Comparison of DEM Results and Lagrangian Experimental Data for the Flow and Mixing of Granules in a Rotating Drum

This work assesses the accuracy of the discrete element method (DEM) for the simulation of solids mixing using non-intrusive Lagrangian radioactive particle tracking data, and explains why it may provide physically sound results even when non-real particle properties are used. The simulation results concern the size segregation of polydisperse granules in a rotating drum operated in rolling mode. Given that the DEM is sensitive to simulation parameters, the granule properties were measured experimentally or extracted from the literature. Several flow phenomena are investigated numerically and experimentally, including the particle residence time, the radial segregation, and the radial variation of the axial dispersion coefficient. An analysis of the DEM model is then presented, with an emphasis on the Young's modulus and friction coefficients. Finally, dimensionless motion equations and corresponding dimensionless numbers are derived to investigate the effect of simulation parameters on particle dynamics. (c) 2013 American Institute of Chemical Engineers AIChE J, 60: 60-75, 2014