On the scaling law of JKR contact model for coarse-grained cohesive particles

Abstract

The computational cost of using discrete element method (DEM) simulations for particulate processes with fine and cohesive particles is enormously large. To overcome this limitation, various coarse-grain DEM models have been developed which use a smaller number of larger sized particles. Although the computational cost is significantly reduced, the accuracy of the simulations depends on the underlying scaling law. We propose a scaling of the Johnson-Kendall-Roberts (JKR) contact model for adhesive viscoelastic particles. A scaling law using a single Bond number or Cohesion number criterion is insufficient to keep the motion of the coarse-grained particles the same as the original particles. The scaling law in this work is developed based on mass, momentum and energy conservation, which achieves good consistency between the kinematic characteristics of the coarse-grained and original particles. The simulated effective coefficients of restitution were compared for a range of particle-wall impact velocities and validated against experimental data.