基于PANS模型的水翼非定常空化特性研究  

Investigation of unsteady cavitation around hydrofoil based on PANS model

作　　者：施卫东[1] 张光建[1] 张德胜[1] 

机构地区：[1]江苏大学流体机械工程技术研究中心,江苏镇江212013

出　　处：《华中科技大学学报（自然科学版）》2014年第4期1-5,10,共6页Journal of Huazhong University of Science and Technology(Natural Science Edition)

基　　金：国家自然科学基金资助项目(51109093);江苏省'333工程'资助项目

摘　　要：采用一种局部时均化模型(PANS)对绕二维Clark-y型水翼的空化流动进行数值计算.分别研究了空化模型中最大密度比对空化计算的影响,PANS模型中关键控制参数fk对云空化非定常特性的影响和云空化阶段空泡形态及升力系数随时间的演变,并与实验结果进行对比.结果表明:最大密度比会影响液相与气相之间的质量传递速率,将最大密度比提高,可大大改善数值预测的精度;随着fk值的减小,PANS模型可释放更多的湍流尺度,较好地预测云空化中强烈的非定常特性;由于云空化呈现出产生-发展-脱落-溃灭的准周期性变化,使得水翼的升力系数变化剧烈,计算出时均升力系数为0.708,与实验值0.760相差约7%;回射流与主流相互作用,在水翼尾部形成的一对旋转方向相反的旋涡是云状空泡形成与发展的主要原因.Cavitating turbulent flow around a 2D Clark-y hydrofoil was simulated using the Partially- Averaged Navier-Stokes （PANS） method. The effect of a maximum density ratio between the liquid and the vapor on cavitating simulation, and the influence of control parameter fk in PANS model on the cloud cavitation instability and the evolution of cavity shape and lift coefficient during cloud cavita- tion were investigated. The results show that the maximum density ratio influences mass transfer rate between the liquid and the vapor. The accuracy of numerical prediction can be greatly improved by in- creasing the maximum density ratio. With decreasing fk, the predicted cavitating flow by PANS mod- el becomes unsteady due to resolving more of the turbulent scales. The evolution of the lift coefficient during the cloud cavitation is very complicated and dramatic, because that the shedding cloud cavity is very unsteady. The calculated time averaged lift coefficient is 0. 708, which is about 7% lower than the experimentally measured value of 0. 760. The vortex pair with the opposite rotation direction caused by interaction between the reentrant and main flow is the main trigger of cloud cavity.

关 键 词：空化流 水翼 湍流模型 空化模型 回射流 旋涡对 

分 类 号：TH311[机械工程—机械制造及自动化]