Transport consistent diffusion coefficient for CMFD acceleration and comparison of convergence properties |
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Authors: | Akio Yamamoto Tomohiro Endo Akinori Giho |
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Affiliation: | 1. Graduate School of Engineering, Nagoya Univeristy, Nagoya, Japan;2. Independent Scholar |
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Abstract: | A diffusion coefficient for the coarse mesh finite difference (CMFD) acceleration is derived from the semi-analytic solution of one-group, one-dimensional, even-parity transport equation. The derived diffusion coefficient, i.e., the transport consistent diffusion coefficient (TCD), depends on the optical length of a mesh and shows similar behavior with the artificial grid diffusion (AGD) and the effective diffusion (EffD) coefficients for an optically thick mesh. Convergence properties of typical diffusion coefficients are evaluated using the linearized Fourier analysis. Analyses of the C5G7 3D benchmark problems with and without voided region are carried out to compare the convergence properties. The number of transport sweeps to reach convergence using TCD is smaller than that using EffD or AGD. |
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Keywords: | CMFD acceleration MOC convergence even-parity transport equation linearized Fourier analysis C5G7 benchmark problem |
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