid distribution in the manifolds of compact heat exchangers. Twelve different manifold designs were used in the experiments, and CO2 and HFC-134a were used as refrigerants.

  10. Recent advances in two-phase flow numerics

    Energy Technology Data Exchange (ETDEWEB)

    Mahaffy, J.H.; Macian, R. [Pennsylvania State Univ., University Park, PA (United States)

    1997-07-01

    The authors review three topics in the broad field of numerical methods that may be of interest to individuals modeling two-phase flow in nuclear power plants. The first topic is iterative solution of linear equations created during the solution of finite volume equations. The second is numerical tracking of macroscopic liquid interfaces. The final area surveyed is the use of higher spatial difference techniques.

  11. Two-phase flow in refrigeration systems

    CERN Document Server

    Gu, Junjie; Gan, Zhongxue

    2013-01-01

    Two-Phase Flow in Refrigeration Systems presents recent developments from the authors' extensive research programs on two-phase flow in refrigeration systems. This book covers advanced mass and heat transfer and vapor compression refrigeration systems and shows how the performance of an automotive air-conditioning system is affected through results obtained experimentally and theoretically, specifically with consideration of two-phase flow and oil concentration. The book is ideal for university postgraduate students as a textbook, researchers and professors as an academic reference book, and b

  12. Investigations of two-phase flame propagation under microgravity conditions

    Science.gov (United States)

    Gokalp, Iskender

    2016-07-01

    Investigations of two-phase flame propagation under microgravity conditions R. Thimothée, C. Chauveau, F. Halter, I Gökalp Institut de Combustion, Aérothermique, Réactivité et Environnement (ICARE), CNRS, 1C Avenue de la Recherche Scientifique, 45071 Orléans Cedex 2, France This paper presents and discusses recent results on two-phase flame propagation experiments we carried out with mono-sized ethanol droplet aerosols under microgravity conditions. Fundamental studies on the flame propagation in fuel droplet clouds or sprays are essential for a better understanding of the combustion processes in many practical applications including internal combustion engines for cars, modern aircraft and liquid rocket engines. Compared to homogeneous gas phase combustion, the presence of a liquid phase considerably complicates the physico-chemical processes that make up combustion phenomena by coupling liquid atomization, droplet vaporization, mixing and heterogeneous combustion processes giving rise to various combustion regimes where ignition problems and flame instabilities become crucial to understand and control. Almost all applications of spray combustion occur under high pressure conditions. When a high pressure two-phase flame propagation is investigated under normal gravity conditions, sedimentation effects and strong buoyancy flows complicate the picture by inducing additional phenomena and obscuring the proper effect of the presence of the liquid droplets on flame propagation compared to gas phase flame propagation. Conducting such experiments under reduced gravity conditions is therefore helpful for the fundamental understanding of two-phase combustion. We are considering spherically propagating two-phase flames where the fuel aerosol is generated from a gaseous air-fuel mixture using the condensation technique of expansion cooling, based on the Wilson cloud chamber principle. This technique is widely recognized to create well-defined mono-size droplets

  13. 发电厂除灰泵浆体水击压强的计算与分析%The Calculation and Analysis of Water-hammer of Liquid-Solid Two -Phase Flow for Ash-Water Pump in Steam Power Plant

    Institute of Scientific and Technical Information of China (English)

    周云龙; 孙斌; 蒋诚

    2001-01-01

    The calculations and analysis on water hammer pressure of liquid-solid two-phase flow and the round velocity of turning back of the pump on ash-water pump in st e am power plant have been done. Based on the calculation results, some protection s against water-hammer for ash-water pump have been presented.%对某电厂除灰泵进行了浆体水击压强及反向转速的计算与分析,根据计算结果提出了除灰泵的水击防护措施。

  14. 搅拌槽内液-固两相体系的数值研究(Ⅱ)临界搅拌转速的预测%Numerical Study of Solid-Liquid Two-Phase Flow in Stirred Tanks with Rushton Impeller(Ⅱ) Prediction of Critical Impeller Speed

    Institute of Scientific and Technical Information of China (English)

    王峰; 毛在砂; 沈湘黔

    2004-01-01

    The critical impeller speed, NJs, for complete suspension of solid particles in the agitated solid-liquid two-phase system in baffled stirred tanks with a standard Rushton impeller is predicted using the computational procedure proposed in Part I. Three different numerical criteria are tested for determining the critical solid suspension. The predicted NJS is compared with those obtained from several empirical correlations. It is suggested the most reasonable criterion for determining the complete suspension of solid particles is the positive sign of simulated axial velocity of solid phase at the location where the solid particles are most difficult to be suspended.

  15. Two-phase flow studies. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Kestin, J.; Maeder, P.F.

    1980-08-01

    Progress on the following is reported: literature survey, design of two-phase flow testing facility, design of nozzle loop, thermophysical properties, design manual, and advanced energy conversion systems. (MHR)

  16. Surface tension of non-ideal binary and ternary liquid mixtures at various temperatures and p = 81.5 kPa

    Energy Technology Data Exchange (ETDEWEB)

    Rafati, A.A., E-mail: rafati_aa@yahoo.co [Department of Physical Chemistry, Faculty of Chemistry, Bu-Ali Sina University, Hamedan 65174 (Iran, Islamic Republic of); Bagheri, A. [Department of Physical Chemistry, Faculty of Chemistry, Bu-Ali Sina University, Hamedan 65174 (Iran, Islamic Republic of); Najafi, M. [Department of Material Engineering, Hamedan University of Technology, Hamedan (Iran, Islamic Republic of)

    2011-03-15

    Experimental surface tensions for binary mixtures (1,2-ethandiol + water), (1,2-ethandiol + acetonitrile), and (acetonitrile + water) at temperatures of 283.15 K, 298.15 K, and 308.15 K and the ternary mixture (1,2-ethandiol/water/acetonitrile) at 298.15 K have been measured with the Du Nouey ring tensiometer. The surface tension of the above mentioned binary and ternary systems were correlated with empirical and thermodynamic based models. The methods of Pando et al. and Ku et al. were used to correlate the ternary surface tension data. The Fu et al., Kalies et al. and Wang et al. models were also applied to predict surface tension in the ternary system. The mean average absolute deviations obtained from the comparison of experimental and calculated surface tension values for ternary system with three models are less than 2.4%, which leads to concluding that these models show a good accuracy in different situations in comparison with other predictive equations.

  17. 制冷剂汽液两相区音速的计算与分析%Calculation and Analysis of Sound Velocity in Vapor-liquid Two-phase Refrigerant Flow

    Institute of Scientific and Technical Information of China (English)

    王艳庭; 张华

    2011-01-01

    Sound velocity of fluid is important thermodynamic parameter. But viewing from the existing literature, there is a lack of sound velocity data. This paper presents the calculation of sound velocity for the adiabatic two-phase flow of refrigerant through capillary tube based on homogenous equilibrium model. According to the definition of sound velocity a=√δρ/δρ and Martin-Hou equation of state the sound velocity is obtained using the finite difference method. The sound velocities of three refrigerants, R22, R134a, R744, have been calculated in this paper. The calculation results have been validated by published experimental data and showed fair agreement with the experimental data with an error band of 4%. According to the calculated two-phase sound velocity data, the sonic curves were drawn in the pressure-enthalpy diagram. The data and curves show that the sound velocity increases with the entropy at the same pressure. From the triple point pressure sound velocity on the isentropic curve increases firstly and then decreases. Sound velocity on the isenthalpic curve decreases monotonically for R134a and R744. But the sound velocity of R22 increases firstly then decreases.%流体的音速是流体重要的热力学参数,从现有文献看,制冷剂两相区的音速数据缺乏.采用均相流模型,从马丁-侯状态方程出发,根据绝热音速的定义α=√(e)p/(e)pad,利用有限差分方法得到了常用的制冷剂R22、R134a、R744两相区的等熵绝热音速数据,并用文献中的两相区音速实验结果对其进行了验证,表明两者音速误差在4%以内.根据计算出的两相区音速数据,利用相关软件在lgp-h图里面绘制了等音速线,对两相区音速数据进行了分析讨论.数据显示相同压力下,随着熵值的增大,音速值逐渐变大;自三相点压力至饱和压力等熵线上的音速会出现先增大后减小的现象;等焓线上的音速,R134a、R744单调递减,R22先增大后减小.

  18. Experimental Investigation on Vortex Shedding from Staggered Cylinders in Gas-Liquid Two-Phase Flow%气液两相流中错列圆柱上旋涡脱落规律的试验研究

    Institute of Scientific and Technical Information of China (English)

    苏新军; 王祺; 林宗虎

    2001-01-01

    通过试验,对气液两相流中相同直径的3排错列圆柱表面上旋涡的脱落与节径比、含气率的关系进行了研究.研究发现:旋涡的周期性脱落仅在含气率α小于等于0.14的范围内发生;对于横向节径比s1/d小于等于2.0的错列圆柱,隙缝流呈现双稳态的偏斜流,而横向节径比s1/d大于2.0时,双稳态的偏斜流消失;两相流斯特拉赫数随含气率的增加而减小.%The relationship between the vortex shedding from the surface ofthree row circular cylinders of the same diameter in staggered arrangement and the ratio of pitch to diameter or void friction is experimentally investigated.The results show that periodical vortex shedding happens when the void fraction is no more than 0.14.As the ratio of transverse pitch to diameter is no more than 2.0,gap-flow is bistable deflective flow.But bistable deflective flow disappears as the ratio more than 2.0.Strouhal number in two-phase flow reduces with the increase of the void friction.

  19. Experimental Investigation of two-phase nitrogen Cryo transfer line

    Science.gov (United States)

    Singh, G. K.; Nimavat, H.; Panchal, R.; Garg, A.; Srikanth, GLN; Patel, K.; Shah, P.; Tanna, V. L.; Pradhan, S.

    2017-02-01

    A 6-m long liquid nitrogen based cryo transfer line has been designed, developed and tested at IPR. The test objectives include the thermo-hydraulic characteristics of Cryo transfer line under single phase as well as two phase flow conditions. It is always easy in experimentation to investigate the thermo-hydraulic parameters in case of single phase flow of cryogen but it is real challenge when one deals with the two phase flow of cryogen due to availibity of mass flow measurements (direct) under two phase flow conditions. Established models have been reported in the literature where one of the well-known model of Lockhart-Martenelli relationship has been used to determine the value of quality at the outlet of Cryo transfer line. Under homogenous flow conditions, by taking the ratio of the single-phase pressure drop and the two-phase pressure drop, we estimated the quality at the outlet. Based on these equations, vapor quality at the outlet of the transfer line was predicted at different heat loads. Experimental rresults shown that from inlet to outlet, there is a considerable increment in the pressure drop and vapour quality of the outlet depending upon heat load and mass flow rate of nitrogen flowing through the line.

  20. Binary and ternary vapor-liquid equilibrium data of the system ethylbenzene+styrene+3-methyl-N-butylpyridinium tetracyanoborate at vacuum conditions and liquid-liquid equilibrium data of their binary systems

    NARCIS (Netherlands)

    Jongmans, Mark; Hermens, E.; Schuur, Boelo; de Haan, A.B.

    2012-01-01

    In this study, binary LLE data at 313.2, 333.2, and 353.2 K, binary VLE data in the pressure range of 3–30 kPa and ternary VLE data at 5, 10, and 15 kPa have been determined for the system ethylbenzene + styrene + [3-mebupy][B(CN)4]. The IL [3-mebupy][B(CN)4] can increase the relative volatility of

  1. 液相三元Al-Ni-Zn合金的热力学性质计算%Calculation of thermodynamic properties in liquid phase for ternary Al-Ni-Zn alloys

    Institute of Scientific and Technical Information of China (English)

    D. (Z)IVKOVI(C); 杜勇; N. TALIJAN; A. KOSTOV; Lj. BALANOVI(C)

    2012-01-01

    The results of the calculation of thermodynamic properties in liquid state for ternary Al-Ni-Zn alloys using the newest version of the general solution model for thermodynamic prediction are presented.Nine sections with different molar ratios of Ni to Zn,Zn to Al and Al to Ni were investigated in a temperature interval of 1800-2000 K.Partial and integral molar thermodynamic properties in liquid phase for the Al-Ni-Zn ternary system are determined and discussed.%将用于热力学预测的最新版本的通用模型用来计算液相三元Al-Ni-Zn合金的热力学性质.对9个具有不同Ni与Zn,Zn与Al和Al与N摩尔比的截面在1800~2000 K的热力学性质进行研究.对液相三元Al-Ni-Zn合金的局部和整体的摩尔热力学性质进行了测定,并对结果进行了讨论.

  2. Stability of stratified two-phase flows in horizontal channels

    CERN Document Server

    Barmak, Ilya; Ullmann, Amos; Brauner, Neima; Vitoshkin, Helen

    2016-01-01

    Linear stability of stratified two-phase flows in horizontal channels to arbitrary wavenumber disturbances is studied. The problem is reduced to Orr-Sommerfeld equations for the stream function disturbances, defined in each sublayer and coupled via boundary conditions that account also for possible interface deformation and capillary forces. Applying the Chebyshev collocation method, the equations and interface boundary conditions are reduced to the generalized eigenvalue problems solved by standard means of numerical linear algebra for the entire spectrum of eigenvalues and the associated eigenvectors. Some additional conclusions concerning the instability nature are derived from the most unstable perturbation patterns. The results are summarized in the form of stability maps showing the operational conditions at which a stratified-smooth flow pattern is stable. It is found that for gas-liquid and liquid-liquid systems the stratified flow with smooth interface is stable only in confined zone of relatively lo...

  3. Two-phase microfluidics: thermophysical fundamentals and engineering concepts

    Science.gov (United States)

    Kuznetsov, V. V.

    2016-10-01

    Thermophysical fundamentals and engineering concepts of the two-phase microfluidic devises based on controlled liquid decay are discussed in this paper. The results of an experimental study of the explosive evaporation at a thin film heater of the MEMS devise in application to thermal inkjet printing are presented. The peculiarities of homogeneous nucleation and bubble growth in the liquid subjected to pulse heating are discussed. Using experimental data a simple equation suitable for predicting the growth rate of a vapor bubble in a non-uniformly superheated liquid was obtained and used to complete a mathematical model of the self-consistent nucleation and vapor bubbles growth in the induced pressure field. The results of numerical calculations according to the proposed model showed good agreement with the experimental data on a time of nucleation and duration of the initial stage of an explosive evaporation of water.

  4. Response of two-phase droplets to intense electromagnetic radiation

    Energy Technology Data Exchange (ETDEWEB)

    Spann, J.F. (Morgantown Energy Technology Center, U.S. Department of Energy, P.O. Box 880, Morgantown, West Virginia 26507-0880 (United States)); Maloney, D.J.; Lawson, W.F.; Casleton, K.H. (Morgantown Energy Technology Center, U.S. Department of Energy, P.O. Box 880, Morgantown, West Virginia 26507-0880 (United States))

    1993-04-20

    The response of two-phase droplets to intense radiant heating is studied to determine the incident power that is required for causing explosive boiling in the liquid phase. The droplets studied consist of strongly absorbing coal particles dispersed in a weakly absorbing water medium. Experiments are performed by confining droplets (radii = 37, 55, and 80 [mu]m) electrodynamically and irradiating them from two sides with pulsed laser beams. Emphasis is placed on the transition region from accelerated droplet vaporization to droplet superheating and explosive boiling. The time scale observed for explosive boiling is more than 2 orders of magnitude longer than published values for pure liquids. The delayed response is the result of energy transfer limitations between the absorbing solid phase and the surrounding liquid.

  5. Response of two-phase droplets to intense electromagnetic radiation

    Science.gov (United States)

    Spann, James F.; Maloney, Daniel J.; Lawson, William F.; Casleton, Kent H.

    1993-01-01

    The response of two-phase droplets to intense radiant heating is studied to determine the incident power that is required for causing explosive boiling in the liquid phase. The droplets studied consist of strongly absorbing coal particles dispersed in a weakly absorbing water medium. Experiments are performed by confining droplets (radii of 37, 55, and 80 microns) electrodynamically and irradiating them from two sides with pulsed laser beams. Emphasis is placed on the transition region from accelerated droplet vaporization to droplet superheating and explosive boiling. The time scale observed for explosive boiling is more than 2 orders of magnitude longer than published values for pure liquids. The delayed response is the result of energy transfer limitations between the absorbing solid phase and the surrounding liquid.

  6. 管壳式换热器壳侧气液两相流动和传热的数值模拟研究%Study on Numerical Simulation of Gas-liquid Two-phase Flow and Heat Transfer of Shell Side in a Shell and Tube Heat Exchanger

    Institute of Scientific and Technical Information of China (English)

    吕金丽; 戈锐; 李想; 张玉宝

    2012-01-01

    采用数值模拟方法,使用FLUENT对管壳式换热器壳侧的两相流动及相变传热进行了模拟计算.根据壳侧流体流动特点,选定合适的湍流模型、两相流模型为混合物模型,并根据汽水转化公式编写了自定义函数UDF来描述相变过程质和量的传递.对管壳式换热器壳侧的流体介质换热发生相变并产生气液两相流动进行了三维的数值模拟研究.得到了管壳式换热器壳程的速度场、温度场、压力场及气液各相的分布情况,对壳侧气液两相流动及相变换热进行了分析.对具有相变情况下的管壳式换热器的结构设计起到参考指导作用.%Numerical simulation methods are adopted in this paper. With the FLUENT software,the paper stimulates the two-phase flow and phase change and heat transfer. A turbulence model and a two-phase flow model are selected in this paper. Based on the characteristics of shell-side in the shell and tube heat exchangers, the paper writes User-defined Function (UDF) to describe the phase transition of quality and quantity through the use of the conversion formula. Flow media of shell and tube heat exchanger shell-side heat transfer occurring phase change and gas-liquid two-phase flow are studied by 3D numerical-simulation, obtaining velocity field, temperature field, pressure field and gas-liquid distribution of shell and tube heat exchanger shell side. The two-phase flow and phase change and heat transfer of shell-side in the shell and tube heat exchangers are analyzed. These will be provided some valuable references for the improvement of tube condenser structure design.

  7. Phase Behaviors of Ternary Systems Formed by Nonionic Surfactant, Ionic Liquid and Water%非离子表面活性剂与离子液体、水三组分体系的相行为

    Institute of Scientific and Technical Information of China (English)

    庄文昌; 王欲晓; 袁影华

    2012-01-01

    Ionic liquids have attracted much attention due to the rise of green chemistry and their own advantages. In this paper, phase behaviors of ternary systems formed by nonionic amphiphilic molecules, ionic liquid and water are researched on by polarizing microscopy and small angle X-ray scattering. Furthermore, ordered structures are also analyzed.%离子液体因绿色化学的兴起并凭借自身的优点而备受关注.文章采用两种不同的离子液体与水构成双极性溶剂,研究了非离子表面活性剂C12E4在其中的聚集行为,同时利用偏光显微镜和小角X射线散射技术对所形成的有序结构进行了分析.

  8. 用于描述三元水醇系统汽液平衡的活度系数模型%Activity coefficient models to describe vapor-liquid equilibrium in ternary hydro-alcoholic solutions

    Institute of Scientific and Technical Information of China (English)

    Claudio A.Faundez; Jose O.Valderrama

    2009-01-01

    In this study,three semipredictive activity coefficient models:Wilson,non-random-two liquid model (NRTL),and universal quasi-chemical model(UNIQUAC),have been used for modeling vapor-liquid equilibrium properties oftemary mixtures that include substances found in alcoholic distillation processes ofwine and musts.In pamcular,vapor-hqmd eqmIIbnum in temary mixtures containing water+ethanol+congener has been modeled using parameters obtained from binary and ternary mixture data.Thc congeners are substances that although present in very lOW concentrations,of the order of part per million.are important cnological parameters.The results given by these difierent models have been compared with literature data and conclusions about the accuracy ofthe models studied are drawn,recommending the best models for correlating and predicting phase equilibrium properties of this type of mixtures.

  9. Computation of two-phase reacting flows in solid-liquid rocket ramjets%固液火箭冲压发动机内两相反应流场数值计算

    Institute of Scientific and Technical Information of China (English)

    马智博; 朱建士

    2001-01-01

    In order to compute three-dimens ional reacting flow fieldsestabl ished in the chambers of solid-liquid rocket ramjets,the block implicit algorit hm was used to solve the Navier-Stokes equations about gas,the Continuum Formul a tion Model and k-ε-Ap model were used to characterize the turbulent fl ow and vaporizatio n of droplets.The modified k-ε-g model was adopted to represent the combu stion of the fuels.Calculations were carried out under different chamber configuration s and initial droplet diameters,from which the effects of these conditions on t he combustion efficiency were analyzed.The numerical results reveal the p r ocesses of droplet vaporization and combustion.%为了计算固液混合式火箭冲压发动机补燃室内的三维反应流场,用块隐式法求解气相Navier-Stokes方程组,用连续介质模型和k-ε-Ap模型计算颗粒相的湍流流动与蒸发过程,用修正的k-ε-g模型描述燃料的燃烧。为了分析发动机设计参数对反应流场的影响,用不同的条件进行计算,并由此分析了补燃室几何结构和液体燃料初始颗粒直径对燃烧效率的影响。算例表明,计算方法有效可行,数值结果能够反映流场结构、液体燃料的蒸发和两种燃料的燃烧过程。

  10. Critical size dependence of domain formation observed in coarse-grained simulations of bilayers composed of ternary lipid mixtures

    Science.gov (United States)

    Pantelopulos, George A.; Nagai, Tetsuro; Bandara, Asanga; Panahi, Afra; Straub, John E.

    2017-09-01

    Model cellular membranes are known to form micro- and macroscale lipid domains dependent on molecular composition. The formation of macroscopic lipid domains by lipid mixtures has been the subject of many simulation investigations. We present a critical study of system size impact on lipid domain phase separation into liquid-ordered and liquid-disordered macroscale domains in ternary lipid mixtures. In the popular di-C16:0 PC:di-C18:2 PC:cholesterol at 35:35:30 ratio mixture, we find systems with a minimum of 1480 lipids to be necessary for the formation of macroscopic phase separated domains and systems of 10 000 lipids to achieve structurally converged conformations similar to the thermodynamic limit. To understand these results and predict the behavior of any mixture forming two phases, we develop and investigate an analytical Flory-Huggins model which is recursively validated using simulation and experimental data. We find that micro- and macroscale domains can coexist in ternary mixtures. Additionally, we analyze the distributions of specific lipid-lipid interactions in each phase, characterizing domain structures proposed based on past experimental studies. These findings offer guidance in selecting appropriate system sizes for the study of phase separations and provide new insights into the nature of domain structure for a popular ternary lipid mixture.

