Investigation on a new method of adaptive drag reduction and non-ablation thermal protection system for hypersonic vehicles

A new adaptive drag reduction and non-ablation thermal protection method named Telescopic Self-aligning Jet-Spike (TSAJS) is proposed to improve the conventional spiked method employed in hypersonic vehicles. Firstly, the paper analyzes the mechanism of the new method, which is based on the forward-facing jet and the spike method. And then numerical simulations are carried out for TSAJS geometries with different L/D ratios, free stream and jet Mach numbers and angles of attack. The flow structures, pressure and heat flux distributions on nose surface and geometry drags are analyzed as well. Results demonstrate that the TSAJS method is able to reduce the drag and surface heat effectively even at large angles of attack. For the L/D =1 TSAJS configuration, the drag coefficient and maximum surface heat are reduced by 65%. Moreover, in our method, the spike nose is not exposed directly to the free stream, which discards the necessary of thermal protection for the spike.