Effect of thermal relaxation of attenuation of shock waves in two-phase medium

Abstract

Molecular relaxation following an explosion in a gaseous or liquid medium proceeds so fast that the perturbation front can be regarded as a discontinuity surface (shock wave). This makes it correct to use the self-adjoint theory of point explosion [3, 6] for describing the evolution of a shock wave during the high-intensity stage of the explosion process also at distances where the shape of the energy source does not play a significant role. In this case the pressure and velocity field building up after an explosion is uniquely determined by the energy of explosion and the thermophysical properties of the gas surrounding the energy source. After explosion in a two-phase medium only the gaseous component reaches equilibrium immediately, owing to the inertia of condensate particles at the base of the wavefront, The hydrodynamic jump is followed by a wide relaxation zone, the equalization time forthe parameters of both phases being one order of magnitude longer than the relaxation time for the gas [2, 8]. Consequently, formation of a shock wave after explosion in a two-phase medium cannot any more be regarded as occurring within an infinitesimally short time and for determining the parameters of such a shock wave one must take into account the relaxatlonal character of the wave process [2].