  11. Phenol wastewater treatment by needle-plate pulsed high voltage discharge in gas-liquid two phase%针-板式高压脉冲气液两相放电降解废水中的苯酚

    Institute of Scientific and Technical Information of China (English)

    董冰岩; 张鹏; 聂亚林; 谢寅寅; 何俊文; 王晖

    2016-01-01

    为了提高脉冲放电对有机物的降解效果,以苯酚为处理对象建立了单针-板电极形式的脉冲放电体系,考察了各因素对苯酚降解的影响并分析了降解过程中间产物及其浓度变化。结果表明,脉冲电压、电极间距、针-液间距、脉冲频率、曝气量等影响因素对苯酚降解率有很大影响;随着脉冲电压的增大,苯酚降解率增大,电压达到一定值后,苯酚降解率增大不再明显,趋于稳定;随着电极间距、针-液间距、脉冲频率、曝气量的增大,苯酚降解率增大,但当这些因素达到一定值后继续增大,苯酚降解率反而降低。100mL浓度为100mg/L的苯酚废水在电极间距10mm、针-液间距7.5mm、脉冲电压26kV、脉冲频率70Hz、曝气量1.5L/min的最佳条件下,放电60min时苯酚降解率为64.63%,放电140min时达到了85.02%。中间产物间苯二酚、对苯二酚、对苯醌、邻苯二酚在放电过程中浓度随着放电时间的延长先增大后减小,最后浓度都趋于零。其中,间苯二酚浓度最低并且分段出现,对苯醌浓度最大,邻苯二酚最先消失,考察产物变化规律以提高苯酚降解的彻底性。%In order to enhance the effect of pulse discharge on degradation of organic matter,a pulse discharge system of single needle-plate electrode aimed at phenol was established. The paper investigated the effect of various factors on phenol degradation and analyzed the degradation of intermediate products and their concentrations in the degradation process. Such factors,as pulse voltage,electrode spacing,needle-liquid spacing,pulse frequency,and air volume,had a great influence on the degradation rate of phenol. Phenol degradation rate increased with the increase of pulse voltage and tended to stablize while pulse voltage reached a specific value. With the increase of electrode spacing,needle-liquid spacing,pulse frequency,air volume,degradation rate of

  12. Spacecraft Thermal Management using Advanced Hybrid Two-Phase Loop Technology

    Science.gov (United States)

    2007-02-01

    HYBRID TWO-PHASE LOOPS The schematic of the Hybrid Two-Phase Loop (HTPL) used for a thermal testing is shown in Figure 3. Main components for the...hybrid two-phase loop with single evaporator. The thermal test starts first by turning on the liquid pump to circulate liquid along the loop. Once the...Vapor Out Evaporator Body (E1) Evaporator Body (E2) Total Heat Input Heat Input (E1) Heat Input (E2) Thermal Resistance (E1) FIGURE 10. Thermal test results

  13. Two Phase Flow Mapping and Transition Under Microgravity Conditions

    Science.gov (United States)

    Parang, Masood; Chao, David F.

    1998-01-01

    In this paper, recent microgravity two-phase flow data for air-water, air-water-glycerin, and air- water-Zonyl FSP mixtures are analyzed for transition from bubbly to slug and from slug to annular flow. It is found that Weber number-based maps are inadequate to predict flow-pattern transition, especially over a wide range of liquid flow rates. It is further shown that slug to annular flow transition is dependent on liquid phase Reynolds number at high liquid flow rate. This effect may be attributed to growing importance of liquid phase inertia in the dynamics of the phase flow and distribution. As a result a new form of scaling is introduced to present data using liquid Weber number based on vapor and liquid superficial velocities and Reynolds number based on liquid superficial velocity. This new combination of the dimensionless parameters seem to be more appropriate for the presentation of the microgravity data and provides a better flow pattern prediction and should be considered for evaluation with data obtained in the future. Similarly, the analysis of bubble to slug flow transition indicates a strong dependence on both liquid inertia and turbulence fluctuations which seem to play a significant role on this transition at high values of liquid velocity. A revised mapping of data using a new group of dimensionless parameters show a better and more consistent description of flow transition over a wide range of liquid flow rates. Further evaluation of the proposed flow transition mapping will have to be made after a wider range of microgravity data become available.

  14. Position of guide vane trailing edge of nuclear reactor coolant pump under gas-liquid two phase condition%气液两相条件下核主泵导叶出口边安放位置

    Institute of Scientific and Technical Information of China (English)

    朱荣生; 习毅; 袁寿其; 付强; 龙云

    2013-01-01

    为了研究气液两相条件下,不同导叶出口边安放位置对核主泵内部压力脉动、含气率脉动的影响,并最终找出最佳的导叶出口边安放位置,采用三维数值模拟软件CFX模拟泵内部的瞬态流场,在泵壳内壁面和出口不同位置设置监测点,以了解各模型内部不同时刻、不同位置的压力、含气率分布.对比不同模型相同点的压力脉动、含气率脉动的时域、频域图可以发现:导叶出口边在泵壳中心平面(C-C平面)时,泵壳壁面上各点所受压力较小且较平稳,即压力脉动引起的振动、噪声较小,从安全性方面考虑,此时导叶出口边安放位置最佳;泵壳壁面上的压力脉动主要受叶轮的转动影响;除了类似隔舌处外,叶轮的转动对泵壳壁面和出口含气率脉动的影响不大,沿着液体绕流方向泵壳内壁面上的含气率逐渐增大,到出口达到最大.%To study the influence of different positions of guide vane trailing edge on the pressure fluctuation and gas fraction fluctuation in volute wall of nuclear reactor coolant pump under gas-liquid phase condition,and find a best position of guide vane trailing edge,the three-dimensional numerical software CFX was used to simulate the internal transient flow field of pump,with monitoring points set in different positions,in the hope of learning pressures and gas fraction distributions at different times and different positions within each model pump.By comparing pressure fluctuations,frequency domains and time domains at the same position of each model,it was found that the pressure is lower and steadier when the guide vane trailing edge is in the center plane of volute.In another word,the vibration and noise caused by pressure fluctuation were lower; it is the best position for safety.At the same time,it was also found that the fluctuation frequency of volute wall was influenced by impeller rotation frequency.Except similar tongue,impeller rotation

  15. Two-phase nozzle flow and the subcharacteristic condition

    DEFF Research Database (Denmark)

    Linga, Gaute; Aursand, Peder; Flåtten, Tore

    2015-01-01

    We consider nozzle flow models for two-phase flow with phase transfer. Such models are based on energy considerations applied to the frozen and equilibrium limits of the underlying relaxation models. In this paper, we provide an explicit link between the mass flow rate predicted by these models a...... leakage of CO2 is presented, indicating that the frozen and equilibrium models provide significantly different predictions. This difference is comparable in magnitude to the modeling error introduced by applying simple ideal-gas/incompressible-liquid equations-of-state for CO2....

  16. Two-phase mixed media dielectric with macro dielectric beads for enhancing resistivity and breakdown strength

    Science.gov (United States)

    Falabella, Steven; Meyer, Glenn A; Tang, Vincent; Guethlein, Gary

    2014-06-10

    A two-phase mixed media insulator having a dielectric fluid filling the interstices between macro-sized dielectric beads packed into a confined volume, so that the packed dielectric beads inhibit electro-hydrodynamically driven current flows of the dielectric liquid and thereby increase the resistivity and breakdown strength of the two-phase insulator over the dielectric liquid alone. In addition, an electrical apparatus incorporates the two-phase mixed media insulator to insulate between electrical components of different electrical potentials. And a method of electrically insulating between electrical components of different electrical potentials fills a confined volume between the electrical components with the two-phase dielectric composite, so that the macro dielectric beads are packed in the confined volume and interstices formed between the macro dielectric beads are filled with the dielectric liquid.

  17. Validation and application of chemometrics-assisted spectrophotometry and liquid chromatography for simultaneous determination of two ternary mixtures containing drotaverine hydrochloride.

    Science.gov (United States)

    El-Gindy, Alaa; Emara, Samy; Shaaban, Heba

    2010-01-01

    Three methods were developed for the determination of two ternary mixtures containing drotaverine hydrochloride (DR) with caffeine and paracetamol (mixture 1) and DR with metronidazole and diloxanide furoate (mixture 2). The first method depends on HPLC separation on an RP C18 column at ambient temperature with the mobile phase methanol-water, pH 3.1 (50 + 50, v/v) and UV detection at 213 nm for mixture 1, and the mobile phase acetonitrile-25 mM potassium dihydrogen phosphate, pH 4.6 (55 + 45, v/v) with UV detection at 235 nm for mixture 2. The other two chemometric methods applied were partial least squares (PLS-1) and principal component regression (PCR). These approaches were successfully applied to quantify the five drugs in two ternary mixtures using information included in the UV absorption spectra of appropriate solutions in the wavelength range of 210-300 nm with 1 nm intervals. Calibration of PCR and PLS-1 models was evaluated by internal validation (prediction of compounds in its own designed training set of calibration), by cross-validation (obtaining statistical parameters that show the efficiency for a calibration fit model), and by external validation (using laboratory-prepared mixtures and pharmaceutical preparations). The proposed methods were successfully applied for the determination of the two ternary combinations in laboratory-prepared mixtures and commercial tablets; the results of PLS-1 and PCR methods were compared with the HPLC method, and a good agreement was found.

  18. Review of two-phase instabilities

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Han Ok; Seo, Han Ok; Kang, Hyung Suk; Cho, Bong Hyun; Lee, Doo Jeong

    1997-06-01

    KAERI is carrying out a development of the design for a new type of integral reactors. The once-through helical steam generator is important design features. The study on designs and operating conditions which prevent flow instability should precede the introduction of one-through steam generator. Experiments are currently scheduled to understand two-phase instability, evaluate the effect of each design parameter on the critical point, and determine proper inlet throttling for the prevention of instability. This report covers general two-phase instability with review of existing studies on this topics. The general classification of two phase flow instability and the characteristics of each type of instability are first described. Special attention is paid to BWR core flow instability and once-through steam generator instability. The reactivity feedback and the effect of system parameters are treated mainly for BWR. With relation to once-through steam generators, the characteristics of convective heating and dryout point oscillation are first investigated and then the existing experimental studies are summarized. Finally chapter summarized the proposed correlations for instability boundary conditions. (author). 231 refs., 5 tabs., 47 figs

  19. Critical thinking: a two-phase framework.

    Science.gov (United States)

    Edwards, Sharon L

    2007-09-01

    This article provides a comprehensive review of how a two-phase framework can promote and engage nurses in the concepts of critical thinking. Nurse education is required to integrate critical thinking in their teaching strategies, as it is widely recognised as an important part of student nurses becoming analytical qualified practitioners. The two-phase framework can be incorporated in the classroom using enquiry-based scenarios or used to investigate situations that arise from practice, for reflection, analysis, theorising or to explore issues. This paper proposes a two-phase framework for incorporation in the classroom and practice to promote critical thinking. Phase 1 attempts to make it easier for nurses to organise and expound often complex and abstract ideas that arise when using critical thinking, identify more than one solution to the problem by using a variety of cues to facilitate action. Phase 2 encourages nurses to be accountable and responsible, to justify a decision, be creative and innovative in implementing change.

  20. Multi-scale cross-correlation characteristics of void fraction wave propagation for gas-liquid two-phase flows in small diameter pip e%小管径气液两相流空隙率波传播的多尺度相关性∗

    Institute of Scientific and Technical Information of China (English)

    翟路生; 金宁德

    2016-01-01

    The void fraction wave is a special physical phenomenon in a gas-liquid two-phase flow system. Understanding the propagation of the void fraction wave is of great significance for uncovering the physical mechanisms in both flow pattern transition and the fluid velocity measurement. In this study, detrended cross-correlation analysis (DCCA) is used to investigate the multi-scale cross-correlation characteristics of the coupled ARFIMA processes. It is found that the DCCA can effectively reveal the multi-scale cross-correlation dynamical behaviors of complex system. Then, we carry out the experimental test in a vertical gas-liquid two-phase flow pipe with small inner diameter. The DCCA is used to detect the cross-correlation characteristics of the void fraction wave on multiple time scales, and the growth rate of the cross-correlation level for the void fraction wave is observed on low time scales. Additionally, the spatial attenuation factor (SAF) of the void fraction wave is calculated to investigate the instability of the wave propagation. The SAF is close to zero under the transitional flow patterns, which means that the void fraction wave is in a stable propagating state. For bubble flows, the void fraction wave presents the attenuation characteristics, whilst the void fraction wave shows the amplification characteristics under the slug and churn flow patterns. Interestingly, the instability behaviors of the void fraction wave are always associated with its multi-scale cross-correlation characteristics. Specifically, the increasing rate of the wave cross-correlation level on low scales is much higher for transitional flow patterns, which is corresponding to the stable propagating characteristic of the void fraction wave. However, when the void fraction wave exhibits attenuation or amplification characteristics under other flow patterns, the increasing rate of the wave cross-correlation level on low scales is much lower.

  1. Y型喷嘴内部气液两相流动及液膜雾化的数学模型%Mathematical Modeling on the Gas-Liquid Two Phase Flow in the Y-Jet Nozzle and Its Atomization Process

    Institute of Scientific and Technical Information of China (English)

    章明川; 吕勇; 王峻晔; 范浩杰; 李德贵; 陈启峰

    2000-01-01

    In accordance with the results of previous experimental investigations,and starting from the formulation of conservation equations of mass ,momentum and energy for the gas ,the liquid and the interaction of them,including the normal stress action at the curved liquid stream head in the mixing chamber ,the heat transfer and the work done by the shear stress at the parallel part of the interface of the two phases ,a mathematical model for the gas-liquid two-phase flow in the Y-jet nozzle was established by the authors. Furthermore,based on the theory of unsteady surface vibration and the theory of aerodynamic atomization in the literature ,the two-stage breakup process of the liquid film from the exit of the nozzle was modeled. Thus a complete mathematical modeling system for the performance prediction and the design optimization of Y-jet nozzles has been formed. And judged by the practice,the modeling system is very effective.%根据前人实验观察结果所得的流动结构,从气液两相各自的质量、动量、能量平衡及其相互作用方程的构造人手,包括混合孔内油流端部界面上的正应力传递,两相平行界面上的剪应力作功及传热等,建立了Y型喷嘴内部流动过程的数学模型。进而,依据不稳定表面波理论及空气动力破碎理论,分别对Y型喷嘴出口油膜的初级破碎及二次雾化过程作了进一步的模化,建立了一套较为完整的Y型喷嘴性能预测及设计优化的数学方法。经检验,实际使用效果良好。

  2. Experimental study of two phase flow in inclined channel

    Energy Technology Data Exchange (ETDEWEB)

    Park, Goon Cherl; Lee, Tae Ho; Lee, Sang Won [Seoul National University, Seoul (Korea, Republic of)

    1997-07-01

    Local two-phase flow parameters were measured to investigate the internal flow structures of steam-water boiling flow in an inclined channel. The vapor phase local flow parameters, such as void fraction, bubble frequency, vapor velocity, interfacial area concentration and chord length, were measured, using two conductivity probe method, and local liquid phase velocity was measured by pitot tube. In order to investigate the effects of channel inclination on two phase flow structure, the experiments were conducted for three angles of inclination; 0 degree(vertical), 30 degree and 60 degree. The experimental flow conditions were confined to the liquid superficial velocities less than 1.4 m/sec and nearly atmospheric pressure, and the flow regime was limited to the subcooled boiling. Using the measured distributions of the local phasic parameters, correlations for the drift-flux parameters such as distribution parameter and drift velocity were proposed. Those correlations were compared with the available correlation applicable to the inclined channel by the calculation of average void fraction using the present data. 44 refs., 4 tabs., 88 figs. (author)

  3. 连续旋转爆轰发动机气液两相爆轰波传播特性二维数值研究%Numerical investigation on two-dimensional gas-liquid two-phase detonation wave propagation characteristics of continuous rotating detonation engine

    Institute of Scientific and Technical Information of China (English)

    李宝星; 翁春生

    2015-01-01

    为了研究液体燃料连续旋转爆轰发动机( Continuous Rotating Detonation Engine,CRDE)中爆轰波形成与传播过程,采用二维CE/SE方法,对汽油、富氧空气两相连续旋转爆轰发动机爆轰过程进行数值模拟,分析了连续旋转爆轰发动机气液两相爆轰流场和爆轰波结构及入口和出口处的流场变化规律,揭示了CRDE自持传播机理. 计算结果表明,燃料以时段阶梯填充方式来起爆旋转爆轰,可快速有效地形成单方向稳定传播的爆轰波;在周向方向上出口处的流场间断面要延后于入口处的间断面,出口流场间断面主要是由斜激波和接触间断面造成的,而入口流场间断面是由爆轰波引起的. 通过对气液两相CRDE的二维数值模拟,可更好地了解液体燃料CRDE的工作过程,为液体燃料CRDE研究提供指导.%In order to discuss the formation and propagation of detonation wave of the liquid fuel continuous rotating detonation engine( CRDE) ,the two-dimensional CE/SE method is used to simulate the detonation process of gasoline and oxygen-enriched air two-phase CRDE.The gas-liquid two-phase detonation flow field of CRDE,the structure of detonation wave,and the variation of flow field at inlet and exit were analyzed,then the self-sustaining mechanism of CRDE was revealed.The results show that rotating detona-tion is initiated by the method of multistep filling fuel,forming a stable detonation wave along one direction propagation rapidly and effectively.In circumferential direction,the discontinuity of exit flow field appears behind the discontinuity of inlet. Oblique shock wave and contact discontinuity are the main reasons of the formation of discontinuity in the exit flow field, while the discontinuity of inlet flow field is caused by detonation wave.The two-dimensional numerical simulation of gas-liquid two-phase CRDE gives us better understanding of the liquid fuel CRDE and provides guidance for the research of liquid

  4. Coupling two-phase fluid flow with two-phase darcy flow in anisotropic porous media

    KAUST Repository

    Chen, J.

    2014-06-03

    This paper reports a numerical study of coupling two-phase fluid flow in a free fluid region with two-phase Darcy flow in a homogeneous and anisotropic porous medium region. The model consists of coupled Cahn-Hilliard and Navier-Stokes equations in the free fluid region and the two-phase Darcy law in the anisotropic porous medium region. A Robin-Robin domain decomposition method is used for the coupled Navier-Stokes and Darcy system with the generalized Beavers-Joseph-Saffman condition on the interface between the free flow and the porous media regions. Obtained results have shown the anisotropic properties effect on the velocity and pressure of the two-phase flow. 2014 Jie Chen et al.

  5. Numerical Research of the Solid and Liquid Two - Phase Flow Influence Factors in the Sand Blower of Horizontal Well%水平井喷砂器内固液两相流动影响因素数值研究

    Institute of Scientific and Technical Information of China (English)

    鹿钦礼; 乔伟彪; 刘帅; 冯云飞

    2012-01-01

    Based on the model of the CFD Eulerian, using the method of the limited volumetry, we build the mathematics model of the solid and liquid two - phase flow. And we simulate sand blower whose lenth is 180 millimeter, inlet radius diameter is 4 millimeter, outlet is annular and inner annular radius diameter is 7 millimeter, outer annular radius diameter is 9 millimeter numerically. Research indicates; under the circumstance of the other invariant condition, the fracturing liquid inlet velocity increasing, the energy of turbulence is lower in the direction of the roller, with the include sand ratio decreasing, the pressure of the fracturing liquid is added in the every faces; with the outlet pressure increasing, the flow velocity of the fracturing liquid is also amplified.%基于计算流体力学中的欧拉模型、采用有限客积法建立固液两相在喷砂器内流动的数学模型.针对总长为180mm,入口半径为4mm,出口为环形且内环半径为7mm、外环半径为9mm的喷砂器进行数值模拟.结果表明:在其它条件不变的情况下,随着压裂液入口速度的增加,轴向距离各截面的湍动能逐渐减少,随着舍沙率的减少,压裂液在各截面的压强逐渐增大,随着出口压力的增加,压裂液流动速度也在增大.

  6. Correlation of three-liquid-phase equilibria involving ionic liquids.

    Science.gov (United States)

    Rodríguez-Escontrela, I; Arce, A; Soto, A; Marcilla, A; Olaya, M M; Reyes-Labarta, J A

    2016-08-03

    The difficulty in achieving a good thermodynamic description of phase equilibria is finding a model that can be extended to a large variety of chemical families and conditions. This problem worsens in the case of systems containing more than two phases or involving complex compounds such as ionic liquids. However, there are interesting applications that involve multiphasic systems, and the promising features of ionic liquids suggest that they will play an important role in many future processes. In this work, for the first time, the simultaneous correlation of liquid-liquid and liquid-liquid-liquid equilibrium data for ternary systems involving ionic liquids has been carried out. To that end, the phase diagram of the water + [P6 6 6 14][DCA] + hexane system has been determined at 298.15 K and 323.15 K and atmospheric pressure. The importance of this system lies in the possibility of using the surface active ionic liquid to improve surfactant enhanced oil recovery methods. With those and previous measurements, thirteen sets of equilibrium data for water + ionic liquid + oil ternary systems have been correlated. The isoactivity equilibrium condition, using the NRTL model, and some pivotal strategies are proposed to correlate these complex systems. Good agreement has been found between experimental and calculated data in all the regions (one triphasic and two biphasic) of the diagrams. The geometric aspects related to the Gibbs energy of mixing function obtained using the model, together with the minor common tangent plane equilibrium condition, are valuable tools to check the consistency of the obtained correlation results.

  7. Numerical simulation of the two-phase flows in a hydraulic coupling by solving VOF model

    Science.gov (United States)

    Luo, Y.; Zuo, Z. G.; Liu, S. H.; Fan, H. G.; Zhuge, W. L.

    2013-12-01

    The flow in a partially filled hydraulic coupling is essentially a gas-liquid two-phase flow, in which the distribution of two phases has significant influence on its characteristics. The interfaces between the air and the liquid, and the circulating flows inside the hydraulic coupling can be simulated by solving the VOF two-phase model. In this paper, PISO algorithm and RNG k-ɛ turbulence model were employed to simulate the phase distribution and the flow field in a hydraulic coupling with 80% liquid fill. The results indicate that the flow forms a circulating movement on the torus section with decreasing speed ratio. In the pump impeller, the air phase mostly accumulates on the suction side of the blades, while liquid on the pressure side; in turbine runner, air locates in the middle of the flow passage. Flow separations appear near the blades and the enclosing boundaries of the hydraulic coupling.

