THE EFFECTS OF N+N2 COLLISIONS ON THE NONEQUILIBRIUM VIBRATIONAL DISTRIBUTIONS OF NITROGEN UNDER REENTRY CONDITIONS

Global (reactive + non-reactive) quasiclassical state-specific rate co efficients for the vibrational excitation and deexicitation of nitroge n molecules by collision with nitrogen atoms have been used to model a reacting flow. The one-dimensional model used describes the relaxatio n of N2 vibrational distributions in the boundary layer surrounding a shuttle reentering the atmosphere. The results single out the strong n on-equilibrium character of the vibrational distributions along the co ordinate normal to the shuttle surface caused by the dissociation-reco mbination processes. The results also show the dependence of the vibra tional distributions upon inclusion in the model of state-specific N N2(upsilon) rates.