Relaxation and flow in linearly sheared two-dimensional foams

TL;DR

This study investigates how shear-induced relaxation affects the flow behavior of two-dimensional foams, revealing a complex relationship between microscopic bubble dynamics and macroscopic rheology.

Contribution

It demonstrates a non-trivial scaling of relaxation time with strain rate and links microscopic bubble motion to the foam's rheological properties.

Findings

Relaxation time scales non-trivially with strain rate.

Rheology is closely connected to bubble relaxation dynamics.

Microscopic bubble motion influences macroscopic flow behavior.

Abstract

We probe the relation between shear induced structural relaxation and rheology in experiments on sheared two-dimensional foams. The relaxation time, which marks the crossover to diffusive bubble motion, is found to scale non-trivially with the local strain rate. The rheology of the foam is shown to be intimately linked to the scaling of the relaxation time, thus connecting macroscopic flow and microscopic bubble motion.