Shock interactions in hypersonic flows outside the sonic circle in front of a blunt body

The problem of shock–shock interaction between a planar oblique shock wave and a bow shock wave is undertaken by considering a wedge and a hemispherical body in a hypersonic flow. The interaction patterns, as classified by Edney, namely Type-I, Type-II, Type-V, and Type-VI, which appear when a planar oblique shock wave interacts the bow shock wave outside the sonic circle are presented. The experiments are conducted at Mach number of 5.62, with air as test gas, in the short duration Hypersonic Shock Tunnel – 2 (HST-2) at Indian Institute of Science, Bangalore. Schlieren visualization is used to capture and identify the shock interaction patterns. Time evolution of the flow using the schlieren images is correlated with the pitot pressure signal to mark the flow establishment and useful test time in the tunnel, during which measurements are taken. Surface convective heat transfer rates are measured using Platinum thin film technique to quantify the heat transfer rates on the surface of a blunt body in the presence of these shock interactions.