Characteristics of a supersonic laminar boundary layer over a rough wall

The characteristics of a supersonic laminar boundary layer over a rough wall were investigated. The boundary layer was produced by, a slender body of revolution at Mach 3 and the roughness consisted of random distributed and two dimensional periodic overlays. Results reported here cover mean flow profiles needed to validate and characterize the flow and detect changes in the profile caused by roughness. The critical roughness needed to cause profile distortions is based on the Reynolds number defined by local properties rather than free stream properties. The height of the distributed roughness needed to cause profile distortions caused great difficulty in interpreting the profile data. The two dimensional periodic overlay with a roughness height greater than the critical roughness height caused an upstream movement of transition. The two dimensional overlay also caused an outward displacement of the boundary layer edge with a simultaneous decrease in the boundary layer thickness causing a distinct distortion of the boundary layer profile and an increase in the surface skin friction.