Interfacial structures and interfacial area transport in downward two-phase bubbly flow

2004 ◽  
Vol 30 (7-8) ◽  
pp. 779-801 ◽  
Author(s):  
M. Ishii ◽  
S.S. Paranjape ◽  
S. Kim ◽  
X. Sun
Keyword(s):  
Bubbly Flow ◽  
Interfacial Area ◽  
Two Phase ◽  
Interfacial Area Transport ◽  
Interfacial Structures

Interfacial Area Transport of Bubbly Flow Under Microgravity Environment

2003 ◽  
Author(s):  
Norihiro Fukamachi ◽  
Tatsuya Hazuku ◽  
Tomoji Takamasa ◽  
Takashi Hibiki ◽  
Mamoru Ishii
Keyword(s):  
Liquid Velocity ◽  
Constitutive Relations ◽  
Bubbly Flow ◽  
Interfacial Area ◽  
Visual Observation ◽  
Microgravity Environment ◽  
Axial Distance ◽  
Two Phase ◽  
Flow Measurements ◽  
Interfacial Area Transport

In relation to the development of the interfacial area transport equation, axial developments of one-dimensional void fraction, bubble number density, interfacial area concentration, and Sauter mean diameter of adiabatic nitrogen-water bubbly flows in a 9 mm-diameter pipe were measured by using an image-processing method under microgravity environment. The flow measurements were performed at four axial locations (axial distance from the inlet normalized by the pipe diameter = 7, 30, 45 and 60) under various flow conditions of superficial gas velocity (0.0083 m/s ∼ 0.022 m/s) and superficial liquid velocity (0.073 m/s ∼ 0.22 m/s). The interfacial area transport mechanism under microgravity environment was discussed in detail based on the obtained data and the visual observation. These data can be used for the development of reliable constitutive relations which reflect the true transfer mechanisms in two-phase flow under microgravity environment.

Effect of Gravity on Axial Development of Vertical Bubbly Flow

2006 ◽  
Author(s):  
Kazuya Abe ◽  
Yoshinori Hirose ◽  
Tatsuya Hazuku ◽  
Tomoji Takamasa ◽  
Takashi Hibiki
Keyword(s):  
Liquid Velocity ◽  
Constitutive Relations ◽  
Bubbly Flow ◽  
Interfacial Area ◽  
Stereo Image ◽  
Microgravity Environment ◽  
Axial Distance ◽  
Two Phase ◽  
Flow Measurements ◽  
Interfacial Area Transport

In relation to the development of the interfacial area transport equation, axial developments of void fraction profile, bubble number density, interfacial area concentration and Sauter mean diameter of adiabatic nitrogen-water bubbly flows in a 9 mm-diameter pipe were measured by using a Stereo Image-processing Method under normal- and micro-gravity environment. The flow measurements were performed at four axial locations (axial distance from the inlet normalized by the pipe diameter = 5, 20, 40 and 60) under various flow conditions of superficial gas velocity (0.00823–0.0303 m/s) and superficial liquid velocity (0.138–0.915 m/s). The interfacial area transport mechanism under microgravity environment was discussed in detail based on the obtained data and the visual observation. These data can be used for the development of reliable constitutive relations which reflect the rigorous transfer mechanisms in two-phase flow under microgravity environment.

Two-Fluid CFD Model of Adiabatic Air-Water Upward Bubbly Flow Through a Vertical Pipe With a One-Group Interfacial Area Transport Equation

2009 ◽  
Author(s):  
Deoras Prabhudharwadkar ◽  
Chris Bailey ◽  
Martin Lopez de Bertodano ◽  
John R. Buchanan
Keyword(s):  
Experimental Data ◽  
Transport Equation ◽  
Bubbly Flow ◽  
Interfacial Area ◽  
Correct Prediction ◽  
Interfacial Area Transport ◽  
One Dimensional ◽  
Interfacial Area Transport Equation ◽  
The One ◽  
Two Fluid

