K.O. Braschke, J. Zoller, F. Freese, A. Dittler, U. Janoske

Powder Technology, 2022, https://doi.org/10.1016/j.powtec.2022.117494

Accurate descriptions of collisions between particles and walls in numerical simulations are difficult, because particles can be of any arbitrary shape. This shape, however, determines particle kinetics after collision and the adhesive deceleration occurring during collision. Available models for collision and adhesion usually limit a particle's shape to be spherical or require long computational times. Therefore, they either lack accuracy for non-spherical geometries or are not suitable for large scale simulations with thousands of particles. In this work we present three approaches for fast adhesive force calculation between an arbitrarily shaped particle and a flat wall based on Hamaker theory. The methods are executed for CFD with IBM simulations, but work on any triangulated geometry. We show that calculated adhesive force is in good agreement with theoretically determined van der Waals force. Further, we show that a simple corrective approach is capable of correctly describing the restitution coefficient curves in the transitional regime for various materials.