DEM simulation of cubical particle percolation in a packed bed

In this paper, percolation of cubical particles through a packed bed is studied using discrete element method (DEM). The influences of some key variables e.g. restitution coefficient, sliding coefficient, rolling coefficient and diameter ratio on cubical particles percolation behaviour were comprehensively analyzed. The results show that, compared with the sphere particles, cubical particles also have a constant vertical velocity during percolating in the packed bed, but it has a larger percolation velocity and a less off-center of radial distance. Restitution coefficient affects the cube percolation behaviour. With increasing the restitution coefficient, the percolation velocity decreases, but the radial dispersion coefficient increases. Effects of sliding friction coefficient and rolling friction coefficient show the same tendency. The percolation velocity and radial dispersion decrease with the increase of friction coefficient. The ratio of cubical particle diameter to packing particle diameter (diameter ratio) is another dominant variable that significantly affect the percolation behaviour. The percolation velocity and radial dispersion coefficient increases with decreasing the diameter ratio. The simulations are useful for understanding percolation and segregation of multi-scale cubical materials and optimization in cubical particles handling and mixing. (C) 2019 Elsevier B.V. All rights reserved.