Aerodynamic Cooling of the Wall in the Trace of a Supersonic Flow behind a Backward-Facing Ledge

The results of an experimental study of the effect of reducing the adiabatic wall temperature (aerodynamic cooling) for a case of separated supersonic flow behind a backward-facing ledge are presented. The study was conducted on an unsteady-state regime during the launching of a wind tunnel before reaching the equilibrium thermal state. The parameters of thermal gas dynamics were compared with the results for the case of continuous flow around the smooth wall. The free-stream Mach number was 2.2 and the Reynolds number along the length of the dynamic boundary layer was at least 20 million at the nozzle exit section. The height of the step ranged from 8 to 12 mm. The graphs of the wall temperature, stagnation flow temperature, adiabatic wall temperature, the total and static pressure, the heat flux, the distribution of the temperature recovery factor, and the relative Stanton number along the length of the model are presented. The studies were carried out in the joint inter-university laboratory of Moscow State University–Bauman Moscow State Technical University, Thermal Gas Dynamics on the experimental base of the Institute of Mechanics, Moscow State University.