arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv physics/0605167physics.flu-dynphysics.ao-ph
收藏

无粘剪切不稳定性的本质:涡动力学观点

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

Liang Sun

摘要:

从数学和物理两方面充分揭示了剪切失稳的本质。在线性背景下,得到了一个一般的充分必要稳定判据。它是Kelvin-Arnol定理的类似物,即,稳定的流动使与涡度相关的动能最小化。结合Kelvin-Helmholtz不稳定性(K-H不稳定性)和波的共振机制,探讨了剪切不稳定性的机理。它需要集中涡和共振波的不稳定性。与集中涡具有相同相速的波动与集中涡相互作用,触发不稳定。我们称这种机制为“集中涡不稳定性”。文中还简述了剪切失稳的物理解释。最后,由定理导出了一些有用的判据.这些结果将激发未来的工作,调查其他流体动力学不稳定性。

英文摘要:

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-Arnol'd 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. We call this mechanism as "concentrated vortex instability". The physical explanation of shear instability is also sketched. Finally, some useful criteria are derived from the theorem. These results would intrigue future works to investigate the other hydrodynamic instabilities.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