Interrelated structures of the transport shock and collisional relaxation layer in a multitemperature, multilevel ionized gas

Abstract

The gas dynamic structures of the transport shock and the downstream collisional relaxation layer are evaluated for partially ionized monatomic gases. Elastic and inelastic collisional nonequilibrium effects are taken into consideration. In the microscopic model of the atom, three electronic levels are accounted for. By using an asymtpotic technique, the shock morphology is found on a continuum flow basis. This procedure gives two distinct layers in which the nonequilibrium effects to be considered are different. A transport shock appears as the inner solution to an outer collisional relaxation layer. The results show four main interesting points: (i) On structuring the transport shock, ionization and excitation rates must be included in the formulation, since the flow is not frozen with respect to the population of the different electronic levels; (ii) an electron temperature precursor appears at the beginning of the transport shock; (iii) the collisional layer is rationally reduced to quadrature for special initial conditions, which (iv) are obtained from new Rankine-Hugoniot relations for the inner shock.