Multi-level coarse-grained discrete element method modeling of cylinder particle flow in a rotating drum

Abstract

The coarse-grained discrete element method (DEM) is probably a feasible option for simulating an actual drum-type biomass boiler, which contains over 10 million cylinder particles. A multi-level study was conducted based on particle and coarse-grained level data to evaluate the adequacy of the coarse-grained approach in terms of geometrical characteristics, kinematic features, and dynamic properties. Two scaling laws for contact parameters were used and compared during the simulations. The results show that the coarse-grained approach can accurately predict the positions of the free surface and active-passive interface, the mixing index, and the orientation properties. Deviations in the velocity fields may occur due to the worse flowability of coarse-grained particles near the free surface. The efficiency is significantly improved by the coarse-grained model compared with the corresponding original case (the same DEM code without a coarse-grained model was used for the original simulations).