PTV experiments and DEM simulations of the coefficient of restitution for irregular particles impacting on horizontal substrates
For systems of particles with irregular shapes, the collisions between particles and between particles and walls are highly complex and strongly related to the contact geometry. In this work, the collision behavior between irregular maltodextrin particles (with a characteristic size of approximately 100 ) and horizontal substrates was experimentally measured by an improved particle tracking velocimetry (PTV), which simultaneously reconstructed the trajectories of many particles during the process of free fall and rebound. In addition, the measurement data were compared with DEM simulations using the multi-sphere model and the superquadric model, regarding the distributions of total and normal coefficients of restitution and corresponding relationships with the rotational speed after collision and the absolute difference of incidence angle and rebound angle. Compared to the superquadric model, the multi-sphere model well predicts the macroscopic particle-wall collision behaviors of irregular non-convex particles.
Keywords: PTV, Coefficient of restitution, Non-spherical DEM, Irregular non-convex particle, Multi-sphere, Superquadric