The effect of N + N2 collisions on the non-equilibrium vibrational distributions of nitrogen under reentry conditions

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