Aerodynamic modification of supersonic flow around truncated cone using pulsed electrical discharges

An experimental study on the use of plasma to improve blunt body aerodynamics in a supersonic flow is presented. Shadow, schlieren, and plasma glow imaging techniques were used simultaneously for flow and plasma visualization. The discharge current and voltage, as well as the flow pressure and temperature at different locations on the surface of the model, were measured. With a proper aspect ratio 0.81 of the physical spike length to the frontal diameter of a 60-deg truncated cone-cylinder designed for the wind-tunnel model, the on-board pulsed electrical discharge produced a conically distributed plasma around the cathode, which modified the main shock wave structure from a detached bow shock to a tip attached conical shock wave. At discharge maximum, the pressure on the frontal surface of the body decreased by more than 30%, the pressure on the cone surface increased by about 5%, and the pressure on the cylinder surface remained unchanged. The temperature measured near the cone surface increased considerably. The energy consumed in each discharge, which lasted less than 50 ms, was about 150 J. The results demonstrate that a plasma aerospike, conical-shaped plasma distributed around a small slender physical spike, can improve the blunt body aerodynamics.