FRONTIERS IN COMPUTATIONAL ASTROPHYSICS

Particle and Flames in Radiative and Magnetic Flows

October 11-15, 2010
Lyon, France

Contribution of Neil Vaytet

Title

A numerical model for 3D multigroup radiation hydrodynamics

Topics

"Explosive fate of stars"

Keywords

Hydrodynamics, Radiative transfer, Multigroup

Abstract

We present a multigroup model for radiation hydrodynamics to account for variations of the gas opacity as a function of frequency. The entropy closure model (M1) is applied to multigroup radiative transfer in the 3D radiation hydrodynamics code HERACLES. In difference from the previous grey model, we are able to reproduce the crucial effects of frequency-variable gas opacities, a situation omnipresent in physics and astrophysics. We also account for the energy exchange between neighbouring groups which is important in flows with strong velocity divergence. These terms were computed using a finite volume method in the frequency domain. Tests for the method span one to three dimensions with various degrees of complexity, addressing in some cases only the radiative transfer aspect of the method, and in others the full RHD scheme coupled to the moving gas. Applications such as radiative shocks in Xe and 3D radiative blastwaves are presented.

Talk