Effect of wind and water shear on wave instabilities

摘要: The effect of vorticity or shear on the inviscid evolution and instability surface waves is discussed. a flat considered in detail. For case water, examined by means Howard's semi-circle theorem, which shown to elucidate qualitative nature domain. This can then be determined numerically without recourse analysis critical layer. dependence growth rate air profile for wind blowing over water at rest similarly considered. bounded laminar profiles, results are found sensitive shape, Miles's approximate formula inaccurate. On other hand, unbounded logarithmic rates relatively insensitive shape. However, there still disagreement between numerical calculations formula, overestimates factor two. A simple model presented both air.