Numerical analysis of time integration errors for nonequilibrium radiation diffusion

Numerical analysis of time integration errors for nonequilibrium radiation diffusion is considered. Two first-order implicit time integration methods are studied. Asymptotic analysis and modified equation analysis are applied to both time integration methods. Numerical experiments are used to highlight the results of the analysis. Asymptotic analysis is used to highlight the source of temperature spiking when a hot radiation wave propagates into a cold material. Modified equation analysis is used to provide insight into the thermal wave speed coming from the two different first-order methods.