Effect of finite-rate catalysis on wall heat flux prediction in hypersonic flow

This work deals with the simulation of hypersonic flows past a copper sphere by using a finite-rate catalysis model coupled with either a state-to-state (StS) or a multitemperature thermochemical nonequilibrium approach. Without detailed state-specific data for copper catalytic recombination, molecules formed on the surface are described with three different statistics: one reproducing the incoming distribution, one considering a uniform distribution, and the third populating only the highest vibrational level. Following recent experimental and theoretical results, very high enthalpy and very low pressure conditions have been considered. The finite-rate partial catalysis model provides results that are closer to the experimental ones than those obtained by a fully catalytic approach. The multitemperature model shows better agreement with experiments, whereas among the StS catalytic approaches the outcomes have shown that the surface recombination on only the highest energy level gives more accurate results.