P21: The First Real-Scale DEM Simulation of a Sandbox Experiment Using 2.4 Billion Particles
Abstract: A novel implementation of the Discrete Element Method (DEM) for a large parallel computer system is presented to simulate a sandbox experiment with realistic particle sizes. To save memory in the pairwise tangential forces and halve the arithmetic costs, interactions are calculated using the action-reaction law. An iterative load-balancer the flexible 2D orthogonal domain decomposition is applied to overcome the load-imbalance problem caused by the Lagrangian nature of DEM. An overlapping communication technique combined with cell-ordering with space-filling curves is also applied to hide the overhead cost because of the MPI communication tasks. We verify our complex parallel implementation with the action-reaction law via a reproducibility test. The parallel scaling test shows good strong, and weak scalabilities up to 2.4 billion particles on the Earth Simulator and the K computer. The world’s first real-scaled numerical sandbox simulation successfully captures the characteristics of real observations.
Award: Best Poster Finalist (BP): no
Two-page extended abstract: pdf