Simple waves and small perturbations in radiative gas dynamics
The paper analyses one-dimensional simple waves and small-amplitude disturbances in radiating and scattering grey gas. The governing equation of radiation acoustics describing the dynamics of simple waves is derived. Radiation-thermal dissipation conditions and radiation resistance force are introduced into this equation to describe the propagation and attenuation of various radiation perturbation waves. To study non-equilibrium wave phenomena in a radiating medium, the phenomenological Whitham method is used. This method is an effective way to analyse fundamental modes when more than one velocity appears in the governing equation. The use of this method is demonstrated in the paper by considering the evolution of one-dimensional harmonic waves caused by a short-wave initial perturbation of the equilibrium state of the radiating and scattering medium. For all wave modes, analytical solutions have been obtained, which allow us to understand their physical significance. These solutions can be, in particular, an additional test for radiative hydrodynamic codes operating in the radiative acoustics regime. The general approach can be useful in the development of higher-order Godunov numerical schemes for radiation hydrodynamics problems.
radiation hydrodynamics, simple waves, Whitham method, radiation transport
Publication language:russian, pages:34
Mathematical modelling in actual problems of science and technics