Improved two-temperature model with correction of non-Boltzmann effect for oxygen and nitrogen

The substantial rise in fluid temperature behind the shock at the head of hypersonic vehicles induces molecular internal energy excitation and dissociation, potentially resulting in thermochemical nonequilibrium flow. The high vibrational energy molecule of oxygen and nitrogen undergo overdistribution and underdistribution states, resulting in increased and decreased dissociation rates in nonequilibrium flow. The latter state dominates and notably increases fluid temperature and wall heat flux, impacting the vehicle's thermal protection design. This study proposes an improved two-temperature dissociation rate model to more accurately simulate the nonequilibrium flow behind the shock.