Essence of inviscid shear instability: a point view of vortex dynamics

摘要：

The essence of shear instability is fully revealed both mathematically and physically. A general sufficient and necessary stable criterion is obtained analytically within linear context. It is the analogue of Kelvin-Arnold theorem, I.e., the stable flow minimizes the kinetic energy associated with vorticity. Then the mechanism of shear instability is explored by combining the mechanisms of both Kelvin-Helmholtz instability (K-H instability) and resonance of waves. It requires both concentrated vortex and resonant waves for the instability. The waves, which have same phase speed with the concentrated vortex, have interactions with the vortex to trigger the instability. The physical explanation of shear instability is also sketched. These results would intrigue future works to investigate the other hydrodynamic instabilities.

关键词： shear instability vortex dyanmics

作者: L.Sun

作者单位: School of Earth and Space Sciences, University of Science and Technology of China, Hefei, 230026, China;LASG, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China.

会议类型: 国际会议

会议名称: The Fifth International Conference on Fluid Mechanics(第五届国际流体力学会议)

会议地点: 上海

会议语种:英文

在线出版日期: 2007-08-15（万方平台首次上网日期，不代表论文的发表时间）