Load balance strategy based on graph partition for multiblock structured grids

Load balance is of significance to the performance of parallel computing. Aiming at a good load balance with as less blocks as possible in parallel computing, an enhanced partitioning strategy based on multilevel graph partition is proposed for multiblock structured grids, including a recursive partition algorithm and an improved subgrid-splitting method, and then extended to the overlapping multiblock grids by establishing the connection between subgrids of different bodies hereafter. Two typical applications, covering the 1 to 1 coincident grid and the overlapping grid, are implemented to compare the behaviors of various partition strategies, as regards load balance, edge-cut and block numbers. Results demonstrate that the subgrid-splitting method is critical to structured grids, and partitioning over-lapping grid integrally is obviously a better alternative. Specifically, the new partitioning strategy shows a good performance in load balance and communication overheads, and meanwhile decreases the amount of blocks enormously as well as the memory requirement caused by the ghost cell of edge-cuts, leading to a better parallel efficiency. The enhanced partition strategy is applicable to both the 1 to 1 coincident grids and overlapping grids.