DETERMINATION OF THE EFFECTIVE RADIAL THERMAL DIFFUSIVITY FOR EVALUATING ENHANCED HEAT TRANSFER IN TUBES UNDER NON-NEWTONIAN LAMINAR FLOW

Detalhes bibliográficos
Autor(a) principal: Morais,A. O.
Data de Publicação: 2015
Outros Autores: Gut,J. A. W.
Tipo de documento: Artigo
Idioma: eng
Título da fonte: Brazilian Journal of Chemical Engineering
Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0104-66322015000200445
Resumo: AbstractEnhanced heat transfer in tubes under laminar flow conditions can be found in coils or corrugated tubes or in the presence of high wall relative roughness, curves, pipe fittings or mechanical vibration. Modeling these cases can be complex because of the induced secondary flow. A modification of the Graetz problem for non-Newtonian power-law flow is proposed to take into account the augmented heat transfer by the introduction of an effective radial thermal diffusivity. The induced mixing was modeled as an increased radial heat transfer in a straight tube. Three experiments using a coiled tube and a tubular heat exchanger with high relative wall roughness are presented in order to show how this parameter can be obtained. Results were successfully correlated with Reynolds number. This approach can be useful for modeling laminar flow reactors (LFR) and tubular heat exchangers available in the chemical and food industries.
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spelling DETERMINATION OF THE EFFECTIVE RADIAL THERMAL DIFFUSIVITY FOR EVALUATING ENHANCED HEAT TRANSFER IN TUBES UNDER NON-NEWTONIAN LAMINAR FLOWHeat transferLaminar flowDiffusivityLaminar flow reactorGraetz problemAbstractEnhanced heat transfer in tubes under laminar flow conditions can be found in coils or corrugated tubes or in the presence of high wall relative roughness, curves, pipe fittings or mechanical vibration. Modeling these cases can be complex because of the induced secondary flow. A modification of the Graetz problem for non-Newtonian power-law flow is proposed to take into account the augmented heat transfer by the introduction of an effective radial thermal diffusivity. The induced mixing was modeled as an increased radial heat transfer in a straight tube. Three experiments using a coiled tube and a tubular heat exchanger with high relative wall roughness are presented in order to show how this parameter can be obtained. Results were successfully correlated with Reynolds number. This approach can be useful for modeling laminar flow reactors (LFR) and tubular heat exchangers available in the chemical and food industries.Brazilian Society of Chemical Engineering2015-06-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersiontext/htmlhttp://old.scielo.br/scielo.php?script=sci_arttext&pid=S0104-66322015000200445Brazilian Journal of Chemical Engineering v.32 n.2 2015reponame:Brazilian Journal of Chemical Engineeringinstname:Associação Brasileira de Engenharia Química (ABEQ)instacron:ABEQ10.1590/0104-6632.20150322s00003318info:eu-repo/semantics/openAccessMorais,A. O.Gut,J. A. W.eng2015-10-08T00:00:00Zoai:scielo:S0104-66322015000200445Revistahttps://www.scielo.br/j/bjce/https://old.scielo.br/oai/scielo-oai.phprgiudici@usp.br||rgiudici@usp.br1678-43830104-6632opendoar:2015-10-08T00:00Brazilian Journal of Chemical Engineering - Associação Brasileira de Engenharia Química (ABEQ)false
dc.title.none.fl_str_mv DETERMINATION OF THE EFFECTIVE RADIAL THERMAL DIFFUSIVITY FOR EVALUATING ENHANCED HEAT TRANSFER IN TUBES UNDER NON-NEWTONIAN LAMINAR FLOW
title DETERMINATION OF THE EFFECTIVE RADIAL THERMAL DIFFUSIVITY FOR EVALUATING ENHANCED HEAT TRANSFER IN TUBES UNDER NON-NEWTONIAN LAMINAR FLOW
spellingShingle DETERMINATION OF THE EFFECTIVE RADIAL THERMAL DIFFUSIVITY FOR EVALUATING ENHANCED HEAT TRANSFER IN TUBES UNDER NON-NEWTONIAN LAMINAR FLOW
Morais,A. O.
