A Numerical Modelling of Two-Phase Flow System

2008 ◽  
Author(s):  
Moon-Sun Chung ◽  
Jong-Won Kim
Keyword(s):  
Sound Speed ◽  
Two Phase Flow ◽  
Flow System ◽  
Fluid Model ◽  
Equation System ◽  
Pressure Jump ◽  
Phase Flow ◽  
Two Dimensional ◽  
Dimensional Model ◽  
Two Phase

A two-dimensional two-fluid model for two-phase flow system is proposed. This two-dimensional model is based on the hyperbolic one-dimensional model which is improved in its mathematical property by adopting the interfacial pressure jump terms in the momentum equations. Owing to this surface-tension effect incorporated in the momentum equations, eigenvalues of the equation system can be obtained analytically and they are proved to be all real. The eigenvectors can also be obtained analytically with linearly independent form. Further, they consist of phasic convective velocities, the sound speed of gas phase, and the sound speed of liquid phase. Consequently, the governing equation system is mathematically hyperbolic with reasonable characteristic speeds by which the upwind numerical method avails. Advantages and possibility of the present model are discussed in some detail.

Numerical Analysis of Two-Phase Pipe Flow of Liquid Helium Using Multi-Fluid Model

2001 ◽  
Vol 123 (4) ◽  
pp. 811-818 ◽  
Author(s):  
Jun Ishimoto ◽  
Mamoru Oike ◽  
Kenjiro Kamijo
Keyword(s):  
Phase Transition ◽  
Gas Phase ◽  
Liquid Helium ◽  
Two Phase Flow ◽  
Fluid Model ◽  
Numerical Results ◽  
Phase Flow ◽  
Two Dimensional ◽  
Two Phase ◽  
Normal Fluid

The two-dimensional characteristics of the vapor-liquid two-phase flow of liquid helium in a pipe are numerically investigated to realize the further development and high performance of new cryogenic engineering applications. First, the governing equations of the two-phase flow of liquid helium based on the unsteady thermal nonequilibrium multi-fluid model are presented and several flow characteristics are numerically calculated, taking into account the effect of superfluidity. Based on the numerical results, the two-dimensional structure of the two-phase flow of liquid helium is shown in detail, and it is also found that the phase transition of the normal fluid to the superfluid and the generation of superfluid counterflow against normal fluid flow are conspicuous in the large gas phase volume fraction region where the liquid to gas phase change actively occurs. Furthermore, it is clarified that the mechanism of the He I to He II phase transition caused by the temperature decrease is due to the deprivation of latent heat for vaporization from the liquid phase. According to these theoretical results, the fundamental characteristics of the cryogenic two-phase flow are predicted. The numerical results obtained should contribute to the realization of advanced cryogenic industrial applications.

A NUMERICAL STUDY OF TWO-PHASE FLOW USING A TWO-DIMENSIONAL TWO-FLUID MODEL

2004 ◽  
Vol 45 (10) ◽  
pp. 1049-1066 ◽  
Author(s):  
Moon-Sun Chung ◽  
Seung-Kyung Pak ◽  
Keun-Shik Chang
Keyword(s):  
Two Phase Flow ◽  
Numerical Study ◽  
Fluid Model ◽  
Phase Flow ◽  
Two Dimensional ◽  
Two Phase ◽  
Two Fluid Model ◽  
Two Fluid

Upwind Solutions for Two-Phase Flow Problems Using a Hyperbolic Two-Fluid Model

2011 ◽  
Author(s):  
Moon-Sun Chung ◽  
Youn-Gyu Jung ◽  
Sung-Jae Yi
Keyword(s):  
Numerical Method ◽  
Two Phase Flow ◽  
Fluid Model ◽  
Equation System ◽  
Benchmark Problems ◽  
Phase Flow ◽  
Two Phase ◽  
Flow Problems ◽  
Complete Set ◽  
Two Fluid Model

This study discusses on the implementation of an upwind method for a new 2-dimensional 2-fluid model including the surface tension effect in the momentum equations. This model consists of a complete set of 8 equations including 2-mass, 4-momentum, and 2-internal energy conservation equations having all real eigenvalues. Based on this equation system with upwind numerical method, the present authors first make a pilot 2-dimensional code and then solve some benchmark problems to verify whether this model and numerical method is able to properly solve some fundamental one-dimensional two-phase flow problems or not.

