低雷诺数下双向受迫振动圆柱尾涡结构分析

Numerical Investigation of the Vortex Formation About the Longitudinally and Transversely Forced Oscillating Cylinder at Low Reynolds Number

本文使用本团队自主开发的一款通用统一的流体力学计算软件UCFD,在Re=100和Re=500时对横、纵双向受迫振动圆柱绕流进行了数值模拟研究,研究发现了一些新的涡结构:在横向振动的基础上增加纵向振动后,在Re=100时,随着纵向振幅的增大,在某些工况下,圆柱的尾涡结构会在2P和P+S模式之间变化;当振动圆柱的纵向振幅增大至0.8D后,圆柱一周期脱落涡可达到5个;Re=500时,随着纵向振幅的增大,圆柱尾涡的2S与P+S结构分布逐渐减少,2P结构分布逐渐变多;当振动圆柱的纵向振幅增大至0.6D后,在某些工况下圆柱一周期脱落5个涡。

The vortex formation in the wake of longitudinally and transversely forced oscillating cylinder at low Reynolds number is investigated through a common unified computational fluid dynamic software developed by our team.The analysis is focused on the structures and module change of the shedding vortex in the wake of the cylinder.Numerical results suggest that the structures of the shedding vortex in the wake of the cylinder has changed with the longitudinal oscillation.When the Reynolds number is Re=100 and amplitude of longitudinally forced oscillation increasing,the vortex formation in the wake will vary between 2 P and P+S modes;it is also found that when the amplitude of longitudinal oscillation equals to 0.8 D,five vortices are shed from cylinder in an oscillatory period at some conditions.When the Reynolds number is Re=500,when amplitude of longitudinally forced oscillation increasing,the region of the 2 S and P+S structure have gradually reduced and the region of 2 P modes becomes larger;it is also found that when the amplitude of longitudinal oscillation equals to 0.6 D,five vortices are shed from cylinder in an oscillatory period at some conditions.