| Speaker: | Cory Hauck, Postdoctoral Research Associate Center for Nonlinear Studies (CNLS) Los Alamos |
| Title: | A numerical regularization technique for multi-scale, linear transport models |
| Time: | 4:15-5:15 pm |
| Place: | Blocker 627 |
| Note: | Note the unusual time |
We present a regularization technique for the PN -equations: a linear hyperbolic system of PDEs that is commonly used to model particle transport through a material medium. In collision-dominated regimes, the PN -equations have a well-known asymptotic limit that is described by a standard diffusion equation. However, this limit is difficult to capture with conventional hyperbolic solvers that are based on the upwind methodology, due to (i) excessive numerical dissipation and (ii) a stiff CFL condition.
The regularization technique, which is derived by splitting the PN -system into fast and slow dynamics, does capture the proper diffusion limit and provides a useful tool for multi-scale problems with regions of both high and low collisionality. We present initial results for some one-dimensional test problems and discuss areas for continued development.
Last revised: 10/13/08 By: abnersg@math