Is there solid-on-solid contact in a sphere-wall collision in a viscous fluid?
Abstract
We study experimentally the collision between a sphere falling through a viscous fluid, and a solid plate below. It is known that there is a well-defined threshold Stokes number above which the sphere rebounds from such a collision. Our experiment tests for direct contact between the colliding bodies, and contrary to prior theoretical predictions, shows that solid-on-solid contact occurs even for Stokes numbers just above the threshold for rebounding. The dissipation is fluid-dominated, though details of the contact mechanics depend on the surface and bulk properties of the solids. Our experiments and a model calculation indicate that mechanical contact between the two colliding objects is generic and will occur for any realistic surface roughness.
Cite
@article{arxiv.1611.03438,
title = {Is there solid-on-solid contact in a sphere-wall collision in a viscous fluid?},
author = {Sumit Kumar Birwa and G. Rajalakshmi and Rama Govindarajan and Narayanan Menon},
journal= {arXiv preprint arXiv:1611.03438},
year = {2018}
}
Comments
12 pages, 11 figures