标题： 涡旋环重新连接 显示英文标题

标题： Vortex Ring Reconnections

摘要： 我们数值研究了在小$Re$数量级下重新连接环形涡旋的纳维-斯托克斯动力学。 我们发现由于重新连接处的涡度梯度平滑以及拉伸反平行涡度次级结构的形成，重新连接是耗散的，这些次级结构将动能传递到小尺度，在那里随后被有效耗散。 此外，重新连接处的松弛激发了凯尔文波，由于强阻尼，这些凯尔文波具有低波数，并且仅直接影响流动的大尺度特性。 显示英文摘要

摘要： We investigate numerically the Navier-Stokes dynamics of reconnecting vortex rings at small $Re$ number. We find that reconnections are dissipative due to the smoothing of vorticity gradients at reconnection kinks and to the formation of secondary structures of stretched anti-parallel vorticity which transfer kinetic energy to small scales where it is subsequently dissipated efficiently. In addition, the relaxation of the reconnection kinks excites Kelvin waves which due to strong damping are of low wavenumber and affect directly only large scale properties of the flow.