State-specific simulation of oxygen vibrational excitation and dissociation behind a normal shock

A complete vibration–vibration–translation (V–V–T) bound–bound transitions rates database for O₂–O₂ collisions is generated using the forced harmonic oscillator (FHO) model with temperature range between 1000 and 20,000 K. The postshock process of oxygen vibrational excitation and dissociation is simulated by solving the system of master equations coupled with the one-dimensional compressible flow equations. The results agree well with existing shock tube data. The state-specific calculations show that inclusion of pure vibration–vibration (V–V) processes could reduce the discrepancy with experimental data and the quasi-steady-state (QSS) approximation is valid when dissociation starts to dominate.