| dc.description.abstract | The intent of this work is to advance the current understanding of high-temperature chemical
kinetics of air species under post-shock conditions. Quantum mechanical-based deterministic
models, based solely on ab-initio-derived data, are used to assess coupled vibrational excitation and chemical reactions of air species at temperatures characteristic of hypersonic flight and reentry. The first post-shock simulations of ab-initio accuracy that resolve both atom-diatom and diatom-diatom interactions are presented. Comparisons of the constructed vibrational-specific state-to-state models are made to a rovibrational-based model to highlight the importance of atomic radicals in the collisional dynamics of high-temperature post-shock environments.
Recent shock-tube experiments, including those of Sharma and Gillespie (1991), Ibraguimova
et al. (2013), and Streicher et al. (2021), are numerically simulated for purposes of model validation and to discuss drawbacks of current experimental data post-processing procedures and diagnostic techniques. Results from modeling Sharma and Gillespie’s experiment indicate that the inclusion of energy transfer to electronically excited and ionic species is potentially required when attempting to deduce N₂ (X) vibrational temperatures through radiative signatures in pure nitrogen shock flows. Through comparisons with Streicher et al.’s data, it is shown that neglecting relaxation in the post-incident shock region may lead to non-negligible errors in determining initial post-reflected shock translational and vibrational temperatures and that the unsteady nature of the reflected shock front may need to be considered to accurately determine such quantities, particularly in cases where the test gas is not diluted with an inert species. | |
