Numerical investigation of hypersonic aerothermal environment and localized extreme thermal ablation over a blunt wedge

Hypersonic vehicles are subjected to severe aerodynamic heating and thermochemical nonequilibrium during flight. Abrupt changes in flow structures can further induce localized extreme thermal ablation, thereby creating a more complex thermal environment. In this study, a tightly coupled multiphysics numerical framework is employed to investigate localized laser-induced ablation under hypersonic conditions. A continuous-wave laser is introduced as a localized extreme heat source to simulate localized thermal ablation over a blunt wedge. The proposed method incorporates injection of ablation products, chemical reactions between the injected species and the freestream, and wall recession through a dynamic mesh technique, enabling accurate prediction of the transient ablation process. Simulations are performed for a blunt wedge flying at Mach 24 and altitudes ranging from 55 to 65 km. The thermal characteristics of a radiative equilibrium wall are first analyzed, followed by fully coupled transient simulations that include the solid domain. The results indicate that the pressure distribution is relatively insensitive to wall catalysis, whereas the wall thermal environment is strongly influenced. Moreover, the catalytic effect on wall heat flux gradually weakens with increasing altitude. Under laser irradiation, the local wall temperature rises rapidly before approaching a quasi-steady state. Continuous injection of high-temperature ablation products promotes heat accumulation within the boundary layer and generates localized compression and expansion structures near the wall, with a reversal of the local compression–expansion pattern occurring near the evolving ablation pit. The resulting pressure disturbance also exhibits a distinct three-dimensional spanwise distribution, characterized by a pronounced central peak and rapid decay toward both sides.