The vortex breakdown of a columnar vortex with axial flow
The vortex breakdown of a columnar vortex with axial ow (q-vortex1) is investigated numerically. The formation of turbulent eddies around the columnar vortex and the vortex-core deformations are studied in detail by visualizing the ow field. In the marginally stable case with q =-1.5, small thin spiral structures are formed inside the vortex core. In the unstable case with q =-0.45, the linear unstable modes grow until the columnar vortex completes one turn. The data for the growth rate agree with that of the linear analysis 2. After the vortex completes two turns, a secondary instability is excited which causes the collapse of the columnar q-vortex, after which many fine scale vortices appear spontaneously.
vortex breakdown vortex structure direct numerical simulation
N.Takahashi T.Miyazaki
Department of Mechanical Engineering and Intelligent Systems, University of Electro-Communications,Chofu, Tokyo, 182-8585, Japan
国际会议
The Fifth International Conference on Fluid Mechanics(第五届国际流体力学会议)
上海
英文
2007-08-15（万方平台首次上网日期，不代表论文的发表时间）