Supersonic flow separation on a backward facing step

Abstract

The paper describes an experimental survey of flow separation on backward facing steps having different heights at a Mach number of 2.4. Reattachment and critical points are found for three regimes, laminar, transitional, and turbulent. Reattachment occurs at a point where the pressure is 35% of the free stream value for turbulent flow, and 60% of this value in the laminar case. The length of the free shear layer is found to be one-half that of the separating streamline, a result which emphasizes the importance of the reattachment region. The flow downstream of the critical point is found to be relatively independent of the base flow. Disturbances in the spanwise direction are always observed in laminar flow but do not affect the base pressure.