# The effect of elastic walls on suspension flow

## TL;DR

This study demonstrates that elastic walls in suspension flows cause shear thinning by inducing particle migration and altering effective viscosity, providing a new rheological model for such systems.

## Contribution

It introduces a novel understanding of how elastic wall deformability influences suspension rheology and offers a closure model for predicting viscosity in elastic channels.

## Key findings

- Elastic walls induce shear thinning in suspension flow.
- Deformable walls cause particles to migrate towards the channel center.
- A closure model for suspension viscosity in elastic channels is proposed.

## Abstract

We study suspensions of rigid particles in a plane Couette flow with deformable elastic walls. We find that, in the limit of vanishing inertia, the elastic walls induce shear thinning of the suspension flow such that the effective viscosity decreases as the wall deformability increases. This shear-thinning behavior originates from the interactions between rigid particles, soft wall and carrier fluid; an asymmetric wall deformation induces a net lift force acting on the particles which therefore migrate towards the bulk of the channel. Based on our observations, we provide a closure for the suspension viscosity which can be used to model the rheology of suspensions with arbitrary volume fraction in elastic channels.