摘要
三维圆球绕流是流体力学中的经典问题,国内外学者曾对此进行过许多研究,但大多局限于较低雷诺数。该文采用基于动力亚格子模型的大涡模拟对亚临界雷诺数（Re=10~4）和超临界雷诺数（Re=1.14×10~6）等高雷诺数下的圆球绕流进行了数值仿真计算。计算结果表明,得到的阻力时均值和经典Re-Cd曲线相吻合,相比于亚临界雷诺数,超临界雷诺数下近球面回流区剧烈收缩,阻力系数锐减;圆球尾流场明显偏离了中心轴（x轴）,导致了侧向力的存在;球后有大尺度的规则涡从圆球表面脱落。
Three-dimensional flow over the sphere is a classical problem in fluid mechanics community. Extensive studies have been conducted, both experimentally and numerically, through the last decades, however mostly on relatively low Reynolds numbers（Re）. The flow field around a sphere in an uniform flow is calculated numerically using LES with a dynamic Smagorinsky subgrid model in subcritical regime（ Re = 10~4） and supercritical regime（ Re = 1.14×10~6）. According to the calculation results, mean drag coefficients predicted in this article are consistent with the classic Re- Cd curve. Compared with the subcritical regime, the length of the recirculation region decreases and the drag coefficient drops a lot in the supercritical regime. The wake of the sphere turns out to be asymmetric with respect to the streamwise direction, which explains the reason why the lateral force exists. More organized large scale eddies are shed into the wake.
出处
《水动力学研究与进展（A辑）》
CSCD
北大核心
2016年第4期496-502,共7页
Chinese Journal of Hydrodynamics
基金
国家高技术研究发展计划(863计划
2012AA091002)~~
关键词
大涡模拟
圆球绕流
回流区
侧向力
Large eddy simulation
flow over the ball
recirculation region
lateral force
