Viscoelastic shear banding in foam

TL;DR

This paper experimentally investigates shear banding phenomena in foam, focusing on the transition between different shear band classes caused by the competition between intrinsic and external dissipation in quasi-two dimensional flow.

Contribution

It provides experimental evidence of shear band class transitions in foam, supporting theoretical predictions about dissipation-driven shear banding in cylindrical geometries.

Findings

Observation of shear band class transitions in foam.

Confirmation of theoretical predictions on dissipation effects.

Insights into flow behavior in complex fluids.

Abstract

Shear banding is an important feature of flow in complex fluids. Essentially, shear bands refer to the coexistence of flowing and non-flowing regions in driven material. Understanding the possible sources of shear banding has important implications for a wide range of flow applications. In this regard, quasi-two dimensional flow offers a unique opportunity to study competing factors that result in shear bands. One proposal is the competition between intrinsic dissipation and an external source of dissipation. In this paper, we report on the experimental observation of the transition between different classes of shear-bands that have been predicted to exist in cylindrical geometry as the result of this competition [R. J. Clancy, E. Janiaud, D. Weaire, and S. Hutzlet, Eur. J. Phys. E, {\bf 21}, 123 (2006)].