Distinct element modelling of cubic particle packing and flow

Processing of granular and powder materials is important in many engineering applications. The unpredictable behaviour of bulk solids often causes problems such as unsteady flows during handling and processing. Mixing and packing of powders are also of great importance, but experimental observation of such processes is not always convenient. Simulation is a powerful tool here. In this paper, a model for cube-shaped particles is developed using the Distinct Element Method. It introduces a model based on multi-contact principles. The Cube shape was considered as an archetypal regular polyhedral shape with fundamentally different characteristics to spheres in packing and flow. Specific industrial applications are also noted. The study closely compares laboratory experiments and simulations in terms of static packing, flow pattern and flow rates for cubes and spheres. The results show that the multiple-contact model is a better solution for surface-surface contact than the single-contact version and should be used for polyhedral shapes. The simulation and experimental results arc generally in close agreement demonstrating that the DEM cube model is a feasible tool. The cubes show "better" packing characteristics but "worse" flow properties as expected, however, it is noted that the system is fairly small in terms of number of particles and wall effects are quite significant here. (c) 2007 Elsevier B.V. All rights reserved.