Linear Instability Analysis of a Horizontal Two-Phase Flow in the Presence of Electrohydrodynamic Extraction Force

2001 ◽  
Vol 124 (1) ◽  
pp. 102-110 ◽  
Author(s):  
Y. Feng ◽  
J. Seyed-Yagoobi
Keyword(s):  
Electric Field ◽  
Two Phase Flow ◽  
Linear Instability ◽  
Vapor Flow ◽  
Phase Flow ◽  
Two Phase ◽  
Convective Boiling ◽  
Stability Maps ◽  
Two Phases ◽  
Linear Instability Analysis

The flow regimes associated with a horizontal internal two-phase (liquid-vapor) flow in the presence and absence of the electric field are investigated with the linear stability analysis. The momentum interchange due to the entrainment between the two phases is included in the analysis. The presence of the electric field promotes instability by providing the electrohydrodynamic (EHD) extraction force. Qualitative stability maps for the annular two-phase flow are provided with and without the electric field presence. Onset of the instability is compared with the experimental data and it is shown that the transition between the EHD-enhanced and EHD-suppressed convective boiling heat transfer is located near the annular-to-mist transition region.

Effects of high electric field on low-velocity gas-solid two-phase flow movement

2014 ◽  
Vol 21 (4) ◽  
pp. 1584-1591 ◽  
Author(s):  
Bo He ◽  
Dongdong Ma ◽  
Yadong Li ◽  
Ran Gu ◽  
Shengtao Li ◽  
...  
Keyword(s):  
Electric Field ◽  
Two Phase Flow ◽  
High Electric Field ◽  
Phase Flow ◽  
Low Velocity ◽  
Two Phase

Prediction of Pump Performance Under Air-Water Two-Phase Flow Based on a Bubbly Flow Model

1993 ◽  
Vol 115 (4) ◽  
pp. 781-783 ◽  
Author(s):  
Kiyoshi Minemura ◽  
Tomomi Uchiyama
Keyword(s):  
Two Phase Flow ◽  
Bubbly Flow ◽  
Phase Flow ◽  
Centrifugal Pumps ◽  
Flow Conditions ◽  
Two Phase ◽  
Performance Change ◽  
Void Fractions ◽  
Two Phases

This paper is concerned with the determination of the performance change in centrifugal pumps operating under two-phase flow conditions using the velocities and void fractions calculated under the assumption of an inviscid bubbly flow with slippage between the two phases. The estimated changes in the theoretical head are confirmed with experiments within the range of bubbly flow regime.

Measuring Flow Pattern Asymmetry of Oil-Water Two Phase Flows Using Multi-channel Rotating Electric Field Conductance Signals

2018 ◽  
Vol 74 (1) ◽  
pp. 25-41 ◽  
Author(s):  
Yuansheng He ◽  
Yingyu Ren ◽  
Yunfeng Han ◽  
Ningde Jin
Keyword(s):  
Electric Field ◽  
Flow Pattern ◽  
Cross Section ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Two Phase ◽  
Time Asymmetry ◽  
Pipe Cross Section ◽  
Multi Scale ◽  
Oil Water

AbstractThe present study is a report on the asymmetry of dispersed oil phase in vertical upward oil-water two phase flow. The multi-channel signals of the rotating electric field conductance sensor with eight electrodes are collected in a 20-mm inner diameter pipe, and typical images of low pattern are captured using a high speed camera. With the multi-channel rotating electric field conductance signals collected at pipe cross section, multi-scale time asymmetry (MSA) and an algorithm of multi-scale first-order difference scatter plot are employed to uncover the fluid dynamics of oil-water two phase flow. The results indicate that MSA can characterise the non-linear behaviours of oil-water two phase flow. Besides, the MSA analysis also beneficial for understanding the underlying inhomogeneous distribution of the flow pattern in different directions at pipe cross section.

NUMERICAL SOLUTION FOR HYPERBOLIC CONSERVATIVE TWO-PHASE FLOW EQUATIONS

2007 ◽  
Vol 04 (02) ◽  
pp. 299-333 ◽  
Author(s):  
D. ZEIDAN ◽  
A. SLAOUTI ◽  
E. ROMENSKI ◽  
E. F. TORO
Keyword(s):  
Numerical Solution ◽  
Riemann Problem ◽  
Two Phase Flow ◽  
Numerical Dissipation ◽  
Phase Flow ◽  
Two Phase ◽  
Flow Equations ◽  
Flow Problems ◽  
Slope Limiter ◽  
Two Phases

We outline an approximate solution for the numerical simulation of two-phase fluid flows with a relative velocity between the two phases. A unified two-phase flow model is proposed for the description of the gas–liquid processes which leads to a system of hyperbolic differential equations in a conservative form. A numerical algorithm based on a splitting approach for the numerical solution of the model is proposed. The associated Riemann problem is solved numerically using Godunov methods of centered-type. Results show the importance of the Riemann problem and of centered schemes in the solution of the two-phase flow problems. In particular, it is demonstrated that the Slope Limiter Centered (SLIC) scheme gives a low numerical dissipation at the contact discontinuities, which makes it suitable for simulations of practical two-phase flow processes.

Numerical Simulation of Forced Convective Boiling in a Microchannel

2018 ◽  
Vol 10 (4) ◽  
Author(s):  
Yun Whan Na ◽  
J. N. Chung
Keyword(s):  
Numerical Simulation ◽  
Two Phase Flow ◽  
Liquid Velocity ◽  
Flow Boiling ◽  
Simulation Method ◽  
Flow Patterns ◽  
Heat Fluxes ◽  
Phase Flow ◽  
Two Phase ◽  
Convective Boiling

Forced convective flow boiling in a single microchannel with different channel heights was studied through a numerical simulation method to investigate bubble dynamics, two-phase flow patterns, and boiling heat transfer. The momentum and energy equations were solved using a finite volume (FV) numerical method, while the liquid–vapor interface of a bubble is captured using the volume of fluid (VOF) technique. The effects of different constant wall heat fluxes and different channel heights on the boiling mechanisms were investigated. The effects of liquid velocity on the bubble departure diameter were also analyzed. The predicted bubble shapes and distribution profiles together with two-phase flow patterns are also provided.

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