Issue 29, 2016

The stabilizing effect of shear thinning on the onset of purely elastic instabilities in serpentine microflows

Abstract

We determine both experimentally and numerically the onset of elastic flow instabilities in viscoelastic polymer solutions with different levels of shear thinning. Previous experiments realized in microfluidic serpentine channels using dilute polymeric solutions showed that the onset of elastic instabilities strongly depends on the channel curvature. The scaling dependence is well captured by the general instability scaling criterion proposed by Pakdel and McKinley [Phys. Rev. Lett., 1996, 76, 2459:1–4]. We determine here the influence of fluid shear thinning on the onset of such purely-elastic flow instabilities. By testing a set of polyethylene oxide solutions of high molecular weight at different polymer concentrations in microfluidic serpentine channels we observe that shear thinning has a stabilizing effect on the microfluidic flow. Three-dimensional numerical simulations performed using the White–Metzner model predict similar trends, which are not captured by a simple scaling analysis using the Pakdel–McKinley criterion.

Graphical abstract: The stabilizing effect of shear thinning on the onset of purely elastic instabilities in serpentine microflows

Supplementary files

Article information

Article type
Paper
Submitted
08 Feb 2016
Accepted
16 May 2016
First published
17 May 2016
This article is Open Access
Creative Commons BY license

Soft Matter, 2016,12, 6167-6175

The stabilizing effect of shear thinning on the onset of purely elastic instabilities in serpentine microflows

L. Casanellas, M. A. Alves, R. J. Poole, S. Lerouge and A. Lindner, Soft Matter, 2016, 12, 6167 DOI: 10.1039/C6SM00326E

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