Modeling of excited oxygen in post normal shock waves

The successful development of hypersonic vehicles requires a detailed knowledge of the flow physics around the vehicle. Specifically, an understanding of the thermochemical nonequilibrium behavior is crucial for this flight regime. The hypersonic flight regime involves an extremely high level of energy, so a small error in the modeling of the energy processes can result in drastic changes in the vehicle design, which motivates modeling the physics involved at a high-fidelity. Recent progress is presented in an ongoing effort to model the excited states of oxygen in post-normal shock waves using computational fluid dynamics. One-dimensional post normal shock flow calculations are carried out using state-of-the-art thermochemical nonequilibrium models. Two-temperature and electronic master equation coupling models are adopted in the present work and discussed in detail. Different approaches of modeling the energy transfer from each mode are also presented. The approaches are assessed using a set of existing experiments where the vibrational temperature was measured. The concentrations of excited states of atomic oxygen determined by the electronic master equation coupling model are compared to Boltzmann distributions.