Asymmetric flows of viscoelastic fluids in symmetric planar expansion geometries
Autor(a) principal: | |
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Data de Publicação: | 2003 |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
Texto Completo: | http://hdl.handle.net/10400.6/609 |
Resumo: | The flow of viscoelastic liquids with constant shear viscosity through symmetric sudden expansions is studied by numerical means. The geometry considered is planar and the constitutive model follows the modified FENE-CR equation, valid for relative dilute solutions of polymeric fluids. For Newtonian liquids in a 1:3 expansion we predict the result that the flow becomes asymmetric for a Reynolds number (based on upstream mean velocity and channel height) of about 54, in agreement with previously published results. For the non-Newtonian case the transition depends on both the concentration and the extensibility parameters of the model, and the trend is for the pitch-fork bifurcation to occur at higher Reynolds numbers. Detailed simulations are carried out for increasing Reynolds number, at fixed concentration and Weissenberg number, and for increasing concentration at a fixed Reynolds number of 60. The results given comprise size and strength of the recirculation zones, bifurcation diagrams, and streamline plots. |
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Asymmetric flows of viscoelastic fluids in symmetric planar expansion geometriesSudden expansionPlanar expansionAsymmetric flowCoanda effectViscoelastic fluidFENE-CRThe flow of viscoelastic liquids with constant shear viscosity through symmetric sudden expansions is studied by numerical means. The geometry considered is planar and the constitutive model follows the modified FENE-CR equation, valid for relative dilute solutions of polymeric fluids. For Newtonian liquids in a 1:3 expansion we predict the result that the flow becomes asymmetric for a Reynolds number (based on upstream mean velocity and channel height) of about 54, in agreement with previously published results. For the non-Newtonian case the transition depends on both the concentration and the extensibility parameters of the model, and the trend is for the pitch-fork bifurcation to occur at higher Reynolds numbers. Detailed simulations are carried out for increasing Reynolds number, at fixed concentration and Weissenberg number, and for increasing concentration at a fixed Reynolds number of 60. The results given comprise size and strength of the recirculation zones, bifurcation diagrams, and streamline plots.uBibliorumOliveira, Paulo J.2010-04-28T10:07:18Z20032003-01-01T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleapplication/pdfhttp://hdl.handle.net/10400.6/609enginfo:eu-repo/semantics/openAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2023-01-16T11:37:31ZPortal AgregadorONG |
dc.title.none.fl_str_mv |
Asymmetric flows of viscoelastic fluids in symmetric planar expansion geometries |
title |
Asymmetric flows of viscoelastic fluids in symmetric planar expansion geometries |
spellingShingle |
Asymmetric flows of viscoelastic fluids in symmetric planar expansion geometries Oliveira, Paulo J. Sudden expansion Planar expansion Asymmetric flow Coanda effect Viscoelastic fluid FENE-CR |
title_short |
Asymmetric flows of viscoelastic fluids in symmetric planar expansion geometries |
title_full |
Asymmetric flows of viscoelastic fluids in symmetric planar expansion geometries |
title_fullStr |
Asymmetric flows of viscoelastic fluids in symmetric planar expansion geometries |
title_full_unstemmed |
Asymmetric flows of viscoelastic fluids in symmetric planar expansion geometries |
title_sort |
Asymmetric flows of viscoelastic fluids in symmetric planar expansion geometries |
author |
Oliveira, Paulo J. |
author_facet |
Oliveira, Paulo J. |
author_role |
author |
dc.contributor.none.fl_str_mv |
uBibliorum |
dc.contributor.author.fl_str_mv |
Oliveira, Paulo J. |
dc.subject.por.fl_str_mv |
Sudden expansion Planar expansion Asymmetric flow Coanda effect Viscoelastic fluid FENE-CR |
topic |
Sudden expansion Planar expansion Asymmetric flow Coanda effect Viscoelastic fluid FENE-CR |
description |
The flow of viscoelastic liquids with constant shear viscosity through symmetric sudden expansions is studied by numerical means. The geometry considered is planar and the constitutive model follows the modified FENE-CR equation, valid for relative dilute solutions of polymeric fluids. For Newtonian liquids in a 1:3 expansion we predict the result that the flow becomes asymmetric for a Reynolds number (based on upstream mean velocity and channel height) of about 54, in agreement with previously published results. For the non-Newtonian case the transition depends on both the concentration and the extensibility parameters of the model, and the trend is for the pitch-fork bifurcation to occur at higher Reynolds numbers. Detailed simulations are carried out for increasing Reynolds number, at fixed concentration and Weissenberg number, and for increasing concentration at a fixed Reynolds number of 60. The results given comprise size and strength of the recirculation zones, bifurcation diagrams, and streamline plots. |
publishDate |
2003 |
dc.date.none.fl_str_mv |
2003 2003-01-01T00:00:00Z 2010-04-28T10:07:18Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://hdl.handle.net/10400.6/609 |
url |
http://hdl.handle.net/10400.6/609 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf |
dc.source.none.fl_str_mv |
reponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação instacron:RCAAP |
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Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
instacron_str |
RCAAP |
institution |
RCAAP |
reponame_str |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
collection |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
repository.name.fl_str_mv |
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repository.mail.fl_str_mv |
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_version_ |
1777301755989590016 |