Some Considerations on the Parameters Selection of DEM Simulation for Tumbling Ball Mills

Linear-spring dashpot model is one of the major contact models applied to the DEM (discrete element method) simulation of the tumbling ball mills. The model parameters such as stiffness, damping coefficient, coefficient of restitution and coefficient of friction, significantly influence the calculation of contact forces and the selection of the critical time step. However, there is no standard as a reference to evaluate values of these parameters. This paper focuses on the selection of parameters for the linear-spring dashpot model. The movement of a single ball in a tumbling mill is performed in a simulation in which the elevated heights of the ball are compared with the theoretically analyzed heights under different coefficient of friction conditions. The results show that this kind of comparison is feasible and meaningful for the selection of model parameters.