DMRPar: A Dynamic Mesh Repartitioning Scheme for Dam Break Simulations in OpenFOAM

Abstract

For parallel dam break simulations in OpenFOAM (Open Source Field Operation and Manipulation), the core procedure is solving linear systems using iterative methods and the iterative convergence rate is significant to the overall efficiency. A dynamic mesh repartitioning scheme DMRPar (Dynamic Mesh Re-Partitioning) considering the iterative convergence feature is implemented in OpenFOAM. Given that the numerical characteristics of linear systems change a lot along with the complex flow field, DMRPar takes linear system information from the previous timestep into account for the repartitioning at the current timestep. The implementation reuses current mesh topology in OpenFOAM and calculates distributed adjacency graph structure for the mesh. The repartitioning heuristic is based on a general multi-level parallel graph partitioning package called ParMetis. Numerical results on two typical dam break simulations show that DMRPar outperforms the traditional static partitioning method significantly in the total simulation time.