Implementation of a chemical kinetics model for hypersonic flows in air for high-performance cfd

The Modified Marrone-Treanor (MMT) chemical kinetics model [1] was developed recently using ab-initio quantum chemistry data. The MMT model has been implemented into a CFD code designed for hypersonic flows, with an emphasis on vehicle-scale calculation. The current feature set includes implicit time-stepping, recombination, electronic energy, and performance comparable to the standard Park model. The effect of non-Boltzmann distributions on chemical kinetics source terms are also quantified, and a relatively simple factor is found to be suitable for correcting the reaction rate and vibrational energy change per dissociation. Larger-scale CFD results are also presented and compared to the standard Park model [2]; the peak heat flux on a Crew Exploration Vehicle (CEV) type geometry is found to be 10% higher for Park than MMT.