梢涡空化CFD数值方法  

Numerical study of tip vortex cavitation using CFD method

作　　者：韩宝玉[1] 熊鹰[1] 刘志华[1] 

机构地区：[1]海军工程大学船舶与动力学院,湖北武汉430033

出　　处：《哈尔滨工程大学学报》2011年第6期702-707,共6页Journal of Harbin Engineering University

基　　金：国家自然科学基金资助项目(51079157)

摘　　要：针对梢涡空化问题,应用雷诺平均的N-S方程并结合改进VOF(volume fraction)模型,对椭圆形水翼梢涡空化特性进行了研究,采用的湍流模型为代数雷诺应力模型.为减小网格离散误差,计算中对梢涡处的网格进行了加密.对未发生空化时梢涡内轴向速度和切向速度分布进行计算,为了准确模拟梢涡涡核内系统旋转和流线曲率影响,将旋转和曲率修正方法应用于湍流模型中,发现经过修正的湍流模型明显提高了预报精度,与实验结果吻合较好,而未经修正的湍流模型过高预报了梢涡内湍流粘性耗散.在此基础上,结合改进VOF模型对梢涡空化的消失空泡数进行了预报,计算结果与实验测量结果相符.The numerical simulation of tip vortex cavitation is significant in the process to alleviate the effects of the cavitation.The characteristics of tip vortex cavitation behind an elliptic foil were studied using Reynolds-averaged Navier-Stokes（RANS） equations with a modified VOF（volume fraction） cavitation model.The turbulence model selected was an explicit algebraic Reynolds stress model.In order to reduce the discrete error induced by the grid,mesh refinement was applied to the area of the tip vortex core in numerical simulation.First,the axis and tangential velocity of the tip vortex flow field with no cavitation were calculated.To consider the effect of system rotation and streamline curvature,the rotation-curvature correction was adapted to the turbulence model and it was found the turbulence model after correction increased the prediction precision.Numerical results show that the corrected eddy viscosity turbulence models agreed well with the experiment,while the unmodified versions over-predicted the turbulence-induced diffusion.Based on that,the desinence cavitation number of tip vortex cavitation was predicted using the RANS method and modified VOF cavitation model,and the numerical result shows good agreement with experimental result.

关 键 词：梢涡空化 改进VOF空化模型 湍流模型 旋转和曲率修正 消失空泡数 

分 类 号：U661.31[交通运输工程—船舶及航道工程]