Experimental Study of a Starting Vortex Ring Generated by a Thin Circular Disk

摘要：

The formation process of vortex ring generated by a thin circular disk was studied experimentally in this paper. A thin circular disk installed a linear motion stage was used to generate the vortex rings. Digital Particle Image Velocimetry (DPIV) was used to measure the velocity and vorticity fields. The finite-time Lyapunov exponent field corresponding to the vortex flow was computed to identify Lagrangian coherent structures of the starting vortex. The results reveal the existence of a flux window between repelling Lagrangian Coherent Structures (rLCS) and attracting Lagrangian Coherent Structures (aLCS), through which the shear flow is entrained into the vortex. The flux window is closed gradually during the starting process. Once the flux window shut down, the formation process of the vortex ring finishes, as the shear flow with vorticity cannot be entrained in the vortex ring.

关键词： starting vortex ring circular disk DPIV LCS vortex formation time

作者: Anlong Yang Laibing Jia Xiezhen Yin

作者单位: Department of University of science and Technology of China, Hefei 230024 P.R. China

会议类型: 国际会议

会议名称: The 3rd International Conference of Bionic Engineering(第三届国际仿生工程会议ICBE10)

会议地点: 珠海

会议语种:英文

页码: 103-108

在线出版日期: 2010-09-14（万方平台首次上网日期，不代表论文的发表时间）