cea-02864635
https://cea.hal.science/cea-02864635
doi:10.1080/00295639.2017.1320891
[CEA] CEA - Commissariat à l'énergie atomique
[DEN] Direction des énergies
Coarse Mesh Rebalance Acceleration Applied to an Iterative Domain Decomposition Method on Unstructured Mesh
Odry, N.
Lautard, J.-J.
Vidal, J.-F.
Rimpault, G.
[PHYS.NUCL] Physics [physics]/Nuclear Theory [nucl-th]
[PHYS.NEXP] Physics [physics]/Nuclear Experiment [nucl-ex]
ART
Coarse mesh rebalance
domain decomposition method
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.
2017-07-31
en
Nuclear Science and Engineering
Academic Press