  8. Vapor–Liquid–Liquid Equilibrium Measurements and Modeling of Ethanethiol + Methane + Water, 1-Propanethiol + Methane + Water and 1-Butanethiol + Methane + Water Ternary Systems at 303, 335, and 365 K and Pressure Up to 9 MPa

    DEFF Research Database (Denmark)

    Awan, Javeed; Kontogeorgis, Georgios; Tsivintzelis, Ioannis;

    2013-01-01

    New vapor–liquid–liquid equilibrium (VLLE) data for ethanethiol + methane + water, 1-propanethiol + methane + water, and 1-butanethiol + methane + water ternary systems have been measured at three temperatures (303, 335, and 365 K) and pressures up to 9 MPa. A “static-analytic” method was used...... for performing the measurements; the total system pressure was maintained by CH4. The objective of this work is to provide experimental VLLE data for mixtures of mercaptans (thiols) with other natural gas contents at its crude form, for which no data are available in the open literature. Such data will help....... However, the model underestimates the water content of the vapor phase, especially at low pressures and at the highest investigated temperature, i.e., at 365 K. Only the ethanthiol + methane + water system showed significant cross-association effects...

  9. Solid-Liquid Equilibria of Several Binary and Ternary Systems Containing Maleic Anhydride%顺丁烯二酸酐在单一溶剂和混合溶剂中的固液平衡研究

    Institute of Scientific and Technical Information of China (English)

    马沛生; 陈明鸣; 董奕

    2002-01-01

    Solid-liquid equilibria (SLE) of three binary systems and seven ternary systems containing maleic anhydride(MA) are measured by visual method. The experimental data are compared with the calculated ones with modified universal quasichemical functional group activity coefficient(UNIFAC) method in which the interaction parameters between groups come from two sources, dortmund data bank(DDB), if there's any, and correlations based on our former presented experimental SLE data of twenty binary systems. New groups of MA, ACCOO group, COO group, >C=O group and cy-CH2 group are defined and the SLE data of maleic anhydride in isopropyl acetate in literature are cited in order to assess the new interaction parameters, correlated with Wilson equation and the λh equation. The modified UNIFAC method with these new regressed interaction parameters is also used to predict other three binary systems containing maleic anhydride.

  10. Numerical simulation of vapor-liquid two-phase flow and boiling in steam generator based on population balance%基于群体平衡原理的蒸汽发生器汽液两相流动与沸腾数值模拟

    Institute of Scientific and Technical Information of China (English)

    杨元龙; 孙宝芝; 杨柳; 郑陆松

    2014-01-01

    Based on similarity principle, a three-dimensional“unit pipe”physical model is built for a steam generator coupled with quatrefoil tube support plates. A multiple size group model considering breakup and coalescence of bubbles is used to describe bubble size distribution and hydraulic characteristic in the secondary side. The process of local vapor-liquid two-phase boiling with phase change is calculated through a thermal phase change model. Numerical investigation is carried out on vapor-liquid two-phase flow and boiling of steam generator at Daya Bay Nuclear Power Plant. Simulation results show that vapor and liquid velocities rapidly increase in the support plate and jet flow appears, and when the flow leaves the support plate orifice, reflow forms rapidly. The periodic distribution from small to large bubble size occurs obviously within adjacent tube support plates and the maximum bubble diameter decreases slowly in the direction of hot and cold legs. In addition, the averaged heat transfer coefficient of secondary side agrees well with the results calculated using Rohsenow’s correlation.%基于相似原理建立了耦合四叶梅花形支撑板的蒸汽发生器“单元管”三维物理模型。采用考虑汽泡聚合与破碎效应的MUSIG (multiple-size-group)模型描述二次侧汽泡尺度分布和水力特性,热相变模型计算二次侧汽液两相沸腾相变过程,对大亚湾蒸汽发生器汽液两相流动与沸腾过程进行数值研究。模拟结果表明,支撑板位置处汽、液相流速均急剧升高,产生射流,在离开支撑板孔口时迅速形成回流。两相邻支撑板间出现明显的汽泡由小到大的周期性变化过程,冷、热端沿程汽泡最大直径缓慢减小。二次侧平均传热系数与 Rohsenow 经验关联式的计算结果吻合较好。

  11. Microgravity Two-Phase Flow Transition

    Science.gov (United States)

    Parang, M.; Chao, D.

    1999-01-01

    Two-phase flows under microgravity condition find a large number of important applications in fluid handling and storage, and spacecraft thermal management. Specifically, under microgravity condition heat transfer between heat exchanger surfaces and fluids depend critically on the distribution and interaction between different fluid phases which are often qualitatively different from the gravity-based systems. Heat transfer and flow analysis in two-phase flows under these conditions require a clear understanding of the flow pattern transition and development of appropriate dimensionless scales for its modeling and prediction. The physics of this flow is however very complex and remains poorly understood. This has led to various inadequacies in flow and heat transfer modeling and has made prediction of flow transition difficult in engineering design of efficient thermal and flow systems. In the present study the available published data for flow transition under microgravity condition are considered for mapping. The transition from slug to annular flow and from bubbly to slug flow are mapped using dimensionless variable combination developed in a previous study by the authors. The result indicate that the new maps describe the flow transitions reasonably well over the range of the data available. The transition maps are examined and the results are discussed in relation to the presumed balance of forces and flow dynamics. It is suggested that further evaluation of the proposed flow and transition mapping will require a wider range of microgravity data expected to be made available in future studies.

  12. Characterization of horizontal air–water two-phase flow

    Energy Technology Data Exchange (ETDEWEB)

    Kong, Ran; Kim, Seungjin, E-mail: skim@psu.edu

    2017-02-15

    Highlights: • A visualization study is performed to develop flow regime map in horizontal flow. • Database in horizontal bubbly flow is extended using a local conductivity probe. • Frictional pressure drop analysis is performed in horizontal bubbly flow. • Drift flux analysis is performed in horizontal bubbly flow. - Abstract: This paper presents experimental studies performed to characterize horizontal air–water two-phase flow in a round pipe with an inner diameter of 3.81 cm. A detailed flow visualization study is performed using a high-speed video camera in a wide range of two-phase flow conditions to verify previous flow regime maps. Two-phase flows are classified into bubbly, plug, slug, stratified, stratified-wavy, and annular flow regimes. While the transition boundaries identified in the present study compare well with the existing ones (Mandhane et al., 1974) in general, some discrepancies are observed for bubbly-to-plug/slug, and plug-to-slug transition boundaries. Based on the new transition boundaries, three additional test conditions are determined in horizontal bubbly flow to extend the database by Talley et al. (2015a). Various local two-phase flow parameters including void fraction, interfacial area concentration, bubble velocity, and bubble Sauter mean diameter are obtained. The effects of increasing gas flow rate on void fraction, bubble Sauter mean diameter, and bubble velocity are discussed. Bubbles begin to coalesce near the gas–liquid layer instead of in the highly packed region when gas flow rate increases. Using all the current experimental data, two-phase frictional pressure loss analysis is performed using the Lockhart–Martinelli method. It is found that the coefficient C = 24 yields the best agreement with the data with the minimum average difference. Moreover, drift flux analysis is performed to predict void-weighted area-averaged bubble velocity and area-averaged void fraction. Based on the current database, functional

  13. Ternary chalcopyrite semiconductors

    CERN Document Server

    Shay, J L; Pamplin, B R

    2013-01-01

    Ternary Chalcopyrite Semiconductors: Growth, Electronic Properties, and Applications covers the developments of work in the I-III-VI2 and II-IV-V2 ternary chalcopyrite compounds. This book is composed of eight chapters that focus on the crystal growth, characterization, and applications of these compounds to optical communications systems. After briefly dealing with the status of ternary chalcopyrite compounds, this book goes on describing the crystal growth of II-IV-V2 and I-III-VI2 single crystals. Chapters 3 and 4 examine the energy band structure of these semiconductor compounds, illustrat

  14. Numerical calculation on gas-liquid two-phase hydrotransport and flow field measurement in volute with probes for vortex pump%旋流泵含气混输数值计算及涡室流场探针测量

    Institute of Scientific and Technical Information of China (English)

    沙毅; 刘祥松

    2014-01-01

    为探索旋流泵内部流场及气液两相流混输特性,该文通过32WB8-12型旋流泵外特性试验和泵最优工况流场五孔探针测量,得出泵性能曲线和5个测点静压ps、绝对速度v、圆周速度vu、径向速度vr和轴向速度vz分布情况。针对N-S方程中四项力在气液两相流动中的具体表现特性进行力学分析,说明了泵内部两相流动特点及关联因素之间约束关系。阐明了旋流泵含气混输抽吸和扬程形成的基本原理,及空化和气液两相流混输的不同特点。选择性能试验最优工况,基于改进重组化群k-ε湍流模型(RNG k-ε模型),应用Fluent软件对泵内部流场进行数值模拟,得到了3个轴面静压、速度矢量和含气率分布图。证明泵进口轴向运动为主流,气体主要集中在压力较低的进口区域。气相的引入,其微团与液相尺寸、形状及弹性模量的不同,造成两相流场惯性力、摩擦力和浮力发生变化,由此解释了外特性变化及气液抽吸与内部流动之间定性的因果关系。探讨了旋流泵内部气液两相流动速度场和过流通道发生畸变的基本原理,为建立旋流泵内部气液及空化流动模型提供实例。%In order to study the characteristics of the flow field and gas-liquid two-phase flow hydrotransport in vortex pumps, the performance test and the measurement of flow field in volute at optimal operating condition with five-hole probes were conducted on a self-built vortex pump (32WB8-12). Based on these experiments, the qv-H,qv-P,qv-η,qv-NPSHc performance curves and the absolute velocityv, circumferential velocityvu, radial velocityvr, axial velocityvz, and the flow static pressure ps, on the 5 measuring points were obtained. The obtained parabolicqv-NPSH performance curve shows the opposite tendency compared to the centrifugal pump. The mechanical properties of the four kinds of forces in gas-liquid two-phase flow were

  15. Living between two worlds: two-phase culture systems for producing plant secondary metabolites.

    Science.gov (United States)

    Malik, Sonia; Hossein Mirjalili, Mohammad; Fett-Neto, Arthur Germano; Mazzafera, Paulo; Bonfill, Mercedes

    2013-03-01

    The two-phase culture system is an important in vitro strategy to increase the production of secondary metabolites (SMs) by providing an enhanced release of these compounds from plant cells. Whereas the first phase supports cell growth, the second phase provides an additional site or acts as a metabolic sink for the accumulation of SMs and also reduces feedback inhibition. This review is focused on several aspects of the two-phase culture system and aims to show the diverse possibilities of employing this technique for the in vitro production of SMs from plant cells. Depending on the material used in the secondary phase, two-phase culture systems can be broadly categorised as liquid-liquid or liquid-solid. The choice of material for the second phase depends on the type of compound to be recovered and the compatibility with the other phase. Different factors affecting the efficiency of two-phase culture systems include the choice of material for the secondary phase, its concentration, volume, and time of addition. Factors such as cell elicitation, immobilization, and permeabilization, have been suggested as important strategies to make the two-phase culture system practically reliable on a commercial scale. Since there are many possibilities for designing a two-phase system, more detailed studies are needed to broaden the range of secondary phases compatible with the various plant species producing SMs with potential applications, mainly in the food and pharmacology industries.

  16. Droplet Manipulations in Two Phase Flow Microfluidics

    Directory of Open Access Journals (Sweden)

    Arjen M. Pit

    2015-11-01

    Full Text Available Even though droplet microfluidics has been developed since the early 1980s, the number of applications that have resulted in commercial products is still relatively small. This is partly due to an ongoing maturation and integration of existing methods, but possibly also because of the emergence of new techniques, whose potential has not been fully realized. This review summarizes the currently existing techniques for manipulating droplets in two-phase flow microfluidics. Specifically, very recent developments like the use of acoustic waves, magnetic fields, surface energy wells, and electrostatic traps and rails are discussed. The physical principles are explained, and (potential advantages and drawbacks of different methods in the sense of versatility, flexibility, tunability and durability are discussed, where possible, per technique and per droplet operation: generation, transport, sorting, coalescence and splitting.

  17. Two phase decision algorithm of replica allocation

    Institute of Scientific and Technical Information of China (English)

    Zuo Chaoshu; Liu Xinsong; Wang Zheng; Li Yi

    2006-01-01

    In distributed parallel server system, location and redundancy of replicas have great influence on availability and efficiency of the system. In order to improve availahility and efficiency of the system, two phase decision algorithm of replica allocation is proposed. The algorithm which makes use of auto-regression model dynamically predicts the future count of READ and WRITE operation, and then determines location and redundancy of replicas by considering availability, CPU and bands of the network. The algorithm can not only ensure the requirement of availability, but also reduce the system resources consumed by all the operations in a great scale. Analysis and test show that communication complexity and time complexity of the algorithm satisfy O( n ), resource optimizing scale increases with the increase of READ count.

  18. Emerging Two-Phase Cooling Technologies for Power Electronic Inverters

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, J.S.

    2005-08-17

    In order to meet the Department of Energy's (DOE's) FreedomCAR and Vehicle Technologies (FVCT) goals for volume, weight, efficiency, reliability, and cost, the cooling of the power electronic devices, traction motors, and generators is critical. Currently the power electronic devices, traction motors, and generators in a hybrid electric vehicle (HEV) are primarily cooled by water-ethylene glycol (WEG) mixture. The cooling fluid operates as a single-phase coolant as the liquid phase of the WEG does not change to its vapor phase during the cooling process. In these single-phase systems, two cooling loops of WEG produce a low temperature (around 70 C) cooling loop for the power electronics and motor/generator, and higher temperature loop (around 105 C) for the internal combustion engine. There is another coolant option currently available in automobiles. It is possible to use the transmission oil as a coolant. The oil temperature exists at approximately 85 C which can be utilized to cool the power electronic and electrical devices. Because heat flux is proportional to the temperature difference between the device's hot surface and the coolant, a device that can tolerate higher temperatures enables the device to be smaller while dissipating the same amount of heat. Presently, new silicon carbide (SiC) devices and high temperature direct current (dc)-link capacitors, such as Teflon capacitors, are available but at significantly higher costs. Higher junction temperature (175 C) silicon (Si) dies are gradually emerging in the market, which will eventually help to lower hardware costs for cooling. The development of high-temperature devices is not the only way to reduce device size. Two-phase cooling that utilizes the vaporization of the liquid to dissipate heat is expected to be a very effective cooling method. Among two-phase cooling methods, different technologies such as spray, jet impingement, pool boiling and submersion, etc. are being developed. The

  19. Ternary optical computer principle

    Institute of Scientific and Technical Information of China (English)

    金翊; 何华灿; 吕养天

    2003-01-01

    The fundamental principle and the characteristics of ternary optical computer, using horizontal polarized light, vertical polarized light and no-intensity to express information, are propounded in thispaper. The practicability to make key parts of the ternary optical computer from modern micro or integrated optical devices, opto-electronic and electro-photonic elements is discussed. The principle can be applied in three-state optical fiber communication via horizontal and vertical polarized light.

  20. Experimental study of a two-phase surface jet

    Science.gov (United States)

    Perret, Matias; Esmaeilpour, Mehdi; Politano, Marcela S.; Carrica, Pablo M.

    2013-04-01

    Results of an experimental study of a two-phase jet are presented, with the jet issued near and below a free surface, parallel to it. The jet under study is isothermal and in fresh water, with air injectors that allow variation of the inlet air volume fraction between 0 and 13 %. Measurements of water velocity have been performed using LDV, and the jet exit conditions measured with PIV. Air volume fraction, bubble velocity and chord length distributions were measured with sapphire optical local phase detection probes. The mean free surface elevation and RMS fluctuations were obtained using local phase detection probes as well. Visualization was performed with laser-induced fluorescence. Measurements reveal that the mean free surface elevation and turbulent fluctuations significantly increase with the injection of air. The water normal Reynolds stresses are damped by the presence of bubbles in the bulk of the liquid, but very close to the free surface the effect is reversed and the normal Reynolds stresses increase slightly for the bubbly flow. The Reynolds shear stresses time it takes the bubbles to pierce the free surface, resulting in a considerable increase in the local air volume fraction. In addition to first explore a bubbly surface jet, the comprehensive dataset reported herein can be used to validate two-phase flow models and computational tools.

  1. Aqueous Nanofluid as a Two-Phase Coolant for PWR

    Directory of Open Access Journals (Sweden)

    Pavel N. Alekseev

    2012-01-01

    Full Text Available Density fluctuations in liquid water consist of two topological kinds of instant molecular clusters. The dense ones have helical hydrogen bonds and the nondense ones are tetrahedral clusters with ice-like hydrogen bonds of water molecules. Helical ordering of protons in the dense water clusters can participate in coherent vibrations. The ramified interface of such incompatible structural elements induces clustering impurities in any aqueous solution. These additives can enhance a heat transfer of water as a two-phase coolant for PWR due to natural forming of nanoparticles with a thermal conductivity higher than water. The aqueous nanofluid as a new condensed matter has a great potential for cooling applications. It is a mixture of liquid water and dispersed phase of extremely fine quasi-solid particles usually less than 50 nm in size with the high thermal conductivity. An alternative approach is the formation of gaseous (oxygen or hydrogen nanoparticles in density fluctuations of water. It is possible to obtain stable nanobubbles that can considerably exceed the molecular solubility of oxygen (hydrogen in water. Such a nanofluid can convert the liquid water in the nonstoichiometric state and change its reduction-oxidation (RedOx potential similarly to adding oxidants (or antioxidants for applying 2D water chemistry to aqueous coolant.

  2. Stability of stratified two-phase flows in horizontal channels

    Science.gov (United States)

    Barmak, I.; Gelfgat, A.; Vitoshkin, H.; Ullmann, A.; Brauner, N.

    2016-04-01

    Linear stability of stratified two-phase flows in horizontal channels to arbitrary wavenumber disturbances is studied. The problem is reduced to Orr-Sommerfeld equations for the stream function disturbances, defined in each sublayer and coupled via boundary conditions that account also for possible interface deformation and capillary forces. Applying the Chebyshev collocation method, the equations and interface boundary conditions are reduced to the generalized eigenvalue problems solved by standard means of numerical linear algebra for the entire spectrum of eigenvalues and the associated eigenvectors. Some additional conclusions concerning the instability nature are derived from the most unstable perturbation patterns. The results are summarized in the form of stability maps showing the operational conditions at which a stratified-smooth flow pattern is stable. It is found that for gas-liquid and liquid-liquid systems, the stratified flow with a smooth interface is stable only in confined zone of relatively low flow rates, which is in agreement with experiments, but is not predicted by long-wave analysis. Depending on the flow conditions, the critical perturbations can originate mainly at the interface (so-called "interfacial modes of instability") or in the bulk of one of the phases (i.e., "shear modes"). The present analysis revealed that there is no definite correlation between the type of instability and the perturbation wavelength.

  3. Two-phase flow instability in a parallel multichannel system

    Institute of Scientific and Technical Information of China (English)

    HOU Suxia

    2009-01-01

    The two-phase flow instabilities observed in through parallel multichannel can be classified into three types, of which only one is intrinsic to parallel multichannel systems. The intrinsic instabilities observed in parallel multichannel system have been studied experimentally. The stable boundary of the flow in such a parallel-channel system are sought, and the nature of inlet flow oscillation in the unstable region has been examined experimentally under various conditions of inlet velocity, heat flux, liquid temperature, cross section of channel and entrance throttling. The results show that parallel multichannel system possess a characteristic oscillation that is quite independent of the magnitude and duration of the initial disturbance, and the stable boundary is influenced by the characteristic frequency of the system as well as by the exit quality when this is low, and upon raising the exit quality and reducing the characteristic frequency, the system increases its instability, and entrance throttling effectively contributes to stabilization of the system.

  4. Mathematical model of two-phase flow in accelerator channel

    Directory of Open Access Journals (Sweden)

    О.Ф. Нікулін

    2010-01-01

    Full Text Available  The problem of  two-phase flow composed of energy-carrier phase (Newtonian liquid and solid fine-dispersed phase (particles in counter jet mill accelerator channel is considered. The mathematical model bases goes on the supposition that the phases interact with each other like independent substances by means of aerodynamics’ forces in conditions of adiabatic flow. The mathematical model in the form of system of differential equations of order 11 is represented. Derivations of equations by base physical principles for cross-section-averaged quantity are produced. The mathematical model can be used for estimation of any kinematic and thermodynamic flow characteristics for purposely parameters optimization problem solving and transfer functions determination, that take place in  counter jet mill accelerator channel design.

  5. Two phase coexistence for the hydrogen-helium mixture

    CERN Document Server

    Fantoni, Riccardo

    2015-01-01

    We use our newly constructed quantum Gibbs ensemble Monte Carlo algorithm to perform computer experiments for the two phase coexistence of a hydrogen-helium mixture. Our results are in quantitative agreement with the experimental results of C. M. Sneed, W. B. Streett, R. E. Sonntag, and G. J. Van Wylen. The difference between our results and the experimental ones is in all cases less than 15% relative to the experiment, reducing to less than 5% in the low helium concentration phase. At the gravitational inversion between the vapor and the liquid phase, at low temperatures and high pressures, the quantum effects become relevant. At extremely low temperature and pressure the first component to show superfluidity is the helium in the vapor phase.

  6. Two-phase anaerobic digestion of vegetable market waste fraction of municipal solid waste and development of improved technology for phase separation in two-phase reactor.

    Science.gov (United States)

    Majhi, Bijoy Kumar; Jash, Tushar

    2016-12-01

    Biogas production from vegetable market waste (VMW) fraction of municipal solid waste (MSW) by two-phase anaerobic digestion system should be preferred over the single-stage reactors. This is because VMW undergoes rapid acidification leading to accumulation of volatile fatty acids and consequent low pH resulting in frequent failure of digesters. The weakest part in the two-phase anaerobic reactors was the techniques applied for solid-liquid phase separation of digestate in the first reactor where solubilization, hydrolysis and acidogenesis of solid organic waste occur. In this study, a two-phase reactor which consisted of a solid-phase reactor and a methane reactor was designed, built and operated with VMW fraction of Indian MSW. A robust type filter, which is unique in its implementation method, was developed and incorporated in the solid-phase reactor to separate the process liquid produced in the first reactor. Experiments were carried out to assess the long term performance of the two-phase reactor with respect to biogas production, volatile solids reduction, pH and number of occurrence of clogging in the filtering system or choking in the process liquid transfer line. The system performed well and was operated successfully without the occurrence of clogging or any other disruptions throughout. Biogas production of 0.86-0.889m(3)kg(-1)VS, at OLR of 1.11-1.585kgm(-3)d(-1), were obtained from vegetable market waste, which were higher than the results reported for similar substrates digested in two-phase reactors. The VS reduction was 82-86%. The two-phase anaerobic digestion system was demonstrated to be stable and suitable for the treatment of VMW fraction of MSW for energy generation.

