DIFFERENT STAGES OF LIQUID FILM GROWTH IN A MICROCHANNEL: TWO-PHASE LATTICE BOLTZMANN STUDY
Autor(a) principal: | |
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Data de Publicação: | 2018 |
Outros Autores: | , , |
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=S0104-66322018000300977 |
Resumo: | Abstract A free energy model is used to describe the droplet formation and break-up process in a T-junction bio-microchannel. Droplets are created as a result of interaction of two immiscible liquids. Different stages for the droplet formation process are analyzed which are: a) growing in the x and y directions, b) growing in the x direction and c) detachment process. The effects of capillary number and flow rate ratio on the droplet formation stages are also studied. The influences of Capillary number, flow rate ratio, viscosity ratio and geometrical parameters on droplet break up, droplet size and detachment time are systematically studied. By increasing the flow rate ratio; the duration of droplet formation and the length of the x-growth stage are decreased for small capillary numbers. For larger capillary numbers; the droplet penetrates toward the downstream; therefore, the length of the x-growth stage is increased. The start of detachment process in the microchannel is also reported, which is related to narrowing of the neck of the liquid film. The results show that the detachment time is increased by decreasing the Capillary number. For Ca>0.02, the detachment time is independent of the flow rate ratios. Moreover; the effects of viscosity ratios on detachment time are not significant in comparison to the effects of capillary number. For Ca<0.04, the size of the droplet is independent of the viscosity ratio, but after the critical Capillary number (i.e., Ca=0.04), the size of the droplet is varied by the viscosity ratio. The time between two consecutive drops is also decreased by increasing the Capillary number. Moreover, this time is decreased by increasing the flow rate ratio until Ca=0.04. After this Capillary number, the flow rate ratios have no significant effect on the time between two consecutive droplets. An exhaustive validation study is performed including (a) the Laplace equation in the stationary droplet; (b) a contact angle test; (c) Taylor deformation test in shear flow and (d) comparison of the droplet length as a function of flow rate ratio between the present work and other studies. |
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Brazilian Journal of Chemical Engineering |
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DIFFERENT STAGES OF LIQUID FILM GROWTH IN A MICROCHANNEL: TWO-PHASE LATTICE BOLTZMANN STUDYStages of Liquid Film GrowthMicrochannelLattice Boltzmann MethodCritical Capillary numberAbstract A free energy model is used to describe the droplet formation and break-up process in a T-junction bio-microchannel. Droplets are created as a result of interaction of two immiscible liquids. Different stages for the droplet formation process are analyzed which are: a) growing in the x and y directions, b) growing in the x direction and c) detachment process. The effects of capillary number and flow rate ratio on the droplet formation stages are also studied. The influences of Capillary number, flow rate ratio, viscosity ratio and geometrical parameters on droplet break up, droplet size and detachment time are systematically studied. By increasing the flow rate ratio; the duration of droplet formation and the length of the x-growth stage are decreased for small capillary numbers. For larger capillary numbers; the droplet penetrates toward the downstream; therefore, the length of the x-growth stage is increased. The start of detachment process in the microchannel is also reported, which is related to narrowing of the neck of the liquid film. The results show that the detachment time is increased by decreasing the Capillary number. For Ca>0.02, the detachment time is independent of the flow rate ratios. Moreover; the effects of viscosity ratios on detachment time are not significant in comparison to the effects of capillary number. For Ca<0.04, the size of the droplet is independent of the viscosity ratio, but after the critical Capillary number (i.e., Ca=0.04), the size of the droplet is varied by the viscosity ratio. The time between two consecutive drops is also decreased by increasing the Capillary number. Moreover, this time is decreased by increasing the flow rate ratio until Ca=0.04. After this Capillary number, the flow rate ratios have no significant effect on the time between two consecutive droplets. An exhaustive validation study is performed including (a) the Laplace equation in the stationary droplet; (b) a contact angle test; (c) Taylor deformation test in shear flow and (d) comparison of the droplet length as a function of flow rate ratio between the present work and other studies.Brazilian Society of Chemical