Elastic instabilities in parallel shear flows of a viscoelastic shear-thinning liquid

Poole, RJ ORCID: 0000-0001-6686-4301 (2016) Elastic instabilities in parallel shear flows of a viscoelastic shear-thinning liquid. PHYSICAL REVIEW FLUIDS, 1 (4). 041301-.

Text Parallel_shear_flows_CLEAN.docx - Author Accepted Manuscript Download (346kB)

Abstract

We report the results of an experimental study of the fully developed flow of a viscoelastic, shear-thinning aqueous polymer solution through two large-scale parallel shear flows: a pipe and channel-flow facility. We show that, at low flow rates, the velocity profile in both geometries is steady and is in good agreement with expected analytical solutions. However, in both geometries at higher flow rates the flow becomes weakly time dependent and the mean velocity profile is radically altered, exhibiting an overshoot near the duct center, a reduced shear rate at the wall, and an inflection point (i.e., a nonmonotonic gradient). Although inertia is not completely negligible at instability onset, we speculate that the origin of these unstable flows lies in the combination of elasticity and strong shear thinning.

Item Type:	Article
Depositing User:	Symplectic Admin
Date Deposited:	11 Jan 2017 09:52
Last Modified:	15 Mar 2024 07:59
DOI:	10.1103/PhysRevFluids.1.041301
Related URLs:	Author Publisher
URI:	https://livrepository.liverpool.ac.uk/id/eprint/3005002