An impulse based model for spherical particle collisions with sliding and rolling

Particle impact behavior description is significant for dense multiphase flow simulation and particle deposition prediction. The paper presents a novel impulse based particle collision model considering sliding and rolling. The collision model includes three components, normal, tangential and adhesion model. Normal collision model is established to predict the normal coefficient of restitution (COR), contact area, total normal impulse etc., by dividing the collision process into three compression stages (elastic, elastic-plastic and fully plastic stages), and an elastic recovery stage. The tangential and angular velocities are calculated based on the normal impulse and the determination of sliding or rolling contact. It is verified that the direction of tangential relative velocity remains the same during the whole collision process, with the assumption that the deformation of the particles does not affect the tangential forces. The adhesion loss is only activated in the recovery stage using Dunn's model, which describes the adhesion force as an idealized line force acting on the contact radius. Several cases are tested to verify the proposed model, including low velocity normal impact of particle and wall, oblique impact of particle and wall with or without spin, sphere moving on a flat plate under gravity, and particle-particle collision. The results show that the proposed model is able to predict the experimental measurements with good accuracy and captures the essential physics of particle-particle and particle-wall impacts. (C) 2017 Elsevier B.V. All rights reserved.