Load balancing method for heterogeneous CFD algorithms

S. A. Sukov

Žurnal Srednevolžskogo matematičeskogo obŝestva, Tome 23 (2021) no. 2, pp. 193-206

Résumé

The problem of load balancing for unstructured heterogeneous numerical algorithms for simulation of physical processes is considered. A computational distribution method for hybrid supercomputers with multicore CPUs and massively parallel accelerators is described. The load balancing procedure includes determination of dual graph vertices and edges weights, devices’ performance test and two-level decomposition of the computational mesh based on domain decomposition method. First level decomposition involves the graph partitioning between supercomputer nodes. On the second level node subdomains are partitioned between the MPI-processes running on the nodes. The details of the proposed approach are considered on the example of an unstructured finite-volume algorithm for modeling the Navier-Stokes equations with polynomial reconstruction of variables and explicit time integration scheme. The parallel version of the algorithm is developed using the MPI, OpenMP and CUDA programming models. The parameters of performance, parallel efficiency and scalability of the heterogeneous program are given. The results mentioned are obtained during the simulation of a supersonic flow around a sphere on a mixed mesh consisting of tetrahedrons, triangular prisms, quadrangular pyramids and hexagons.