Direct numerical simulation of aerodynamic heating in moving shock wave/boundary layer interactions

Shock wave and boundary layer are of critical concern in high-speed flight due to the severe aerodynamic heating imposed on walls. However, various non-ideal factors, such as control-surface motion and non-uniform inflow mixing, usually force shock waves into large-scale unsteady motion, causing actual heat flux to deviate from static-state predictions. This work conducts direct numerical simulation of unsteady interaction between moving oblique shock waves and a turbulent boundary layer in freestream Ma6, using wedge translation to generate shock waves moving in upstream and downstream directions. The evolution of the flow field and the distribution of aerodynamic heating characteristics were analyzed. The interaction zone size exhibits a non-monotonic dependence on the upstream-moving shock speed, which is dominated by a competition between shock intensification and depression of the equivalent sonic line. Notably, upstream shock motion results in an elevated peak Stanton number, whereas downstream shock motion produces a ‘pseudo-laminar’ distribution of the Stanton number within the separation zone, with values falling below those in the undisturbed boundary layer. Two streamline patterns based on Moore-Rott-Sears (MRS) condition are presented to elucidate the inherent unsteady effects, complemented by the evolution of turbulent kinetic energy, and aerodynamic heating generation and transport process. This work also assesses the applicability of traditional power-law correlation between peak wall pressure and heat flux, along with the free interaction theory, under conditions of shock motion. Meanwhile, it is found that the streamwise velocity fluctuation root-mean-square downstream of reattachment position exhibits a bimodal distribution during upstream shock movement.