Thickening of viscoelastic flow in a model porous medium

We study numerically two-dimensional creeping viscoelastic flow past a biperiodic square array of cylinders within the Oldroyd B, FENE-CR and FENE-P constitutive models of dilute polymer solutions. Our results capture the initial mild decrease then dramatic upturn (`thickening') seen experiment...

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Bibliographic Details
Published inJournal of non-Newtonian fluid mechanics Vol. 251; pp. 56 - 68
Main Authors Hemingway, E.J., Clarke, A., Pearson, J.R.A., Fielding, S.M.
Format Journal Article
LanguageEnglish
Published Amsterdam Elsevier BV 01.01.2018
Subjects
Barriers
Constitutive models
Creep (materials)
Cylinder liners
Dilution
Drag coefficients
Flow geometry
Geometry
Mathematical models
Porosity
Porous media
Thickening
Two dimensional flow
Two dimensional models
Viscoelasticity
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Summary:We study numerically two-dimensional creeping viscoelastic flow past a biperiodic square array of cylinders within the Oldroyd B, FENE-CR and FENE-P constitutive models of dilute polymer solutions. Our results capture the initial mild decrease then dramatic upturn (`thickening') seen experimentally in the drag coefficient as a function of increasing Weissenberg number. By systematically varying the porosity of the flow geometry, we demonstrate two qualitatively different mechanisms underpinning this thickening effect: one that operates in the highly porous case of widely spaced obstacles, and another for more densely packed obstacles, with a crossover between these two mechanisms at intermediate porosities. We also briefly consider 2D creeping viscoelastic flow past a linear array of cylinders confined to a channel, where we find that the flow is steady for all Weissenberg numbers explored.
ISSN:0377-0257
1873-2631
DOI:10.1016/j.jnnfm.2017.11.002