Experimental and numerical investigations of the flow control mechanism with combined spike-porous jet techniques in hypersonic flow

Abstract

This paper investigates the flow reconstruction characteristics using combined mechanical spike and porous jet techniques in a Mach 6 hypersonic flow, combining experimental measurements with computational simulations. Experimental results demonstrate high test repeatability and agree well with the corresponding numerical simulations in capturing both flow structures and the pressure distributions. Schlieren images indicate that the combined spike-porous jet techniques effectively reshape the flow morphology, and the reattachment shock is pushed away from the blunt body. Surface pressure measurements show a significant pressure reduction, demonstrating the effectiveness of two novel spike-porous jet configurations. For the opposing jet device, the increase in the jet total pressure ratio further lowers surface pressure, and the jet structure expands. Increasing the single length also reduces the surface pressure along the blunt body, with a notable drop observed as L/D increases from 0.6 to 1.0. Moreover, a self-sustained porous-jet device that requires no external working-fluid supply is proposed, exhibiting strong sensitivity to angle of attack. At 8° angle of attack, the peak pressure coefficient increases by 71.84% compared to the zero-angle-of-attack condition. As the angle of attack increases, schlieren imaging reveals increasingly asymmetric shock patterns, and the windward side exhibits markedly higher pressure coefficients than that on the leeward side.