Modeling and sensitivity analysis of particle impact with a wall with integrated damping mechanisms

Impact of adhesive particles with a wall occurs in many applications, over a wide range of impact speeds. Prediction of whether or not an impacting particle will stick to the wall, and if not prediction of the rebound velocity of the particle, is critical for estimating particle deposition rate and for simulation of particle transport using approaches such as the hard-sphere discrete element method (DEM). The problem is complicated by the fact that several different damping mechanisms act to inhibit particle rebound from the wall, even for the relatively simple case of normal particle impact While comparisons of theoretical expressions for different damping mechanisms (e.g., viscoelastic damping, squeeze-film damping, plastic damping, van der Waals adhesion, etc.) are typically conducted with consideration of only one damping mechanism, in practice all of these mechanisms must be accounted for to make appropriate comparison of predictions with experimental data. The current paper presents a simplified model that integrates previous theoretical expressions for these different damping mechanisms. The integrated analytical expression yields predictions for particle normal restitution coefficient that are in excellent agreement with experimental data over a wide range of impact velocities. A sensitivity analysis was conducted using the method of variances to examine the influence of different parameters and different damping forces on measures of the restitution coefficient output. (C) 2018 Published by Elsevier B.V.