  7. Two phase continuous digestion of solid manure on-farm

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, W.; Lehto, M. [MTT Agrifood Research Finland, Vihti (Finland). Animal Production Research; Evers, L.; Granstedt, A. [Biodynamic Research Inst., Jaerna (Sweden)

    2007-07-01

    Present commercially available biogas plants are mainly suitable for slurry and co-substrates. Cattle, horse and poultry farms using a solid manure chain experience a crucial competitive disadvantage, because conversion to slurry technology requires additional investments. Based on the technological progress of anaerobic digestion of municipal solid waste, so called 'dry fermentation' prototype plants were developed for anaerobic digestion of organic material containing 15-50% total solids (Hoffman, 2001). These plants show added advantages compared to slurry digestion plants: Less reactor volume, less process energy, less transport capacity, less odour emissions. On-farm research (Gronauer and Aschmann, 2004; Kusch and Oechsner, 2004) and prototype research (Linke, 2004) on dry fermentation in batch reactors show that loading and discharging of batch reactors remains difficult and/or time-consuming compared to slurry reactors. Additionally a constant level of gas generation requires offset operation of several batch reactors. Baserga et al. (1994) developed a pilot plant of 9.6 m{sup 3} capacity for continuous digestion of solid beef cattle manure on-farm. However, on-farm dry fermentation plants are not common and rarely commercially available. We assume that lack of tested technical solutions and scarceness of on-farm research results are the main reason for low acceptance of dry fermentation technology on-farm. We report about an innovative two phase farm-scale biogas plant. The plant continuously digests dairy cattle manure and organic residues of the farm and the surrounding food processing units. The two phase reactor technology was chosen for two reasons: first it offers the separation of a liquid fraction and a solid fraction for composting after hydrolysis and secondly the methanation of the liquid fraction using fixed film technology results in a very short hydraulic retention time, reduction in reactor volume, and higher methane content of the

  8. Pb-free Sn-Ag-Cu ternary eutectic solder

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, I.E.; Yost, F.G.; Smith, J.F.; Miller, C.M.; Terpstra, R.L.

    1996-06-18

    A Pb-free solder includes a ternary eutectic composition consisting essentially of about 93.6 weight % Sn-about 4.7 weight % Ag-about 1.7 weight % Cu having a eutectic melting temperature of about 217 C and variants of the ternary composition wherein the relative concentrations of Sn, Ag, and Cu deviate from the ternary eutectic composition to provide a controlled melting temperature range (liquid-solid ``mushy`` zone) relative to the eutectic melting temperature (e.g. up to 15 C above the eutectic melting temperature). 5 figs.

  9. Estimation of flow velocity for a debris flow via the two-phase fluid model

    Directory of Open Access Journals (Sweden)

    S. Guo

    2014-06-01

    Full Text Available The two-phase fluid model is applied in this study to calculate the steady velocity of a debris flow along a channel bed. By using the momentum equations of the solid and liquid phases in the debris flow together with an empirical formula to describe the interaction between two phases, the steady velocities of the solid and liquid phases are obtained theoretically. The comparison of those velocities obtained by the proposed method with the observed velocities of two real-world debris flows shows that the proposed method can estimate accurately the velocity for a debris flow.

  10. Binary and Ternary Vapor-Liquid Equilibrium Data of the System (Ethylbenzene+Styrene+4-Methyl-N-butylpyridinium Tetrafluoroborate) at Vacuum Conditions and Liquid-Liquid Equilibrium Data of Their Binary Systems

    NARCIS (Netherlands)

    Jongmans, Mark; Raijmakers, M.; Schuur, Boelo; de Haan, A.B.

    2012-01-01

    Ethylbenzene and styrene are currently separated by ordinary fractional distillation, which is challenging due the low relative volatility of this mixture of 1.3 to 1.4. Extractive distillation is a promising alternative to save capital and operational expenditures. Recently, ionic liquids (ILs) hav

  11. Application of vapor-liquid two-phase flow technology in upgrading high/low pressure heater drain system of thermal power plant%汽液两相流技术在火电厂高低压加热器疏水改造中应用

    Institute of Scientific and Technical Information of China (English)

    张辉

    2012-01-01

    Aiming at the problems existed in traditional basis pneumatic regulating mode such as the water level of high/low pressure heater becoming out of control, operation of heater with full water level or no water level, water - level fluctuation of heater and so on, the application of vapor - liquid two - phase flow automatic - regulation water level control device in upgrading high/low heater hydrophobic modification system of 125 MW turboset has guaranteed the stability of water level of heater, enhanced the safety of the turboset and saved the fire coal and costs of maintenance.%针对传统的基地式气动调节方式存在的高、低压加热器水位失控,加热器满水位或无水位运行及加热器水位波动大等问题,将汽液两相流自调节水位控制装置应用在125 MW汽轮发电机组高、低加热器疏水改造系统上,保证了加热器的水位稳定性,提高了机组的安全性,节约了燃煤和维护费用.

  12. Demixing and gelation behavior of ternary cellulose acetate solutions

    NARCIS (Netherlands)

    Reuvers, A.J.; Altena, F.W.; Smolders, C.A.

    1986-01-01

    The demixing behavior on cooling of ternary systems of cellulose acetate/solvent/water has been examined for CA concentrations up to 40 wt% CA in several solvents. Cloud points have been measured as a function of cooling rate. The rapid process of liquid - liquid demixing can be discriminated from t

  13. Pressure Loss across Tube Bundles in Two-phase Flow

    Energy Technology Data Exchange (ETDEWEB)

    Sim, Woo Gun; Banzragch, Dagdan [Hannam Univ., Daejon (Korea, Republic of)

    2016-03-15

    An analytical model was developed by Sim to estimate the two-phase damping ratio for upward two-phase flow perpendicular to horizontal tube bundles. The parameters of two-phase flow, such as void fraction and pressure loss evaluated in the model, were calculated based on existing experimental formulations. However, it is necessary to implement a few improvements in the formulations for the case of tube bundles. For the purpose of the improved formulation, we need more information about the two-phase parameters, which can be found through experimental test. An experiment is performed with a typical normal square array of cylinders subjected to the two-phase flow of air-water in the tube bundles, to calculate the two-phase Euler number and the two-phase friction multiplier. The pitch-to-diameter ratio is 1.35 and the diameter of cylinder is 18mm. Pressure loss along the flow direction in the tube bundles is measured with a pressure transducer and data acquisition system to calculate the two-phase Euler number and the two-phase friction multiplier. The void fraction model by Feenstra et al. is used to estimate the void fraction of the two-phase flow in tube bundles. The experimental results of the two phase friction multiplier and two-phase Euler number for homogeneous and non-homogeneous two-phase flows are compared and evaluated against the analytical results given by Sim's model.

  14. The study of dynamic differential pressure signal of gas-liquid two-phase flow based on adaptive Chirplet transformation%基于自适应线性调频小波的多孔孔板气液两相流动态差压信号的时频分析研究

    Institute of Scientific and Technical Information of China (English)

    陈飞; 孙斌

    2015-01-01

    The gas-liquid two-phase flow shows non-stationary characteristics which cannot be well analyzed by traditional frequency or time domain analysis.In this study,the dynamic differ-ential pressure signal of two-phase flow is sampled for flow characteristics analysis and flow pat-tern identification.A time-frequency analysis technique with adaptive Chirplet transformation is introduced,which could profile the energy intensity and density distribution of non-stationary signal.The multi-hole orifices plate flowmeter is used to generate the dynamic differential pres-sure signal in a horizontal gas-liquid two-phase pipe.The dynamic differential pressure signals sampled in the pipe are of non-stationary characteristics which are determined by the flow patterns.The adaptive Chirplet transformation is adopted to process the dynamic differential pressure signals.The stages of the method are:Firstly,the differential signals are decomposed and reconstructed by optimized parameters and the ratio of the residual energy of the signal to the total energy is kept lower than 10% to ensure the useful components of the signal are completely decomposed.Secondly,the time-frequency distribution characteristics of different flow patterns are analyzed by transforming the reconstructed signals.The time-frequency spectra of the trans-formation contain signal components’time-frequency information which reflects the flow proper-ties of different flow patterns.The time-frequency spectra show that the energy of bubbly flow is mainly concentrated in a relatively high-frequency band (15-35)Hz with a low energy intensity. The energy of slug flow is distributed in the low-frequency band (0-5)Hz and the high-frequency band (10-35)Hz,and the signal energy is increased.The energy of plug flow is of low frequency characteristic ranging (0-5)Hz,and the energy intensity is the largest among the three flow pat-terns.Thirdly,three eigenvalues from the spectra are extracted and a 3D scatter plot chart is

  15. 基于气液两相流入口蒸汽参数对管壳式冷凝器性能的影响%The Effect to the Performance of Shell-and-tube Condenser of Inlet Steam Parameters Based on Gas-liquid Two-phase Flow

    Institute of Scientific and Technical Information of China (English)

    黄国权; 戈锐; 李想; 张玉宝

    2012-01-01

    采用数值模拟方法,使用CFD软件FLUENT对管壳式冷凝器壳侧按两相流动及相变传热进行了模拟计算,选定合适的湍流模型、两相流模型为混合物模型,并根据汽水转化公式编写了自定义函数UDF来描述相变过程质和量的传递.针对壳侧流体介质为高温饱和水蒸汽情况下,分别对不同的介质入口速度和入口温度情况下换热器壳侧传热系数、湍流动能和压强变化的模拟结果进行了比较,得出了流体介质入口速度与温度对换热器壳侧传热特点和传热性能的影响规律.从而对冷凝器壳侧结构参数的优化及流动介质进行合理的选择起到指导作用.%Numerical-simulation methods are adopted here.With the help of CFD and FLUENT software, the two-phase flow and phase change and heat transfer is simulatedA turbulence model and a two-phase flow model are selected. Based on the characteristics of shell-side in the shell-and-tube condenser, User梔efined Function (UDF)is introduced to describe the phase transition of quality and quantity through the use of the conversion formula, analyzing the influence on the condenser coefficients and its pressure. Choosing saturated vapor as the liquid medium at the inlet of shell-side of the shell-and-tube heat exchangers , it focuses on comparing the simulation results on the heat coefficient,turbulent momentum and pressure distribution of the shell-and梩ube heat exchangers at the inlet.The experimental results reveal the influence law of the velocity and temperature of fluid medium inlet to the characteristics and the performance of the heat exchanger shell side.These provide some valuable references to the improvement of tube condenser structure parameter optimization, and the choice of flow media

  16. New results in gravity dependent two-phase flow regime mapping

    Science.gov (United States)

    Kurwitz, Cable; Best, Frederick

    2002-01-01

    Accurate prediction of thermal-hydraulic parameters, such as the spatial gas/liquid orientation or flow regime, is required for implementation of two-phase systems. Although many flow regime transition models exist, accurate determination of both annular and slug regime boundaries is not well defined especially at lower flow rates. Furthermore, models typically indicate the regime as a sharp transition where data may indicate a transition space. Texas A&M has flown in excess of 35 flights aboard the NASA KC-135 aircraft with a unique two-phase package. These flights have produced a significant database of gravity dependent two-phase data including visual observations for flow regime identification. Two-phase flow tests conducted during recent zero-g flights have added to the flow regime database and are shown in this paper with comparisons to selected transition models. .

  17. Formation of a two-phase microstructure in Fe-Cr-Ni alloy during directional solidification

    Science.gov (United States)

    Fu, J. W.; Yang, Y. S.; Guo, J. J.; Ma, J. C.; Tong, W. H.

    2008-12-01

    The formation and evolution of a two-phase coupled growth microstructure in AISI 304 stainless steel are investigated using a quenching method during directional solidification. It is found that the two-phase microstructure, which is composed of coupled growth of thin lathy delta ferrite (δ) and austenite (γ), forms from the melt first during solidification. As solidification proceeds, the retained liquid transforms into austenite directly. On cooling, the subsequent incomplete solid-state transformation from ferrite to austenite results in the disappearance of the thinner lathy delta ferrite, and the final two-phase coupled growth microstructure is formed. The formation mechanism of the two-phase coupled growth microstructure is analyzed theoretically based on the nucleation and constitutional undercooling (NCU) criterion. Transmission electron microscope (TEM) and EDS analyses were carried out to identify the phases and determine the phase composition, respectively.

  18. True ternary fission

    Science.gov (United States)

    Vijayaraghavan, K. R.; Balasubramaniam, M.; von Oertzen, W.

    2015-04-01

    The study of the ternary fission of nuclei has received new interest recently. It is of general interest for nuclear dynamics, although the process is very rare. In the present work, we discuss the possibilities of true ternary fission (fragment masses A >30 ) in 252Cf for different mass splits. These mass splits are strongly favored in a collinear geometry. Based on the three cluster model (TCM), it is shown that the true ternary fission into fragments with almost equal masses is one of the possible fission modes in 252Cf . For general decays it is shown that the formation of the lightest fragment at the center has the highest probability. Further the formation of tin isotopes and/or other closed shell fragments are favored. For the decay products the presence of closed shell nuclei among the three fragments enhances the decay probabilities.

  19. Polymer-ionic liquid ternary systems for Li-battery electrolytes: Molecular dynamics studies of LiTFSI in a EMIm-TFSI and PEO blend

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Luciano T., E-mail: ltcosta@id.uff.br [Instituto de Química-Departamento de Físico-Química, Universidade Federal Fluminense, Outeiro de São João Batista s/n CEP, 24020-150 Niterói, Rio de Janeiro (Brazil); Sun, Bing; Jeschull, Fabian; Brandell, Daniel [Department of Chemistry—Ångström Laboratory, Uppsala University, P.O. Box 538, SE-751 21 Uppsala (Sweden)

    2015-07-14

    This paper presents atomistic molecular dynamics simulation studies of lithium bis(trifluoromethane)sulfonylimide (LiTFSI) in a blend of 1-ethyl-3-methylimidazolium (EMIm)-TFSI and poly(ethylene oxide) (PEO), which is a promising electrolyte material for Li- and Li-ion batteries. Simulations of 100 ns were performed for temperatures between 303 K and 423 K, for a Li:ether oxygen ratio of 1:16, and for PEO chains with 26 EO repeating units. Li{sup +} coordination and transportation were studied in the ternary electrolyte system, i.e., PEO{sub 16}LiTFSI⋅1.0 EMImTFSI, by applying three different force field models and are here compared to relevant simulation and experimental data. The force fields generated significantly different results, where a scaled charge model displayed the most reasonable comparisons with previous work and overall consistency. It is generally seen that the Li cations are primarily coordinated to polymer chains and less coupled to TFSI anion. The addition of EMImTFSI in the electrolyte system enhances Li diffusion, associated to the enhanced TFSI dynamics observed when increasing the overall TFSI anion concentration in the polymer matrix.

  20. Polymer-ionic liquid ternary systems for Li-battery electrolytes: Molecular dynamics studies of LiTFSI in a EMIm-TFSI and PEO blend.

    Science.gov (United States)

    Costa, Luciano T; Sun, Bing; Jeschull, Fabian; Brandell, Daniel

    2015-07-14

    This paper presents atomistic molecular dynamics simulation studies of lithium bis(trifluoromethane)sulfonylimide (LiTFSI) in a blend of 1-ethyl-3-methylimidazolium (EMIm)-TFSI and poly(ethylene oxide) (PEO), which is a promising electrolyte material for Li- and Li-ion batteries. Simulations of 100 ns were performed for temperatures between 303 K and 423 K, for a Li:ether oxygen ratio of 1:16, and for PEO chains with 26 EO repeating units. Li(+) coordination and transportation were studied in the ternary electrolyte system, i.e., PEO16LiTFSI⋅1.0 EMImTFSI, by applying three different force field models and are here compared to relevant simulation and experimental data. The force fields generated significantly different results, where a scaled charge model displayed the most reasonable comparisons with previous work and overall consistency. It is generally seen that the Li cations are primarily coordinated to polymer chains and less coupled to TFSI anion. The addition of EMImTFSI in the electrolyte system enhances Li diffusion, associated to the enhanced TFSI dynamics observed when increasing the overall TFSI anion concentration in the polymer matrix.

  1. Vapor Compressor Driven Hybrid Two-Phase Loop Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This Small Business Innovation Research Phase I project will demonstrate a vapor compressor driven hybrid two-phase loop technology. The hybrid two-phase loop...

  2. Microgravity two-phase flow regime modeling

    Energy Technology Data Exchange (ETDEWEB)

    Lee, D.; Best, F.R.; Faget, N.

    1987-01-01

    A flow pattern or flow regime is the characteristics spatial distribution of the phases of fluid in a duct. Since heat transfer and pressure drop are dependent on the characteristic distribution of the phases, it is necessary to describe flow patterns in an appropriate manner so that a hydrodynamic or heat transfer theory applicable to that pattern can be chosen. The objective of the present analysis is to create a flow regime map based on physical modeling of vapor/liquid interaction phenomena in a microgravity environment. In the present work, four basic flow patterns are defined: dispersed flow, stratified flow, slug flow, and annular flow. Fluid properties, liquid and vapor flow rates, and pipe size were chosen as the principal parameters. It is assumed that a transition from one flow pattern to another will occur when there is a change in the dominant force which controls that flow pattern. The forces considered in this modeling are surface tension force, both force, inertial force, friction, and turbulent fluctuations.

  3. Thermo-fluid dynamics of two-phase flow

    CERN Document Server

    Ishii, Mamoru; Ishii, Mamoru; Ishii, M

    2006-01-01

    Provides a very systematic treatment of two phase flow problems from a theoretical perspectiveProvides an easy to follow treatment of modeling and code devlopemnt of two phase flow related phenomenaCovers new results of two phase flow research such as coverage of fuel cells technology.

  4. Comparison of two-phase and three-phase methanol synthesis processes

    NARCIS (Netherlands)

    van de Graaf, G.H; Beenackers, A.A C M

    1996-01-01

    A comparison is made between the ICI (two-phase) methanol synthesis process and a three-phase slurry process based on a multi-stage agitated reactor. The process calculations are based on a complete reactor system consisting of the reactor itself, a recycling system and a gas-liquid separator. The b

  5. Investigation of the overall transient performance of the industrial two-phase closed loop thermosyphon

    NARCIS (Netherlands)

    Vincent, Charles C.J.; Kok, Jacobus B.W.

    1992-01-01

    The two-phase closed loop thermosyphon is investigated with emphasis on the overall performance in transient operation. The control volume approach is the base of a global analysis describing the motion of vapor and liquid phases of the thermosyphon system in one-dimensional equations. Interfacial s

  6. Comparison of two-phase and three-phase methanol synthesis processes

    NARCIS (Netherlands)

    van de Graaf, G.H; Beenackers, A.A C M

    1996-01-01

    A comparison is made between the ICI (two-phase) methanol synthesis process and a three-phase slurry process based on a multi-stage agitated reactor. The process calculations are based on a complete reactor system consisting of the reactor itself, a recycling system and a gas-liquid separator. The

  7. Reynolds transport theorem for a two-phase flow

    Science.gov (United States)

    Collado, Francisco J.

    2007-01-01

    Transport equations for one-dimensional (1d), steady, two-phase flow have been proposed based on the fact that if the phases have different velocities, they cannot cover the same distance (the control volume length) in the same time. Thus, working in the same control volume for the two phases, the time scales of the phases have to be different. From this approach, transport balances for 1D, steady, two-phase flow have been already derived, supplying acceptable correlations for two-phase flow. Here, based on the strict application of the Reynolds transport theorem, general transport balances for two-phase flow are suggested.

  8. Numerical Simulation of the Gas-liquid Two-phase Flow and Combustion in the Outlet of Venturi Burner%文丘利型油燃烧器出口 气液两相流动与燃烧的数值模拟

    Institute of Scientific and Technical Information of China (English)

    马哲树; 涂淑平; 姚寿广

    2001-01-01

    According to the characteristics of spray combustion in the oil-burned boiler equipped with Ven turi Burner and based on the simulation results of internal and external aerodynamic field under cold condi tion and gas-phase combustion field employed EBU model, the numerical simulation of the gas-liquid two phase flow and combustion in the outlet of venturi burner are presented. Distributions of pressure, velocity, temperature and ingredient concentration in chamber are provided. By theoretical analysis and contrast with the experimental results about Venturi Burner, the models, numerical methods and the numerical results given in this paper are credible. The numerical results can be used to guide the further design and operation of this type oil-burned boiler.%针对选配文丘利型油燃烧器的燃油锅炉中液雾燃烧的特点,在冷态等温流场数值模拟结果及 EBU-Arrhenius模型模拟气相燃烧所得结果的基础上,数值模拟了单只文丘利油燃烧器出口的气液两相 流动与燃烧,给出了流场中的速度场、温度场以及浓度场的分布信息,这些结论可为该型燃油锅炉的进 一步设计和运行以及燃烧室的布置提供有益的依据。

  9. Ternary fission of superheavy elements

    Science.gov (United States)

    Balasubramaniam, M.; Vijayaraghavan, K. R.; Manimaran, K.

    2016-01-01

    Ternary fission of superheavy nuclei is studied within the three-cluster model potential energy surfaces (PESs). Due to shell effects, the stability of superheavy nuclei has been predicted to be associated with Z =114 , 120, and 126 for protons and N =184 for neutrons. Taking some representative nuclei we have extended the ternary fission studies to superheavy nuclei. We adopted two minimization procedures to minimize the potential and considered different arrangements of the fragments. The PES from one-dimensional minimization reveals a strong cluster region favoring various ternary breakups for an arrangement in which the lightest fragment is kept at the center. The PES obtained from two-dimensional minimization reveals strong preference of ternary fragmentation in the true ternary fission region. Though the dominant decay mode of superheavy nuclei is α decay, the α -accompanied ternary breakup is found to be a nonfavorable one. Further, the prominent ternary combinations are found to be associated with the neutron magic number.

  10. Diffuse interface simulation of ternary fluids in contact with solid

    Science.gov (United States)

    Zhang, Chun-Yu; Ding, Hang; Gao, Peng; Wu, Yan-Ling

    2016-03-01

    In this article we developed a geometrical wetting condition for diffuse-interface simulation of ternary fluid flows with moving contact lines. The wettability of the substrate in the presence of ternary fluid flows is represented by multiple contact angles, corresponding to the different material properties between the respective fluid and the substrate. Displacement of ternary fluid flows on the substrate leads to the occurrence of moving contact point, at which three moving contact lines meet. We proposed a weighted contact angle model, to replace the jump in contact angle at the contact point by a relatively smooth transition of contact angle over a region of 'diffuse contact point' of finite size. Based on this model, we extended the geometrical formulation of wetting condition for two-phase flows with moving contact lines to ternary flows with moving contact lines. Combining this wetting condition, a Navier-Stokes solver and a ternary-fluid model, we simulated two-dimensional spreading of a compound droplet on a substrate, and validated the numerical results of the drop shape at equilibrium by comparing against the analytical solution. We also checked the convergence rate of the simulation by investigating the axisymmetric drop spreading in a capillary tube. Finally, we applied the model to a variety of applications of practical importance, including impact of a circular cylinder into a pool of two layers of different fluids and sliding of a three-dimensional compound droplet in shear flows.

