Stability analysis of the confined mixing layer

Abstract

This paper investigates the linear stability of confined mixing layers with special emphasis on effects of heat release and compressibility. Velocity and density profiles for laminar flows are obtained by solving the compressible boundary-layer equations. The results show that reflection of supersonic disturbances by the walls makes the confined supersonic mixing layer more unstable than the unconfined free shear layer. Decreasing the distance between the walls makes the flow more unstable. However, subsonic disturbances are relatively unaffected by the walls. Mach number hardly changes the growth rates of supersonic disturbances. The most unstable supersonic disturbances are three-dimensional in confined flows.