Coupled dynamics of flow, microstructure, and conductivity in sheared suspensions

TL;DR

This paper develops a coupled model for predicting the evolution of electrical conductivity in sheared suspensions of conductive particles, validated against experimental rheo-electrical measurements.

Contribution

It introduces a novel combined discrete-continuum model linking microstructure evolution to conductivity in flowing suspensions, validated with experimental data.

Findings

Model accurately predicts steady and unsteady flow conductivity.

Close agreement between model and experimental measurements.

Provides insights into microstructure-conductivity relationship under shear.

Abstract

We propose a model for the evolution of the conductivity tensor for a flowing suspension of electrically conductive particles. We use discrete particle numerical simulations together with a continuum physical framework to construct an evolution law for the suspension microsutructure during flow. This model is then coupled with a relationship between the microstructure and the electrical conductivity tensor. The parameters of the joint model are fit experimentally using rheo- electrical conductivity measurements of carbon black suspensions under flow over a range of shear rates. The model is applied to the case of steady shearing as well as time-varying conductivity of unsteady flow experiments. We find that the model prediction agrees closely with the measured experimental data in all cases.