Nonequilibrium Vibrational Kinetics during Hypersonic Flow of a Solid Body in Nitrogen and Its Influence on the Surface Heat Flux

Nonequilibrium nitrogen dissociation-recombination kinetics in the boundary layer and on the surface of a solid body during hypersonic flow, the subsequent relaxation of the released energy, and their influence on the surface heat flux have been investigated by numerical simulations. It is shown that the homogeneous (in the gas phase) and heterogeneous (on the surface) recombination energy of nitrogen atoms is transferred to the vibrational degrees of freedom. Strongly nonequilibrium vibrational distributions of nitrogen molecules are formed with strong influences on the boundary layer chemistry and the surface heat flux. These effects seem to be of significant importance for the reentry of vehicles such as the Space Shuttle as well as for typical problems met in plasma chemistry.