The effects of attached flexible tail length on the flow structure of an oscillating cylinder  

作　　者：HU Ye WANG JinJun 

机构地区：[1]Key Laboratory of Fluid Mechanics,Ministry of Education,Beihang University

出　　处：《Science China(Physics,Mechanics & Astronomy)》2013年第2期340-352,共13页中国科学：物理学、力学、天文学（英文版）

基　　金：supported by the National Natural Science Foundation of China (Grant No. 10832001);the Innovation Foundation of BUAA for PhD Graduates

摘　　要：Particle Imaging Velocimetry （PIV） is utilized to investigate the flow structures of an oscillating cylinder attached to a flexible tail. At the same oscillation frequency and amplitude, the mean streamwise velocity along the wake central-line and the mean vertical velocity around the trailing edge of the flexible tail can be greatly increased with the tail length. Meanwhile, the longer the flexible tail is, the larger its deformation is. In order to study the influence of flexible tail length on the wake pattern of the experimental model, the relationships between the swirling strength Aci of vortex structure near the tail end and the velocity of tail trailing edge have been revealed. Moreover, the convection tracks and the Aci of vortex cores for different flexible tails are discussed.Particle Imaging Velocimetry(PIV) is utilized to investigate the flow structures of an oscillating cylinder attached to a flexible tail.At the same oscillation frequency and amplitude,the mean streamwise velocity along the wake central-line and the mean vertical velocity around the trailing edge of the flexible tail can be greatly increased with the tail length.Meanwhile,the longer the flexible tail is,the larger its deformation is.In order to study the influence of flexible tail length on the wake pattern of the experimental model,the relationships between the swirling strength Λ ci of vortex structure near the tail end and the velocity of tail trailing edge have been revealed.Moreover,the convection tracks and the Λci of vortex cores for different flexible tails are discussed.

关 键 词：oscillating cylinder flexible tail tail deformation vortex structures mean flow characteristics 

分 类 号：O35[理学—流体力学]