An Upwind Numerical Method for a Hyperbolic One-Dimensional Two-Fluid Model

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

This study discusses on the implementation of an upwind method for a one-dimensional two-fluid model including the surface tension effect in the momentum equations. This model consists of a complete set of six equations including two-mass, two-momentum, and two-internal energy conservation equations having all real eigenvalues. Based on this equation system with upwind numerical method, the present authors first make a pilot 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.

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.

On the Implementation of Computational Methods for a Hyperbolic Two-Fluid Model

2012 ◽  
Author(s):  
Moon-Sun Chung ◽  
Youn-Gyu Jung ◽  
Sung-Jae Yi
Keyword(s):  
Numerical Method ◽  
Fluid Model ◽  
Computer Code ◽  
Equation System ◽  
Benchmark Problems ◽  
Surface Tension Effect ◽  
Two Phase ◽  
Complete Set ◽  
Two Fluid Model ◽  
Two Fluid

In this study, we focused on the implementation of numerical methods for a 2-fluid system 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 conservations having all real eigenvalues. Based on this equation system with upwind numerical method, we first make a pilot 2-dimensional computer code and then solve some benchmark problems in order to check whether this model and numerical method is able to properly analyze some fundamental two-phase flow systems or not.

A Physically Based, One-Dimensional Two-Fluid Model for Direct Contact Condensation of Steam Jets Submerged in Subcooled Water

2015 ◽  
Vol 1 (2) ◽  
Author(s):  
David Heinze ◽  
Thomas Schulenberg ◽  
Lars Behnke
Keyword(s):  
Direct Contact ◽  
Two Phase Flow ◽  
Fluid Model ◽  
Interfacial Area ◽  
Phase Flow ◽  
Two Phase ◽  
One Dimensional ◽  
Two Fluid Model ◽  
Contact Condensation ◽  
Two Fluid

A simulation model for the direct contact condensation of steam in subcooled water is presented that allows determination of major parameters of the process, such as the jet penetration length. Entrainment of water by the steam jet is modeled based on the Kelvin–Helmholtz and Rayleigh–Taylor instability theories. Primary atomization due to acceleration of interfacial waves and secondary atomization due to aerodynamic forces account for the initial size of entrained droplets. The resulting steam-water two-phase flow is simulated based on a one-dimensional two-fluid model. An interfacial area transport equation is used to track changes of the interfacial area density due to droplet entrainment and steam condensation. Interfacial heat and mass transfer rates during condensation are calculated using the two-resistance model. The resulting two-phase flow equations constitute a system of ordinary differential equations, which is solved by means of the explicit Runge–Kutta–Fehlberg algorithm. The simulation results are in good qualitative agreement with published experimental data over a wide range of pool temperatures and mass flow rates.

A Linear Stability Analysis for an Improved One-Dimensional Two-Fluid Model

2003 ◽  
Vol 125 (2) ◽  
pp. 387-389 ◽  
Author(s):  
Jin Ho Song
Keyword(s):  
Stability Analysis ◽  
Linear Stability ◽  
Linear Stability Analysis ◽  
Fluid Model ◽  
Two Phase ◽  
One Dimensional ◽  
Proposed Model ◽  
Two Fluid Model ◽  
The One ◽  
Two Fluid

A linear stability analysis is performed for a two-phase flow in a channel to demonstrate the feasibility of using momentum flux parameters to improve the one-dimensional two-fluid model. It is shown that the proposed model is stable within a practical range of pressure and void fraction for a bubbly and a slug flow.

scholarly journals Prediction of Gas-Liquid Two-Phase Flow Performance of a Centrifugal Pump Using a One-Dimensional, Two-Fluid Model

1997 ◽  
Vol 63 (611) ◽  
pp. 2377-2385
Author(s):  
Kiyoshi MINEMURA ◽  
Tomomi UCHIYAMA ◽  
Katsuhiko KINOSHITA ◽  
Lin LYU ◽  
Shinji SYODA ◽  
...  
Keyword(s):  
Centrifugal Pump ◽  
Two Phase Flow ◽  
Fluid Model ◽  
Phase Flow ◽  
Two Phase ◽  
One Dimensional ◽  
Two Fluid Model ◽  
Two Fluid

Numerical Calculation of Two-Phase Flow Based on a Two-Fluid Model With Flow Regime Transitions

2012 ◽  
Author(s):  
Moon-Sun Chung ◽  
Youn-Gyu Jung ◽  
Sung-Jae Yi
Keyword(s):  
Flow Regime ◽  
Fluid Model ◽  
Numerical Test ◽  
Equation System ◽  
Analytical Form ◽  
Pressure Jump ◽  
Two Phase ◽  
Two Fluid Model ◽  
Regime Transitions ◽  
Two Fluid

Numerical test and eigenvalue analysis for a two-phase channel flows for energy conversion systems like fuel cells or water electrolysers with flow regime transitions are performed by using the well-posed system of equation that takes into account the pressure jump at the phasic interface. The interfacial pressure jump terms derived from the definition of surface tension which is based on the surface physics make the conventional two-fluid model hyperbolic without any additive terms, i.e., virtual mass or artificial viscosity terms. The four-equation system has three sets of eigenvalues; each of them has an analytical form of real eigenvalues relevant to the sonic speeds with phasic velocities of three typical flow regimes such as dispersed, slug, and separated flows. Further, the eigenvalues for the flow transition regions can also be obtained numerically for smooth calculation of flow regime transitions. The sonic speeds agree well not only with the earlier experimental data but also with those of an analytical model. Owing to the hyperbolicity of this model, we can adopt an upwind method, which is one of the well-known Godunov type upwind methods. A typical example of two-phase flows shows that the present model can simulate the phase separation caused by density difference of two-phase fluids.

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