On the solution of the time-dependent inertial-frame equation of radiative transfer in moving media to O(v/c) (largest velocity dependent term)

• Published in: Journal of computational physics 1982-04, Vol.46, p.97-137
• Main Authors: Mihalas, D, Klein, R I
• Format: Article
• Language: English
• ISSN: 0021-9991
• DOI: 10.1016/0021-9991(82)90007-9

It is demonstrated that practical schemes can be developed for treating the hybrid time-dependent transfer equation including O(v /c) terms both stably and efficiently, and their coupling into radiation-hydrodynamical calculations is sketched. The mixed-frame equation of transfer and the frequency-dependent and frequency-integrated moment equations are developed. The relative sizes of the terms in the transfer equation and the requirement for keeping all v/c terms in order to obtain exact consistency with the energy equation for the radiating fluid are addressed. The computational approach is discussed in Feautrier variables, including a second-order formulation. Several schemes for the solution method are presented along with test calculations for an unattenuated square wave, attenuated radiation front, irradiated grey atmosphere, and velocity effects in a moving atmosphere. How the transfer equation to O(v/c) can be coupled to the hydrodynamic equations in both an Eulerian and Lagrangian formulation is indicated.