Distinct Element Model of Energy Dissipation in Vibrated Binary Particulate Mixtures

Distinct element model (DEM) simulations of energy dissipation in vibrated particle beds are compared with experimental results. DMX, a 3-D DEM of polydisperse spheres in an open-top vibrating cylinder, was used. Simulations were conducted for vibrating mono and binary particle systems. Energy dissipation rate per vibration cycle at different frequencies and maximum accelerations was examined. Experimental data from previous publications were compared with the simulations. Reasonable qualitative agreement was achieved on scaled-up (by number of particles) simulation results. These show that DEM can capture the harmonic phenomena, showing resonance in dissipation at several frequencies at low accelerations (<1 g). At high acceleration levels (>1 g) no harmonics are observed. At low frequency levels where the vibration amplitudes are higher, the DEM reproduces experimental energy dissipation levels better than a continuum viscoelastic model. For a larger diameter vessel (fewer layers and decreased wall effects) the resonant dissipation frequency increases. Quantitative agreement between DMX predictions and the experiments is reasonable given the scatter in the experimental results; at high frequency there is at least an order of magnitude difference in the rate of dissipation, which was also observed in viscoelastic model predictions. Results show that even with using only 100 particles the agreement between DMX predictions and the experiments is qualitatively reasonable. This will enable the examination of many more situations and combinations as it can be carried out relatively “fast.”