Nonequilibrium kinetics and heat transfer in O2/O mixtures near catalytic surfaces

Nonequilibrium vibrational-chemical kinetics and heat transfer in an O(2)/O mixture near the surface of a space vehicle under reentry conditions are studied. Vibration-translation, vibration-vibration energy exchange, dissociation-recombination processes in the gas phase as well as heterogeneous recombination, dissociation, and deactivation of vibrational states on a silica surface are taken into account. The effect of nonequilibrium kinetics and surface catalysis on the total heat flux and averaged dissociation-rate coefficients is examined. It is shown that both heterogeneous recombination and dissociation on the surface must be incorporated in the kinetic scheme. The contribution of thermal conductivity. thermal and mass diffusion, and vibrational energy diffusion to the heat transfer is evaluated. In particular. vibrational energy diffusion near the surface is found to play an important role.