Engineering and Computer Science Faculty Publications

Title

Particle Impact Theory Including Surface Asperity Deformation and Recovery

Document Type

Article

Publication Date

12-2011

Journal Title

Journal of Aerosol Science

Volume

42

Issue

12

First Page

852

Last Page

858

Abstract

A new particle impact theory was proposed, which incorporated plastic deformation and elastic recovery of surface asperities into the overall energy balance of the impact process. Asperity heights were assumed to follow a truncated Gaussian distribution. The energy transfer associated with the deformation and recovery of asperities was derived based on the previous theoretical treatments of thermal contact resistance. It was found that even nanometer level roughness had significant effects on the rebound of micron size particles. The energy loss thus caused could explain the mysterious strong power–law dependence on particle size of critical velocity. Measurements of Wall et al. were compared with the theory. Good agreement had been reached between the theory and experiments for both coefficients of restitution and particle size dependence of critical velocity.

Keywords

Particle-surface impact process, Critical velocity, Surface asperities, Plastic deformation, Model