Discontinuous Finite Element Quasidiffusion Methods
- North Carolina State Univ., Raleigh, NC (United States). Dept. of Nuclear Engineering
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Here in this paper, two-level methods for solving transport problems in one-dimensional slab geometry based on the quasi-diffusion (QD) method are developed. A linear discontinuous finite element method (LDFEM) is derived for the spatial discretization of the low-order QD (LOQD) equations. It involves special interface conditions at the cell edges based on the idea of QD boundary conditions (BCs). We consider different kinds of QD BCs to formulate the necessary cell-interface conditions. We develop two-level methods with independent discretization of the high-order transport equation and LOQD equations, where the transport equation is discretized using the method of characteristics and the LDFEM is applied to the LOQD equations. We also formulate closures that lead to the discretization consistent with a LDFEM discretization of the transport equation. The proposed methods are studied by means of test problems formulated with the method of manufactured solutions. Numerical experiments are presented demonstrating the performance of the proposed methods. Lastly, we also show that the method with independent discretization has the asymptotic diffusion limit.
- Research Organization:
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
- Sponsoring Organization:
- USDOE National Nuclear Security Administration (NNSA)
- Grant/Contract Number:
- AC52-06NA25396
- OSTI ID:
- 1440477
- Report Number(s):
- LA-UR-17-30746; TRN: US1900743
- Journal Information:
- Nuclear Science and Engineering, Vol. 191, Issue 2; ISSN 0029-5639
- Publisher:
- American Nuclear Society - Taylor & FrancisCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
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