Proposed Use of the One-Dimensional Two-Fluid Model With Momentum Flux Parameters

2000 ◽  
Author(s):  
Jin Ho Song ◽  
H. D. Kim
Keyword(s):  
Differential Equations ◽  
Void Fraction ◽  
Momentum Flux ◽  
Fluid Model ◽  
Sufficient Conditions ◽  
Wave Number ◽  
One Dimensional ◽  
Two Fluid Model ◽  
The One ◽  
Two Fluid

Abstract The dynamic character of a system of the governing differential equations for the one-dimensional two-fluid model, where the appropriate momentum flux parameters are employed to consider the velocity and void fraction distribution in a flow channel, is analyzed. In response to a perturbation in the form of a traveling wave, a linear stability analysis is performed for the governing differential equations. The analytical expression for the growth factor as a function of wave number, void fraction, drag coefficient, and relative velocity is derived. It provides the necessary and sufficient conditions for the stability of the one-dimensional two-fluid model in terms of momentum flux parameters. It is analytically shown that the one-dimensional two-fluid model is mathematically well posed by use of appropriate momentum flux parameters, while the conventional two-fluid model makes the system unconditionally unstable. It is suggested that the velocity and void distributions should be properly accounted for in the one-dimensional two-fluid model by use of momentum flux parameters.

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.

Review of Applicability of the One-dimensional Two-fluid Model to the Prediction of Wave Growth and Slug Evolution in Horizontal Pipes

2010 ◽  
Author(s):  
Raad I. Issa ◽  
Liejin Guo ◽  
D. D. Joseph ◽  
Y. Matsumoto ◽  
Y. Sommerfeld ◽  
...  
Keyword(s):  
Fluid Model ◽  
Wave Growth ◽  
One Dimensional ◽  
Horizontal Pipes ◽  
Two Fluid Model ◽  
The One ◽  
Two Fluid

scholarly journals A Characteristic Analysis of One-Dimensional Two-Fluid Model with Interfacial Area Transport Equation

2010 ◽  
Vol 2010 ◽  
pp. 1-19 ◽  
Author(s):  
Xia Wang ◽  
Xiaodong Sun
Keyword(s):  
Transport Equation ◽  
Momentum Flux ◽  
Fluid Model ◽  
Interfacial Area ◽  
Characteristic Analysis ◽  
Interfacial Area Transport ◽  
One Dimensional ◽  
Interfacial Area Transport Equation ◽  
Two Fluid Model ◽  
Two Fluid

An interfacial area transport equation (IATE), proposed to dynamically describe the interfacial structure evolution of two-phase flows, could help improve the predictive capability of the two-fluid model. The present study aims to investigate the well-posedness issue of a one-dimensional two-fluid model with the IATE (named “two-fluid-IATE model” hereafter) using a characteristic analysis. The momentum flux parameters, which take into account the coupling of the volumetric fraction of phase and velocity distributions over the cross-section of a flow passage, are employed. A necessary condition for the system to achieve hyperbolicity under an adiabatic flow condition is identified. A case study is performed for an adiabatic liquid-liquid slug flow, which shows that the hyperbolicity of the two-fluid-IATE model is guaranteed if appropriate correlations of the momentum flux parameters are applied in the two-fluid-IATE model.

Hyperbolicity of One-Dimensional Two-Fluid Model With Interfacial Area Transport Equations

2009 ◽  
Author(s):  
Xia Wang ◽  
Xiaodong Sun
Keyword(s):  
Flow Regime ◽  
Momentum Flux ◽  
Fluid Model ◽  
Interfacial Area ◽  
Structure Evolution ◽  
Characteristic Analysis ◽  
Interfacial Area Transport ◽  
One Dimensional ◽  
Two Fluid Model ◽  
Two Fluid

Two-fluid model with an empirical flow regime concept is widely used for two-phase flow analyses but suffers from its static and often non-hyperbolic nature. Recently, an interfacial area transport equation (IATE) has been proposed within the framework of the two-fluid model to dynamically describe the interfacial structure evolution and model the interfacial area concentration with the ultimate goal of modeling flow regime transition dynamically. Studies showed that the two-fluid model with the IATE (termed “two-fluid-IATE model” hereafter) could provide a more accurate prediction of the phase distributions and therefore improve the predictive capability of the two-fluid model. The inclusion of the IATE in the two-fluid model, however, brings about a subject of concern, namely, the well-posedness of the model. The objective of the present study is to investigate the issue of the hyperbolicity of a one-dimensional two-fluid-IATE model by employing momentum flux parameters, which take into account the coupling of the void fraction (volumetric fraction of the dispersed phase) and radial velocity distributions over the cross section of a flow passage. A characteristic analysis of the partial differential equations of the one-dimensional two-fluid model and two-group IATEs for an adiabatic flow was performed to identify a necessary condition for the system to achieve hyperbolicty. A case study was performed for an adiabatic liquid-liquid slug flow and the analysis showed that the hyperbolicty of the two-fluid-IATE model was guaranteed if appropriate correlations of the momentum flux parameters were applied in the two-fluid-IATE model.

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