Steady and unsteady laminar flows of newtonian and generalized newtonian fluids in a planar T-junction
Autor(a) principal: | |
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Data de Publicação: | 2008 |
Outros Autores: | , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
Texto Completo: | http://hdl.handle.net/10400.6/629 |
Resumo: | An investigation of laminar steady and unsteady flows in a two-dimensional T-junction was carried out for Newtonian and a non-Newtonian fluid analogue to blood. The flow conditions considered are of relevance to hemodynamical applications and the localization of coronary diseases, and the main objective was to quantify the accuracy of the predictions and to provide benchmark data that are missing for this prototypical geometry. Under steady flow, calculations were performed for a wide range of Reynolds numbers and extraction flow rate ratios, and accurate data for the recirculation sizes were obtained and are tabulated. The two recirculation zones increased with Reynolds number, but the behaviour was non-monotonic with the flow rate ratio. For the pulsating flows a periodic instability was found, which manifests itself by the breakdown of the main vortex into two pieces and the subsequent advection of one of them, while the secondary vortex in the main duct was absent for a sixth of the oscillating period. Shear stress maxima were found on the walls opposite the recirculations, where the main fluid streams impinge onto the walls. For the blood analogue fluid, the recirculations were found to be 10% longer but also short lived than the corresponding Newtonian eddies, and the wall shear stresses are also significantly different especially in the branch duct. |
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Steady and unsteady laminar flows of newtonian and generalized newtonian fluids in a planar T-junctionT-junctionNewtonianInstabilityBlood analogueCarreau-Yasuda modelTwodimensionalAn investigation of laminar steady and unsteady flows in a two-dimensional T-junction was carried out for Newtonian and a non-Newtonian fluid analogue to blood. The flow conditions considered are of relevance to hemodynamical applications and the localization of coronary diseases, and the main objective was to quantify the accuracy of the predictions and to provide benchmark data that are missing for this prototypical geometry. Under steady flow, calculations were performed for a wide range of Reynolds numbers and extraction flow rate ratios, and accurate data for the recirculation sizes were obtained and are tabulated. The two recirculation zones increased with Reynolds number, but the behaviour was non-monotonic with the flow rate ratio. For the pulsating flows a periodic instability was found, which manifests itself by the breakdown of the main vortex into two pieces and the subsequent advection of one of them, while the secondary vortex in the main duct was absent for a sixth of the oscillating period. Shear stress maxima were found on the walls opposite the recirculations, where the main fluid streams impinge onto the walls. For the blood analogue fluid, the recirculations were found to be 10% longer but also short lived than the corresponding Newtonian eddies, and the wall shear stresses are also significantly different especially in the branch duct.uBibliorumMiranda, Amílcar I. P.Oliveira, Paulo J.Pinho, Fernando2010-04-28T10:07:32Z20082008-01-01T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleapplication/pdfhttp://hdl.handle.net/10400.6/629enginfo: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:RCAAP2023-12-15T09:35:55Zoai:ubibliorum.ubi.pt:10400.6/629Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-20T00:42:39.341036Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãofalse |
dc.title.none.fl_str_mv |
Steady and unsteady laminar flows of newtonian and generalized newtonian fluids in a planar T-junction |
title |
Steady and unsteady laminar flows of newtonian and generalized newtonian fluids in a planar T-junction |
spellingShingle |
Steady and unsteady laminar flows of newtonian and generalized newtonian fluids in a planar T-junction Miranda, Amílcar I. P. T-junction Newtonian Instability Blood analogue Carreau-Yasuda model Twodimensional |
title_short |
Steady and unsteady laminar flows of newtonian and generalized newtonian fluids in a planar T-junction |
title_full |
Steady and unsteady laminar flows of newtonian and generalized newtonian fluids in a planar T-junction |
title_fullStr |
Steady and unsteady laminar flows of newtonian and generalized newtonian fluids in a planar T-junction |
title_full_unstemmed |
Steady and unsteady laminar flows of newtonian and generalized newtonian fluids in a planar T-junction |
title_sort |
Steady and unsteady laminar flows of newtonian and generalized newtonian fluids in a planar T-junction |
author |
Miranda, Amílcar I. P. |
author_facet |
Miranda, Amílcar I. P. Oliveira, Paulo J. Pinho, Fernando |
author_role |
author |
author2 |
Oliveira, Paulo J. Pinho, Fernando |
author2_role |
author author |
dc.contributor.none.fl_str_mv |
uBibliorum |
dc.contributor.author.fl_str_mv |
Miranda, Amílcar I. P. Oliveira, Paulo J. Pinho, Fernando |
dc.subject.por.fl_str_mv |
T-junction Newtonian Instability Blood analogue Carreau-Yasuda model Twodimensional |
topic |
T-junction Newtonian Instability Blood analogue Carreau-Yasuda model Twodimensional |
description |
An investigation of laminar steady and unsteady flows in a two-dimensional T-junction was carried out for Newtonian and a non-Newtonian fluid analogue to blood. The flow conditions considered are of relevance to hemodynamical applications and the localization of coronary diseases, and the main objective was to quantify the accuracy of the predictions and to provide benchmark data that are missing for this prototypical geometry. Under steady flow, calculations were performed for a wide range of Reynolds numbers and extraction flow rate ratios, and accurate data for the recirculation sizes were obtained and are tabulated. The two recirculation zones increased with Reynolds number, but the behaviour was non-monotonic with the flow rate ratio. For the pulsating flows a periodic instability was found, which manifests itself by the breakdown of the main vortex into two pieces and the subsequent advection of one of them, while the secondary vortex in the main duct was absent for a sixth of the oscillating period. Shear stress maxima were found on the walls opposite the recirculations, where the main fluid streams impinge onto the walls. For the blood analogue fluid, the recirculations were found to be 10% longer but also short lived than the corresponding Newtonian eddies, and the wall shear stresses are also significantly different especially in the branch duct. |
publishDate |
2008 |
dc.date.none.fl_str_mv |
2008 2008-01-01T00:00:00Z 2010-04-28T10:07:32Z |
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/10400.6/629 |
url |
http://hdl.handle.net/10400.6/629 |
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 |
instname_str |
Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
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RCAAP |
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RCAAP |
reponame_str |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
collection |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
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Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
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1799136326883213312 |