OpenMP Parallelization of Multicolour Particle Contact Detection Method with Computational Block Parallelism for Sorting
Takahiro Katagiri, Hiroshi Takeda, Yasuyoshi Horibata · 2014
In the Discrete Element Method (DEM), particle contact detection is the most important process, and consumes the largest fraction of the execution time. All particles have a chance to make contact with other particles. The calculation domain is divided into cells. The cell is a cube, the edge length of which is as long as the particle diameter. A set of cells is called contact detection grid. Particle contact detection consists of three steps. First, for each particle, we specify the cell in which it is located. Second, we sort the particles so that particles in a cell become neighbours. Third, we calculate the distance between two particles. In this paper, we propose computational block parallelism for the sorting. We divide the calculation domain into a number of computational blocks. Each computational block contains a large number of cells. Sorting is done in each computational block in a loop implemented via do construct. The loop is shared among threads.