Giant fluctuations in sheared viscoelastic fluids emerging in a mesoscale simulation

TL;DR

This paper presents a mesoscale simulation of shear-induced giant fluctuations in viscoelastic fluids, introducing a velocity-dependent friction force that captures experimental observations efficiently on a desktop PC.

Contribution

It introduces a novel particle simulation model with a velocity-dependent friction force to study large density fluctuations in sheared viscoelastic fluids.

Findings

Simulation results agree with experimental observations.

The model efficiently captures giant fluctuations in polymer solutions.

The approach uses sparse matrix algebra for computational efficiency.

Abstract

Shear flow is known to induce huge density fluctuations in otherwise clear and uniform polymer solutions. This effect is rooted in the elasticity of the entangled polymer network, and can span distances over a thousand chains wide. It has been observed in many scattering experiments, and later explained by mathematical theories. Here we inspect this phenomenon from a direct particle simulation viewpoint. The main novelty is a velocity dependent friction force, coupling the entire system and solved efficiently with sparse matrix algebra. Our minimalist model runs on a desktop PC and the results agree well with experiments.