Document Type

Article

Publication Date

11-1-2011

Publication Title

Journal of Non-Newtonian Fluid Mechanics

Abstract

The effect of stress diffusivity is examined in both the Oldroyd-B and FENE-P models of a viscoelastic fluid in the low Reynolds (Stokes) limit for a 2D periodic time-dependent flow. A local analytic solution can be obtained when assuming a flow of the form u=Wi-1(x,-y), where Wi is the Weissenberg number. In this case the width of the birefringent strand of the polymer stress scales with the added viscosity as ν1/2, and is independent of the Weissenberg number. Also, the " expected" maximum extension of the polymer coils remains finite with any stress diffusion and scales as Wi·ν-1/2. These predictions closely match the full simulations. As many investigations of viscoelastic fluids incorporate both finite extension as well as polymer stress diffusion we also investigate the FENE-P model with diffusion to see which effect dominates for various model parameters. With this penalization the percent of maximum extension can be predicted based on Wi, ν, and b, the maximum extensibility length.

Keywords

FENE-P, Oldroyd-B, Stress diffusion, Viscoelastic fluid models

Volume

166

Issue

21-22

First Page

1221

Last Page

1228

DOI

10.1016/j.jnnfm.2011.07.009

ISSN

03770257

Comments

Archived as published.

Included in

Mathematics Commons

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