Motion of a Viscoelastic Micellar Fluid Around a Cylinder: Flow and Fracture

TL;DR

This study investigates how a viscoelastic micellar fluid behaves around a moving cylinder, revealing flow, tearing, and fracture phenomena influenced by speed and size, with implications for understanding crack propagation in complex fluids.

Contribution

It provides the first experimental analysis of viscoelastic crack propagation driven by a moving object in a micellar fluid, highlighting low tear strength and crack dynamics.

Findings

Crack propagation driven by the cylinder indicates very low tear strength.

At high speeds, cracks propagate with fluctuating speeds close to the cylinder speed.

Flow response varies from fluid-like to solid-like depending on parameters.

Abstract

We present an experimental study of the motion of a viscoelastic micellar material around a moving cylinder, which ranges in response from fluid-like flow to solid-like tearing and fracture, depending on the cylinder radius and velocity. The observation of viscoelastic crack propagation driven by the cylinder indicates an extremely low tear strength, approximately equal to the steady state surface tension of the fluid. At the highest speeds a driven crack is observed in front of the cylinder, propagating with a fluctuating speed equal on average to the cylinder speed, here as low as 5% of the elastic wave speed in the medium.