Hybrid MPI+OpenMP Parallel Method on Polyhedral Grid Generation in OpenFoam

Grid generation is an important step of computational fluid dynamics.In the process of large-scale numerical simulation,the time consumption of grid generation increases with the number of grids which often increases with the simulation accuracy.Based on the grid generation algorithm in an open-source software called OpenFoam,this paper proposes a hybrid parallel me-thod of OpenMP and MPI for polyhedral grid generation.By theoretical analysis,we show that when the hybrid parallel method is used to generate the same quality grids,increasing the number of threads and grid cells will reduce the time consumption of grid generation.Three numerical simulations using different solvers show that the grids generated by the hybrid parallel method and the original method have close qualifications,and the simulation results are almost indistinguishable from those of the original method.Furthermore,the time consumption of this method to generate the same quality and quantity grids can be reduced to less than a quarter of the time consumption without using OpenMP parallel method.