%0 Journal Article
%T Coarse Mesh Rebalance Acceleration Applied to an Iterative Domain Decomposition Method on Unstructured Mesh
%+ CEA-Direction des Energies (ex-Direction de l'Energie NuclĂ©aire) (CEA-DES (ex-DEN))
%A Odry, N.
%A Lautard, J.-J.
%A Vidal, J.-F.
%A Rimpault, G.
%< avec comitĂ© de lecture
%@ 0029-5639
%J Nuclear Science and Engineering
%I Academic Press
%V 187
%N 3
%P 240-253
%8 2017-07-31
%D 2017
%R 10.1080/00295639.2017.1320891
%K Coarse mesh rebalance
%K domain decomposition method
%Z Physics [physics]/Nuclear Theory [nucl-th]
%Z Physics [physics]/Nuclear Experiment [nucl-ex]Journal articles
%X An iterative domain decomposition method (DDM) is implemented inside the APOLLO3 Sntransport core solver MINARET. Based on a block-Jacobi algorithm, the method inherently suffers a convergencepenalty in terms of both computing time and number of iterations. An acceleration method has to bedeveloped in order to overcome this difficulty. This paper investigates a nonlinear coarse mesh rebalance (CMR)method that favors the way information propagates through the core when domain decomposition is used. Thefundamental idea involves updating each subdomain boundary condition thanks to a core-sized low-ordercalculation on a coarse spatial mesh. The numerical convergence is sped up. Performances are meeting theexpectations since the CMR acceleration systematically succeeds in overbalancing the domain decompositionadditional cost. The aim of such a DDM + CMR algorithm is eventually to introduce more parallelism whensolving the spatial transport equation. Nevertheless, parallel computing is not addressed in this paper.
%G English
%L cea-02864635
%U https://cea.hal.science/cea-02864635
%~ CEA
%~ DEN