Parallel load‐balanced simulation for short‐range interaction particle methods with hierarchical particle grouping based on orthogonal recursive bisection

We describe an efficient load‐balancing algorithm for parallel simulations of particle‐based discretization methods such as the discrete element method or smoothed particle hydrodynamics. Our approach is based on an orthogonal recursive bisection of the simulation domain that is the basis for recursive particle grouping and assignment of particle groups to the parallel processors. Particle grouping is carried out based on sampled discrete particle distribution functions. For interaction detection and computation, which is the core part of particle simulations, we employ a hierarchical pruning algorithm for an efficient exclusion of non‐interacting particles via the detection of non‐overlapping bounding boxes. Load balancing is based on a hierarchical PI‐controller approach, where the differences of processor per time step waiting times serve as controller input.