绕水翼超空化流场的数值模拟

基于Reynolds平均法,采用RNG k-ε模型及Mixture两相流模型,对绕水翼ys930的超空化流动进行了数值模拟,得到了绕水翼各个超空化阶段的超空化形态及各阶段的临界空化数与水翼攻角、来流雷诺数之间的关系,确定了临界空化数与来流雷诺数在不同攻角条件下的0.4次方经验关系式,给出了系数的取值区间.结果表明:超空化的发展经历了超空穴形成、汽液两相共存和完全发展3个阶段;各阶段的临界空化数随水翼攻角的增大而增大,基本呈线性关系;由于回射流的作用,在水翼前缘处形成一个逆时针旋涡,使逐渐长大的空泡脱离水翼吸力面并向下游脱落;在不同空化数下,空泡脱落的位置不同,导致空泡长度的变化.

Numerical simulation of supercavitating flow around hydrofoil

Based on Reynolds average method,supercavitating flow around ys930 hydrofoil were simulated by RNG k-ε model and Mixture two-phase model to obtain the relations among critical cavitation numbers of each supercavitation form,attack angle,and Reynolds number were obtained.Empirical formulas between critical cavitation numbers and Reynolds number in different conditions of attack angle were determined,and coefficient intervals were provided.The results show that the supercavitation development comprises three stages of cavity formation,two phases coexistence and fully developed phase.The critical cavitation numbers in each stage increase consistently with the increase of attack angle in a linear relationship.Because of re-entrant jet,a counterclockwise vortex makes cavity go off the suction side of the hydrofoil and falls off downstream.In different cavitation numbers,cavity falls off in different positions,leading to the change of cavity length.