Geometric scaling of a purely elastic flow instability in serpentine channels

• Type: Article in International Scientific Journal
• Date: 2012

Authors

J. Zilz (Author) Other; R. J. Poole (Author) Other; M. A. Alves (Author) FEUP; D. Bartolo (Author) Other; B. Levaché (Author) Other; A. Lindner (Author) Other

Journal

Title: Journal of Fluid Mechanics

Vol. 712

Pages: 203-218

ISSN: 0022-1120

Publisher: Cambridge University Press

Indexing

ISI Web of Knowledge - 41 Citations

ISI Web of Science

Scopus - 56 Citations

Scientific classification

FOS: Engineering and technology > Mechanical engineering

Associated Projects

EXTENSION - EXTENSION – Escoamento extensional de fluidos complexos em microcanais

Other information

Authenticus ID: P-002-2DB

DOI: 10.1017/jfm.2012.411

Abstract (EN): A combined experimental, numerical and theoretical investigation of the geometric scaling of the onset of a purely elastic flow instability in serpentine channels is presented. Good qualitative agreement is obtained between experiments, using dilute solutions of flexible polymers in microfluidic devices, and three-dimensional numerical simulations using the upper-convected Maxwell model. The results are confirmed by a simple theoretical analysis, based on the dimensionless criterion proposed by Pakdel & McKinley (Phys. R e v.Lett., vol. 77, 1996, pp. 2459-2462) for onset of a purely elastic flow instability. Three-dimensional simulations show that the instability is primarily driven by the curvature of the streamlines induced by the flow geometry and not due to the weak secondary flow in the azimuthal direction. In addition, the simulations also reveal that the instability is time-dependent and that the flow oscillates with a well-defined period and amplitude close to the onset of the supercritical instability.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 16