Mechanism Responsible for the Complete Suppression of Kármán Vortex in Flows Past a Wavy Square-Section Cylinder
LIN Li-Ming1, LING Guo-Can2, WU Ying-Xiang1
1The Division of Engineering Sciences, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190 2The Stake Key Laboratory of Nonlinear Mechanics, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190
Mechanism Responsible for the Complete Suppression of Kármán Vortex in Flows Past a Wavy Square-Section Cylinder
LIN Li-Ming1, LING Guo-Can2, WU Ying-Xiang1
1The Division of Engineering Sciences, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190 2The Stake Key Laboratory of Nonlinear Mechanics, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190
摘要The Kármán vortex shedding is totally suppressed in flows past a wavy square-section cylinder at a Reynolds number of 100 and the wave steepness of 0.025. Such a phenomenon is illuminated by the numerical simulations. In the present study, the mechanism responsible for it is mainly attributed to the vertical vorticity. The geometric disturbance on the rear surface leads to the appearance of spanwise flow near the base. The specific vertical vorticity is generated on the rear surface and convecting into the near wake. The wake flow is recirculated with the appearance of the pair of recirculating cells. The interaction between the upper and lower shear layers is weakened by such cells, so that the vortex rolls could not be formed and the near wake flow becomes stable.
Abstract：The Kármán vortex shedding is totally suppressed in flows past a wavy square-section cylinder at a Reynolds number of 100 and the wave steepness of 0.025. Such a phenomenon is illuminated by the numerical simulations. In the present study, the mechanism responsible for it is mainly attributed to the vertical vorticity. The geometric disturbance on the rear surface leads to the appearance of spanwise flow near the base. The specific vertical vorticity is generated on the rear surface and convecting into the near wake. The wake flow is recirculated with the appearance of the pair of recirculating cells. The interaction between the upper and lower shear layers is weakened by such cells, so that the vortex rolls could not be formed and the near wake flow becomes stable.
LIN Li-Ming;LING Guo-Can;WU Ying-Xiang. Mechanism Responsible for the Complete Suppression of Kármán Vortex in Flows Past a Wavy Square-Section Cylinder[J]. 中国物理快报, 2010, 27(3): 34702-034702.
LIN Li-Ming, LING Guo-Can, WU Ying-Xiang. Mechanism Responsible for the Complete Suppression of Kármán Vortex in Flows Past a Wavy Square-Section Cylinder. Chin. Phys. Lett., 2010, 27(3): 34702-034702.
2010, Vol. 27 
