Please use this identifier to cite or link to this item: http://hdl.handle.net/10216/106897
Author(s): Zilz, J
Poole, RJ
Alves, MA
Bartolo, D
Levache, B
Lindner, A
Title: Geometric scaling of a purely elastic flow instability in serpentine channels
Issue Date: 2012
Abstract: 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.
Subject: Engenharia mecânica
Mechanical engineering
Call Number: 64864
URI: http://hdl.handle.net/10216/106897
Related Information: info:eu-repo/grantAgreement/FCT - Fundação para a Ciência e Tecnologia/Projectos de I&DT em Todos os Domínios Científicos/PTDC/EME-MFE/114322/2009/EXTENSION - Escoamento extensional de fluidos complexos em microcanais/EXTENSION
Document Type: Artigo em Revista Científica Internacional
Rights: restrictedAccess
Appears in Collections:FEUP - Artigo em Revista Científica Internacional

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