Numerical Study of the Mixing Co-Axial Jets
Autor(a) principal: | |
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Data de Publicação: | 2011 |
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/10400.6/11541 |
Resumo: | This paper presents a numerical study of the effect of the turbulence intensity in the turbulent mixing of coaxial confined jets. The objective of this work is to study the effect of the initial levels of turbulence of each coaxial jet in the process of turbulent mixing for diameter ratios less than 2, which is the case of very low bypass turbofan engines. The computational method was tested using the available experimental data, and revealed good capabilities for the simulation of this kind of flows. The effect of the velocity ratio of the two streams is presented for velocity ratios of the two streams of 0.3, 1.5, and 6, and turbulence intensity ratios between 10 -5 and 10 5. The results revealed that for relatively high turbulence intensities of the outer jet a vortex is always present for velocity ratios of 6 or larger, and this is independent of the turbulence intensity ratio. When the turbulence intensity of the inner jet is kept constant and the ratio of turbulence intensities is increased, the recirculation zone decreases in size, its center moves further upstream until it disappears completely. The existence of a favorable pressure gradient as a similar effect, revealing that this is an additional parameter to be taken into consideration together with the velocity ratio and turbulence intensity ratio as far as the recirculation zone is concerned. |
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spelling |
Numerical Study of the Mixing Co-Axial JetsCo-axial jetsGas turbine enginesThis paper presents a numerical study of the effect of the turbulence intensity in the turbulent mixing of coaxial confined jets. The objective of this work is to study the effect of the initial levels of turbulence of each coaxial jet in the process of turbulent mixing for diameter ratios less than 2, which is the case of very low bypass turbofan engines. The computational method was tested using the available experimental data, and revealed good capabilities for the simulation of this kind of flows. The effect of the velocity ratio of the two streams is presented for velocity ratios of the two streams of 0.3, 1.5, and 6, and turbulence intensity ratios between 10 -5 and 10 5. The results revealed that for relatively high turbulence intensities of the outer jet a vortex is always present for velocity ratios of 6 or larger, and this is independent of the turbulence intensity ratio. When the turbulence intensity of the inner jet is kept constant and the ratio of turbulence intensities is increased, the recirculation zone decreases in size, its center moves further upstream until it disappears completely. The existence of a favorable pressure gradient as a similar effect, revealing that this is an additional parameter to be taken into consideration together with the velocity ratio and turbulence intensity ratio as far as the recirculation zone is concerned.Fundação para a Ciência e a TecnologiaPraise Worthy PrizeuBibliorumNeves, Fernando M. S. P.Barata, Jorge M MSilva, André2011-072060-07-01T00:00:00Z2011-07-01T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleapplication/pdfhttp://hdl.handle.net/10400.6/11541eng1970-8734info:eu-repo/semantics/embargoedAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2023-12-15T09:54:07Zoai:ubibliorum.ubi.pt:10400.6/11541Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-20T00:51:18.693028Repositório 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 |
Numerical Study of the Mixing Co-Axial Jets |
title |
Numerical Study of the Mixing Co-Axial Jets |
spellingShingle |
Numerical Study of the Mixing Co-Axial Jets Neves, Fernando M. S. P. Co-axial jets Gas turbine engines |
title_short |
Numerical Study of the Mixing Co-Axial Jets |
title_full |
Numerical Study of the Mixing Co-Axial Jets |
title_fullStr |
Numerical Study of the Mixing Co-Axial Jets |
title_full_unstemmed |
Numerical Study of the Mixing Co-Axial Jets |
title_sort |
Numerical Study of the Mixing Co-Axial Jets |
author |
Neves, Fernando M. S. P. |
author_facet |
Neves, Fernando M. S. P. Barata, Jorge M M Silva, André |
author_role |
author |
author2 |
Barata, Jorge M M Silva, André |
author2_role |
author author |
dc.contributor.none.fl_str_mv |
uBibliorum |
dc.contributor.author.fl_str_mv |
Neves, Fernando M. S. P. Barata, Jorge M M Silva, André |
dc.subject.por.fl_str_mv |
Co-axial jets Gas turbine engines |
topic |
Co-axial jets Gas turbine engines |
description |
This paper presents a numerical study of the effect of the turbulence intensity in the turbulent mixing of coaxial confined jets. The objective of this work is to study the effect of the initial levels of turbulence of each coaxial jet in the process of turbulent mixing for diameter ratios less than 2, which is the case of very low bypass turbofan engines. The computational method was tested using the available experimental data, and revealed good capabilities for the simulation of this kind of flows. The effect of the velocity ratio of the two streams is presented for velocity ratios of the two streams of 0.3, 1.5, and 6, and turbulence intensity ratios between 10 -5 and 10 5. The results revealed that for relatively high turbulence intensities of the outer jet a vortex is always present for velocity ratios of 6 or larger, and this is independent of the turbulence intensity ratio. When the turbulence intensity of the inner jet is kept constant and the ratio of turbulence intensities is increased, the recirculation zone decreases in size, its center moves further upstream until it disappears completely. The existence of a favorable pressure gradient as a similar effect, revealing that this is an additional parameter to be taken into consideration together with the velocity ratio and turbulence intensity ratio as far as the recirculation zone is concerned. |
publishDate |
2011 |
dc.date.none.fl_str_mv |
2011-07 2011-07-01T00:00:00Z 2060-07-01T00:00:00Z |
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/10400.6/11541 |
url |
http://hdl.handle.net/10400.6/11541 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
1970-8734 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/embargoedAccess |
eu_rights_str_mv |
embargoedAccess |
dc.format.none.fl_str_mv |
application/pdf |
dc.publisher.none.fl_str_mv |
Praise Worthy Prize |
publisher.none.fl_str_mv |
Praise Worthy Prize |
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) |
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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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1799136402623954944 |