Please use this identifier to cite or link to this item: https://hdl.handle.net/10216/105580
Author(s): A. M. Afonso
M. A. Alves
R. J. Poole
P. J. Oliveira
F. T. Pinho
Title: Viscoelastic flows in mixing-separating cells
Issue Date: 2011
Abstract: The flow of Newtonian and viscoelastic fluids in a mixing-separating geometry that consists of two opposed channel flows interacting through a gap in the common separating wall is investigated. The flow in this type of geometry was studied experimentally by Cochrane et al. (Philos Trans R Soc Lond A301:163-181, 1981) using Newtonian and viscoelastic fluids at low Reynolds numbers (Re < 50). In this numerical study, by use of a finite-volume method, the effects of Deborah (De) and Reynolds numbers and gap size on the two-dimensional flow dynamics are assessed. The normalized gap size varies between 0 and 5, Re varies between 0 and 50 and De varies between 0 and the maximum attainable value. Due to the anti-symmetry of the fully developed inlet conditions and the symmetry of the flow geometry, the Newtonian creeping flow is anti-symmetric. Increasing the gap size of the separating walls leads to an increase of the reversed flow-rate ratio (R (r) ), which is defined as the ratio of the reversed and the total flow rate. For creeping flow of viscoelastic fluids, here described by the upper-convected Maxwell model, two distinct flow patterns are observed. Below a critical gap size, the reversed flow is slightly enhanced when the Deborah number increases. Further increase of De leads to a subsequent decrease in R (r) towards zero. For a supercritical gap size, increasing the Deborah number leads to a monotonic increase in R (r) .
Subject: Outras ciências da engenharia e tecnologias
Other engineering and technologies
Scientific areas: Ciências da engenharia e tecnologias::Outras ciências da engenharia e tecnologias
Engineering and technology::Other engineering and technologies
URI: https://repositorio-aberto.up.pt/handle/10216/105580
Document Type: Artigo em Revista Científica Internacional
Rights: restrictedAccess
Appears in Collections:FEUP - Artigo em Revista Científica Internacional

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