The study of the effect of shock interaction of axisymmetric concave conic shapes in hypersonic flow

Heat transfer and pressure distributions have been measured on three concave biconic configurations in the von Karman Institute Longshot free piston wind tunnel at M = 15 and 20. The test flow parameters achieved closely simulate aerodynamic re-entry conditions. Information derived from the measurements and also single spark and high speed cine schlieren flow visualisation photographs enabled a qualitative description of the complicated two-shock steady flow system to be made and to explain the reason for the very high pressures and heat transfer rates measured on the concave surface. The effect of changing tip geometry, surface roughness, model incidence and flow conditions on the interaction is examined experimentally.