Interfacial Area Transport

2010 ◽  
pp. 217-242
Author(s):  
Mamoru Ishii ◽  
Takashi Hibiki
Keyword(s):  
Interfacial Area ◽  
Interfacial Area Transport

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.

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 in a Small Diameter Pipe Under Microgravity Environment

2002 ◽  
Author(s):  
Tatsuya Hazuku ◽  
Tomoji Takamasa ◽  
Takashi Hibiki ◽  
Mamoru Ishii
Keyword(s):  
Velocity Profile ◽  
Normal Gravity ◽  
Interfacial Area ◽  
Bubble Coalescence ◽  
Microgravity Environment ◽  
Flow Conditions ◽  
Interfacial Area Transport ◽  
Interfacial Area Transport Equation ◽  
Diameter Pipe ◽  
Entrainment Effect

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 under a microgravity environment using an image-processing method. The interfacial area transport mechanism was determined based on visual observation. Marked bubble coalescence occurred when fast-moving bubbles near the channel center overtook and swept up slower-moving bubbles in the vicinity of the channel wall (velocity profile entrainment). Negligible bubble breakup was observed because of weak turbulence under tested flow conditions. Axial changes of measured interfacial area concentrations were compared with the interfacial area transport equation considering the bubble expansion and wake entrainment as observed under a normal gravity environment. The velocity profile entrainment effect under microgravity was likely to be comparable to the wake entrainment effect under normal gravity in the tested flow conditions. This apparently led to insignificant differences between measured interfacial area concentrations and those predicted by the interfacial area transport equation with the wake entrainment model under normal gravity. Possible bubble coalescence mechanisms would differ, however, between normal gravity and microgravity conditions.

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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