Title
Accurate Front Capturing Asymptotic Preserving Scheme For Nonlinear Gray Radiative Transfer Equation
Abstract
We develop an asymptotic preserving scheme for the gray radiative transfer equation. Two asymptotic regimes are considered: one is a diffusive regime described by a nonlinear diffusion equation for the material temperature; the other is a free streaming regime with zero opacity. To alleviate the restriction on time step and capture the correct front propagation in the diffusion limit, an implicit treatment is crucial. However, this often involves a large-scale nonlinear iterative solver as the spatial and angular dimensions are coupled. Our idea is to introduce an auxiliary variable that leads to a "redundant" system, which is then solved with a three-stage update: prediction, correction, and projection. The benefit of this approach is that the implicit system is local to each spatial element, independent of angular variable, and thus only requires a scalar Newton's solver. We also introduce a spatial discretization with a compact stencil based on even-odd decomposition. Our method preserves both the nonlinear diffusion limit with correct front propagation speed and the free streaming limit, with a hyperbolic CFL condition.
Year
DOI
Venue
2021
10.1137/20M1318031
SIAM JOURNAL ON SCIENTIFIC COMPUTING
Keywords
DocType
Volume
front capturing, asymptotic preserving, radiative transfer equation, nonlinearity
Journal
43
Issue
ISSN
Citations 
3
1064-8275
0
PageRank 
References 
Authors
0.34
0
3
Name
Order
Citations
PageRank
Min Tang100.34
Li Wang225056.88
Xiaojiang Zhang300.34