Coherent structures in open channel flows with bed load transport over an hydraulically rough bed

Detalhes bibliográficos
Autor(a) principal: Santos, Bruno José Oliveira
Data de Publicação: 2013
Tipo de documento: Dissertação
Idioma: eng
Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
Texto Completo: http://hdl.handle.net/10362/11204
Resumo: Dissertação para obtenção do Grau de Mestre em Engenharia Civil – Perfil de Estruturas
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spelling Coherent structures in open channel flows with bed load transport over an hydraulically rough bedBursting phenomenaCoherent structuresQuadrant thresholdPIVSediment transportDissertação para obtenção do Grau de Mestre em Engenharia Civil – Perfil de EstruturasThe degradation of forests through the impacts of devastating wildfires increase unprotected soils area which consequently favours soil erosion processes. The sediment production is continuously reaching water courses in these areas which may result in important impacts in the flow morphodynamics and hydrodynamics. Sediment overfeeding induces important changes in the turbulent structure of the flow, mainly in momentum fluxes and exchange of momentum and mass between different layers in the flow structure, consequently affecting its ecological features. Coherent structures play an important role on sediment transport and mixing processes which are important in the fluxes that govern the turbulent structure. This study is aimed at evaluating the impacts of sediment transport on flow hydrodynamics, namely on the statistics characterizing coherent movements. In order to accomplish the purposed objective, experimental tests were undertook in laboratorial environment where two-dimensional instantaneous flow velocity fields in both directions, streamwise and vertical, were measured through means of Particle Image Velocimetry (PIV) technique. Two laboratory tests were simulated, consisting on a framework gravel bed with sand matrix and a framework gravel bed with sediment transport imposed at near capacity conditions. For both tests, the quadrant threshold analysis technique was employed and shear stress distribution statistics were analysed and discussed in what concerns their contribution and persistence. The results show that, in the near bed region, mobile bed conditions make sweep events assume a major role in the shear stress production processes. Also, larger events become less frequent in the pythmenic region, comparing with the immobile bed results. The impacts of mobile sediment in the near bed region over the flow structure are analysed and discussed in detail through probability density function distributions, in dimensional and non-dimensional data.Fundação para a Ciência e Tecnologia - PTDC/ECM/099752/2008 ; undo de Europeu de Desenvolvimento Económico e Regional(FEDER) através do Programa Operacional Factores de Competitividade(COMPETE)FCOMP 01 0124 FEDER 009735Faculdade de Ciências e TecnologiaFranca, MárioFerreira, RuiRUNSantos, Bruno José Oliveira2014-01-28T11:17:14Z20132013-01-01T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesisapplication/pdfhttp://hdl.handle.net/10362/11204enginfo: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:RCAAP2024-03-11T03:45:35Zoai:run.unl.pt:10362/11204Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-20T03:20:08.221745Repositório 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 Coherent structures in open channel flows with bed load transport over an hydraulically rough bed
title Coherent structures in open channel flows with bed load transport over an hydraulically rough bed
spellingShingle Coherent structures in open channel flows with bed load transport over an hydraulically rough bed
Santos, Bruno José Oliveira
Bursting phenomena
Coherent structures
Quadrant threshold
PIV
Sediment transport
title_short Coherent structures in open channel flows with bed load transport over an hydraulically rough bed
title_full Coherent structures in open channel flows with bed load transport over an hydraulically rough bed
title_fullStr Coherent structures in open channel flows with bed load transport over an hydraulically rough bed
title_full_unstemmed Coherent structures in open channel flows with bed load transport over an hydraulically rough bed
title_sort Coherent structures in open channel flows with bed load transport over an hydraulically rough bed
author Santos, Bruno José Oliveira
author_facet Santos, Bruno José Oliveira
author_role author
dc.contributor.none.fl_str_mv Franca, Mário
Ferreira, Rui
RUN
dc.contributor.author.fl_str_mv Santos, Bruno José Oliveira
dc.subject.por.fl_str_mv Bursting phenomena
Coherent structures
Quadrant threshold
PIV
Sediment transport
topic Bursting phenomena
Coherent structures
Quadrant threshold
PIV
Sediment transport
description Dissertação para obtenção do Grau de Mestre em Engenharia Civil – Perfil de Estruturas
publishDate 2013
dc.date.none.fl_str_mv 2013
2013-01-01T00:00:00Z
2014-01-28T11:17:14Z
dc.type.status.fl_str_mv info:eu-repo/semantics/publishedVersion
dc.type.driver.fl_str_mv info:eu-repo/semantics/masterThesis
format masterThesis
status_str publishedVersion
dc.identifier.uri.fl_str_mv http://hdl.handle.net/10362/11204
url http://hdl.handle.net/10362/11204
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.publisher.none.fl_str_mv Faculdade de Ciências e Tecnologia
publisher.none.fl_str_mv Faculdade de Ciências e Tecnologia
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
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 Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação
repository.mail.fl_str_mv
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