Non-equilibrium kinetics, diffusion and heat transfer in shock heated flows of N2/N and O2/O mixtures

In this paper, the influence of vibrational and dissociation kinetics on heat transfer and diffusion in nonequilibrium flows of N-2/N and O-2/O mixtures in the relaxation zone behind shock waves is studied on the basis of the state-to-state and one-temperature kinetic theory approaches. The results of calculations of vibrational level populations n(i), gas temperature T, total energy flux q, diffusion velocities of molecules at different vibrational states V-i and atoms V-a in the relaxation zone behind a shock front are presented for the free stream Mach numbers M = 18, 15, 10. The contribution of different dissipative processes to the total energy flux is evaluated for various flow conditions. Characteristic features of non-equilibrium kinetics, diffusion and energy transfer in two considered mixtures are discussed. The impact of vibrational excitation of N-2 and O-2 molecules in the free stream on a relaxation zone structure and transport properties behind a shock is shown. (C) 2015 Elsevier B.V. All rights reserved.