绕锥头回转体通气超空化流场结构研究

Research on Flow Field Structure of Ventilated Supercavity around an Axisymmetric Body

采用实验与数值计算的方法对绕锥头回转体通气超空化流场结构进行研究。为捕捉通气空化空泡区域内复杂的旋涡结构,数值计算采用滤波器湍流模型;为更加细致地描述空泡区域内的流场结构,应用欧拉和拉格朗日两种分析方法对空泡区域的流场进行分析。研究结果表明:超空化形成以后,从通气孔出流的气体沿着水气相交界面向空泡尾部流动,到达空泡尾流区后,部分气体直接脱离空泡区域向下游发展,部分气体在反向射流的作用下补充到空泡区域内部;原本存留在空泡中前部的气体在空泡内部做不规则运动,不能脱离空泡区域;空泡尾流区的部分流体脱离空泡区域形成脱落空泡团,部分流体在反向射流的作用下在空泡区域作旋涡运动。

To understand the flow field structure of ventilated supercavity,the ventilated cavity flows around an axisymmetric body are researched by the experimental and numerical methods.A filter-based turbulence model is applied to accurately capture the vortex separation in numerical simulations.The methods of Euler and Lagrangian Coherent Structures （LCS） are used to describe the flow field structure in the domain of ventilated supercavity.The results show that the numerical results are consistent with the experimental results.The air entrained from the ventilated hole transports along the air-water interface to the end of cavity.Some portions of air escape from the domain of cavity,while some portions of air flow into the domain of cavity by the reentrance.The air existing in the middle of ventilated cavity moves regularly and cannot escape from the cavity.Some portions of fluid in the rear of ventilated cavity escape from the cavity and form the shedding bubbles,while some portions of fluid vortically move in the cavity.