A numerical study on the influence of particle shape on hopper discharge within the polyhedral and multi-sphere discrete element method

In this study 3D DEM-simulations of hopper discharge using non-cohesive, monodisperse spherical and polyhedral particles as well as particle shapes generated by the multi-sphere method are carried out. For this purpose an overview of the Common Plane algorithm for contact detection between polyhedral particles is given and an important refinement of the contact point definition is presented. In the hopper the effect of increasing particle angularity on the flow properties is investigated. Moreover, three different hopper designs are chosen, to further examine the influence of hopper angle and hopper opening size on the flow properties in combination with varying particle shapes. It is demonstrated that particles with an increasing angularity reduce the mass flow rate from the hopper and in case of the flat bottom hopper (α = 0°) increase the residual quantity after discharge. In all simulations significant differences between polyhedral and clustered particles were observed, which indicates that the type of particle shape approximation is a parameter that has to be considered in DEM-simulations of hopper discharge.