Elastic turbulence in shear banding wormlike micelles

TL;DR

This paper investigates the instability and turbulence phenomena in shear banding wormlike micelles under high shear rates, revealing elastic turbulence similar to that in polymer solutions and proposing a new flow scenario.

Contribution

It demonstrates the onset of elastic turbulence in shear banding wormlike micelles and links flow instability to shear stress jumps, expanding understanding of complex fluid dynamics.

Findings

Flow becomes unstable at high Weissenberg numbers.

Flow pattern shows elastic turbulence similar to polymer solutions.

Shear stress jump correlates with turbulence nucleation.

Abstract

We study the dynamics of the Taylor-Couette flow of shear banding wormlike micelles. We focus on the high shear rate branch of the flow curve and show that for sufficiently high Weissenberg numbers, this branch becomes unstable. This instability is strongly sub-critical and is associated with a shear stress jump. We find that this increase of the flow resistance is related to the nucleation of turbulence. The flow pattern shows similarities with the elastic turbulence, so far only observed for polymer solutions. The unstable character of this branch led us to propose a scenario that could account for the recent observations of Taylor-like vortices during the shear banding flow of wormlike micelles.