On the instability of certain motions of an ideal incompressible fluid

Abstract

Short-wave instabilities in the general three-dimensional time-dependent flows of an ideal incompressible fluid are considered. A new geometrical optics equation for the perturbed vorticity amplitude is derived. It is shown that under certain conditions this equation can be solved explicitly. Using this observation a number of known instability conditions are obtained and some new ones are derived. © 1994 Academic Press, Inc. All rights reserved.