Consistent kinetic and continuum dissociation models for high-temperature air

We present analysis using recently developed continuum (rate-based) models for dissociation that are analytically consistent with kinetic (state specific cross-section based) models, which are formulated based on quantum chemistry predictions. The continuum model incorporates the effect of non-Boltzmann distributions, recently quantified and modeled using direct molecular simulation (DMS). The state specific rate model is verified from quasi-classical trajectory calculations and the continuum model from comparison to DMS ab-intio predictions. The kinetic rates are intended to be used in direct simulation Monte Carlo simulations (DSMC) and continuum models in computational fluid dynamics (CFD) simulations. Analytical consistency between kinetic and continuum models will ensure seamless integration of DSMC and CFD, a necessary requirement for multiscale hybird CFD-DSMC approaches. Finally, using rigorous mathematical arguments, a simplified correction to the equilibrium rate constant is derived, whose form is shown to resemble closely the popular Marrone-Treanor model, with additional terms explicitly accounting for rotational energy, centrifugal barrier and the role of non-Boltzmann distributions.