On application of GPUs for modelling of hydrodynamic characteristics of screw marine propellers in OpenFOAM package

OpenFOAM is a proven engineering tool for applied hydrodynamics numerical modeling which is typically characterized by complex geometries and large grids of 107-108 cells. Since such calculations are often very long and resource-intesive, any way of speeding them up is of high practical interest. Based on one practical problem of a screw propeller characteristics modeling, optimizations to OpenFOAM via the originally developed SLAE solution plugin is proposed. The plugin is based on SparseLinSol (SLS) library, developed by the authors. The library uses Krylov subspace iterative methods with the Classic AMG preconditioner to effectively solve large SLAEs on supercomputers and features original hybrid communications model which implements MPI and Posix Shared Memory combination. The library also is able to utilize NVIDIA GPU accelerators for a significant part of the implemented algorithms. Test results on 128-node computational system equipped with NVIDIA X2070 accelerators show that: (i) OpenFOAM numerical modeling results are close to those achieved with Star-CCM package and experimental results; (ii) developed SLAE solution methods are more robust than those implemented in original OpenFOAM GAMG-based SLAE solver; (iii) hybrid communication model improves solver scalability a lot and the solver scales linearly up to the maximum number of nodes used in current tests; (iv) GPU usage makes calculations 1.4-3 times faster; (v) SLS solver is faster than hypre solver on the same set of implemented methods and test matrices

multigrid methods, GPU, marine screw propellers, scalability, OpenFOAM package

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