Incipient Separation of a Turbulent Boundary Layer at High Reynolds Number in Two-Dimensional Supersonic Flow over a Compression Corner

An experimental study was made of the conditions necessary to promote incipient separation of a turbulent boundary layer in two-dimensional supersonic flow over a compression corner. The aim was to extend Kuehn's earlier results to higher Reynolds numbers. Measurements were obtained for Mach numbers in the range 2 to 5 and at Reynolds numbers , based on the boundary-layer thickness, in the range 10^6 to 10^7, nearly two orders of magnitude greater than those reported earlier. The main result was that the trend with Reynolds number established by Kuehn for the pressure rise for incipient separation does not continue to the high Reynolds number values of the present experiments; in fact, it is reversed. Pressure distributions were also obtained for conditions with and without separation. For the latter case, the upstream influence was considerably less than one boundary-layer thickness end the initial part of the pressure rise was practically a jump, suggesting that the oblique shock has its origin deep in the boundary layer.