Accelerated DEM simulation of the hopper-screw feeder and tablet-press feeder using the multi-level coarse-graining technique

A recently proposed multi-level coarse-graining method (MCG) for DEM simulation [1] is demonstrated in this work for two additional powder handling systems, namely, a hopper screw feeder and a tablet-press feeder. In contrast to the original demonstration by De et al., these two systems are characterized by moving geometry, which generates complex flow patterns consisting of rapid particle movement and recirculation. Despite these complexities, the proposed MCG technique successfully captures these systems' critical features of the powder flow. It substantially reduces the computation time compared to the fully resolved DEM simulations. The detailed time analysis reveals that the moving mesh consumes significant computation time and reduces the degree of speed-up achieved by MCG for some cases. To alleviate this situation, the transition planes in MCG should be positioned appropriately, along with an efficient neighbor-searching algorithm. Despite these constraints, significant speed-up could be achieved for both the systems.