Numerical simulation of thermal environment characteristics within the streamwise gap induced by supersonic flow

Gaps represent a common feature on the surface of supersonic vehicles, and their presence engenders localized thermal phenomena, including elevated heat flux and thermal invasion. These occurrences significantly imperil the aircraft's thermal stability and safety. This study employs numerical simulation to investigate supersonic streamwise gap flow and offers a comprehensive analysis of the impact of geometric and leakage on the distribution of wall heat flux. The computational results manifest a high alignment between regions of high heat flux and high Mach number. Consequently, these findings underscore the pivotal role of convective heat transfer governing the distribution of heat flux within the gap. Most notably, the sensitivity of wall heat flux is most pronounced with respect to gap width. A reduction in gap width yields a substantial reduction in wall heat flux, with this alteration primarily stemming from its impact on the shear interactions between the supersonic mainstream and the vortices within the gaps. Furthermore, changes in gap length influence the invasion characteristics of the supersonic mainstream, thereby instigating consequential shifts in the distribution of heat flux density along the inner surfaces of the gaps. In contrast, variations in gap depth exert a comparatively modest impact on the distribution of heat flux density. The introduction of leakage effects at the base of the gaps results in a significant intensification of supersonic mainstream penetration and concomitant convective heat transfer in the bottom exit region. This phenomenon engenders localized zones characterized by elevated heat flux density, thus severely compromising the aircraft's thermal sealing performance.