  11. Thermodynamic description of Au-Ag-Si ternary system

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Based on the available experimental information, the Ag-Si binary system was thermodynamically assessed using the CALPHAD method. The solution phases, including liquid, fcc-Al and diamond-A4, were modeled as substitutional solutions, of which the excess Gibbs energies were expressed by Redlich-Kister polynomial functions. Combined with previous assessment of the Ag-Au and Au-Si binary systems, thermodynamic description of the Au-Ag-Si ternary system was performed to reproduce the reported phase equilibria. Thermodynamic properties of liquid alloys, liquidus projection and several vertical and isothermal sections of this ternary system were calculated, which are in reasonable agreement with the reported experimental data.

  12. Solidification pathways of ternary Cu62.5Fe27.5Sn10 alloy modulated through liquid undercooling and containerless processing

    Science.gov (United States)

    Xia, Z. C.; Wang, W. L.; Wu, Y. H.; Luo, S. B.; Wei, B.

    2016-11-01

    The active control of microstructure evolution is still a challenging factor for the development of advanced immiscible alloys. Here, we make an attempt to modulate the solidification pathways of undercooled Cu62.5Fe27.5Sn10 alloy by glass fluxing and drop tube techniques. Through regulating the liquid undercooling, three types of microstructures, dendrite, dispersive structure and macrosegregation pattern, were formed under the normal gravity condition. Below the first critical undercooling of 15 K, the alloy melt displayed the normal peritectic solidification. At moderate undercoolings above 15 K, the metastable liquid phase separation took place and the solidified microstructure appeared as homogeneously dispersed structure. If undercooling further overtook the second threshold of 107 K, macrosegregation occurred and the bulk alloy separated into an Fe-rich zone and a Cu-rich zone. Under the free fall condition, the alloy droplets with the droplet diameter beyond 805 μm showed the equilibrium peritectic solidification. If the droplet diameter decreased below 805 μm, the metastable liquid phase separation was induced and the microstructural morphology of Cu62.5Fe27.5Sn10 alloy droplet evolved from dendrite into dispersive structure. Furthermore, experimental and simulated results revealed that the temperature gradient had great influence on the size distribution of Fe-rich globules.

  13. A phenomenological model of two-phase (air/fuel droplet developing and breakup

    Directory of Open Access Journals (Sweden)

    Pavlović Radomir R.

    2013-01-01

    Full Text Available Effervescent atomization namely the air-filled liquid atomization comprehends certain complex two-phase phenomenon that are difficult to be modeled. Just a few researchers have found the mathematical expressions for description of the complex atomization model of the two-phase mixture air/diesel fuel. In the following review, developing model of twophase (air/fuel droplet of Cummins spray pump-injector is shown. The assumption of the same diameters of the droplet and the opening of the atomizer is made, while the air/fuel mass ratio inside the droplet varies.

  14. Problems of heat transfer and hydraulics of two-phase media

    CERN Document Server

    Kutateladze, S S

    1969-01-01

    Problems of Heat Transfer and Hydraulics of Two-Phase Media presents the theory of heat transfer and hydrodynamics. This book discusses the various aspects of heat transfer and the flow of two-phase systems. Organized into two parts encompassing 22 chapters, this book starts with an overview of the laws of similarity for heat transfer to or from a flowing liquid with various physical properties and allowed for variation in viscosity and thermal conductivity. This book then explores the general functional relationship that exists between viscosity and thermal conductivity for thermodynamically

  15. The performance of a cryogenic pump for the two-phase flow condition

    OpenAIRE

    YAMADA, HITOSHI; WATANABE, Mitsuo; Hasegawa, Satoshi; Kamijo, Kenjiro; 山田, 仁; 渡辺, 光男; 長谷川, 敏; 上條, 謙二郎

    1985-01-01

    An experimental investigation was carried out in order to obtain the performance characteristics of a cryogenic pump under a two-phase flow condition. The experiment used an oxygen pump with an inducer and liquid nitrogen as the test fluid. The vapor volumetric fraction at the pump inlet was calculated with an assumption of a constant enthalpy process across an orifice which was used to generate the two-phase flow at the pump inlet. The results showed that the pump head rise did hardly decrea...

  16. Conceptual design of two-phase fluid mechanics and heat transfer facility for spacelab

    Science.gov (United States)

    North, B. F.; Hill, M. E.

    1980-01-01

    Five specific experiments were analyzed to provide definition of experiments designed to evaluate two phase fluid behavior in low gravity. The conceptual design represents a fluid mechanics and heat transfer facility for a double rack in Spacelab. The five experiments are two phase flow patterns and pressure drop, flow boiling, liquid reorientation, and interface bubble dynamics. Hardware was sized, instrumentation and data recording requirements defined, and the five experiments were installed as an integrated experimental package. Applicable available hardware was selected in the experiment design and total experiment program costs were defined.

  17. On the peculiarities of LDA method in two-phase flows with high concentrations of particles

    Science.gov (United States)

    Poplavski, S. V.; Boiko, V. M.; Nesterov, A. U.

    2016-10-01

    Popular applications of laser Doppler anemometry (LDA) in gas dynamics are reviewed. It is shown that the most popular method cannot be used in supersonic flows and two-phase flows with high concentrations of particles. A new approach to implementation of the known LDA method based on direct spectral analysis, which offers better prospects for such problems, is presented. It is demonstrated that the method is suitable for gas-liquid jets. Owing to the progress in laser engineering, digital recording of spectra, and computer processing of data, the method is implemented at a higher technical level and provides new prospects of diagnostics of high-velocity dense two-phase flows.

  18. Heat transfer study of a two-phase refrigerant with liquid-solid phase change inside a smooth plates heat exchanger; Etude des transferts de chaleur d'un fluide frigoporteur diphasique a changement de phase liquide-solide dans un echangeur a plaques lisses

    Energy Technology Data Exchange (ETDEWEB)

    Demasles, H.

    2002-05-15

    The purpose of the work is to study two-phase mixture heat exchange composed of water particles suspended in silicone oil circulating in a closed loop. Water, contained in polymer porous matrix, is freezing by successive passages in plane plate heat exchanger. Thermo-hydraulic literature data analysis about these fluids in exchangers shows important blanks in exchange coefficient and pressure drop forecast methods and in experimental data. Experimental results, issued of global energy balance on a test section specifically conceived and made for this study, show doping effect on exchange coefficient. Before phase change, micro-convective effects of rotating particles improve exchange coefficient of 2,3 factor. Supplementary enhancement included between 2 and 16 appeared during phase change. Trial measured discrepancy are certainly induced by bed layer formation due to low flow speed. At the end of particle freezing, when latent heat is not involved anymore in exchange enhancement, important heat transfer reduction is observed. This is attributed to the cooling suspension rheological evolution and the change of flow particle distribution. Modelling results corroborate heat exchange improvement due to phase change: particles act as sources when discharging there latent heat. They stop fluid temperature dropping and enable to keep a high wall temperature gradient. A deepened suspension rheological study is necessary for a better understanding of observed phenomenon, nevertheless these first results show already an important energetic profit brings by particles in range temperature of 0 and -6 deg C. (author)

  19. Passive Two-Phase Cooling of Automotive Power Electronics: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, G.; Jeffers, J. R.; Narumanchi, S.; Bennion, K.

    2014-08-01

    Experiments were conducted to evaluate the use of a passive two-phase cooling strategy as a means of cooling automotive power electronics. The proposed cooling approach utilizes an indirect cooling configuration to alleviate some reliability concerns and to allow the use of conventional power modules. An inverter-scale proof-of-concept cooling system was fabricated, and tests were conducted using the refrigerants hydrofluoroolefin HFO-1234yf and hydrofluorocarbon HFC-245fa. Results demonstrated that the system can dissipate at least 3.5 kW of heat with 250 cm3 of HFC-245fa. An advanced evaporator design that incorporates features to improve performance and reduce size was conceived. Simulation results indicate its thermal resistance can be 37% to 48% lower than automotive dual side cooled power modules. Tests were also conducted to measure the thermal performance of two air-cooled condensers--plain and rifled finned tube designs. The results combined with some analysis were then used to estimate the required condenser size per operating conditions and maximum allowable system (i.e., vapor and liquid) temperatures.

  20. Simulation and modeling of two-phase bubbly flows

    Energy Technology Data Exchange (ETDEWEB)

    Sylvain L Pigny; Pierre F Coste [DEN/DER/SSTH, CEA/Grenoble, 38054 Grenoble Cedex 9 (France)

    2005-07-01

    Full text of publication follows: Phenomena related to bubbles in two-phase recirculating flows are investigated, via the computational code SIMMER, concerning an experiment in which air is injected in the lower part of a tank filled of water and initially at rest. Averaged mass and momentum transport equations are solved for air and water. Close to the injector, the formation of individual large bubbles is represented in the calculations, via direct simulation. Small scale phenomena, related to small bubbles behavior or turbulence in the liquid continuous phase, are modeled, in a statistical way, via classical closure laws. In a first calculation, the splitting of large bubbles is not represented. It is shown that this phenomenon, the space scale of which is close to the cell size, cannot be simulated, in view of the present computational resources. Nevertheless, relatively fine meshes are used, for an accurate description of hydrodynamical phenomena, and the splitting phenomenon is too large to be modeled via closure laws. A specific approach for the intermediate scales is therefore developed to represent it. (authors)

  1. Vapor–Liquid–Liquid Equilibrium Measurements and Modeling of the Methanethiol + Methane + Water Ternary System at 304, 334, and 364 K

    DEFF Research Database (Denmark)

    Awan, Javeed; Tsivintzelis, Ioannis; Valtz, Alain;

    2012-01-01

    New vapor–liquid–liquid equilibrium (VLLE) data for methanethiol (CH3SH) + methane (CH4) + water (H2O) have been obtained at three temperatures (304, 334, and 364 K) and pressures up to 9 MPa. A “static-analytical” method was used to perform all of the measurements. The objective was to provide...... experimental VLLE data for CH3SH with other natural gas contents at its crude form for which limited or no data are available in the open literature. Such kinds of data are required for the industrial modeling of sulfur emissions. It is observed from the experimental data that the solubility of CH4...

  2. Volumetric behaviour of the ternary liquid system composed of methyl tert-butyl ether, toluene, and isooctane at temperatures from (298.15 to 328.15) K: Experimental data and correlation

    Energy Technology Data Exchange (ETDEWEB)

    Moravkova, L.; Wagner, Z.; Sedlakova, Z. [E. Hala Laboratory of Thermodynamics, Institute of Chemical Process Fundamentals of the ASCR, v.v.i., 165 02 Prague 6 (Czech Republic); Linek, J., E-mail: linek@icpf.cas.c [E. Hala Laboratory of Thermodynamics, Institute of Chemical Process Fundamentals of the ASCR, v.v.i., 165 02 Prague 6 (Czech Republic)

    2010-07-15

    The densities and speeds of sound of (methyl tert-butyl ether left braceMTBEright brace + toluene + isooctane) were measured at four temperatures over the range (298.15 to 328.15) K and the respective values of excess volumes V{sub m}{sup E} and adiabatic compressibility kappa{sub S} were calculated. The V{sub m}{sup E} and kappa{sub S} values for the ternary and corresponding binaries were fitted to the Redlich-Kister equation considering various numbers of ternary constants. The necessary number of ternary constants needed to describe the system is discussed.

  3. Next steps in two-phase flow: executive summary

    Energy Technology Data Exchange (ETDEWEB)

    DiPippo, R.

    1980-09-01

    The executive summary includes the following topics of discussion: the state of affairs; the fundamental governing equations; the one-dimensional mixture model; the drift-flux model; the Denver Research Institute two-phase geothermal flow program; two-phase flow pattern transition criteria; a two-fluid model under development; the mixture model as applied to geothermal well flow; DRI downwell instrumentation; two-phase flow instrumentation; the Sperry Research Corporation downhole pump and gravity-head heat exchanger systems; and the Brown University two-phase flow experimental program. (MHR)

  4. 汽化效应对燃气蒸汽式弹射气液两相流场的影响%Influence of vaporization effect on gas-liquid two-phase flow field of ejection in combustion gas and vapor mode

    Institute of Scientific and Technical Information of China (English)

    刘伯伟; 姜毅

    2014-01-01

    为研究汽化效应对燃气蒸汽式弹射发射过程的影响,建立了某型集中注水式弹射装置的二维轴对称模型,利用耦合Mixture多相流模型与组分输运模型求解发射过程中的气液两相冻结流场,通过向守恒方程添加源项的方式引入液态水的汽化模型,利用Soave-Redlich-Kwong真实气体模型模拟水蒸汽的状态变化,得到了发射过程中液态水的流型及汽化过程,通过两种工况与试验结果的比较,验证了仿真结果的可靠性。结果表明,与不考虑汽化效应相比,考虑汽化效应使仿真流场的最大平均温度降低524 K,弹托底部最大平均温度降低223 K,考虑汽化效应得到的内弹道过程与试验结果更加一致,对该类问题的仿真与改进具有指导意义。%To study the influence of vaporization effect on launching process of ejection in combustion gas and vapor mode,2D axisymmetric model of an ejection device with water injection in block was established. The coupling of mixture multiphase model and species transport model was used to solve gas-liquid two-phase frozen flow field. A vaporization model of water was introduced by adding source terms to conservation equations. Soave-Redlich-Kwong real gas model was used to simulate the state change of va-por. The flow pattern and vaporization process of water were obtained. By comparison of two conditions and experimental results,the reliability of simulation results was verified. The research shows,compared with the condition without considering vaporization effect, the maximum average temperature of flow field with considering vaporization effect reduces 524 K,and the maximum average temper-ature nearing sabot reduces 223 K. Interior ballistic process with vaporization effect is more identical to the experimental results, which has guiding significance to the simulation and improvement of this kind of problems.

  5. Two-phase pressure drop across a hydrofoil-based micro pin device using R-123

    Energy Technology Data Exchange (ETDEWEB)

    Kosar, Ali [Mechatronics Engineering Program, Sabanci University, Orhanli, Tuzla, 34956 Istanbul (Turkey)

    2008-05-15

    The two-phase pressure drop in a hydrofoil-based micro pin fin heat sink has been investigated using R-123 as the working fluid. Two-phase frictional multipliers have been obtained over mass fluxes from 976 to 2349 kg/m{sup 2} s and liquid and gas superficial velocities from 0.38 to 1.89 m/s and from 0.19 to 24 m/s, respectively. It has been found that the two-phase frictional multiplier is strongly dependent on flow pattern. The theoretical prediction using Martinelli parameter based on the laminar fluid and laminar gas flow represented the experimental data fairly well for the spray-annular flow. For the bubbly and wavy-intermittent flow, however, large deviations from the experimental data were recorded. The Martinelli parameter was successfully used to determine the flow patterns, which were bubbly, wavy-intermittent, and spray-annular flow in the current study. (author)

  6. Improved Ternary Subdivision Interpolation Scheme

    Institute of Scientific and Technical Information of China (English)

    WANG Huawei; QIN Kaihuai

    2005-01-01

    An improved ternary subdivision interpolation scheme was developed for computer graphics applications that can manipulate open control polygons unlike the previous ternary scheme, with the resulting curve proved to be still C2-continuous. Parameterizations of the limit curve near the two endpoints are given with expressions for the boundary derivatives. The split joint problem is handled with the interpolating ternary subdivision scheme. The improved scheme can be used for modeling interpolation curves in computer aided geometric design systems, and provides a method for joining two limit curves of interpolating ternary subdivisions.

  7. Phase separation in polymer solutions. I. Liquid-liquid phase separation of PPO poly (2, 6-dimethyl 1, 4-phenylene oxide) in binary mixtures with toluene and ternary mixtures with toluene and ethyl alcohol

    NARCIS (Netherlands)

    Emmerik, van P.T.; Smolders, C.A.

    1972-01-01

    In the system poly(2, 6-dimethy1-1, 4-phenylene oxide) (PPO)-toluene three phase separation lines can be detected: the melting point curve, the cloud point curve, and the spinodial. Because crystallization of PPO occurs very slowly, a phase transition will always be initiated by liquid-liquid phase

  8. Phase separation in polymer solutions. I. Liquid-liquid phase separation of PPO poly (2, 6-dimethyl 1, 4-phenylene oxide) in binary mixtures with toluene and ternary mixtures with toluene and ethyl alcohol

    NARCIS (Netherlands)

    van Emmerik, P.T.; Smolders, C.A.

    1972-01-01

    In the system poly(2, 6-dimethy1-1, 4-phenylene oxide) (PPO)-toluene three phase separation lines can be detected: the melting point curve, the cloud point curve, and the spinodial. Because crystallization of PPO occurs very slowly, a phase transition will always be initiated by liquid-liquid phase

  9. Two-Phase Technology at NASA/Johnson Space Center

    Science.gov (United States)

    Ungar, Eugene K.; Nicholson, Leonard S. (Technical Monitor)

    1999-01-01

    Since the baseline International Space Station (ISS) External Active Thermal Control System (EATCS) was changed from a two-phase mechanically pumped system to a single phase cascade system in the fall of 1993, two-phase EATCS research has continued at a low level at JSC. One of-the lessons of the ISS EATCS selection was that two-phase thermal control systems must have significantly lower power than comparable single phase systems to overcome their larger radiator area, larger line and fluid mass, and perceived higher technical risk. Therefore, research at JSC has concentrated on low power mechanically pumped two-phase EATCSs. In the presentation, the results of a study investigating the trade of single and two-phase mechanically pumped EATCSs for space vehicles will be summarized. The low power two-phase mechanically pumped EATCS system under development at JSC will be described in detail and the current design status of the subscale test unit will be reviewed. Also, performance predictions for a full size EATCS will be presented. In addition to the discussion of two-phase mechanically pumped EATCS development at JSC, two-phase technologies under development for biological water processing will be discussed. These biological water processor technologies are being prepared for a 2001 flight experiment and subsequent usage on the TransHab module on the International Space Station.

  10. Two Phases of Coherent Structure Motions in Turbulent Boundary Layer

    Institute of Scientific and Technical Information of China (English)

    LIU Jian-Hua; JIANG Nan

    2007-01-01

    Two phases of coherent structure motion are acquired after obtaining conditional phase-averaged waveforms for longitudinal velocity of coherent structures in turbulent boundary layer based on Harr wavelet transfer. The correspondences of the two phases to the two processes (i.e. ejection and sweep) during a burst are determined.

  11. Simultaneous determination of a ternary mixture of doxylamine succinate, pyridoxine hydrochloride, and folic acid by the ratio spectra-zero-crossing, double divisor-ratio spectra derivative, and column high-performance liquid chromatographic methods.

    Science.gov (United States)

    Pathak, Ashutosh; Rajput, Sadhana J

    2008-01-01

    Three simple, rapid, and accurate methods, i.e., the derivative ratio spectra-zero-crossing method (method I), double divisor-ratio spectra derivative method (method II), and column reversed-phase high-performance liquid chromatographic (RP-HPLC) method (method III) were developed for the simultaneous determination of doxylamine succinate (DOX), pyridoxine hydrochloride (PYR), and folic acid (FA) in their ternary mixtures and in tablets. In methods I and II, the calibration graphs were linear in the range of 2.5-80, 1.0-40, and 1.0-30 microg/mL for DOX, PYR, and FA, respectively. In the HPLC method, the separation of these compounds was performed using mobile phase consisting of 0.05 M phosphate buffer (pH 6.3)-methanol-acetonitrile (50 + 20 + 30, v/v/v), and UV detection was performed at 263 nm. Linearity was observed between the concentrations of the analytes and peak areas [correlation coefficient (r) > or =0.9998] in the concentration range of 1.0-200, 4.0-600, and 4.0-600 microg/mL for DOX, PYR, and FA, respectively. The standard deviation of retention time in method III was 0.011, 0.015, and 0.016 for DOX, PYR, and FA, respectively. The precision studies for all of the methods gave relative standard deviation values of <2%. The results obtained from the methods were statistically compared by means of Student's t-test and the variance ratio F-test. It was concluded that all of the developed methods were equally accurate, sensitive, and precise. These methods could be applied to determine DOX, PYR, and FA in their combined dosage forms.

  12. Volumetric behaviour of binary and ternary liquid systems composed of ethanol, isooctane, and toluene at temperatures from (298.15 to 328.15) K. Experimental data and correlation

    Energy Technology Data Exchange (ETDEWEB)

    Moravkova, L.; Wagner, Z.; Sedlakova, Z. [E. Hala Laboratory of Thermodynamics, Institute of Chemical Process Fundamentals of the ASCR, v.v.i., 165 02 Prague 6 (Czech Republic); Linek, J., E-mail: linek@icpf.cas.cz [E. Hala Laboratory of Thermodynamics, Institute of Chemical Process Fundamentals of the ASCR, v.v.i., 165 02 Prague 6 (Czech Republic)

    2011-12-15

    Highlights: > We measured density and speed of sound at four temperatures within (298.15 to 328.15) K. > Excess quantities were calculated and fitted to the Redlich-Kister equation. > The complete ternary data were fitted to the modified Redlich-Kister equation. > Even for the systems with self-associating alcohol, only one ternary parameter is sufficient. - Abstract: The densities and speeds of sound of (ethanol + isooctane), (ethanol + toluene), and (ethanol + isooctane + toluene) were measured at four temperatures over the range (298.15 to 328.15) K, and the respective values of excess volumes V{sub m}{sup E} and adiabatic compressibility {kappa}{sub S} were calculated. The V{sub m}{sup E} and {kappa}{sub S} values for the binary systems were fitted to the Redlich-Kister equation. The respective ternary data together with corresponding binary data were then fitted to the modified Redlich-Kister equation considering various numbers of ternary constants. It was found that even for the systems containing self-associating alcohol, only one ternary parameter is sufficient to describe well the ternary system.

