Boundary Conditions of Radiation Gasdynamics

Abstract

For every particular problem of radiation gasdynamics, we have certain initial and boundary conditions. Our problem is to find solutions of the fundamental equations which satisfy these initial and boundary conditions. By initial conditions we mean the velocity distributions and the states of the gas as well as the specific intensity of radiation at certain initial time t = 0. Customarily in radiation gasdynamics, we do not give the spatial distribution of these initial conditions but we only require that the initial values be consistent with the boundary conditions for t = 0 and the fundamental equations. Hence we need to examine the boundary conditions only. In the case of dynamical system with a finite number of degrees of freedom, the motion is determined by the initial position and velocity. For a continuous medium, which has an infinite number of degrees of freedom, the motion is determined not only by the initial conditions but also by the boundary conditions, such as, for example, conditions on the velocity on the boundary of a domain considered at all the time t ≧ 0.