Rapid two-dimensional imaging of bubbles and slugs in a three-dimensional, gas-solid, two-phase flow system using ultrafast magnetic resonance

2007 ◽  
Vol 75 (2) ◽  
Author(s):  
C. R. Müller ◽  
D. J. Holland ◽  
J. F. Davidson ◽  
J. S. Dennis ◽  
L. F. Gladden ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Two Phase Flow ◽  
Flow System ◽  
Three Dimensional ◽  
Phase Flow ◽  
Two Dimensional ◽  
Two Phase

Numerical Simulation of Softness Abrasive Two-Phase Flow Field on Level Set Method

2010 ◽  
Vol 154-155 ◽  
pp. 197-201
Author(s):  
Shi Ming Ji ◽  
Xiao Xing Weng ◽  
Da Peng Tan
Keyword(s):  
Topological Structure ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Two Dimensional ◽  
Dimensional Model ◽  
Characteristic Parameters ◽  
Two Phase ◽  
Abrasive Flow Machining ◽  
Mechanics Model ◽  
And Control

The soft abrasive flow machining was proposed for solving the problems of difficult contact finishing in course of mould manufacturing. It could reach the specular level and control turbulence abrasive flow. Based on the topological structure transformation of LSM, a two- dimensional model of the two-phase flow is established. This mechanics model with the SIMPLE (semi-implicit method for pressure-linked equations) algorithm incorporated is used to simulate the movement of the turbulent flow by using of k-ε model. The computed results show that this 2D model can preferably simulate the movement of the two-phase flow, and the characteristic parameters of abrasive two-phase flow are derived.

Fundamental Study on Two-Phase Flow Characteristics in Chimney of Pb-Bi Cooled Direct Contact Boiling Water Fast Reactor

2004 ◽  
Author(s):  
Toyou Akashi ◽  
Akira Yamada ◽  
Minoru Takahashi
Keyword(s):  
Fast Reactor ◽  
Direct Contact ◽  
Two Phase Flow ◽  
Flow System ◽  
Fluid Model ◽  
Flow Characteristics ◽  
Boiling Water ◽  
Phase Flow ◽  
Two Phase ◽  
Fundamental Study

The lead-bismuth-steam two-phase flow in the chimney of the lead-bismuth cooled direct contact boiling water fast reactor (PBWFR) was simulated experimentally using water-air two-phase flow system and analytically using the multi-dimensional two-fluid model computer program ACE-3D for the design of the ring header nozzles and chimney of the PBWFR. It has been found that the downward flow appeared in the chimney according to the analytical results. The analytical simulation will be verified by the experiment data, and the air injection flow rate, and the number, caliber and arrangement of injection nozzles in the ring header will be chosen adequately to improve the performance of the lift pump. Also, the analytical program will be extended for the simulation of a steam-Pb-Bi flow system.

On the Characteristics of a Two-Dimensional Two-Fluid Model

2008 ◽  
Author(s):  
Moon-Sun Chung ◽  
Sung-Jae Lee ◽  
Jong-Won Kim
Keyword(s):  
Two Phase Flow ◽  
Flow Problem ◽  
Fluid Model ◽  
Phase Flow ◽  
Two Dimensional ◽  
Two Phase ◽  
One Dimensional ◽  
Pipe System ◽  
Two Fluid Model ◽  
Two Fluid

In this study, we will suggest a two-dimensional two-fluid model considering the effect of mass and momentum interactions to simulate more realistic two-phase flow than the conventional model did. A hyperbolic two-fluid model had been developed for one-dimensional two-phase flow by Chung et al. [1] and it has been improved and applied to analyze one-dimensional two-phase flow problem including surface tension effect for either ordinary pipe system or minichannels. However, in order to simulate the two-dimensional two-phase flow problem efficiently in the future, the above one-dimensional model has need to be extended to two-dimensional equations and adopted to an upwind numerical method.

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