Separation ahead of Protuberances in Supersonic Turbulent Boundary Layers

Abstract

The data were obtained using the optical-surface indicator technique of visualizing the flow; its accuracy and reproducibility are discussed. The proturberances are immersed in the boundary layer on the wall of a supersonic wind tunnel. The relative importance of various nondimensional groups is evaluated. The variation of primary separation distance is presented as a function of obstacle dimensions, Mach number, and Reynolds number, the last being the least significant. These results do not support some scaling laws found in the literature. An alternative correlation is proposed which applies to both small and large cylindrical protuberances.