Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7053433 | International Journal of Heat and Fluid Flow | 2018 | 17 Pages |
Abstract
For the modeling of the interfacial structure characteristics, an experiment of vertical adiabatic air-water flow has been conducted under an atmosphere pressure condition. The experimental facility is composed of 5â¯Ãâ¯5 rods arranged on a square pitch in a square casing with 9.5â¯mm outside rod diameter and 12.6â¯mm pitch, simulating a prototypic rod bundle in nuclear reactors. The miniaturized four-sensor conductivity probe has been developed to allow for the experimental measurement in the small flow channel. Extensive data are acquired for one-dimensional flow parameters including axial development of void fraction, interfacial area concentration and gas velocity. The effect of a prototypic spacer grids with mixing vanes on the flow structure has been discussed at various flow conditions based on the experimental data. Two competing effects, “swirling effect” and “bubble breaker effect”, are identified. The effect vanishes out within a short distance from the space grid. A drift-flux correlation is developed for predicting void fraction of adiabatic bubbly two-phase flow in a vertical rod bundle. Existing interfacial area correlations are tested and Hibiki-Ishii correlation (2002b) is recommended as most accurate correlation to predict the interfacial area concentration. It is expected that the newly obtained data in the 5â¯Ãâ¯5 rod bundle is useful for developing the interfacial area transport equation and benchmarking a computational code.
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Fluid Flow and Transfer Processes
Authors
Liu Hang, Pan Liang-ming, Hibiki Takashi, Zhou Wen-xiong, Ren Quan-yao, Li Song-song,