Discrete element method

摘要

A discrete element method for modelling granular or particulate material, the method including a multiple grid search method wherein the multiple grid search method is a hierarchical grid search method, and wherein entities, such as particles and boundary elements, are allocated to cells of respective grids based on size. The search method further includes: (a) performing a search of cells in a first of the grid levels to determine pairs of entities which satisfy predetermined criteria to be included in a neighbor list for which both entities belong to the first grid level; (b) mapping each nonempty cell in the first grid level to each of the other grid levels, determining neighboring cells in each of the other grid levels and determining all pairs of entities belonging to a pair of levels that satisfy the predetermined criteria for inclusion in the neighbor list; and (c) repeating (a) and (b) for all grid levels.

主权项

1. A discrete element method (DEM) executed by a particle simulation computer system to model granular or particulate material, the method comprising:
performing, using one or more computer processing modules, a multiple hierarchical grid search method, wherein entities including particles of the material and boundary elements with which the particles can interact, are allocated to cells of respective grids based on size, and wherein the search method searches cells of grids in a grid hierarchy for proximity between entities, and comprises: (a) performing a search of cells in a first of the grid level to determine pairs of entities which satisfy predetermined criteria to be included in a neighbour list for which both entities belong to the first grid level; (b) mapping each non-empty cell in the first grid level to each of the other grid levels of the grids, determining neighbouring cells in each of the other grid levels and determining all pairs of entities belonging to a pair of levels that satisfy the predetermined criteria for inclusion in the neighbour list; (c) repeating (a) and (b) for all grid levels; (d) generating control data and one or more neighbour lists based on the searching and mapping, representing modelled motion of the material over time; and (e) using the generated control data to control equipment handling the material.