A gas dynamics scheme for a two moments model of radiative transfer

Christophe Buet (1) , Bruno Despres (1)

1 DSSI - Département des Sciences de la Simulation et de l'Information

We address the discretization of the Levermore's two moments and entropy model of the radiative transfer equation. We present a new approach for the discretization of this model: first we rewrite the moment equations as a Compressible Gas Dynamics equation by introducing an additionnal quantity that plays the role of a density. After that we discretize using a Lagrange-projection scheme. The Lagrange-projection scheme permits us to incorporate the source terms in the fluxes of an acoustic solver in the Lagrange step, using the well-known "piecewise steady approximation" and thus to capture correctly the diffusion regime. Moreover we show that the discretization is entropic and preserve the flux-limited property of the moment model. Numerical examples illustrate the feasability of our approach.

Mots clés: radiative transfer; moments model; gas dynamics; lagrangian coordinates

Domaines: Analyse numérique [math.NA]

Christophe Buet, Bruno Despres. A gas dynamics scheme for a two moments model of radiative transfer. 2008. ⟨hal-00127189v2⟩