  13. Performance characteristics of two-phase-flow turbo-expanders used in water-cooled chillers

    Energy Technology Data Exchange (ETDEWEB)

    Brasz, J.J. [United Technologies Carrier, New York, NY (United States)

    1999-07-01

    Use of two-phase-flow throttle loss recovery devices in water-cooled chillers requires satisfactory part-load operation. This paper describes the results of two-phase-flow impulse turbine testing and the data reduction of the test results into a two-phase-flow turbine off-design performance model. It was found that the main parameter controlling the efficiency of two-phase-flow turbine is the ratio of the nozzle spouting velocity to the rotor speed. The turbine mass flow rate is mainly controlled by inlet subcooling of the entering liquid. The strong sensitivity of turbine mass flow rate on inlet subcooling allows the use of a conventional float valve upstream of the turbine as an effective means of controlling the turbine during part-load operation. For a well-designed two-phase-flow turbine, nozzle spouting velocity and therefore turbine efficiency is hardly affected by the amount of inlet subcooling. Also, capacity can be substantially reduced by a reduction in the amount of inlet subcooling entering the turbine nozzles. Hence, turbine part-load efficiency equals its full-load efficiency over a wide range of flow rates using this control concept. (Author)

  14. DSMC simulation of two-phase plume flow with UV radiation

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jie; Liu, Ying; Wang, Ning; Jin, Ling [College of Aerospace Science and Engineering, National University of Defense Technology, Changsha, Hunan, 410073 (China)

    2014-12-09

    Rarefied gas-particle two-phase plume in which the phase of particles is liquid or solid flows from a solid propellant rocket of hypersonic vehicle flying at high altitudes, the aluminum oxide particulates not only impact the rarefied gas flow properties, but also make a great difference to plume radiation signature, so the radiation prediction of the rarefied gas-particle two-phase plume flow is very important for space target detection of hypersonic vehicles. Accordingly, this project aims to study the rarefied gas-particle two-phase flow and ultraviolet radiation (UV) characteristics. Considering a two-way interphase coupling of momentum and energy, the direct simulation Monte Carlo (DSMC) method is developed for particle phase change and the particle flow, including particulate collision, coalescence as well as separation, and a Monte Carlo ray trace model is implemented for the particulate UV radiation. A program for the numerical simulation of the gas-particle two-phase flow and radiation in which the gas flow nonequilibrium is strong is implemented as well. Ultraviolet radiation characteristics of the particle phase is studied based on the calculation of the flow field coupled with the radiation calculation, the radiation model for different size particles is analyzed, focusing on the effects of particle emission, absorption, scattering as well as the searchlight emission of the nozzle. A new approach may be proposed to describe the rarefied gas-particle two-phase plume flow and radiation transfer characteristics in this project.

  15. Design and evaluation of a two-phase turbine for low quality steam--water mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Comfort, W.J. III

    1977-05-16

    A new two-phase turbine was designed and built for testing in the laboratory, using a low quality steam-water mixture as a working fluid. The measured performance compares well with performance predictions of a numerical model of the expander. Details of the selection of the type of expander are given. The design of an experimental expander for use in a clean two-phase flow laboratory experiment and the development of a numerical model for performance analysis and extrapolations are described. Experiments including static cascade performance with two-phase fluid, disk friction and windage measurements, and two-phase performance measurements of the experimental expander are reported. Comparisons of the numerical model and experimental results, and the prediction of the performance of an advanced design, indicating how performance improvements can be achieved, are also included. An engine efficiency of 23 percent for a single-nozzle test was measured. Full admission performance, based upon the numerical model and achievable nozzle thrust coefficients indicate that an engine efficiency of between 38 and 48 percent can be realized with present technology. If maximum liquid removal loss is assumed, this performance range is predicted to be 38 to 41 percent. Droplet size reduction and the development and implementation of enhanced two-phase flow analysis techniques should make it possible to achieve the research goal of 70 percent engine efficiency.

  16. Experimental Observation of Two Phase Flow of R123 Inside a Herringbone Microfin Tube

    Institute of Scientific and Technical Information of China (English)

    Akio Miyara; Mohammad Ariful Islam; Yoshihiko Mizuta; Atsushi Kibe

    2003-01-01

    Vapor-liquid two phase flow behavior of R123 inside herringbone microfin tubes has been studied. Herringbone microfin tube is a kind of internally finned tube in which microfins are installed inside the tube where the microfins form multi-V-shape in flow direction. For the present experiment three different types of herringbone microfin tubes with helix angle β = 8°, 14° and 28° are used. Experimental observations showed how flow diverges and converges inside herringbone microfin tube due to fin arrangement. The effect is more remarkable for larger helix angle. From the measurements of the cross-sectional liquid flow rate distribution, the liquid removal and collection and the entrained droplet are discussed. Quantity of liquid droplets is increased with increase of helix angle. The tube with helix angle β = 28° shows higher quantity of liquid droplets than others.

  17. Drop volumes and terminal velocities in aqueous two-phase systems

    Energy Technology Data Exchange (ETDEWEB)

    Bhavasar, P. M.; Jafarabad, K. R.; Pandit, A. B.; Sawant, S. B.; Joshi, J. B. [Bombay Univ. (India). Dept. of Chemical Technology

    1996-12-01

    Two phase aqueous extraction techniques employed in liquid-liquid extraction equipment such as spray columns and plate columns were studied, with particular attention to predicting drop sizes prior to jetting, and their terminal velocity. In the particular system studied, the values obtained by conventional models as found in the literature were considered inapplicable. A generalised model was constructed using video photographic measurements, and a correlation was developed for the terminal velocities of the drops in aqueous two-phase systems. This simplified model was found to be successful in expressing the terminal rise/fall velocities of droplets covering a specific range of Morton numbers (representing physical properties) from 0.00211 to 11050 and Eotvos numbers (representative of drop size) from 0.091 to 288. 22 refs., 6 figs.

  18. Two-phase Cryogenic Avalanche Detector with electroluminescence gap operated in argon doped with nitrogen

    CERN Document Server

    Bondar, A; Dolgov, A; Nosov, V; Shekhtman, L; Shemyakina, E; Sokolov, A

    2016-01-01

    A two-phase Cryogenic Avalanche Detector (CRAD) with electroluminescence (EL) gap, operated in argon doped with a minor (49$\\pm$7 ppm) admixture of nitrogen, has been studied. The EL gap was optically read out using cryogenic PMTs located on the perimeter of the gap. We present the results of the measurements of the N$_2$ content, detector sensitivity to X-ray-induced signals, EL gap yield and electron lifetime in the liquid. The detector sensitivity, at a drift field in liquid Ar of 0.6 kV/cm, was measured to be 9 and 16 photoelectrons recorded at the PMTs per keV of deposited energy at 23 and 88 keV respectively. Such two-phase detectors, with enhanced sensitivity to the S2 (ionization-induced) signal, are relevant in the field of argon detectors for dark matter search and low energy neutrino detection.

  19. Membrane-less micro fuel cell based on two-phase flow

    Science.gov (United States)

    Hashemi, S. M. H.; Neuenschwander, M.; Hadikhani, P.; Modestino, M. A.; Psaltis, D.

    2017-04-01

    Most microfluidic fuel cells use highly soluble fuels and oxidants in streams of liquid electrolytes to overcome the mass transport limitations that result from the low solubility of gaseous reactants such as hydrogen and oxygen. In this work, we address these limitations by implementing controlled two-phase flows of these gases in a set of microchannels electrolytically connected through a narrow gap. Annular flows of the gases reshape the concentration boundary layer over the surface of electrodes and increase the mass-transport limited current density in the system. Our results show that the power density of a two-phase system with hydrogen and oxygen streams is an order of magnitude higher than that of single phase system consisting of liquid electrolytes saturated with the same reactants. The reactor design described here can be employed to boost the performance of MFFCs and put them in a more competitive position compared to membrane based fuel cells.

  20. MICROGRAVITY EXPERIMENTS OF TWO-PHASE FLOW PATTERNS ABOARD MIR SPACE STATION

    Institute of Scientific and Technical Information of China (English)

    赵建福; 解京昌; 林海; 胡文瑞; A.V. Ivanov; A.Yu. Belyaev

    2001-01-01

    A first experimental study on two-phase flow patterns at a long-term,steady microgravity condition was conducted on board the Russian Space Station "MIR" in August 1999. Carbogal and air are used as the liquid and the gas phase,respectively. Bubble, slug, slug-annular transitional, and annular flows are observed.A new region of annular flow with lower liquid superficial velocity is discovered,and the region of the slug-annular transitionalfiow is wider than that observed by experiments on board the parabolic aircraft. The main patterns are bubble, slug annular transitional and annular flows based on the experiments on board MIR space station. Some influences on the two-phase flow patterns in the present experiments are discussed.

  1. Two-phase Cryogenic Avalanche Detector with electroluminescence gap operated in argon doped with nitrogen

    Science.gov (United States)

    Bondar, A.; Buzulutskov, A.; Dolgov, A.; Nosov, V.; Shekhtman, L.; Shemyakina, E.; Sokolov, A.

    2017-02-01

    A two-phase Cryogenic Avalanche Detector (CRAD) with electroluminescence (EL) gap, operated in argon doped with a minor (49±7 ppm) admixture of nitrogen, has been studied. The EL gap was optically read out using cryogenic PMTs located on the perimeter of the gap. We present the results of the measurements of the N2 content, detector sensitivity to X-ray-induced signals, EL gap yield and electron lifetime in the liquid. The detector sensitivity, at a drift field in liquid Ar of 0.6 kV/cm, was measured to be 9 and 16 photoelectrons recorded at the PMTs per keV of deposited energy at 23 and 88 keV respectively. Such two-phase detectors, with enhanced sensitivity to the S2 (ionization-induced) signal, are relevant in the field of argon detectors for dark matter search and low energy neutrino detection.

  2. Film boiling on spheres in single- and two-phase flows.

    Energy Technology Data Exchange (ETDEWEB)

    Liu, C.; Theofanous, T. G.

    2000-08-29

    Film boiling on spheres in single- and two-phase flows was studied experimentally and theoretically with an emphasis on establishing the film boiling heat transfer closure law, which is useful in the analysis of nuclear reactor core melt accidents. Systematic experimentation of film boiling on spheres in single-phase water flows was carried out to investigate the effects of liquid subcooling (from 0 to 40 C), liquid velocity (from 0 to 2 m/s), sphere superheat (from 200 to 900 C), sphere diameter (from 6 to 19 mm), and sphere material (stainless steel and brass) on film boiling heat transfer. Based on the experimental data a general film boiling heat transfer correlation is developed. Utilizing a two-phase laminar boundary-layer model for the unseparated front film region and a turbulent eddy model for the separated rear region, a theoretical model was developed to predict the film boiling heat transfer in all single-phase regimes. The film boiling from a sphere in two-phase flows was investigated both in upward two-phase flows (with void fraction from 0.2 to 0.65, water velocity from 0.6 to 3.2 m/s, and steam velocity from 3.0 to 9.0 m/s) and in downward two-phase flows (with void fraction from 0.7 to 0.95, water velocity from 1.9 to 6.5 m/s, and steam velocity from 1.1 to 9.0 m/s). The saturated single-phase heat transfer correlation was found to be applicable to the two-phase film boiling data by making use of the actual water velocity (water phase velocity), and an adjustment factor of (1 - {alpha}){sup 1/4} (with a being the void fraction) for downward flow case only. Slight adjustments of the Reynolds number exponents in the correlation provided an even better interpretation of the two-phase data. Preliminary experiments were also conducted to address the influences of multi-sphere structure on the film boiling heat transfer in single- and two-phase flows.

  3. Preliminary Two-Phase Terry Turbine Nozzle Models for RCIC Off-Design Operation Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Haihua [Idaho National Lab. (INL), Idaho Falls, ID (United States); O' Brien, James [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2017-06-12

    This report presents the effort to extend the single-phase analytical Terry turbine model to cover two-phase off-design conditions. The work includes: (1) adding well-established two-phase choking models – the Isentropic Homogenous Equilibrium Model (IHEM) and Moody’s model, and (2) theoretical development and implementation of a two-phase nozzle expansion model. The two choking models provide bounding cases for the two-phase choking mass flow rate. The new two-phase Terry turbine model uses the choking models to calculate the mass flow rate, the critical pressure at the nozzle throat, and steam quality. In the divergent stage, we only consider the vapor phase with a similar model for the single-phase case by assuming that the liquid phase would slip along the wall with a much slower speed and will not contribute the impulse on the rotor. We also modify the stagnation conditions according to two-phase choking conditions at the throat and the cross-section areas for steam flow at the nozzle throat and at the nozzle exit. The new two-phase Terry turbine model was benchmarked with the same steam nozzle test as for the single-phase model. Better agreement with the experimental data is observed than from the single-phase model. We also repeated the Terry turbine nozzle benchmark work against the Sandia CFD simulation results with the two-phase model for the pure steam inlet nozzle case. The RCIC start-up tests were simulated and compared with the single-phase model. Similar results are obtained. Finally, we designed a new RCIC system test case to simulate the self-regulated Terry turbine behavior observed in Fukushima accidents. In this test, a period inlet condition for the steam quality varying from 1 to 0 is applied. For the high quality inlet period, the RCIC system behaves just like the normal operation condition with a high pump injection flow rate and a nominal steam release rate through the turbine, with the net addition of water to the primary system; for

  4. Heat pipes et two-phase loops for spacecraft applications. ESA programmes

    Energy Technology Data Exchange (ETDEWEB)

    Supper, W. [European Space Agency / ESTEC. Thermal control and life support division (France)

    1996-12-31

    This document is a series of transparencies presenting the current and future applications of heat pipes in spacecraft and the activities in the field of capillary pumped two-phase loops: thermal tests, high-efficiency low pressure drop condensers, theoretical understanding of evaporator function, optimization of liquid and vapor flows, trade-off between low and high conductivity wicks, development of high capillary capacity wicks etc.. (J.S.)

  5. Two-Phase Working Fluids for the Temperature Range 50 to 350 C

    Science.gov (United States)

    Saaski, E. W.; Owzarski, P. C.

    1977-01-01

    The decomposition and corrosion of two-phase heat transfer liquids and metal envelopes have been investigated on the basis of molecular bond strengths and chemical thermodynamics. Potentially stable heat transfer fluids for the temperature range 100 C to 350 C have been identified, and reflux heat pipes tests initiated with 10 fluids and carbon steel and aluminum envelopes to experimentally establish corrosion behavior and noncondensable gas generation rates.

  6. Measurement and Correlation of Liquid-Liquid Equilibrium Data for Ethanol-Water-KF and Ethanol-Water-K2CO3 Systems

    Institute of Scientific and Technical Information of China (English)

    许文友; 袁希纲

    2002-01-01

    The liquid-liquid equilibrium data for two ternary systems, ethanol-water-KF and ethanol- water-K2CO3, were determined at 25oC. Experiments show that by adding KF or K2CO3 into the ethanol-water system two phases are formed: an ethanol-rich phase with negligible salt and a water-rich phase with negligible ethanol, thus water can be separated out easily. A mathematical calculation of the liquid-liquid equilibrium data was carried out with the Pitzer theory on water activity in the aqueous phase, and with the Wilson or NRTL or UNIQUAC equations for that in the ethanol phase, which is in good agreement with experimental data.

  7. Thermo-Fluid Dynamics of Two-Phase Flow

    CERN Document Server

    Ishii, Mamrou

    2011-01-01

    "Thermo-fluid Dynamics of Two-Phase Flow, Second Edition" is focused on the fundamental physics of two-phase flow. The authors present the detailed theoretical foundation of multi-phase flow thermo-fluid dynamics as they apply to: Nuclear reactor transient and accident analysis; Energy systems; Power generation systems; Chemical reactors and process systems; Space propulsion; Transport processes. This edition features updates on two-phase flow formulation and constitutive equations and CFD simulation codes such as FLUENT and CFX, new coverage of the lift force model, which is of part

  8. Tunable two-phase coexistence in half-doped manganites

    Indian Academy of Sciences (India)

    P Chaddah; A Banerjee

    2008-02-01

    We discuss our very interesting experimental observation that the low-temperature two-phase coexistence in half-doped manganites is multi-valued (at any field) in that we can tune the coexisting antiferromagnetic-insulating (AF-I) and the ferromagnetic-metallic (FM-M) phase fractions by following different paths in (; ) space. We have shown experimentally that the phase fraction, in this two-phase coexistence, can take continuous infinity of values. All but one of these are metastable, and two-phase coexistence is not an equilibrium state.

  9. 糠醛-环己醇-莰烯三元气液平衡数据的测定%Measurement of Vapor-Liquid Equilibrium Data in Furfural-Cyclohexanol-Camphene Ternary System

    Institute of Scientific and Technical Information of China (English)

    王凯; 程毅; 许兰淑; 李瑞

    2016-01-01

    A self-made vapor-liquid equilibrium device was used to measure the vapor-liquid equilibrium data of furfural-cyclohexanol, furfural-camphene and furfural-cyclohexanol-camphene at 101. 3 kPa. The Wilson equation parameters were obtained by the correlation and calculation of the measured data. The calculated data of temperature and the mass fractions of gaseous components of furfural-cyclohexanol and furfural-comphene at 101. 3kPa were obtained by Wilson equation and agreed with the industrial data well. The thermodynamic consistency of the two groups binary vapor-liquid equilibrium data were checked with the area integral method. The results met the with requirements. The data of furfural-cyclohexanol-camphene ternary vapor-liquid equilibrium were measured and fitted. The results showed that at 421.5K, the molar fraction of furfural was the maximum and the molar fraction of cyclohexanol was the minimum in the vapor phase, so that furfural and cyclohexanol could be separated at this temperature. And it could be regarded as basic theory for the separation of furfural and cyclohexanol in engineering.%利用自制气液平衡装置测定糠醛-环己醇、糠醛-莰烯和糠醛-环己醇-莰烯在101.3 kPa下的气液平衡数据。对所测得的数据进行关联与计算,得到Wilson方程参数。代入Wilson模型,计算出101.3 KPa条件下糠醛-环己醇、糠醛-莰烯2组二元体系的温度与气相组分的质量分数,与实验值比偏差不大,说明实验可行。用面积积分法验证两组二元气液平衡数据的热力学一致性,结果符合要求。通过测定糠醛-环己醇-莰烯三元气液平衡数据,并进行拟合,得到421.5K时糠醛的气相物质的量分数相对最高,环己醇的气相物质的量分数又相对最低,即在该温度下分离糖醛分环己醇较好,可为工程上分离糠醛和环己醇提供理论依据。

  10. Fractionation of wheat gliadins by counter-current distribution using an organic two-phase system.

    Science.gov (United States)

    Truust, H; Johansson, G

    1998-06-26

    A liquid liquid two-phase system based on N,N-dimethylformamide and the two polymers, poly(ethyleneglycol) and Ficoll, useful for partitioning of hydrophobic proteins, has been developed. The system has been applied to a counter-current distribution process in 56 steps for analysing the heterogeneity of proteins extracted with N,N-dimethylformamide from wheat flour. The counter-current distribution patterns of proteins, extracted from eight kinds of wheat, have been analysed. The minimum number of hypothetical proteins necessary to describe the patterns was found to be seven. The relative amount of these hypothetical components varied among the wheats.

  11. Time dependent two phase flows in Magnetohydrodynamics: A ...

    African Journals Online (AJOL)

    Journal of the Nigerian Association of Mathematical Physics ... Open Access DOWNLOAD FULL TEXT Subscription or Fee Access. Time dependent two phase flows in Magnetohydrodynamics: A Greens function approach. BK Jha, HM Jibril ...

  12. Gravity Independence of Microchannel Two-Phase Flow Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Most of the amassed two-phase flow and heat transfer knowledge comes from experiments conducted in Earth’s gravity. Space missions span varying gravity levels,...

  13. Vapor Compressor Driven Hybrid Two-Phase Loop Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Phase I project successfully demonstrated the feasibility of the vapor compression hybrid two-phase loop (VCHTPL). The test results showed the high...

  14. TWO PHASE FLOW SPLIT MODEL FOR PARALLEL CHANNELS

    African Journals Online (AJOL)

    Ifeanyichukwu Onwuka

    The equations are solved using the Broyden'smethod ... channel system subjected to a two-phase flow transient, and the results have been very .... system pressure, the heat addition rates inside ... three dimensional flows in the LP.

  15. Particle modulations to turbulence in two-phase round jets

    Institute of Scientific and Technical Information of China (English)

    Bing Wang; Huiqiang Zhang; Yi Liu; Xiaofen Yan; Xilin Wang

    2009-01-01

    The particle modulations to turbulence in round jets were experimentally studied by means of two-phase velocity measurements with Phase Doppler Anemometer (PDA). Laden with very large particles, no significant attenuations of turbulence intensities were measured in the far-fields, due to small two-phase slip velocities and particle Reynolds number. The gas-phase turbulence is enhanced by particles in the near-fields, but it is significantly attenuated by the small particles in the far-fields. The smaller particles have a more profound effect on the attenuation of turbulence intensities. The enhancements or attenuations of turbulence intensities in the far-fields depends on the energy production, transport and dissipation mechanisms between the two phases, which are determined by the particle prop-erties and two-phase velocity slips. The non-dimensional parameter CTI is introduced to represent the change of turbulence intensity.

  16. Transient two-phase performance of LOFT reactor coolant pumps

    Energy Technology Data Exchange (ETDEWEB)

    Chen, T.H.; Modro, S.M.

    1983-01-01

    Performance characteristics of Loss-of-Fluid Test (LOFT) reactor coolant pumps under transient two-phase flow conditions were obtained based on the analysis of two large and small break loss-of-coolant experiments conducted at the LOFT facility. Emphasis is placed on the evaluation of the transient two-phase flow effects on the LOFT reactor coolant pump performance during the first quadrant operation. The measured pump characteristics are presented as functions of pump void fraction which was determined based on the measured density. The calculated pump characteristics such as pump head, torque (or hydraulic torque), and efficiency are also determined as functions of pump void fractions. The importance of accurate modeling of the reactor coolant pump performance under two-phase conditions is addressed. The analytical pump model, currently used in most reactor analysis codes to predict transient two-phase pump behavior, is assessed.

  17. Scaling of Two-Phase Systems Across Gravity Levels Project

    Data.gov (United States)

    National Aeronautics and Space Administration — There is a defined need for long term earth based testing for the development and deployment of two-phase flow systems in reduced-gravity, including lunar gravity,...

