空化模型中水气最大密度比对空化流动计算的影响

he filter-based model (FBM), which was introduced into CFX by user defined subroutine, and a homogeneous cavitation model were used to calculate cavitating flow around a 2D Clark-y hydrofoil. The effect of a maximum density ratio between liquid and vapor on sheet and cloud cavitating simulation was investigated. The results show that the maximum density ratio has a significant impact on cavitating simulation, the predicted cavitation with default 1000 is underestimated compared with experiment. With the increasing of maximum density ratio, the interaction interface between liquid and vapor becomes unstable, accompanying the intermittent shedding of small-scale cavities. The cavity length and vapor volume fraction also increase. When the maximum density is increased to some value, its effect on cavitation flow calculation becomes not obvious. Smaller maximum density ratio can ensure numerical stability but the result predicted with true density ratio is more accurate, so 20000 is selected as the value of maximum density ratio in cavitation model.