Dynamics and rheology of particles in shear-thinning fluids

TL;DR

This paper investigates how rigid spherical particles behave in shear-thinning fluids, providing analytical formulas and quantifying differences from Newtonian fluids, including corrections to suspension viscosity.

Contribution

It offers new analytical formulas for particle dynamics in shear-thinning fluids and calculates the first correction to Einstein viscosity for dilute suspensions.

Findings

Sedimenting spheres exhibit different dynamics compared to Newtonian fluids.

Quantitative differences are demonstrated through analytical formulas.

First correction to suspension viscosity in shear-thinning fluids is derived.

Abstract

Particle motion in non-Newtonian fluids can be markedly different than in Newtonian fluids. Here we look at the change in dynamics for a few problems involving rigid spherical particles in shear-thinning fluids in the absence of inertia. We give analytical formulas for sedimenting spheres, obtained by means of the reciprocal theorem, and demonstrate quantitively differences in comparison to a Newtonian fluid. We also calculate the first correction to the suspension viscosity, the Einstein viscosity, for a dilute suspension of spheres in a weakly shear-thinning fluid.