Shock Wave Solutions for Radiation Hydrodynamics

This study describes a semi-analytic solution of planar radiative shock waves in which the radiation model is grey nonequilibrium diffusion. The solution may be used to verify radiation-hydrodynamics codes. Comparisons are made with the equilibrium diffusion solutions of Lowrie and Rauenzahn [1]. Although the physics of radiative shocks are fairly well known, previous solutions have been approximate and therefore unsuitable for code verification. Previous work has also assumed that the material temperature reaches its maximum at the post-shock state of the embedded hydrodynamic shock (Zel’dovich spike). We show that in certain cases, the temperature may actually continue to increase after the hydrodynamic shock and reaches its maximum at a specific value of the local Mach number. This is the first semi-analytic solution we know of for high-energy density, nonequilibrium radiation hydrodynamics.