Stepped spillways with aerators: hydrodynamic pressures and air entrainment
Autor(a) principal: | |
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Data de Publicação: | 2021 |
Outros Autores: | , , , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | RBRH (Online) |
Texto Completo: | http://old.scielo.br/scielo.php?script=sci_arttext&pid=S2318-03312021000100203 |
Resumo: | ABSTRACT The possibility of damage due to the phenomenon of cavitation leads the design of stepped spillways considering maximum specific discharges of 15 to 30 m2/s, a limit considerably lower than that practiced on smooth chutes. Aerators promote the insertion of air in the flow, allowing for the increase of specific flow rates. This work analyzes the pressures on the vertical faces of the steps and the air entrainment coefficient in the flow, through an experimental study in a physical model with a stepped chute angle of 53.13o, considering the installation of aerators in different places of the channel. Comparing the tested conditions with the natural aeration, it is concluded that the installation of the aerator does not change the magnitude of the minimum extreme hydrodynamic pressures, but anticipates the beginning of the flow aeration. A new equation is proposed to estimate the air entrainment coefficient, as well as a methodology for forecasting extreme pressures on the vertical faces of the steps, both valid in the range 3.0 ≤ Fr ≤ 6.0. |
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Stepped spillways with aerators: hydrodynamic pressures and air entrainmentHydraulic structuresCavitationDeflectorABSTRACT The possibility of damage due to the phenomenon of cavitation leads the design of stepped spillways considering maximum specific discharges of 15 to 30 m2/s, a limit considerably lower than that practiced on smooth chutes. Aerators promote the insertion of air in the flow, allowing for the increase of specific flow rates. This work analyzes the pressures on the vertical faces of the steps and the air entrainment coefficient in the flow, through an experimental study in a physical model with a stepped chute angle of 53.13o, considering the installation of aerators in different places of the channel. Comparing the tested conditions with the natural aeration, it is concluded that the installation of the aerator does not change the magnitude of the minimum extreme hydrodynamic pressures, but anticipates the beginning of the flow aeration. A new equation is proposed to estimate the air entrainment coefficient, as well as a methodology for forecasting extreme pressures on the vertical faces of the steps, both valid in the range 3.0 ≤ Fr ≤ 6.0.Associação Brasileira de Recursos Hídricos2021-01-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersiontext/htmlhttp://old.scielo.br/scielo.php?script=sci_arttext&pid=S2318-03312021000100203RBRH v.26 2021reponame:RBRH (Online)instname:Associação Brasileira de Recursos Hídricos (ABRH)instacron:ABRH10.1590/2318-0331.262120200110info:eu-repo/semantics/openAccessFerla,RuteNovakoski,Carolina KuhnPriebe,Priscila dos SantosPrá,Mauricio DaiMarques,Marcelo GiulianTeixeira,Eder Danieleng2021-03-30T00:00:00Zoai:scielo:S2318-03312021000100203Revistahttps://www.scielo.br/j/rbrh/https://old.scielo.br/oai/scielo-oai.php||rbrh@abrh.org.br2318-03311414-381Xopendoar:2021-03-30T00:00RBRH (Online) - Associação Brasileira de Recursos Hídricos (ABRH)false |
dc.title.none.fl_str_mv |
Stepped spillways with aerators: hydrodynamic pressures and air entrainment |
title |
Stepped spillways with aerators: hydrodynamic pressures and air entrainment |
spellingShingle |
Stepped spillways with aerators: hydrodynamic pressures and air entrainment Ferla,Rute Hydraulic structures Cavitation Deflector |
title_short |
Stepped spillways with aerators: hydrodynamic pressures and air entrainment |
title_full |
Stepped spillways with aerators: hydrodynamic pressures and air entrainment |
title_fullStr |
Stepped spillways with aerators: hydrodynamic pressures and air entrainment |
title_full_unstemmed |
Stepped spillways with aerators: hydrodynamic pressures and air entrainment |
title_sort |
Stepped spillways with aerators: hydrodynamic pressures and air entrainment |
author |
Ferla,Rute |
author_facet |
Ferla,Rute Novakoski,Carolina Kuhn Priebe,Priscila dos Santos Prá,Mauricio Dai Marques,Marcelo Giulian Teixeira,Eder Daniel |
author_role |
author |
author2 |
Novakoski,Carolina Kuhn Priebe,Priscila dos Santos Prá,Mauricio Dai Marques,Marcelo Giulian Teixeira,Eder Daniel |
author2_role |
author author author author author |
dc.contributor.author.fl_str_mv |
Ferla,Rute Novakoski,Carolina Kuhn Priebe,Priscila dos Santos Prá,Mauricio Dai Marques,Marcelo Giulian Teixeira,Eder Daniel |
dc.subject.por.fl_str_mv |
Hydraulic structures Cavitation Deflector |
topic |
Hydraulic structures Cavitation Deflector |
description |
ABSTRACT The possibility of damage due to the phenomenon of cavitation leads the design of stepped spillways considering maximum specific discharges of 15 to 30 m2/s, a limit considerably lower than that practiced on smooth chutes. Aerators promote the insertion of air in the flow, allowing for the increase of specific flow rates. This work analyzes the pressures on the vertical faces of the steps and the air entrainment coefficient in the flow, through an experimental study in a physical model with a stepped chute angle of 53.13o, considering the installation of aerators in different places of the channel. Comparing the tested conditions with the natural aeration, it is concluded that the installation of the aerator does not change the magnitude of the minimum extreme hydrodynamic pressures, but anticipates the beginning of the flow aeration. A new equation is proposed to estimate the air entrainment coefficient, as well as a methodology for forecasting extreme pressures on the vertical faces of the steps, both valid in the range 3.0 ≤ Fr ≤ 6.0. |
publishDate |
2021 |
dc.date.none.fl_str_mv |
2021-01-01 |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://old.scielo.br/scielo.php?script=sci_arttext&pid=S2318-03312021000100203 |
url |
http://old.scielo.br/scielo.php?script=sci_arttext&pid=S2318-03312021000100203 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
10.1590/2318-0331.262120200110 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
text/html |
dc.publisher.none.fl_str_mv |
Associação Brasileira de Recursos Hídricos |
publisher.none.fl_str_mv |
Associação Brasileira de Recursos Hídricos |
dc.source.none.fl_str_mv |
RBRH v.26 2021 reponame:RBRH (Online) instname:Associação Brasileira de Recursos Hídricos (ABRH) instacron:ABRH |
instname_str |
Associação Brasileira de Recursos Hídricos (ABRH) |
instacron_str |
ABRH |
institution |
ABRH |
reponame_str |
RBRH (Online) |
collection |
RBRH (Online) |
repository.name.fl_str_mv |
RBRH (Online) - Associação Brasileira de Recursos Hídricos (ABRH) |
repository.mail.fl_str_mv |
||rbrh@abrh.org.br |
_version_ |
1754734702249377792 |