Shock waves produced by heat deposition in rarefied gases

We discuss dissipation effects in the course of the evolution of blast waves in a rarefied atomic gas. To this aim we make use of two Monte Carlo codes developed in the past by our group; namely, a stochastic solver for the BGK equation and an implementation of the DSMC method. As a test case we perform one dimensional (+ 2D in velocity space) simulation of pure Argon. We show and discuss the effect of heat and mass diffusion on the otherwise isoentropic flow behind the shock front, and the effect of viscosity and heat conduction on the shock front shape. As expected, these effects lead to the cooling of the hot central region and to the blurring of the shock front, without affecting sensibly the shock propagation speed. The comparison of DSCM and BGK results is used to estimate the level of confidence that can be expected by a non kinetic-level method which forcibly cannot take into account details of the translational relaxation. © 2002 by the author(s). Published by the American Institute of Aeronautics and Astronautics, Inc.