Mesoscopic simulation study of wall roughness effects in micro-channel flows of dense emulsions

TL;DR

This study uses lattice Boltzmann simulations to investigate how wall roughness influences flow behavior and plastic rearrangements in dense emulsions confined in micro-channels, linking microscopic dynamics to macroscopic rheology.

Contribution

It introduces a mesoscopic simulation approach to analyze the impact of wall roughness on plastic events and flow in dense emulsions, connecting microscopic plasticity to bulk flow properties.

Findings

Wall roughness activates plastic events near boundaries.

Spatial correlations in plastic rearrangements influence flow behavior.

Fluidity field analysis links microscopic plasticity to macroscopic rheology.

Abstract

We study the Poiseuille flow of a soft-glassy material above the jamming point, where the material flows like a complex fluid with Herschel- Bulkley rheology. Microscopic plastic rearrangements and the emergence of their spatial correlations induce cooperativity flow behavior whose effect is pronounced in presence of confinement. With the help of lattice Boltzmann numerical simulations of confined dense emulsions, we explore the role of geometrical roughness in providing activation of plastic events close to the boundaries. We probe also the spatial configuration of the fluidity field, a continuum quantity which can be related to the rate of plastic events, thereby allowing us to establish a link between the mesoscopic plastic dynamics of the jammed material and the macroscopic flow behaviour.