Influence of rotations in energy transfer of a particle colliding on a flat surface

• Published in: Powder technology Vol. 445; p. 120100
• Main Authors: Fernández, F.E., Aguirre, M.A., Martino, R.G., Boschan, A., Piva, M.F.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.09.2024
• Subjects: Coefficient of restitution; Energy dissipation; Particle collision; Energy dissipation; Particle collision; Coefficient of restitution
• ISSN: 0032-5910
• DOI: 10.1016/j.powtec.2024.120100

To understand the influence of rotations on the dissipation of energy in the interaction between a grain and its environment, we investigate the relaxation process of a single particle bouncing on a flat horizontal surface. For this purpose, faceted particles were used to promote the appearance of rotations in each bounce. The evolution of potential, translational and rotational kinetic energies was analyzed during the whole relaxation process, particularly focusing on the behavior just before and after each collision. The rebounding action of an individual grain results in energy dissipation commonly quantified by ϵ, the coefficient of restitution. This coefficient is defined as the ratio of the normal velocity component prior to impact (Vn) to the corresponding component immediately following the collision (Vn′), i.e. related to translational kinetic energy associated with motion in the normal direction. We identify a critical impact velocity below which, in certain collisions, ϵ>1. This phenomenon can be attributed to stored rotational kinetic energy which is transferred to translational kinetic energy during the collision, thereby increasing the normal velocity Vn′ and resulting in the observed high values of ϵ. [Display omitted] •Dependent on impact velocity, some collisions lead to a coefficient of restitution ϵ>1.•ϵ>1 mostly appears when rotational energy is transferred to motion normal to impact.•N-faceted particles with N≤15 can induce more notorious rotations.