1142 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
and polyhedral DEM simulations. The multi-sphere DEM
simulations produced more distinct stagnant zones and the
velocity contours were similar to that of the spherical par-
ticles discharge contours. This was because of a bit smooth
shape representation of the cubes using multi-sphere DEM
approach leading to free flow of particles from the hop-
per. The velocity contours show that the maximum velocity
values are near the orifice for the experiment as well as the
simulation studies. The velocity magnitude values at three
different heights inside the hopper are shown in Figure 9.
At a height of 0.312 m, the polyhedral DEM simulations
are in close agreement with the experimental values. At
height h =0 m, away from the centreline, the variation is
11.05% for the polyhedral based DEM simulation and the
multi-sphere DEM simulations show an average variation
of 13.50%, however along the centreline the variation is at
the maximum. This pattern is repeated for all the heights
similar to the results from the spherical DEM simulation
results. The DEM simulation results are overpredicting the
velocity magnitude values. As the height from the hopper
base increases the DEM simulation results come closer to
the experimental values. Of the simulations, the multi-
sphere DEM results are showing larger velocity magnitudes
than the polyhedral DEM results. The experimental veloc-
ity contours match well with the polyhedral DEM simula-
tions than multi-sphere DEM simulations because of the
varied flow pattern observed during the discharge of the
multi-sphere approximated cube shaped particles.
Figure 8. Velocity contours for cubic particles discharge from the hopper (a) Experiment, (b) Polyhedral DEM simulation and
(c) Multi-sphere DEM simulation
Figure 9. Velocity magnitude across the hopper at different heights for cube shaped particle discharge
and polyhedral DEM simulations. The multi-sphere DEM
simulations produced more distinct stagnant zones and the
velocity contours were similar to that of the spherical par-
ticles discharge contours. This was because of a bit smooth
shape representation of the cubes using multi-sphere DEM
approach leading to free flow of particles from the hop-
per. The velocity contours show that the maximum velocity
values are near the orifice for the experiment as well as the
simulation studies. The velocity magnitude values at three
different heights inside the hopper are shown in Figure 9.
At a height of 0.312 m, the polyhedral DEM simulations
are in close agreement with the experimental values. At
height h =0 m, away from the centreline, the variation is
11.05% for the polyhedral based DEM simulation and the
multi-sphere DEM simulations show an average variation
of 13.50%, however along the centreline the variation is at
the maximum. This pattern is repeated for all the heights
similar to the results from the spherical DEM simulation
results. The DEM simulation results are overpredicting the
velocity magnitude values. As the height from the hopper
base increases the DEM simulation results come closer to
the experimental values. Of the simulations, the multi-
sphere DEM results are showing larger velocity magnitudes
than the polyhedral DEM results. The experimental veloc-
ity contours match well with the polyhedral DEM simula-
tions than multi-sphere DEM simulations because of the
varied flow pattern observed during the discharge of the
multi-sphere approximated cube shaped particles.
Figure 8. Velocity contours for cubic particles discharge from the hopper (a) Experiment, (b) Polyhedral DEM simulation and
(c) Multi-sphere DEM simulation
Figure 9. Velocity magnitude across the hopper at different heights for cube shaped particle discharge