Fluid squeeze-out between rough surfaces: comparison of theory with experiment

TL;DR

This paper develops an analytical theory for fluid squeeze-out between rough and flat surfaces, validated by experiments, enhancing understanding of fluid removal dynamics in contact mechanics.

Contribution

It introduces a combined theoretical approach using Persson contact mechanics and Bruggeman effective medium theory to predict fluid squeeze-out, validated through experimental comparison.

Findings

The theory accurately predicts fluid removal times.

Experimental results agree with theoretical predictions.

The approach improves understanding of fluid dynamics in rough surface contact.

Abstract

We study the time dependency of the (average) interfacial separation between an elastic solid with a flat surface and a rigid solid with a randomly rough surface, squeezed together in a fluid. We use an analytical theory describing the fluid flow factors, based on the Persson contact mechanics theory and the Bruggeman effective medium theory, to calculate the removal of the fluid from the contacting interface of the two solids. In order to test this approach, we have performed simple squeeze-out experiments. The experimental results are compared to the theory predictions.