Title

Elastic secondary flows in sharp 90 degree micro-bends: a comparison of PEO and DNA solutions

Document Type

Article

Publication Title

Journal of Rheology

ISSN

0148-6055

Volume

54

Issue

2

DOI

10.1122/1.3308643

First Page

375

Last Page

392

Publication Date

3-1-2010

Abstract

The growth or absence of elastic secondary flows is documented for flows of dilute and semi-dilute polymer solutions in sharp 90° micro-bends in channels of rectangular cross-section; secondary flows are not present for Newtonian flows under similar conditions. Flow visualization shows that a vortex is present in the inner, upstream corner of the bend and grows with increasing Reynolds (Re) and Weissenberg (Wi) numbers for flows of shear-thinning, semi-dilute polymeric solutions containing λ-DNAλ-DNA (9.9×10−7−2, 0.42−4−33.5×10−4−3, 1.8−4−23.3×10−4−2, 1.1