Dissociation-recombination models in hypersonic boundary layer O2/O flows

► We evaluate the vibrational non-equilibrium in oxygen hypersonic boundary layer flows. ► We adopt a state-to-state vibrational kinetics model. ► We use updated quasicassical trajectory atom-molecule collision rate coefficients. ► Multiquanta transitions and direct dissociation-recombination are important. ► We calculate the heat flux through the boundary layer.