KH instability
 

Hello Sirs

I was trying to understand the mechanism of classical Kelvin-Helmholtz instability, it is easy to visualize the classical example - wind over calm water.

I understand the mechanism in this situation - lower pressures above the crest of the wave due to the curvature effect amplifying the ripple. In this case wave breaking and droplet generation occurs when the critical wind velocity is about 6.5 m/s.

I have a question regarding the OPPOSITE SITUATION - a fast flowing water stream in a stagnant atmosphere. In this case, will it need a stream velocity of 6.5 for the wave breaking etc. to happen?

I would be greatful if some one can help me understand this, thanks so much

Kumar