Analysis of dissociation and internal energy transfer in high energy N₂ + O₂ collisions using the quasiclassical trajectory method

We perform quasiclassical trajectory analysis of N₂ + O₂ collisions sampled from ther-mal equilibrium between 5000 and 13000 K. Approximately 1.8 billion trajectories are computed using a potential energy surface recently published by Varga et al.¹ The reac-tion rate constant for O₂ 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 N₂ + N₂ 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. Addition-ally, 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 distri-butions, 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 ows.