Experimental study on the flow field and aeroheating characteristics induced by a combinational aerospike and multi-jet scheme in large angle of attack

Abstract

In the current study, a novel combination of the aerospike and multi-counterflowing-jet scheme is proposed for drag and heat reduction in high speed flight. The flow field and aeroheating characteristics in condition of large angle of attack are quantitatively investigated in a shock tunnel. The instantaneous flow field structure and aeroheating distribution are acquired using high-speed schlieren technique and heat flux sensors. The experimental results reveal that the counterflowing jets can push the leading bow shock wave off the model and form a pair of detached bow shock waves. The detached bow shock waves propagate at a constant velocity of about 49.8m/s and stop to oscillate ahead of the aerospike. The stagnation region between the detached bow shock wave and interface notably intensifies the local aeroheating within it. When it moves away, the local aeroheating is significantly alleviated accordingly. As the counterflowing jets start issuing, a high heat flux region yields near the nozzle and moves upstream. In case of jets not strong enough to push the stagnation region far away from the aerospike, the local aeroheating would be intensified instead of reduced. After the detached bow shock waves stop propagating upstream, the thermal load on the windward part of the blunt nose cone is reduced by more than 98%. Basing on the variation regulation and final position of the high heat flux region, it is suggested to rearrange the jet nozzle along the stagnation ling to alleviate the aeroheating more effectively.