Non-linear breaking of weak waves in a thermally conducting and dissociating gas flow

The singular surface theory is used to determine the mode of propagation of a weak wave and to evaluate the behaviour at the wave head. It is shown that the velocity of propagation relative to the normal gas velocity is the effective isothermal velocity of sound. The effects of dissociation, thermal conduction and the initial wave front curvature on the weak waves are discussed. The growth and decay properties of weak discontinuities headed by wave fronts in a thermally conducting and dissociating gas flow are investigated. Exact predictions of true non-linear progress of the flow variable gradients at the wave front are made for converging and diverging waves. It is found that under dissociation effects, shock wave formation is either disallowed or delayed while thermal conduction accelerates the process of termination of a weak wave into a shock wave.