以单排Clark-Y型水翼叶栅为例,采用滤波器湍流模型(FBM)对绕栅中水翼的空化流动进行数值研究。雷诺数和空化数结合水洞实验工况进行设置,滤波尺寸根据加密区最大网格尺度取出经验值,模型通过二次开发方法嵌入至CFX软件中。对栅中水翼空化流动特性的分析表明,栅中翼形前缘和后缘部分均可能发生准周期性的空泡脱落现象,其脱落周期随空化数的降低而变大;前缘和后缘空泡的脱落均对翼型阻力产生影响,但前者影响更大,随空化数的降低,脱落现象逐渐局限于后缘部分,使翼型所受阻力的波动大为减弱。
The cavitation flow around a cascade hydrofoil was numerical studied with the filter-based turbulence model(FBM) based on the Clark-Y cascade hydrofoil.The Reynolds number and the cavitation number were set according to the water tunnel experiment and the empirical value of the filter size was given based on the largest grid size of the refined region.Through second development, the FBM model was embed in the CFX software.The results demonstrate that the phenomenon of quasi-periodical cavity shedding will occur near the leading part and the trailing part of the cascade hydrofoil,and the shedding period will increase with the decrease of cavitation number;the cavity shedding in both parts can influence the drag acting on the hydrofoil,but the leading part shedding is dominant;with the decrease of cavitation number,the shedding will be gradually limited into the trailing part,and the drag fluctuating will be weaken to a great extent.