This paper describes in detail the assessment of the CFD code CFX to predict adiabatic liquid-gas two-phase bubbly flow. This study has been divided into two parts. In the first exercise, the effect of Lift Force, Wall Force and the Turbulent Diffusion Force have been assessed using experimental data from the literature for air-water upward bubbly flows through a pipe. The data used here had a characteristic near wall void peaking which was largely influenced by the joint action of the three forces mentioned above. The simulations were performed with constant bubble diameter assuming no bubble interactions. This exercise resulted in selection of the most appropriate closure form and closure coefficients for the above mentioned forces for the range of flow conditions chosen. In the second exercise, the One-Group Interfacial Area Transport equation was introduced in the two-fluid model of CFX. The interfacial area density plays important role in the correct prediction of interfacial mass, momentum and energy transfer and is affected by bubble breakup and coalescence processes in adiabatic flows. The One-Group Interfacial Area Transport Equation (IATE) has been developed and implemented for one-dimensional models and validated using cross-sectional area averaged experimental data over the last decade by various researchers. The original one-dimensional model has been extended to multidimensional flow predictions in this study and the results are presented in this paper. The paper also discusses constraints posed by the commercial CFD code CFX and the solutions worked out to obtain the most accurate implementation of the model.

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.

One-dimensional interfacial area transport for bubbly two-phase flow in vertical 5 × 5 rod bundle

2018 ◽  
Vol 72 ◽  
pp. 257-273 ◽  
Author(s):  
Hang Liu ◽  
Liang-ming Pan ◽  
Takashi Hibiki ◽  
Wen-xiong Zhou ◽  
Quan-yao Ren ◽  
...  
Keyword(s):  
Two Phase Flow ◽  
Interfacial Area ◽  
Phase Flow ◽  
Two Phase ◽  
Interfacial Area Transport ◽  
One Dimensional ◽  
Rod Bundle

MEASUREMENT OF INTERFACIAL AREA TRANSPORT OF GAS-LIQUID TWO-PHASE FLOW IN A MINI PIPE USING IMAGE-PROCESSING

2004 ◽  
Vol 2004.9 (0) ◽  
pp. 73-76
Author(s):  
Norihiro Fukamachi ◽  
Tatsuya Hazuku ◽  
Tomoji Takamasa ◽  
Takashi Hibiki ◽  
Mamoru Ishii
Keyword(s):  
Image Processing ◽  
Two Phase Flow ◽  
Interfacial Area ◽  
Phase Flow ◽  
Two Phase ◽  
Interfacial Area Transport

Recent Progress in the Studies of Gas-Liquid Two-Phase Flows at Microgravity Conditions

2003 ◽  
Author(s):  
Tomoji Takamasa ◽  
Takashi Hibiki
Keyword(s):  
Recent Progress ◽  
Interfacial Area ◽  
Phase System ◽  
Two Phase Flows ◽  
Two Phase ◽  
Interfacial Area Transport ◽  
Drift Flux ◽  
Wide Range ◽  
Microgravity Conditions ◽  
Heat Loads

In a thermal system of spacecraft, two-phase flow system now is an excellent alternative to the conventional single-phase system in transporting large amount of thermal energy at a uniform temperature regardless of variations in the heat loads. In addition, two-phase flows exist in a wide range of applications and enabling technologies in space. This report outlines recent progress in the studies of gas-liquid two-phase flows at microgravity conditions, especially for which regarding to interfacial area transport and drift flux.

Interfacial area transport of bubbly flow under microgravity environment

2003 ◽  
Vol 29 (2) ◽  
pp. 291-304 ◽  
Author(s):  
T. Takamasa ◽  
T. Iguchi ◽  
T. Hazuku ◽  
T. Hibiki ◽  
M. Ishii
Keyword(s):  
Bubbly Flow ◽  
Interfacial Area ◽  
Microgravity Environment ◽  
Interfacial Area Transport
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