Analysis of Dissociation and Internal Energy Transfer in High Energy N_2 + O_2 Collisions Using the Quasiclassical Trajectory Method

摘要

We perform quasiclassical trajectory analysis of N_2 + O_2 collisions sampled from thermal equilibrium between 5000 and 13000 K. Approximately 1.8 billion trajectories are computed using a potential energy surface recently published by Varga et al. The reaction rate constant for O_2 dissociation is found to be lower than reported in the literature, especially at low temperatures. The nitrogen dissociation rate is similar to literature and is consistent with previous work using N_2 + N_2 collisions. The exchange reactions, which produce at least one NO and are not accounted for in current models, are found to be prevalent. The dissociation and exchange event has a reaction rate constant approximately an order of magnitude higher than nitrogen dissociation. Exchange reactions are found to rely disproportionately on the internal energy of oxygen at low temperatures. Additionally, the opacity functions for both exchange reactions are found to sharpen as temperature decreases. Product nitric oxide is found to have roughly Boltzmann internal energy distributions, with a temperature strongly dependent on the type of exchange reaction. These data and analysis lay the foundation for rigorous models and rates necessary for CFD calculations of high-enthalpy flows.