Motion and distribution of particles past multiple fixed cylinders with different arrangements in a confined moving bed

The dynamics of a confined granular bed moving under gravity past stationary cylinders with different arrangements has been studied through discrete element modeling. The formation of a stagnation zone ahead and a void zone just below the cylinders is the most unique features. For a single cylinder, the exit width and geometry does not affect the stagnation zone, but it influences the void zone. For the inline arrangement, if cylinders are closely spaced, a single large stagnation zone on the top and a single void zone beneath are noticed. The tandem arrangement does not significantly affect the stagnation zone on the top cylinder. The stagnation zone between the cylinders and the void zone below the bottom cylinder minimally increases with the pitch. It is also interesting to note that the rate of drainage is affected only marginally by the arrangement and the number of cylinders.