Effect of concentrated energy deposition on the aerodynamic drag of a blunt body in hypersonic flow

Abstract

Experimental results on the effect of energy deposition using an electric arc discharge, upstream of a 60° half angle blunt cone configuration in a hypersonic flow stream is reported. Investigations involving drag measurements and high speed Schlieren flow visualization have been carried out in a hypersonic shock tunnel using air and argon as the test gases; and an unsteady drag reduction of about 50% (maximum reduction) has been observed in the energy deposition experiments done in argon environment. These studies also show that the effect of discharge on the flow field is more pronounced in argon environment as compared to air, which confirms that thermal effects are mainly responsible for flow alteration with discharge. It has also been observed that the interaction of the hypersonic flow with the discharge filament results in the development of an unsteady flow field. We thank the Director and Associate Director, IISc for the financial support to buy the high speed camera. Financial support by DRDL, DST, and ARDB is acknowledged with thanks. We express our sincere thanks to Mr. Subbarayadu and all the members of the HEA laboratory for their help in conducting the experiments. Fruitful discussions with Dr. Datta Gaitonde, AFRL, USA is also heartily acknowledged.