Characteristic features of boundary-layers in vibration–dissociation non-equilibrium

The interaction between vibrational excitation and chemical reactions in high-temperature flows is examined through an example of a typical boundary-layer, i.e. the thermal layer generated by a shock wave reflecting at the end-wall of a shock-tube. During the development of this boundary-layer in space and time, particular features are pointed out, like the existence of a freezing zone close to the wall, responsible of dissociation rate constants remaining significant in this zone where the translational temperature is decreasing. The catalytic role of the wall is also examined and its influence is important on the vibrational temperature profiles and therefore on the rate constants themselves.