Potential of localized flow heating for wave drag reduction

Abstract

Effects of steady energy addition (EA) into the Mach 3 supersonic flow upstream of conically-nosed and spherically-blunted bodies were investigated in this study numerically and experimentally. Low-voltage DC-arc discharge was applied to explore energy addition effects in the Ludwieg-Tube Facility by means of drag force measurements and shadowgraph flow visualizations. Numerical simulations were performed by solving the Reynolds-averaged Navier-Stokes equations with the DLR-TAU-Code. Numerical and experimental results demonstrate in good agreement that the optimal power effectiveness appears at a heating power just enough to induce a full-scale recirculation bubble ahead of the blunt body. They reveal that at a higher flow density the effectiveness of EA becomes larger as long as the heating ratio remains over-critical.