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Bifurcation phenomena in viscoelastic flows through a symmetric 1: 4 expansion

2007Journal article Open access
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dc.contributor.authorRocha, Gerardo N.pt
dc.contributor.authorPoole, R. J.
dc.contributor.authorOliveira, Paulo J.
dc.date.accessioned2010-04-28T10:07:14Z
dc.date.available2010-04-28T10:07:14Z
dc.date.issued2007
dc.description.abstractIn this work we present an investigation of viscoelastic flow in a planar sudden expansion with expansion ratio D/d = 4. We apply the modified FENE–CR constitutive model based on the non-linear finite extensibility dumbbells (FENE) model. The governing equations were solved using a finite volume method with the high-resolution CUBISTA scheme utilised for the discretisation of the convective terms in the stress and momentum equations. Our interest here is to investigate two-dimensional steady-state solutions where, above a critical Reynolds number, stable asymmetric flow states are known to occur.We report a systematic parametric investigation, clarifying the roles of Reynolds number (0.01 < Re < 100),Weissenberg number (0 < We < 100) and the solvent viscosity ratio (0.3 < β < 1). For most simulations the extensibility parameter of the FENE model was kept constant, at a value L2 = 100, but some exploration of its effect in the range 100–500 shows a rather minor influence. The results given comprise flow patterns, streamlines and vortex sizes and intensities, and pressure and velocity distributions along the centreline (i.e. y = 0). For the Newtonian case, in agreement with previous studies, a bifurcation to asymmetric flow was observed for Reynolds numbers greater than about 36. In contrast viscoelasticity was found to stabilise the flow; setting β = 0.5 and We = 2 as typical values, resulted in symmetric flow up to a Reynolds number of about 46. We analyse these two cases in particular detail.pt
dc.identifier.urihttp://hdl.handle.net/10400.6/592
dc.languageeng
dc.subjectPlanar symmetric expansionpt
dc.subjectAsymmetric flowpt
dc.subjectViscoelastic fluidpt
dc.subjectFENE–CR modelpt
dc.subjectFENE–MCR modelpt
dc.subjectFinite volume methodpt
dc.titleBifurcation phenomena in viscoelastic flows through a symmetric 1: 4 expansionpt
dc.typejournal article
dspace.entity.typePublication
oaire.citation.issueVol. 141, No. 1 , pp. 1-17pt
oaire.citation.titleJournal of Non-Newtonian Fluid Mechanicspt
person.familyNamePoole
person.familyNameOliveira
person.givenNameRobert
person.givenNamePaulo J.
person.identifier.ciencia-id7A15-7012-C5DF
person.identifier.orcid0000-0001-6686-4301
person.identifier.orcid0000-0001-9843-7558
person.identifier.ridB-7960-2008
person.identifier.ridA-4638-2009
person.identifier.scopus-author-id7102334697
person.identifier.scopus-author-id24280605700
rcaap.rightsopenAccess
rcaap.typearticlept
relation.isAuthorOfPublication8354a555-8319-44e6-95e0-4ca1fc7db4dd
relation.isAuthorOfPublicationf4a5da68-73fb-4a8b-9418-669d76d75f39
relation.isAuthorOfPublication.latestForDiscovery8354a555-8319-44e6-95e0-4ca1fc7db4dd

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