Application of the stagnation cavity on V-shaped blunt leading edges for thermal protection

Motivated by the heating issue on V-shaped blunt leading edges (VBLEs), this paper introduces a stagnation cavity for flow control to reduce heat flux. The generation mechanisms of the central heating peak at the stagnation point are investigated. On the VBLE designed using the shock configuration of regular reflection from the same family (sRR), the central heating peak generated from opposing shock-induced supersonic jets (SSJs) collision is higher than the baseline case with primary Mach reflection. This results from reduced pressure loss during upstream shock interactions in sRR configuration, yielding higher collision-induced peak pressure. To address this, a stagnation cavity is implemented to mitigate compression from the separation bubble on the SSJs near the stagnation point. This maintains relatively higher jet velocity at impact, intensifying collision severity and increasing total pressure dissipation. Consequently, both peak pressure and heat flux decrease despite stronger collision dynamics. Parametric analysis is conducted to examine the correlation between the cavity geometry and the heating level. It is revealed that increasing the depth could result in a greater decrease in heat flux, leading to a reduction rate of up to 32%. Furthermore, adjusting the circumferential angle range can optimize the heat flux distributions, thereby avoiding severe fluctuations. • Problem & A stagnation cavity is introduced to reduce central heat flux of V-shaped blunt leading edges with sRR shock configuration. • Cavity reduces compression of opposing supersonic jets, enhancing pressure dissipation despite intensified collision. • Cavity achieves simultaneous peak pressure and heat flux reduction despite intensified collision dynamics. • 32% heat flux reduction via cavity depth; Circumferential angle optimizes flow distribution and minimizes fluctuations.