Thermochemical Relaxation Through Collisions and Radiation

A consistent thermochemical relaxation model is presented to calculate high enthalpy flows in a wide velocity and density range. It is based on the coupled vibration-chemistry-vibration model. All types of internal energy, vibrational, rotational, and electronic energy are taken into account. The reaction rate modeling is calibrated using quasi-classical trajectory calculations for dissociation and exchange reactions. The electronic excitation is calculated using quasi-steady-state theory. Radiation is computed using a Monte Carlo method. To couple the flow-field solver and the radiation transport code, the radiative source terms can be implemented into the flow field solver. Recalculation of the bow shock ultraviolet and FIRE flight experiments show good agreement with measurements. (Author)