Could the Rebound Characteristics of Oblique Impact for SiO₂ Particles Represent the Ash Particles?

Collisions between particles or with a surface have been widely applied, in which the restitution coefficients are the important parameter to describe the particle rebound behavior. SiO₂ particles are often used instead of ash particles in theoretical analyses; however, whether this is justifiable has not been confirmed. This paper compares the rebound characteristics of oblique impact for SiO₂ particles and ash particles by experimental and theoretical analyses. Based on the rigid-body theory, the tangential restitution coefficients, rebound angle-particle center, and reflection angle-contact path predicted by SiO₂ particles are basically in agreement with the experimental results for ash particles, especially at large impact angles. However, there is a slight error at 2.2 m/s as the velocity approaches the critical capture velocity.