Repository logo
 

Unsteady flow and particle migration in dense, non-Brown suspensions

Accepted version
Peer-reviewed

Loading...
Thumbnail Image

Type

Article

Change log

Authors

Hermes, M 
Guy, BM 
Poon, WCK 
Poy, G 
Cates, ME 

Abstract

We present experimental results on dense corn-starch suspensions as examples of non-Brownian, nearly-hard particles that undergo continuous and discontinuous shear thickening (CST and DST) at intermediate and high densities respectively. Our results offer strong support for recent theories involving a stress-dependent effective contact friction among particles. We show however that in the DST regime, where theory might lead one to expect steady-state shear bands oriented layerwise along the vorticity axis, the real flow is unsteady. To explain this, we argue that steady-state banding is generically ruled out by the requirement that, for hard non-Brownian particles, the solvent pressure and the normal-normal component of the particle stress must balance separately across the interface between bands. (Otherwise there is an unbalanced migration flux.) However, long-lived transient shear bands remain possible.

Description

Keywords

4012 Fluid Mechanics and Thermal Engineering, 40 Engineering

Journal Title

Journal of Rheology

Conference Name

Journal ISSN

0148-6055
1520-8516

Volume Title

Publisher

Society of Rheology
Sponsorship
Engineering and Physical Sciences Research Council (EP/J007404/1)
EPSRC (EP/J007404)
Relationships
Is supplemented by: