Open AccessThe Suppression of Energy Discretization Errors in Multigroup Transport Calculations
Author(s) -
Edward W. Larsen
Publication year - 2013
Language(s) - English
Resource type - Reports
DOI - 10.2172/1087139
Subject(s) - discretization , grid , neutron transport , multigrid method , energy (signal processing) , energy transport , computer science , diffusion , space (punctuation) , convection–diffusion equation , mathematics , mathematical optimization , algorithm , statistical physics , neutron , physics , mathematical analysis , geometry , partial differential equation , statistics , engineering physics , quantum mechanics , thermodynamics , operating system
The Objective of this project is to develop, implement, and test new deterministric methods to solve, as efficiently as possible, multigroup neutron transport problems having an extremely large number of groups. Our approach was to (i) use the standard CMFD method to "coarsen" the space-angle grid, yielding a multigroup diffusion equation, and (ii) use a new multigrid-in-space-and-energy technique to efficiently solve the multigroup diffusion problem. The overall strategy of (i) how to coarsen the spatial and energy grids, and (ii) how to navigate through the various grids, has the goal of minimizing the overall computational effort. This approach yields not only the fine-grid solution, but also coarse-group flux-weighted cross sections that can be used for other related problems