The effects of incomplete vibrational accommodation and finite-rate surface catalysis on peak heat flux prediction of hypersonic compression corner

In high-enthalpy shock tunnels, gas molecules are excited to higher vibrational and chemical energy states. However, rapid expansion and acceleration through the nozzle leave insufficient time for vibrational deexcitation and recombination, leading to significant gas–surface interaction effects on wall heat transfer. This research utilizes computational fluid dynamics (CFD) to study the influence of vibrational accommodation and finite-rate catalysis on flow field structure and peak heat flux in hypersonic compression corner flows under thermochemical nonequilibrium free-stream conditions, characterized by low-to-medium Reynolds numbers and high Mach numbers. The results indicate that vibrational accommodation and finite-rate catalysis have a negligible influence on the structure of the flow separation bubble. However, both significantly affect the peak heat fluxes, which can be decomposed into three components: translational-rotational heat flux, vibrational heat flux, and catalytic heat flux. More importantly, a validated theoretical method is proposed to predict the peak heat flux by accounting for the effects of incomplete vibrational accommodation and finite-rate catalysis. Furthermore, the proposed theoretical framework suggests an equivalence relation between the vibrational accommodation coefficient and the catalytic coefficient, indicating a quantitative interplay between the two and their comparable influence on heat flux under certain flow conditions.