One-dimensional drift-flux model for two-phase flow in pool rod bundle systems

2012 ◽  
Vol 40 ◽  
pp. 166-177 ◽  
Author(s):  
Shao-Wen Chen ◽  
Yang Liu ◽  
Takashi Hibiki ◽  
Mamoru Ishii ◽  
Yoshitaka Yoshida ◽  
...  
Keyword(s):  
Two Phase Flow ◽  
Phase Flow ◽  
Two Phase ◽  
One Dimensional ◽  
Drift Flux Model ◽  
Drift Flux ◽  
Rod Bundle ◽  
Flux Model

ICONE11-36015 ONE-DIMENSIONAL DRIFT-FLUX MODEL FOR DOWNWARD TWO-PHASE FLOW

2003 ◽  
Vol 2003 (0) ◽  
pp. 214 ◽  
Author(s):  
Takashi HIBIKI ◽  
Hiroshi GODA ◽  
Seungjin KIM ◽  
Mamoru ISHII ◽  
Jennifer UHLE
Keyword(s):  
Two Phase Flow ◽  
Phase Flow ◽  
Two Phase ◽  
One Dimensional ◽  
Drift Flux Model ◽  
Drift Flux ◽  
Flux Model

Investigation of the Structure Velocity in a 3x3 Rod Bundle Under Bubbly and Cap-Bubbly Flow Regimes

2020 ◽  
Author(s):  
Pei-Syuan Ruan ◽  
Shao-Wen Chen ◽  
Min-Song Lin ◽  
Jin-Der Lee ◽  
Jong-Rong Wang
Keyword(s):  
Two Phase Flow ◽  
Bubbly Flow ◽  
Flow Regimes ◽  
Phase Flow ◽  
Two Phase ◽  
Drift Flux Model ◽  
Drift Flux ◽  
Rod Bundle ◽  
Flux Model ◽  
Sudden Jump

Abstract This paper presents the experimental results and analyses of the structure velocity of air-water two-phase flow in a 3 × 3 rod bundle channel. A total of 56 flow conditions were tested and investigated for rod-gap, sub-channel, rod-wall and global regions of rod bundle geometry. The experimental tests were carried out under bubbly and cap-bubbly flow regimes with superficial gas and liquid velocities of 0–1 m/s and 1–1.7 m/s, respectively. The conductivity probes were set at different heights to measure the global and local void fractions. The structure velocity of air-water two-phase flow is the average bubble velocity calculated by the method in this study. The structure velocity were determined by utilizing the cross-correlation technique to analyze the time lags of the bubbles passing through the conductivity probes. The results of this study indicated that the structure velocity may increase with increasing superficial gas and liquid velocities. In low superficial gas velocity region, the structure velocity may first slightly increase and follow by a sudden jump which appear in most regions. After the sudden jump, the structure velocity may keep increasing mildly. The present structure velocities have been compared with the area-averaged gas velocities predicted by the drift flux model, and it appears that most structure velocities show a good agreement with the averaged gas velocities from the drift flux model after the jump.

Combination of Petroleum Correlations and Drift-Flux Approaches: A New Model for Two-Phase Flow Pressure Gradient Calculation for Horizontal and Slightly Inclined Upward Flowlines

2014 ◽  
Author(s):  
Rinaldo Antonio de Melo Vieira ◽  
Artur Posenato Garcia
Keyword(s):  
Pressure Gradient ◽  
Single Phase ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Two Phase ◽  
New Model ◽  
One Dimensional ◽  
Drift Flux Model ◽  
Drift Flux ◽  
Flux Model

One-dimensional single-phase flow has only one characteristic velocity, which is the area-averaged velocity. On the other hand, one-dimensional two-phase flow has several characteristics velocities, such as center of volume mixture velocity and center of mass mixture velocity. Under slip condition, usually they are quite different. In a simple way, one may think that the petroleum correlations and the drift-flux model are an attempt to “adapt” the single-phase momentum equation for a mixture of more than one phase, where the several parameters in the single-phase equation are replaced by average-mixture ones. These two models use different considerations for this “adaptation”. For instance, for friction loss calculation, petroleum correlations use the mixture volume velocity while drift-flux models use the mixture mass velocity. Normally, the volume velocity is higher than the mass velocity, and petroleum correlations may calculate friction gradients higher than the ones obtained by drift-flux models. This is very important, especially for horizontal and slightly inclined upward flows, where the friction pressure gradient is dominant. This work compares the pressure gradient evaluated by these two models for horizontal and slightly inclined upward flowlines using available data found in literature. The comparison shows that, depending on the situation, one model gives better results than the other. Based on the results, a new approach for two-phase flow friction calculation is proposed. The new model represents a combination of the approach used by the Petroleum Correlations and the Drift-Flux Model, using different characteristic velocities (volume, mass and a new one defined by the authors). The new model is very simple to implement and shows good agreement with the tested data.

Interfacial Structures and Regime Transition in Co-Current Downward Bubbly Flow

2004 ◽  
Vol 126 (4) ◽  
pp. 528-538 ◽  
Author(s):  
S. Kim ◽  
S. S. Paranjape ◽  
M. Ishii ◽  
J. Kelly
Keyword(s):  
Two Phase Flow ◽  
Bubbly Flow ◽  
Superficial Velocity ◽  
Phase Flow ◽  
Two Phase ◽  
Drift Flux Model ◽  
Drift Flux ◽  
Flow Parameters ◽  
Interfacial Structures ◽  
Flux Model

The vertical co-current downward air-water two-phase flow was studied under adiabatic condition in round tube test sections of 25.4-mm and 50.8-mm ID. In flow regime identification, a new approach was employed to minimize the subjective judgment. It was found that the flow regimes in the co-current downward flow strongly depend on the channel size. In addition, various local two-phase flow parameters were acquired by the multi-sensor miniaturized conductivity probe in bubbly flow. Furthermore, the area-averaged data acquired by the impedance void meter were analyzed using the drift flux model. Three different distributions parameters were developed for different ranges of non-dimensional superficial velocity, defined by the ration of total superficial velocity to the drift velocity.

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