The normal restitution coefficient and critical sticking velocity of disk-shaped adhesive particles

The particle-wall collision is an important phenomenon in gas-solid flows. For non-spherical particles like diskshaped particles, the classic models based on quasi-spherical assumptions cannot be directly applied. It is still challenging to evaluate the loss of kinetic energy by resolving the adhesion and viscoelastic damping because of their strong coupling. To address this issue, we employ the finite element method (FEM) to conduct a numerical investigation of the particle-wall collision dynamics of adhesive, disk-shaped particles. The viscoelastic model and adhesion are coupled to naturally reproduce the energy dissipation. Our findings reveal that the nonspherical nature of the particles influences energy dissipation through two distinct mechanisms: viscoelastic dissipation by changing the collision time and adhesion by changing the contact area. Explicit expressions of the restitution and the critical sticking velocity of the disk-shaped particles are given, which can be directly used in the numerical simulation under the Euler-Lagrange framework.