High Speed Boundary Layer Stability and Control

摘要

In the present paper an overview of the recent studies of a hypersonic laminar boundary layer and shock layer receptivity and stability are presented. Main attention is paid to investigations of nonlinear wave interaction. It is shown that nonlinear interactions of the second mode play significant role in laminar-turbulent transition and intermode interaction is different for solid and porous walls. The paper deals with two different techniques of transition control. The first one, namely, ultrasonically absorptive coating (UAC) is a passive technique which uses porous materials on the wall to suppress growing acoustic disturbances in the boundary layer. The second one is based on wave interference and intermode interaction and uses blowing-suction method to suppress acoustic in the boundary layer.