  18. Comparison of Experimental and Numerical Two-Phase Flows in a Porous Micro-Model

    Directory of Open Access Journals (Sweden)

    Dustin Crandall

    2009-12-01

    Full Text Available Characterizing two-phase flow in porous media is important to provide estimates of sweep efficiency in enhanced oil recovery and storage estimates in potential geological CO2 sequestration repositories. To further the current understanding of two-phase flow in porous media a micro-model of interconnected channels was designed and fabricated using stereolithography to experimentally study gas-liquid flows. This flowcell was created with a wide variability of throat dimensions to represent naturally occurring porous media. Low flow rate experiments of immiscible two-phase drainage were performed within this cell. Additionally, a computational model for analyzing two-phase flows in the same flowcell was developed and used to simulate conditions not possible with our laboratory settings. The computational model was first tested for the identical conditions used in the experimental studies, and was shown to be in good agreement with the experimentally determined fractal dimension of the invading gas structure, time until breakthrough, and fluid saturation. The numerical model was then used to study two-phase air-water flows in flowcells with the same geometry and different gas-liquid-solid contact angles. The percent saturation of air and the motion of the fluids through the cell were found to vary with changes in these parameters. Finally, to simulate flows expected during geologic carbon sequestration, the fluid properties and interface conditions were set to model the flow of CO2 into a brine-saturated porous medium at representative subsurface conditions. The CO2 flows were shown to have larger gas saturations than the previous air into water studies. Thus the accuracy of the computational model was supported by the flowcell experiments, and the computational model extended the laboratory results to conditions not possible with the apparatus used in the experiments.

  19. Analysis of the nonlinear dynamic characteristics of two-phase flow based on an improved matrix pencil method☆

    Institute of Scientific and Technical Information of China (English)

    Hongwei Li⁎; Junpeng Liu; Yunlong Zhou; Bin Sun

    2016-01-01

    Gas–liquid two-phase flow is complex and has uncertainty in phase interfaces, which make the two-phase flow look very complicated. Even though the flow behavior (e.g. coalescence, crushing and separation) of single bubble or bubble groups in the liquid phase looks random, combining some established character-istics and methodologies can find regularities among the randomness. In order to excavate the nonlinear dynamic characteristics of gas–liquid two-phase flow, the authors developed an improved matrix pencil (IMP) method to analyze the pressure difference signals of the two-phase flow. This paper elucidates the influence of signal length on MP calculation results and the anti-noise-interference ability of the MP method. An IMP algorithm was applied to the fluctuation signals of gas–liquid two-phase flow to extract the mode frequency and damping ratio, which were combined with the component energy index (CEI) en-tropy to identify the different flow patterns. It is also found that frequency, damping ratio, CEI entropy and stability diagram together not only identify flow patterns, but also provide a new way to examine and un-derstand the evolution mechanism of physical dynamics embedded in flow patterns. Combining these characteristics and methods, the evolution of the nonlinear dynamic physical behavior of gas bubbles is revealed.

  20. Two-phase cooling fluids; Les fluides frigoporteurs diphasiques

    Energy Technology Data Exchange (ETDEWEB)

    Lallemand, A. [Institut National des Sciences Appliquees (INSA), 69 - Lyon (France)

    1997-12-31

    In the framework of the diminution of heat transfer fluid consumption, the concept of indirect refrigerating circuits, using cooling intermediate fluids, is reviewed and the fluids that are currently used in these systems are described. Two-phase cooling fluids advantages over single-phase fluids are presented with their thermophysical characteristics: solid fraction, two-phase mixture enthalpy, thermal and rheological properties, determination of heat and mass transfer characteristics, and cold storage through ice slurry

  1. Numerical investigation of the mechanism of two-phase flow instability in parallel narrow channels

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Lian [Key Laboratory of Low-grade Energy Utilization Technologies and Systems, Chongqing University (China); Chen, Deqi, E-mail: chendeqi@cqu.edu.cn [Key Laboratory of Low-grade Energy Utilization Technologies and Systems, Chongqing University (China); CNNC Key Laboratory on Nuclear Reactor Thermal Hydraulics Technology, Nuclear Power Institute of China, Chengdu 610041 (China); Huang, Yanping, E-mail: hyanping007@163.com [CNNC Key Laboratory on Nuclear Reactor Thermal Hydraulics Technology, Nuclear Power Institute of China, Chengdu 610041 (China); Yuan, Dewen; Wang, Yanling [CNNC Key Laboratory on Nuclear Reactor Thermal Hydraulics Technology, Nuclear Power Institute of China, Chengdu 610041 (China); Pan, Liangming [Key Laboratory of Low-grade Energy Utilization Technologies and Systems, Chongqing University (China)

    2015-06-15

    Highlights: • A mathematical model is proposed to predict the two-phase flow instability. • The mathematical model predicted result agrees well with the experimental result. • Oscillation characteristics of the two-phase flow instability is discussed in detail. - Abstract: In this paper, the mechanism of two-phase flow instability in parallel narrow channels is studied theoretically, and the characteristic of the flow instability is discussed in detail. Due to the significant confining effect of the narrow channel on the vapor–liquid interface, the two-phase flow resistance in the narrow channel is probably different from that in conventional channel. Therefore, the vapor confined number (N{sub conf}), defined by the size of narrow channel and bubble detachment diameter, is considered in the “Chisholm B model” to investigate the two-phase flow pressure drop. The flow instability boundaries are plotted in parameter plane with phase-change-number (N{sub pch}) and subcooling-number (N{sub sub}) under different working conditions. It is found that the predicted result agrees well with the experimental result. According to the predicted result, the oscillation behaviors near the flow instability boundary indicate that the Supercritical Hopf bifurcation appears in high sub-cooled region and the Subcritical Hopf bifurcation appears in low sub-cooled region. Also, a detailed analysis about the effects of key parameters on the characteristic of two-phase flow instability and the flow instability boundary is proposed, including the effects of inlet subcooling, heating power, void distribution parameter and drift velocity.

  2. Two-phase flow research. Phase 1: Two-phase nozzle research

    Science.gov (United States)

    Toner, S. J.

    1981-07-01

    Experimental performance of converging-diverging nozzles operating on air-water mixtures is presented for a wide range of parameters. Thrust measurements characterized the performance and photographic documentation was used to visually observe the off-design regimes. Thirty-six nozzle configurations were tested to determine the effects of convergence angle, area ratio, and nozzle length. In addition, the pressure ratio and mass flowrate ratio were varied to experimentally map off-design performance. The test results indicate the effects of wall friction and infer temperature and velocity differences between phases and the effect on nozzle performance. The slip ratio between the phases, gas velocity to liquid velocity, is shown to be below about 4 or 5.

  3. Thermodynamic modelling of phase equilibrium for water + poly(Ethylene glycol + salt aqueous two-phase systems

    Directory of Open Access Journals (Sweden)

    R.A.G. Sé

    2002-04-01

    Full Text Available The NRTL (nonrandom, two-liquid model, expressed in mass fraction instead of mole fraction, was used to correlate liquid-liquid equilibria for aqueous two-phase polymer-salt solutions. New interaction energy parameters for this model were determined using reported data on the water + poly(ethylene glycol + salt systems, with different molecular masses for PEG and the salts potassium phosphate, sodium sulfate, sodium carbonate and magnesium sulfate. The correlation of liquid-liquid equilibrium is quite satisfactory.

  4. Local Flow Regime Transition Criteria of Gas-Liquid Two-phase Flow in Vertical Upward Tube with a Horizontal Rod%垂直上升管内有水平柱体时气液两相局部流型转变的研究

    Institute of Scientific and Technical Information of China (English)

    胡志华; 杨燕华; 刘磊; 周芳德

    2006-01-01

    The upward multiphase cross flow and heat transfer in the vertical tube may occur in oil production and chemical facilities. In this study, the local flow patterns of an upward gas-water two phase cross flow in a vertical tube with a horizontal rod have been investigated with an optical probe and the digital high speed video system. The local flow patterns are defined as the bubble, slug, churn and annular flow patterns. Optical probe signals are analyzed in terms of probability density function, and it is proved that the local flow patterns can be recognized by this method. The transition mechanisms between the different flow patterns have been analyzed and the corresponding transitional models are proposed. Finally, local flow pattern maps of the upward gas-water two-phase flow in the vertical tube with a horizontal rod are constructed.

  5. STUDIES OF TWO-PHASE PLUMES IN STRATIFIED ENVIRONMENTS

    Energy Technology Data Exchange (ETDEWEB)

    Scott A. Socolofsky; Brian C. Crounse; E. Eric Adams

    1998-11-18

    Two-phase plumes play an important role in the more practical scenarios for ocean sequestration of CO{sub 2}--i.e. dispersing CO{sub 2} as a buoyant liquid from either a bottom-mounted or ship-towed pipeline. Despite much research on related applications, such as for reservoir destratification using bubble plumes, our understanding of these flows is incomplete, especially concerning the phenomenon of plume peeling in a stratified ambient. To address this deficiency, we have built a laboratory facility in which we can make fundamental measurements of plume behavior. Although we are using air, oil and sediments as our sources of buoyancy (rather than CO{sub 2}), by using models, our results can be directly applied to field scale CO{sub 2} releases to help us design better CO{sub 2} injection systems, as well as plan and interpret the results of our up-coming international field experiment. The experimental facility designed to study two-phase plume behavior similar to that of an ocean CO{sub 2} release includes the following components: 1.22 x 1.22 x 2.44 m tall glass walled tank; Tanks and piping for the two-tank stratification method for producing step- and linearly-stratified ambient conditions; Density profiling system using a conductivity and temperature probe mounted to an automated depth profiler; Lighting systems, including a virtual point source light for shadowgraphs and a 6 W argon-ion laser for laser induced fluorescence (LIF) imaging; Imaging system, including a digital, progressive scanning CCD camera, computerized framegrabber, and image acquisition and analysis software; Buoyancy source diffusers having four different air diffusers, two oil diffusers, and a planned sediment diffuser; Dye injection method using a Mariotte bottle and a collar diffuser; and Systems integration software using the Labview graphical programming language and Windows NT. In comparison with previously reported experiments, this system allows us to extend the parameter range of

  6. Mathematical modeling of a gas jet impinging on a two phase bath

    Science.gov (United States)

    Delgado-Álvárez, J.; Ramírez-Argáez, Marco A.; González-Rivera, C.

    2012-09-01

    In this work a three phase 3D mathematical model was developed using the Volume Of Fluid (VOF) algorithm, which is able to accurately describe the cavity geometry and size as well as the liquid flow patterns created when a gas jet impinges on a two phase liquid free surface. These phenomena are commonly found in steelmaking operations such as in the Electric Arc Furnace (EAF) and the Basic Oxygen Furnace (BOF) where oxygen jets impinge on a steel bath and they control heat, momentum and mass transfer. The cavity formed in the liquids by the impinging jet depends on a force balance at the free surface where the inertial force of the jet governs these phenomena. The inertial force of the jet and its angle play important roles, being the lowest angle the best choice to shear the bath and promote stronger circulation and better mixing in the liquids.

  7. A two-dimensional parabolic model for vertical annular two-phase flow

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, F.M.; Toledo, A. Alvarez; Paladino, E.E. [Graduate Program in Mechanical Engineering, Universidade Federal de Rio Grande do Norte, Natal, RN (Brazil)], e-mail: emilio@ct.ufrn.br

    2010-07-01

    This work presents a solution algorithm for predicting hydrodynamic parameters for developing and equilibrium, adiabatic, annular, vertical two-phase flow. It solves mass and momentum transport differential equations for both the core and the liquid film across their entire domains. Thus, the velocity and shear stress distributions from the tube center to the wall are obtained, together with the average film thickness and the pressure gradient, making no use of empirical closure relations nor assuming any known velocity profile to solve the triangular relationship in the liquid film. The model was developed using the Finite Volume Method and an iterative procedure is proposed to solve all flow variables for given phase superficial velocities. The procedure is validated against the analytical solution for laminar flow and experimental data for gas-liquid turbulent flow with entrainment. For the last case, an algebraic turbulence model is used for turbulent viscosity calculation for both, liquid film and gas core. (author)

  8. Measurement and Correlation of Equilibrium Data for Aqueous Two-phase System Ethanol+Water+K2HPO4

    Institute of Scientific and Technical Information of China (English)

    LIN Jin-qing; TAN Ping-hua; JIN Chun-ying; LI Ming-chun

    2004-01-01

    The isothermal solubility data of aqueous two-phase system ethanol+water+K2HPO4 were determined with the turbidity titration method at 303.2 K. The binodal curves were described by using the Mistry equation very well. An experimental procedure for measuring the liquid-liquid equilibrium data of the aqueous two-phase system was proposed, in which the concentrations of the coexisting phases were determined with the corresponding densities of the solution. The tie lines were satisfactorily described by using the Othmer Tobias and Bancroft equations.

  9. Numerical modeling of two-phase binary fluid mixing using mixed finite elements

    KAUST Repository

    Sun, Shuyu

    2012-07-27

    Diffusion coefficients of dense gases in liquids can be measured by considering two-phase binary nonequilibrium fluid mixing in a closed cell with a fixed volume. This process is based on convection and diffusion in each phase. Numerical simulation of the mixing often requires accurate algorithms. In this paper, we design two efficient numerical methods for simulating the mixing of two-phase binary fluids in one-dimensional, highly permeable media. Mathematical model for isothermal compositional two-phase flow in porous media is established based on Darcy\\'s law, material balance, local thermodynamic equilibrium for the phases, and diffusion across the phases. The time-lag and operator-splitting techniques are used to decompose each convection-diffusion equation into two steps: diffusion step and convection step. The Mixed finite element (MFE) method is used for diffusion equation because it can achieve a high-order and stable approximation of both the scalar variable and the diffusive fluxes across grid-cell interfaces. We employ the characteristic finite element method with moving mesh to track the liquid-gas interface. Based on the above schemes, we propose two methods: single-domain and two-domain methods. The main difference between two methods is that the two-domain method utilizes the assumption of sharp interface between two fluid phases, while the single-domain method allows fractional saturation level. Two-domain method treats the gas domain and the liquid domain separately. Because liquid-gas interface moves with time, the two-domain method needs work with a moving mesh. On the other hand, the single-domain method allows the use of a fixed mesh. We derive the formulas to compute the diffusive flux for MFE in both methods. The single-domain method is extended to multiple dimensions. Numerical results indicate that both methods can accurately describe the evolution of the pressure and liquid level. © 2012 Springer Science+Business Media B.V.

  10. Ternary fission of (_

    Directory of Open Access Journals (Sweden)

    Dariush Naderi

    2017-05-01

    Full Text Available Using three cluster model, the ternary fission of (_"98" ^"252" Cf is studied. We applied collinear and equatorial configurations to study the ternary fission of (_"98" ^"252" Cf when three fragments are Sn, Ni and Ca. The potential energy of collinear and equatorial configurations is calculated. We calculated the potential energy for odd and even values of A3. Also, we compared the potential energy for (_"50" ^(A_"1" Sn+(_"28" ^(A_"2" Ni+(_"20" ^(A_"3" Ca and (_"50" ^(A_"1" -"1" Sn+(_"28" ^(A_"2" +"1" Ni+(_"20" ^(A_"3" Ca to investigate the influence of neutron numbers of three fragments. Obtained results show that for (_"50" ^(A_"1" Sn+(_"28" ^(A_"2" Ni+(_"20" ^(A_"3" Ca reaction with even A3 in collinear and equatorial configurations, the potential energy and penetration probability have ,respectively, minimum and maximum values in A3=48 whereas for odd values of A3 the minimum value for the potential energy and the maximum value of penetration probability take place in A3=49. For (_"50" ^(A_"1" -"1" Sn+(_"28" ^(A_"2" +"1" Ni+(_"20" ^(A_"3" Ca reactions in collinear and equatorial cases, the minimum value of potential energy and maximum value of penetration probability take place in A3=49 and A3=50, respectively, for even and odd values of A3. Also, among all the possible reactions the lowest value of potential energy and highest value of penetration probability happen for (_"50" ^132Sn+(_"28" ^72Ni+(_"20" ^48Ca configuration.

  11. Forced Two-Phase Helium Cooling Scheme for the Mu2e Transport Solenoid

    Energy Technology Data Exchange (ETDEWEB)

    Tatkowski, G. [Fermilab; Cheban, S. [Fermilab; Dhanaraj, N. [Fermilab; Evbota, D. [Fermilab; Lopes, M. [Fermilab; Nicol, T. [Fermilab; Sanders, R. [Fermilab; Schmitt, R. [Fermilab; Voirin, E. [Fermilab

    2015-01-01

    The Mu2e Transport Solenoid (TS) is an S-shaped magnet formed by two separate but similar magnets, TS-u and TS-d. Each magnet is quarter-toroid shaped with a centerline radius of approximately 3 m utilizing a helium cooling loop consisting of 25 to 27 horizontal-axis rings connected in series. This cooling loop configuration has been deemed adequate for cooling via forced single phase liquid helium; however it presents major challenges to forced two-phase flow such as “garden hose” pressure drop, concerns of flow separation from tube walls, difficulty of calculation, etc. Even with these disadvantages, forced two-phase flow has certain inherent advantages which make it a more attractive option than forced single phase flow. It is for this reason that the use of forced two-phase flow was studied for the TS magnets. This paper will describe the analysis using helium-specific pressure drop correlations, conservative engineering approach, helium properties calculated and updated at over fifty points, and how the results compared with those in literature. Based on the findings, the use of forced-two phase helium is determined to be feasible for steady-state cooling of the TS solenoids

  12. Lane of parallel through carry in ternary optical adder

    Institute of Scientific and Technical Information of China (English)

    JIN Yi; HE Huacan; AI Lirong

    2005-01-01

    At the present 50 to 100 microseconds are necessary for a liquid crystal to change its state from opacity to clarity; 1.14× 10-5 microseconds are however proved to be enough for light to pass through a clarity liquid crystal device. Rooted from this great difference in time, an optical adder was constructed with parallel through carry lanes (PTCL) composed of liquid crystals. Because all carries in PTCL process in parallel, the carry delay in the ternary optical computer's adder is avoided. Eliminating the carry delay in adder of ternary optical computer by physical means, the PTCL is also applicable for other types of optical adders. Moreover a light diagram of the adder and one PTCL structure are provided.

  13. SECOND-ORDER MOMENT MODEL FOR DENSE TWO-PHASE TURBULENT FLOW OF BINGHAM FLUID WITH PARTICLES

    Institute of Scientific and Technical Information of China (English)

    ZENG Zhuo-xiong; ZHOU Li-xing; LIU Zhi-he

    2006-01-01

    The USM-θ model of Bingham fluid for dense two-phase turbulent flow was developed, which combines the second-order moment model for two-phase turbulence with the particle kinetic theory for the inter-particle collision. In this model, phases interaction and the extra term of Bingharn fluid yield stress are taken into account. An algorithm for USM-θ model in dense two-phase flow was proposed, in which the influence of particle volume fraction is accounted for. This model was used to simulate turbulent flow of Bingham fluid single-phase and dense liquid-particle two-phase in pipe. It is shown USM-θ model has better prediction result than the five-equation model, in which the particle-particle collision is modeled by the particle kinetic theory, while the turbulence of both phase is simulated by the two-equation turbulence model. The USM-θ model was then used to simulate the dense two-phase turbulent up flow of Bingham fluid with particles. With the increasing of the yield stress, the velocities of Bingham and particle decrease near the pipe centre. Comparing the two-phase flow of Bingham-particle with that of liquid-particle, it is found the source term of yield stress has significant effect on flow.

  14. Modeling of annular two-phase flow using a unified CFD approach

    Energy Technology Data Exchange (ETDEWEB)

    Li, Haipeng, E-mail: haipengl@kth.se; Anglart, Henryk, E-mail: henryk@kth.se

    2016-07-15

    Highlights: • Annular two-phase flow has been modeled using a unified CFD approach. • Liquid film was modeled based on a two-dimensional thin film assumption. • Both Eulerian and Lagrangian methods were employed for the gas core flow modeling. - Abstract: A mechanistic model of annular flow with evaporating liquid film has been developed using computational fluid dynamics (CFD). The model is employing a separate solver with two-dimensional conservation equations to predict propagation of a thin boiling liquid film on solid walls. The liquid film model is coupled to a solver of three-dimensional conservation equations describing the gas core, which is assumed to contain a saturated mixture of vapor and liquid droplets. Both the Eulerian–Eulerian and the Eulerian–Lagrangian approach are used to describe the droplet and vapor motion in the gas core. All the major interaction phenomena between the liquid film and the gas core flow have been accounted for, including the liquid film evaporation as well as the droplet deposition and entrainment. The resultant unified framework for annular flow has been applied to the steam-water flow with conditions typical for a Boiling Water Reactor (BWR). The simulation results for the liquid film flow rate show good agreement with the experimental data, with the potential to predict the dryout occurrence based on criteria of critical film thickness or critical film flow rate.

  15. Influences of physical properties of two-phase mixture on void fraction in an annular vessel

    Institute of Scientific and Technical Information of China (English)

    LI Xiao-Ming; BI Qin-Cheng; FENG Quan-Ke; CHEN Ting-Kuan; DU She-Jiao

    2004-01-01

    To keep the void fraction of two-phase hydrogen in the moderator cell of the cold neutron source (CNS)of China Advanced Research Reactor (CARR) to a specified range, an annular vessel with the same size as the actual moderator cell was used as test section. Deionized water and alcohol, sucrose, and sodium chloride solutions with different concentrations were used as working fluid to find out influences of physical properties, such as density, viscosity and surface tension, of the two-phase mixture on void fraction. The tests proved that the ratio of surface tension to density of liquid phase has great influence on void fraction: the larger the ratio, the smaller the void fraction.Since the ratio of surface tension to density of Freon 113 is lower than that of liquid hydrogen, Freon 113 can be used as a working fluid to study the void fraction in the two-phase hydrogen thermosiphon loop in the CNS of CARR and the results will be conservative.

  16. Two-phase flow patterns characteristics analysis based on image and conductance sensors

    Science.gov (United States)

    Wang, Zhenya; Jin, Ningde; Wang, Chun; Wang, Jinxiang

    2008-10-01

    In order to study the temporal and spatial evolution characteristics of gas-liquid two-phase flow pattern, the two-phase flow monitoring system composed of high-speed dynamic camera and Vertical Multi-Electrode Array conductance sensor (VMEA) was utilized to shoot dynamic images and acquire the conductance fluctuating signals of 5 typical vertical gas-liquid two-phase flow patterns in a 125mm i.d. upward pipe. Gray level co-occurrence matrix (GLCM) was used to extract four time-varying characteristic parameter indices which represented different flow image texture structures and also Lempel-Ziv complexity of them were calculated. Then the transition of flow structure and flow property were comprehensively analyzed, combining the result derived from image information with recurrence plots (RPs) and Lempel-Ziv complexity of conductance fluctuating signals. The study showed that the line texture structure of RPs enabled to indicate flow pattern characteristics; the flow image texture structure characteristic parameters sequence described the variance of flow structure and dynamical complexity of different flow patterns.

