Calculation of transport coefficients with vibrational nonequilibrium

An extended Enskog asymptotic expansion method is used to find approximate solutions of the Boltzmann equation in the cases of strong thermal nonequil ibrium. The formalism to determine thermal conductivities in the expanding Row of a binary mixture of a diatomic and its parent atoms through a supers onic nozzle is applied. Results show that the diffusion of highly excited v ibrational levels, which become overpopulated during the expansion, substan tially contributes to the transport of energy. This effect cannot be repres ented by simplified theories such as the multitemperature model.