Incipient Separation of a Supersonic Turbulent Boundary Layer at High Reynolds Numbers

Two-dimensional compression corner and axisymmetric flare geometries were used in this study of shock wave interaction with a compressible turbulent boundary layer. The study was carried out at a Mach number of 2.9 and over a Reynolds number range of 10 5<Re60<107 (Re^up to 10 9). Detailed surface pressure, schlieren, and oil-flow data were obtained for several corner angles. A major finding of this study is that incipient separation is a gradual rather than an abrupt phenomenon. Incipient separation corner angles were found to be within a band of about 16°-18° and essentially independent of Reynolds number over the range studied.