Study on collision between single coarse particle and wall in viscous media using CFD–DEM

Collision between particle and wall is common in granular two-phase flow. This study is helpful to optimise flow conveying system, reduce attrition between materials and devices, and improve development of economy. The collision between a single coarse particle (3 mm in diameter) and wall in a viscous media was investigated by Hertz–Mindlin no-slip contact model based on the coupled computational fluid dynamics and discrete element method (CFD-DEM). Effects of impact velocity and viscosity of media on contact processes and contact force are studied in this research. The calculated results from the collision model are consistent with experimental data, and contact velocity and viscosity of media show significant effects on the contact force of particles. With the reduction of the dimensionless number St, the ratio of unloading time to loading time increases significantly.