  17. Thick GEM versus thin GEM in two-phase argon avalanche detectors

    CERN Document Server

    Bondar, A; Grebenuk, A; Pavlyuchenko, D; Tikhonov, Y; Breskin, Amos

    2008-01-01

    The performance of thick GEMs (THGEMs) was compared to that of thin GEMs in two-phase Ar avalanche detectors, in view of their potential application in coherent neutrino-nucleus scattering, dark-matter search and in other rare-event experiments. The detectors comprised a 1 cm thick liquid-Ar layer followed by either a double-THGEM or a triple-GEM multiplier, operated in the saturated vapor above the liquid phase. Three types of THGEMs were studied: those made of G10 and Kevlar and that with resistive electrodes (RETHGEM). Only the G10-made THGEM showed a stable performance in two-phase Ar with gains reaching 3000. Successful operation of two-phase Ar avalanche detectors with either thin- or thick-GEM multipliers was demonstrated at low detection thresholds, of 4 and 20 primary electrons respectively. Compared to the triple-GEM the double-THGEM multiplier yielded slower anode signals; this allowed applying a pulse-shape analysis to effectively reject noise signals. Noise rates of both multipliers were evaluate...

  18. Proportional electroluminescence in two-phase argon and its relevance to rare-event experiments

    CERN Document Server

    Bondar, A; Dolgov, A; Nosov, V; Shekhtman, L; Shemyakina, E; Sokolov, A

    2015-01-01

    Proportional electroluminescence (EL) in gaseous Ar has for the first time been systematically studied in the two-phase mode, at 87 K and 1.00 atm. Liquid Ar had a minor (56 ppm) admixture of N2, which allowed to understand, inter alia, the effect of N2 doping on the EL mechanism in rare-event experiments using two-phase Ar detectors. The measurements were performed in a two-phase Cryogenic Avalanche Detector (CRAD) with EL gap located directly above the liquid-gas interface. The EL gap was optically read out in the Vacuum Ultraviolet (VUV), near 128 nm (Ar excimer emission), and in the near Ultraviolet (UV), at 300-450 nm (N2 Second Positive System emission), via cryogenic PMTs and a Geiger-mode APD (GAPD). Proportional electroluminescence was measured to have an amplification parameter of 109+-10 photons per drifting electron per kV overall in the VUV and UV, of which 51+-6% were emitted in the UV. The measured EL threshold, at an electric field of 3.7+-0.2 kV/cm, was in accordance with that predicted by th...

  19. An improved large eddy simulation of two-phase flows in a pump impeller

    Institute of Scientific and Technical Information of China (English)

    Xuelin Tang; Fujun Wang; Yulin Wu

    2007-01-01

    An improved large eddy simulation using a dynamic second-order sub-grid-scale (SGS) stress model has been developed to model the governing equations of dense turbulent particle-liquid two-phase flows in a rotating coordi-nate system, and continuity is conserved by a mass-weighted method to solve the filtered governing equations. In the cur-rent second-order SGS model, the SGS stress is a function of both the resolved strain-rate and rotation-rate tensors, and the model parameters are obtained from the dimensional consis-tency and the invariants of the strain-rate and the rotation-rate tensors. In the numerical calculation, the finite volume method is used to discretize the governing equations with a staggered grid system. The SIMPLEC algorithm is applied for the solution of the discretized governing equations. Body-fitted coordinates are used to simulate the two-phase flows in complex geometries. Finally the second-order dynamic SGS model is successfully applied to simulate the dense turbu-lent particle-liquid two-phase flows in a centrifugal impeller. The predicted pressure and velocity distributions are in good agreement with experimental results.

  20. Characteristics of pressure drop for singlephase and two-phase flow across sudden contraction in microtubes

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Single-phase and gas-liquid two-phase pressure drops caused by a sudden con-traction in microtubes were experimentally investigated at room temperature and atmospheric pressure,using nitrogen and water. The experimental results on pressure drop with a novel measurement method,the tiny gaps on the tubes,were used to characterize the sudden contraction pressure drop for tube diameters from 850 to 330 μm. The ranges of the gas and liquid superficial velocity were 2.55―322.08 and 0.98―9.78 m/s in the smaller tube respectively. In single-phase flow experiments,the contraction loss coefficients were larger than the experimental results from conventional tubes in the laminar flow. While in the turbulent flow,the contraction loss coefficients were slightly smaller than those from conventional tubes and predicted well by Kc=0.5×(1-σ2)0.75. In two-phase flow experiments,the slip flow model with a velocity slip ratio S=(ρL/ρG)1/3 showed a good prediction that reveals the occurrence of velocity slip. An empirical correlation for two-phase flow pressure drops caused by the sudden contraction was developed based on the proposed contraction loss coefficients correlation for single-phase flow and Mar-tinelli factor.

  1. Single- and Two-Phase Flow Characterization Using Optical Fiber Bragg Gratings

    Directory of Open Access Journals (Sweden)

    Virgínia H.V. Baroncini

    2015-03-01

    Full Text Available Single- and two-phase flow characterization using optical fiber Bragg gratings (FBGs is presented. The sensor unit consists of the optical fiber Bragg grating positioned transversely to the flow and fixed in the pipe walls. The hydrodynamic pressure applied by the liquid or air/liquid flow to the optical fiber induces deformation that can be detected by the FBG. Given that the applied pressure is directly related to the mass flow, it is possible to establish a relationship using the grating resonance wavelength shift to determine the mass flow when the flow velocity is well known. For two phase flows of air and liquid, there is a significant change in the force applied to the fiber that accounts for the very distinct densities of these substances. As a consequence, the optical fiber deformation and the correspondent grating wavelength shift as a function of the flow will be very different for an air bubble or a liquid slug, allowing their detection as they flow through the pipe. A quasi-distributed sensing tool with 18 sensors evenly spread along the pipe is developed and characterized, making possible the characterization of the flow, as well as the tracking of the bubbles over a large section of the test bed. Results show good agreement with standard measurement methods and open up plenty of opportunities to both laboratory measurement tools and field applications.

  2. Parity violation in ternary fission

    Science.gov (United States)

    Gönnenwein, F.; Belozerov, A. V.; Beda, A. G.; Burov, S. I.; Danilyan, G. V.; Martem'yanov, A. N.; Pavlov, V. S.; Shchenev, V. A.; Bondarenko, L. N.; Mostovoĭ, Yu. A.; Geltenbort, P.; Last, J.; Schreckenbach, K.

    1994-01-01

    The parity-violating correlation between incoming neutron spin and fragment momentum has been measured simultaneously for binary and ternary fission of 233U(n, f) and 239Pu(n, f). The experiment has been performed with a polarized cold neutron beam of the Institut Laue-Langevin in Grenoble/France. The ratios of the parity-violating asymmetry coefficients, α ternf and α binnf, for ternary and binary fission, respectively, are found to be {α ternf}/{α binnf = 1.05 ± 0.10 } and 1.12 ± 0.08 for the 233U and 239Pu target nucleus, respectively. Both experiments are compatible with {α ternf}/{α binnf = 1 }. The implications of this result for models of ternary fission are discussed. The conclusion drawn is that ternary particles are emitted at the very last stage of fission.

  3. An experimental study of single-phase and two-phase flows in microchannels

    Science.gov (United States)

    Chung, Peter Mang-Yu

    Recent literature on pressure drop and flow rate measurements in microchannels indicate that both the liquid and gas flow may deviate significantly from convention. Thus, an evaluation was made of the friction factor constant for laminar flow and critical Reynolds number for the laminar-to-turbulent flow transition. Experiments were performed to study the single-phase flow behaviour of water or nitrogen gas through a 100 mum circular microchannel. The liquid flow data were well predicted by the conventional friction factor equations for larger channels, and the critical Reynolds number was close to tradition. For single-phase gas flow, the measured friction factor agreed with theory if the effect of compressibility was considered. Rarefaction did not contribute to the experimental results. The effect of scaling on two-phase flow was investigated to identify micro-scale phenomena. Experiments were conducted with a mixture of nitrogen gas and water in circular channels of 530--50 mum diameter. The two-phase flow was characterized by the flow patterns, void fraction, and frictional pressure drop. In the 530 and 250 mum channels, the flow characteristics were typical of those obtained in minichannels. In the 100 and 50 mum channels, the flow behaviour was unconventional---the occurrence of slug flow dominated, the void fraction-volumetric quality relationship departed from tradition, and mass flux no longer influenced the two-phase frictional multiplier. Unique to these channels, the slug flow exhibited a ring-shaped liquid film or serpentine-like gas core. The sizing effect indicates that the critical diameter for a microchannel lies between 250 and 100 mum. A new model is proposed to expose physical insight into the observed flow patterns. To investigate the effect of channel geometry on two-phase microchannel flow, the same experiment was conducted in a 96 mum square microchannel and the data were compared with those obtained in the 100 mum circular microchannel

  4. Necessary conditions for ternary algebras

    Energy Technology Data Exchange (ETDEWEB)

    Fairlie, David B [Department of Mathematical Sciences, University of Durham, Science Laboratories, South Rd, Durham DH1 3LE (United Kingdom); Nuyts, Jean, E-mail: david.fairlie@durham.ac.u, E-mail: jean.nuyts@umons.ac.b [Physique Theorique et Mathematique, Universite de Mons, 20 Place du Parc, B-7000 Mons (Belgium)

    2010-11-19

    Ternary algebras, constructed from ternary commutators, or as we call them, ternutators, defined as the alternating sum of products of three operators, have been shown to satisfy cubic identities as necessary conditions for their existence. Here we examine the situation where we permit identities not solely constructed from ternutators or nested ternutators and we find that in general, these impose additional restrictions; for example, the anti-commutators or commutators of the operators must obey some linear relations among themselves.

  5. Ternary generalizations of Grassmann algebra

    CERN Document Server

    Abramov, V V

    1996-01-01

    We propose the ternary generalization of the classical anti-commutativity and study the algebras whose generators are ternary anti-commutative. The integral over an algebra with an arbitrary number of generators N is defined and the formula of a change of variables is proved. In analogy with the fermion integral we define an analogue of the Pfaffian for a cubic matrix by means of Gaussian type integral and calculate its explicit form in the case of N=3.

  6. Velocity and energy relaxation in two-phase flows

    CERN Document Server

    Meyapin, Yannick; Gisclon, Marguerite

    2009-01-01

    In the present study we investigate analytically the process of velocity and energy relaxation in two-phase flows. We begin our exposition by considering the so-called six equations two-phase model [Ishii1975, Rovarch2006]. This model assumes each phase to possess its own velocity and energy variables. Despite recent advances, the six equations model remains computationally expensive for many practical applications. Moreover, its advection operator may be non-hyperbolic which poses additional theoretical difficulties to construct robust numerical schemes |Ghidaglia et al, 2001]. In order to simplify this system, we complete momentum and energy conservation equations by relaxation terms. When relaxation characteristic time tends to zero, velocities and energies are constrained to tend to common values for both phases. As a result, we obtain a simple two-phase model which was recently proposed for simulation of violent aerated flows [Dias et al, 2010]. The preservation of invariant regions and incompressible li...

  7. A SAS Package for Logistic Two-Phase Studies

    Directory of Open Access Journals (Sweden)

    Walter Schill

    2014-04-01

    Full Text Available Two-phase designs, in which for a large study a dichotomous outcome and partial or proxy information on risk factors is available, whereas precise or complete measurements on covariates have been obtained only in a stratified sub-sample, extend the standard case-control design and have been proven useful in practice. The application of two-phase designs, however, seems to be hampered by the lack of appropriate, easy-to-use software. This paper introduces sas-twophase-package, a collection of SAS-macros, to fulfill this task. sas-twophase-package implements weighted likelihood, pseudo likelihood and semi- parametric maximum likelihood estimation via the EM algorithm and via profile likelihood in two-phase settings with dichotomous outcome and a given stratification.

  8. Two-Phase flow instrumentation for nuclear accidents simulation

    Science.gov (United States)

    Monni, G.; De Salve, M.; Panella, B.

    2014-11-01

    The paper presents the research work performed at the Energy Department of the Politecnico di Torino, concerning the development of two-phase flow instrumentation and of models, based on the analysis of experimental data, that are able to interpret the measurement signals. The study has been performed with particular reference to the design of power plants, such as nuclear water reactors, where the two-phase flow thermal fluid dynamics must be accurately modeled and predicted. In two-phase flow typically a set of different measurement instruments (Spool Piece - SP) must be installed in order to evaluate the mass flow rate of the phases in a large range of flow conditions (flow patterns, pressures and temperatures); moreover, an interpretative model of the SP need to be developed and experimentally verified. The investigated meters are: Turbine, Venturi, Impedance Probes, Concave sensors, Wire mesh sensor, Electrical Capacitance Probe. Different instrument combinations have been tested, and the performance of each one has been analyzed.

  9. A mechanical erosion model for two-phase mass flows

    CERN Document Server

    Pudasaini, Shiva P

    2016-01-01

    Erosion, entrainment and deposition are complex and dominant, but yet poorly understood, mechanical processes in geophysical mass flows. Here, we propose a novel, process-based, two-phase, erosion-deposition model capable of adequately describing these complex phenomena commonly observed in landslides, avalanches, debris flows and bedload transport. The model is based on the jump in the momentum flux including changes of material and flow properties along the flow-bed interface and enhances an existing general two-phase mass flow model (Pudasaini, 2012). A two-phase variably saturated erodible basal morphology is introduced and allows for the evolution of erosion-deposition-depths, incorporating the inherent physical process including momentum and rheological changes of the flowing mixture. By rigorous derivation, we show that appropriate incorporation of the mass and momentum productions or losses in conservative model formulation is essential for the physically correct and mathematically consistent descript...

  10. Simulating confined swirling gas-solid two phase jet

    Institute of Scientific and Technical Information of China (English)

    金晗辉; 夏钧; 樊建人; 岑可法

    2002-01-01

    A k-ε-kp multi-fluid model was used to simulate confined swirling gas-solid two phase jet comprised of particle-laden flow from a center tube and a swirling air stream entering the test section from the coaxial annular. After considering the drag force between the two phases and gravity, a series of numerical simulations of the two-phase flow of 30μm, 45μm, 60μm diameter particles were performed on a x×r=50×50 mesh grid respectively. The results showed that the k-ε-kp multi-fluid model can be applied to predict moderate swirling multi-phase flow. When the particle diameter is large, the collision of the particles with the wall will influence the prediction accuracy. The bigger the diameter of the particles, the stronger the collision with the wall, and the more obvious the difference between measured and calculated results.

  11. Identification of two-phase flow regimes under variable gravity conditions

    Energy Technology Data Exchange (ETDEWEB)

    Kamiel S Gabriel [University of Ontario Institute of Technology 2000 Simcoe Street North, Oshawa, ON L1H 7K4 (Canada); Huawei Han [Mechanical Engineering Department, University of Saskatchewan 57 Campus Dr., Saskatoon, Saskatchewan, S7N 5A9 (Canada)

    2005-07-01

    Full text of publication follows: Two-phase flow is becoming increasingly important as we move into new and more aggressive technologies in the twenty-first century. Some of its many applications include the design of efficient heat transport systems, the transfer and storage of cryogenic fluids, and condensation and flow boiling processes in heat exchangers and energy transport systems. Two-phase flow has many applications in reduced gravity environments experienced in orbiting spacecraft and earth observation satellites. Examples are heat transport systems, the transfer and storage of cryogenic fluids, and condensation and flow boiling processes in heat exchangers. A concave parallel plate capacitance sensor has been developed to measure void fraction for the purpose of objectively identifying flow regimes. The sensor has been used to collect void-fraction data at microgravity conditions aboard the NASA and ESA zero-gravity aircraft. It is shown that the flow regimes can be objectively determined from the probability density functions of the void fraction signals. It was shown that under microgravity conditions four flow regimes exist: bubbly flow, characterized by discrete gas bubbles flowing in the liquid; slug flow, consisting of Taylor bubbles separated by liquid slugs which may or may not contain several small gas bubbles; transitional flow, characterized by the liquid flowing as a film at the tube wall, and the gas phase flowing in the center with the frequent appearance of chaotic, unstable slugs; and annular flow in which the liquid flows as a film along the tube wall and the gas flows uninterrupted through the center. Since many two-phase flow models are flow regime dependent, a method that can accurately and objectively determine flow regimes is required. (authors)

  12. Two-phase flow patterns in adiabatic and diabatic corrugated plate gaps

    Science.gov (United States)

    Polzin, A.-E.; Kabelac, S.; de Vries, B.

    2016-09-01

    Correlations for two-phase heat transfer and pressure drop can be improved considerably, when they are adapted to specific flow patterns. As plate heat exchangers find increasing application as evaporators and condensers, there is a need for flow pattern maps for corrugated plate gaps. This contribution presents experimental results on flow pattern investigations for such a plate heat exchanger background, using an adiabatic visualisation setup as well as a diabatic setup. Three characteristic flow patterns were observed in the considered range of two-phase flow: bubbly flow, film flow and slug flow. The occurrence of these flow patterns is a function of mass flux, void fraction, fluid properties and plate geometry. Two different plate geometries having a corrugation angle of 27° and 63°, respectively and two different fluids (water/air and R365mfc liquid/vapor) have been analysed. A flow pattern map using the momentum flux is presented.

  13. Thermal test results of the two-phase thermal bus technology demonstration loop

    Science.gov (United States)

    Edelstein, Fred; Liandris, Maria; Rankin, J. Gary

    1987-01-01

    A two-phase heat transport system, the Thermal Bus Technology Demonstrator, has been built and tested for NASA Johnson Space Center for application on Space Station. The loop is a separated two-phase system that uses evaporator flow control valves and liquid condenser flooding to achieve temperature control. Both ambient and thermal vacuum tests have been completed in NASA's Chamber A, initially using Freon-11 and then ammonia as the working fluid. Overall, the tests were quite successful, with the bus achieving all major test objectives, including operation at 19.5 kW and set points at 35 F (1.7 C), 70 F (21.1 C) and 104 F (40.0 C), load sharing, asymmetrical heating and isothermality around the loop. Low plate to vapor temperature drops were obtained for the monogroove cold plate using ammonia and are indicative of the high evaporative film coefficients obtainable with this design.

  14. Use of two-phase flow heat transfer method in spacecraft thermal system

    Science.gov (United States)

    Hye, A.

    1985-01-01

    In space applications, weight, volume and power are critical parameters. Presently liquid freon is used in the radiator planels of the Space Shuttle to dissipate heat. This requires a large amount of freon, large power for pumps, large volume and weight. Use of two-phase flow method to transfer heat can reduce them significantly. A modified commercial vapor compression refrigerator/freezer was sucessfully flown in STS-4 to study the effect of zero-gravity on the system. The duty cycle was about 5 percent higher in flight as compared to that on earth due to low flow velocity in condenser. The vapor Reynolds number at exit was about 4000 as compared to about 12,000. Efforts are underway to design a refrigerator/freezer using an oil-free compressor for Spacelab Mission 4 scheduled to fly in January 1986. A thermal system can be designed for spacecraft using the two-phase flow to transfer heat economically.

  15. Two Phase Flow and Space-Based Applications

    Science.gov (United States)

    McQuillen, John

    1999-01-01

    A reduced gravity environment offers the ability to remove the effect of buoyancy on two phase flows whereby density differences that normally would promote relative velocities between the phases and also alter the shape of the interface are removed. However, besides being a potent research tool, there are also many space-based technologies that will either utilize or encounter two-phase flow behavior, and as a consequence, several questions must be addressed. This paper presents some of these technologies missions. Finally, this paper gives a description of web-sites for some funding.

  16. Ternary phase diagram calculations of pentaerythritol-pentaglycerine-neopentylglycol system

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, A.; Talekar, A. [Chemical and Materials Engineering Department (MS388), University of Nevada, Reno, NV 89557 (United States); Chandra, D., E-mail: dchandra@unr.edu [Chemical and Materials Engineering Department (MS388), University of Nevada, Reno, NV 89557 (United States); Chien, W.-M. [Chemical and Materials Engineering Department (MS388), University of Nevada, Reno, NV 89557 (United States)

    2012-05-10

    Highlights: Black-Right-Pointing-Pointer Ternary phase diagrams of polyalcohols are developed using the CALPHAD method. Black-Right-Pointing-Pointer These ternary phase diagrams are thermodynamically calculated for the first time. Black-Right-Pointing-Pointer Orientational disorder is observed in the high temperature (energy storage) phase. Black-Right-Pointing-Pointer Polyalcohols are potential thermal energy storage materials. - Abstract: The pentaerythritol (PE)-pentaglycerine (PG)-neopentylglycol (NPG) ternary system has been thermodynamically assessed using the CALPHAD method and Thermo-Calc software. The PE-PG, PG-NPG, PE-NPG binary systems have also been calculated using CALPHAD on the basis of reported binary experimental data. The solution phases are modeled as substitutional solutions, in which the excess Gibbs energies are expressed by the Redlich-Kister-Muggianu polynomial. The PE-NPG binary phase diagram was modeled using Henrian solution model, and the liquid phase was assumed ideal. The PG-NPG system was optimized using regular and sub-regular solution models and show invariant equilibria at 298 K. The PE-NPG binary system was calculated from room temperature to the liquid phase temperatures. The modeled phase diagrams and the experimental data are in good agreement. A set of self consistent thermodynamic parameters formulating the Gibbs energies of various phases in the PE-PG-NPG ternary system are obtained in the present work. Thermodynamic properties, several vertical and isopleth sections have been calculated and are in good agreement with experimental data.

  17. Low Energy Consumption Technique for Processing Rapeseed with Two-phase Extraction System without Ammonia

    Institute of Scientific and Technical Information of China (English)

    Shi Meiren; Qin Jinping; SQian Renyuan

    2000-01-01

    the mother liquid of methanol phase obtained from rapeseed two-phase extraction process can directly be reused in large amounts to process rapeseed again together with some fresh methanol phase, so long as it is treated with a litter of proper additives in advance. The ratio of the reused mother liquid may be more than 3/ 4 of the total amount of the methanol phase needed for processing rapeseed, so the energy consumption can be decreased tremendously. The meal obtained by use of the reused mother liquid keeps the quality as good as those obtained by use of totally fresh methanol phase with light color, weak taste, crispness, good palatability, high protein content, and a low level of glucosinolates much more less than that stipulated by the State for the fodder of grade A.

  18. Modelling two-phase transport of 3H/3He

    NARCIS (Netherlands)

    Visser, A.; Schaap, J.D.; Leijnse, T.; Broers, H.P.; Bierkens, M.F.P.

    2008-01-01

    Degassing of groundwater by excess denitrification of agricultural pollution complicates the interpretation of 3H/3He data and hinders the estimation of travel times in nitrate pollution studies. In this study we used a two-phase flow and transport model (STOMP) to evaluate the method presented by