Three-dimensional numerical simulation of a vortex ring impacting a bump  

作　　者：Heng Ren Changyue Xu 

机构地区：[1]China Electronics Technology Group Corporation No.38 Research Institute [2]College of Aerospace Engineering, Nanjing University of Aeronautics and Astronautics

出　　处：《Theoretical & Applied Mechanics Letters》2014年第3期42-48,共7页力学快报（英文版）

基　　金：supported by the National Natural Science Foundation of China(11202100);the Natural Science Fund in Jiangsu Province(BK2011723)

摘　　要：A vortex ring impinging on a three-dimensional bump is studied using large eddy simulation for a Reynolds number Re = 4 × 104 based on the initial translation speed and diameter of the vortex ring. The effects of bump height on the vortical flow phenomena and the underlying physical mechanisms are inves- tigated. Based on the analysis of the evolution of vortical structures, two typical kinds of vortical structures, i.e., the wrapping vortices and the hair-pin vortices, are identified and play an important role in the flow state evolution. The circu- lation of the primary vortex ring reasonably elucidates some typical phases of flow evolution. Furthermore, the mechanism of flow transition from laminar to turbulent state has been revealed based on analysis of turbulent kinetic energy.A vortex ring impinging on a three-dimensional bump is studied using large eddy simulation for a Reynolds number Re = 4 × 104 based on the initial translation speed and diameter of the vortex ring. The effects of bump height on the vortical flow phenomena and the underlying physical mechanisms are inves- tigated. Based on the analysis of the evolution of vortical structures, two typical kinds of vortical structures, i.e., the wrapping vortices and the hair-pin vortices, are identified and play an important role in the flow state evolution. The circu- lation of the primary vortex ring reasonably elucidates some typical phases of flow evolution. Furthermore, the mechanism of flow transition from laminar to turbulent state has been revealed based on analysis of turbulent kinetic energy.

关 键 词：large eddy simulation vortex ring BUMP vortical structure turbulent state 

分 类 号：O35[理学—流体力学]