Assessment of Collisional-Energy-Based Models for Atmospheric Species Reactions in Hypersonic Flows

A recently proposed set of direct simulation Monte Carlo chemical reaction models, based solely on the collisional energy and the vibrational energy levels of the species involved, is applied to calculate equilibrium and nonequilibrium chemical reaction rates for atmospheric reactions in hypersonic flows. The direct simulation Monte Carlo model predictions are in good agreement with Park's model, several theoretical models, and experimental measurements. Physically plausible modifications to some of the direct simulation Monte Carlo models are presented that improve agreement. The observed agreement provides strong evidence that modeling of chemical reactions based on collisional energy and vibrational energy levels provides an accurate method for predicting equilibrium and nonequilibrium chemical reaction rates.