Engineering2018-09-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersiontext/htmlhttp://old.scielo.br/scielo.php?script=sci_arttext&pid=S0104-66322018000300977Brazilian Journal of Chemical Engineering v.35 n.3 2018reponame:Brazilian Journal of Chemical Engineeringinstname:Associação Brasileira de Engenharia Química (ABEQ)instacron:ABEQ10.1590/0104-6632.20180353s20160700info:eu-repo/semantics/openAccessNazari,MohsenSani,Hajar MohamadzadeKayhani,Mohammad HassanDaghighi,Yasamaneng2019-01-15T00:00:00Zoai:scielo:S0104-66322018000300977Revistahttps://www.scielo.br/j/bjce/https://old.scielo.br/oai/scielo-oai.phprgiudici@usp.br||rgiudici@usp.br1678-43830104-6632opendoar:2019-01-15T00:00Brazilian Journal of Chemical Engineering - Associação Brasileira de Engenharia Química (ABEQ)false |
dc.title.none.fl_str_mv |
DIFFERENT STAGES OF LIQUID FILM GROWTH IN A MICROCHANNEL: TWO-PHASE LATTICE BOLTZMANN STUDY |
title |
DIFFERENT STAGES OF LIQUID FILM GROWTH IN A MICROCHANNEL: TWO-PHASE LATTICE BOLTZMANN STUDY |
spellingShingle |
DIFFERENT STAGES OF LIQUID FILM GROWTH IN A MICROCHANNEL: TWO-PHASE LATTICE BOLTZMANN STUDY Nazari,Mohsen Stages of Liquid Film Growth Microchannel Lattice Boltzmann Method Critical Capillary number |
title_short |
DIFFERENT STAGES OF LIQUID FILM GROWTH IN A MICROCHANNEL: TWO-PHASE LATTICE BOLTZMANN STUDY |
title_full |
DIFFERENT STAGES OF LIQUID FILM GROWTH IN A MICROCHANNEL: TWO-PHASE LATTICE BOLTZMANN STUDY |
title_fullStr |
DIFFERENT STAGES OF LIQUID FILM GROWTH IN A MICROCHANNEL: TWO-PHASE LATTICE BOLTZMANN STUDY |
title_full_unstemmed |
DIFFERENT STAGES OF LIQUID FILM GROWTH IN A MICROCHANNEL: TWO-PHASE LATTICE BOLTZMANN STUDY |
title_sort |
DIFFERENT STAGES OF LIQUID FILM GROWTH IN A MICROCHANNEL: TWO-PHASE LATTICE BOLTZMANN STUDY |
author |
Nazari,Mohsen |
author_facet |
Nazari,Mohsen Sani,Hajar Mohamadzade Kayhani,Mohammad Hassan Daghighi,Yasaman |
author_role |
author |
author2 |
Sani,Hajar Mohamadzade Kayhani,Mohammad Hassan Daghighi,Yasaman |
author2_role |
author author author |
dc.contributor.author.fl_str_mv |
Nazari,Mohsen Sani,Hajar Mohamadzade Kayhani,Mohammad Hassan Daghighi,Yasaman |
dc.subject.por.fl_str_mv |
Stages of Liquid Film Growth Microchannel Lattice Boltzmann Method Critical Capillary number |
topic |
Stages of Liquid Film Growth Microchannel Lattice Boltzmann Method Critical Capillary number |
description |
Abstract A free energy model is used to describe the droplet formation and break-up process in a T-junction bio-microchannel. Droplets are created as a result of interaction of two immiscible liquids. Different stages for the droplet formation process are analyzed which are: a) growing in the x and y directions, b) growing in the x direction and c) detachment process. The effects of capillary number and flow rate ratio on the droplet formation stages are also studied. The influences of Capillary number, flow rate ratio, viscosity ratio and geometrical parameters on droplet break up, droplet size and detachment time are systematically studied. By increasing the flow rate ratio; the duration of droplet formation and the length of the x-growth stage are decreased for small capillary numbers. For larger capillary numbers; the droplet penetrates toward the downstream; therefore, the length of the x-growth stage is increased. The start of detachment process in the microchannel is also reported, which is related to narrowing of the neck of the liquid film. The results show that the detachment time is increased by decreasing the Capillary number. For Ca>0.02, the detachment time is independent of the flow rate ratios. Moreover; the effects of viscosity ratios on detachment time are not significant in comparison to the effects of capillary number. For Ca<0.04, the size of the droplet is independent of the viscosity ratio, but after the critical Capillary number (i.e., Ca=0.04), the size of the droplet is varied by the viscosity ratio. The time between two consecutive drops is also decreased by increasing the Capillary number. Moreover, this time is decreased by increasing the flow rate ratio until Ca=0.04. After this Capillary number, the flow rate ratios have no significant effect on the time between two consecutive droplets. An exhaustive validation study is performed including (a) the Laplace equation in the stationary droplet; (b) a contact angle test; (c) Taylor deformation test in shear flow and (d) comparison of the droplet length as a function of flow rate ratio between the present work and other studies. |
publishDate |
2018 |
dc.date.none.fl_str_mv |
2018-09-01 |
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=S0104-66322018000300977 |
url |
http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0104-66322018000300977 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
10.1590/0104-6632.20180353s20160700 |
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.35 n.3 2018 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 |
_version_ |
1754213175979409408 |