On the role of buoyancy in determining the stability of curved mixing layers

It is well known that buoyancy forces and centrifugal effects can render a flow unstable to longitudinal vortex structures. Such competing instability mechanisms can be found in flows such as the curved mixing layer formed by the passage of two streams of fluid at different temperatures in the wake of a curved body. Via an asymptotic consideration of the problem we are abl e to characterize the interplay between these mechanisms. We are also able to determine the level of convex curvature required to stabilize unstably s tratified mixing layers and the level of concave curvature required to dest abilize stably stratified mixing layers. (C) 1999 American Institute of Phy sics. [S1070-6631(99)03806-4].