Heat transfer
Laminar flow
Diffusivity
Laminar flow reactor
Graetz problem
title_short DETERMINATION OF THE EFFECTIVE RADIAL THERMAL DIFFUSIVITY FOR EVALUATING ENHANCED HEAT TRANSFER IN TUBES UNDER NON-NEWTONIAN LAMINAR FLOW
title_full DETERMINATION OF THE EFFECTIVE RADIAL THERMAL DIFFUSIVITY FOR EVALUATING ENHANCED HEAT TRANSFER IN TUBES UNDER NON-NEWTONIAN LAMINAR FLOW
title_fullStr DETERMINATION OF THE EFFECTIVE RADIAL THERMAL DIFFUSIVITY FOR EVALUATING ENHANCED HEAT TRANSFER IN TUBES UNDER NON-NEWTONIAN LAMINAR FLOW
title_full_unstemmed DETERMINATION OF THE EFFECTIVE RADIAL THERMAL DIFFUSIVITY FOR EVALUATING ENHANCED HEAT TRANSFER IN TUBES UNDER NON-NEWTONIAN LAMINAR FLOW
title_sort DETERMINATION OF THE EFFECTIVE RADIAL THERMAL DIFFUSIVITY FOR EVALUATING ENHANCED HEAT TRANSFER IN TUBES UNDER NON-NEWTONIAN LAMINAR FLOW
author Morais,A. O.
author_facet Morais,A. O.
Gut,J. A. W.
author_role author
author2 Gut,J. A. W.
author2_role author
dc.contributor.author.fl_str_mv Morais,A. O.
Gut,J. A. W.
dc.subject.por.fl_str_mv Heat transfer
Laminar flow
Diffusivity
Laminar flow reactor
Graetz problem
topic Heat transfer
Laminar flow
Diffusivity
Laminar flow reactor
Graetz problem
description AbstractEnhanced heat transfer in tubes under laminar flow conditions can be found in coils or corrugated tubes or in the presence of high wall relative roughness, curves, pipe fittings or mechanical vibration. Modeling these cases can be complex because of the induced secondary flow. A modification of the Graetz problem for non-Newtonian power-law flow is proposed to take into account the augmented heat transfer by the introduction of an effective radial thermal diffusivity. The induced mixing was modeled as an increased radial heat transfer in a straight tube. Three experiments using a coiled tube and a tubular heat exchanger with high relative wall roughness are presented in order to show how this parameter can be obtained. Results were successfully correlated with Reynolds number. This approach can be useful for modeling laminar flow reactors (LFR) and tubular heat exchangers available in the chemical and food industries.
publishDate 2015
dc.date.none.fl_str_mv 2015-06-01
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=S0104-66322015000200445
url http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0104-66322015000200445
dc.language.iso.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv 10.1590/0104-6632.20150322s00003318
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 Brazilian Society of Chemical Engineering
publisher.none.fl_str_mv Brazilian Society of Chemical Engineering
dc.source.none.fl_str_mv Brazilian Journal of Chemical Engineering v.32 n.2 2015
reponame:Brazilian Journal of Chemical Engineering
instname:Associação Brasileira de Engenharia Química (ABEQ)
instacron:ABEQ
instname_str Associação Brasileira de Engenharia Química (ABEQ)
instacron_str ABEQ
institution ABEQ
reponame_str Brazilian Journal of Chemical Engineering
collection Brazilian Journal of Chemical Engineering
repository.name.fl_str_mv Brazilian Journal of Chemical Engineering - Associação Brasileira de Engenharia Química (ABEQ)
repository.mail.fl_str_mv rgiudici@usp.br||rgiudici@usp.br
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