Swirling flows in horizontally vibrated beds of dense granular materials

► A granular material in a rectangular container with two hollow cylinders was studied as it underwent horizontal vibrations. ► Swirling granular flows were observed in the cylinders while the grains cascaded down the outer surface of the piles that formed outside the cylinders. ► The swirling-convection regime was simulated with a Lagrangian approach combined with large-eddy simulations.