Investigation of the heat flux reduction scheme on a V-shaped blunt leading edge based on secondary recirculation jets

Abstract

Complex shock interactions on the lips of hypersonic vehicles typically induce severe aerodynamic thermal loads. Considering a V-shaped blunt leading edge as the simplified model of the lip, the design, optimization, and performance of secondary recirculation jets for reducing aerodynamic thermal loads are investigated. The secondary recirculation jet scheme is crucial in reshaping the shock interaction structures, allowing the high-pressure gas downstream of the main shock structures to be transported back into the upstream flow field. Numerical results show that setting the bleed hole of the secondary recirculation jet scheme upstream of the shock wave/boundary layer interaction region yields the greatest reduction in heat flux. The combined effect of the oblique shock upstream of the blow hole and the bow shock at the windward edge of the bleed hole weakens the shock wave/boundary layer interaction structure, thereby reducing the associated heat flux peak. Prior to optimization, the scheme reduces the heat flux peak by approximately 25%. Once the critical design parameters have been optimized and a stagnation bulge has been introduced, the scheme achieves excellent heat flux peak reduction ability of approximately 43%. Simulations under a wide range of freestream conditions show that the optimal scheme has strong applicability to nonzero attack and sideslip angles and is suitable for hypersonic flows below Mach 9.0. In general, the secondary recirculation jet scheme designed in this work exhibits excellent ability to reduce the peak and average values of the heat flux.