Title
Micro-Macro Schemes for Kinetic Equations Including Boundary Layers.
Abstract
We introduce a new micro-macro decomposition of collisional kinetic equations in the specific case of the diffusion limit, which naturally incorporates the incoming boundary conditions. The idea is to write the distribution function f in all its domain as the sum of an equilibrium adapted to the boundary (which is not the usual equilibrium associated with f) and a remaining kinetic part. This equilibrium is defined such that its incoming velocity moments coincide with the incoming velocity moments of the distribution function. A consequence of this strategy is that no artificial boundary condition is needed in the micro-macro models and the exact boundary condition on f is naturally transposed to the macro part of the model. This method provides an "asymptotic preserving" numerical scheme that generates a very good approximation of the space boundary values at the diffusive limit, without any mesh refinement in the boundary layers. Our numerical results are in very good agreement with the exact so-called Chandrasekhar value, which is explicitly known in some simple cases.
Year
DOI
Venue
2012
10.1137/120865513
SIAM JOURNAL ON SCIENTIFIC COMPUTING
Keywords
Field
DocType
transport equations,radiative transfert,diffusion limit,asymptotic preserving schemes,boundary layer,micro-macro decomposition
Boundary value problem,Mathematical optimization,Robin boundary condition,Boundary layer thickness,Mathematical analysis,Free boundary problem,Boundary layer,Singular boundary method,Neumann boundary condition,Mathematics,Mixed boundary condition
Journal
Volume
Issue
ISSN
34
6
1064-8275
Citations 
PageRank 
References 
10
0.78
13
Authors
2
Name
Order
Citations
PageRank
Mohammed Lemou112815.85
Florian Méhats28014.01