Enhanced transient flow and heat transfer analysis in diverse regeneration cooling modes incorporating thermal-fluid-structure interaction effects

As the Mach number of hypersonic vehicles continues to increase, the aerodynamic heating effects at varying heat flux densities pose significant challenges to the thermal protection of scramjets. To accurately predict their thermal protection characteristics, this study employs a transient thermal-fluid–solid coupling method to investigate the unsteady thermal–hydraulic properties and wall deformation at different time instances, focusing on issues such as flow, heat transfer and thermal stress in supercritical n-decane within typical regeneration cooling channels and jet-regeneration cooling channels. The results reveal that increasing the heat flux density alters the crossflow structure within the channel, causing the vortex center location and recirculation zones to shift downwards. In contrast, the formation and development of vortices due to jet impingement exhibits good stability. Higher heat fluxes are detrimental to fluid mixing within the channel, posing a potential risk for heat transfer deterioration (HTD), whereas jet impingement demonstrates excellent localized cooling performance. The equivalent stress, which is independent of time, is predominantly concentrated at the edges and centerline of the channel surface, where the risk of fracture is relatively high. The findings of this study will provide theoretical support for the structural design and thermal protection performance of regeneration cooling channels.