Experimental investigation of intermittent airflow separation and microscale wave breaking in wavy two-phase pipe flow

We perform an experimental analysis of co-current, stratified wavy pipe flow, with the aim of investigating the effect of small scale wave breaking (microscale breaking) on the airflow. Particle image velocimetry is applied simultaneously in the gas and liquid phases. Active wave breaking is identif...

Full description

Saved in:
Bibliographic Details
Published in:Journal of fluid mechanics 2019-11, Vol.878, p.796-819
Main Authors: Vollestad, P., Ayati, A. A., Jensen, A.
Format: Article
Language:English
Subjects:
Aerodynamics
Air flow
Breaking waves
Flow rates
Flow separation
Flow velocity
Fluid dynamics
Friction
Gas flow
Inertia
Liquid phases
Particle image velocimetry
Phase velocity
Pipe flow
Simulation
Slopes
Stabilizing
Statistical analysis
Statistical methods
Temperature
Turbulence
Two phase flow
Velocity
Velocity distribution
Vorticity
Water waves
Wave breaking
Wave crest
Wave crests
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
cited_by cdi_FETCH-LOGICAL-c292t-197e5d770eeddcc43caa2693b478613e3671edf93252553e7519f3b46e400063
cites cdi_FETCH-LOGICAL-c292t-197e5d770eeddcc43caa2693b478613e3671edf93252553e7519f3b46e400063
container_end_page 819
container_issue
container_start_page 796
container_title Journal of fluid mechanics
container_volume 878
creator Vollestad, P.
Ayati, A. A.
Jensen, A.
description We perform an experimental analysis of co-current, stratified wavy pipe flow, with the aim of investigating the effect of small scale wave breaking (microscale breaking) on the airflow. Particle image velocimetry is applied simultaneously in the gas and liquid phases. Active wave breaking is identified by high levels of vorticity on the leeward side of individual waves, and the statistics of the airflow above breaking and non-breaking waves are extracted from the gas-phase velocity fields. Keeping the liquid superficial velocity constant ( $U_{sl}=0.1~\text{m}~\text{s}^{-1}$ ), we consider two experimental cases of different gas flow rates. The lowest flow rate ( $U_{sg}=1.85~\text{m}~\text{s}^{-1}$ ) is slightly higher than the onset of microscale breaking, while the higher flow rate ( $U_{sg}=2.20~\text{m}~\text{s}^{-1}$ ) is within the regime where wave breaking is observed to be frequent, and the root-mean-square interface elevation $\unicode[STIX]{x1D702}_{rms}$ is independent of gas flow rate. Results show that for the lowest gas flow rate considered, active wave breaking has a stabilizing effect on the airflow above the waves, reducing the sheltered region on the leeward side of the wave and the turbulence above the wave crest compared with non-breaking waves at similar steepness. At the higher gas flow rate the effect of active wave breaking is found to be small, and the main geometrical properties of the waves are found to dominate the evolution of the separated flow region.
doi_str_mv 10.1017/jfm.2019.660
format article
fullrecord <record><control><sourceid>proquest_crist</sourceid><recordid>TN_cdi_cristin_nora_10852_74877</recordid><sourceformat>XML</sourceformat><sourcesystem>PC</sourcesystem><sourcerecordid>2353052444</sourcerecordid><originalsourceid>FETCH-LOGICAL-c292t-197e5d770eeddcc43caa2693b478613e3671edf93252553e7519f3b46e400063</originalsourceid><addsrcrecordid>eNo1kEtPwzAQhC0EEqVw444lrqT47eaIKl5SJS69W26yKS5JHGy3pf8eR4XTSrOzo50PoVtKZpRQ_bhtuhkjtJwpRc7QhApVFloJeY4mhDBWUMrIJbqKcUsI5aTUE7R__hkguA76ZFvs-j3E5DY2Od9j32QhQehcSnmPrQtN6w84wmDDyWL7GneuCj5WtgV8sHvA6wD2y_WbfDwKR5wOvhg-bQQ8uAHwmHGNLhrbRrj5m1O0enleLd6K5cfr--JpWVSsZKmgpQZZa00A6rqqBK-sZarka6HninLgSlOom5IzyaTkoCUtm7xVIAghik_R3Sm2Ci736k3vgzWUzCUzWsy1zo77k2MI_nuXy5ut34U-_2QYl5xIJoTIrof_HB9jgMYMmZkNx5xlRvQmozcjepPR81_mAXd0</addsrcrecordid><sourcetype>Open Access Repository</sourcetype><iscdi>true</iscdi><recordtype>article</recordtype><pqid>2353052444</pqid></control><display><type>article</type><title>Experimental investigation of intermittent airflow separation and microscale wave breaking in wavy two-phase pipe flow</title><source>NORA - Norwegian Open Research Archives</source><source>Cambridge University Press</source><creator>Vollestad, P. ; Ayati, A. A. ; Jensen, A.</creator><creatorcontrib>Vollestad, P. ; Ayati, A. A. ; Jensen, A.</creatorcontrib><description>We perform an experimental analysis of co-current, stratified wavy pipe flow, with the aim of investigating the effect of small scale wave breaking (microscale breaking) on the airflow. Particle image velocimetry is applied simultaneously in the gas and liquid phases. Active wave breaking is identified by high levels of vorticity on the leeward side of individual waves, and the statistics of the airflow above breaking and non-breaking waves are extracted from the gas-phase velocity fields. Keeping the liquid superficial velocity constant ( $U_{sl}=0.1~\text{m}~\text{s}^{-1}$ ), we consider two experimental cases of different gas flow rates. The lowest flow rate ( $U_{sg}=1.85~\text{m}~\text{s}^{-1}$ ) is slightly higher than the onset of microscale breaking, while the higher flow rate ( $U_{sg}=2.20~\text{m}~\text{s}^{-1}$ ) is within the regime where wave breaking is observed to be frequent, and the root-mean-square interface elevation $\unicode[STIX]{x1D702}_{rms}$ is independent of gas flow rate. Results show that for the lowest gas flow rate considered, active wave breaking has a stabilizing effect on the airflow above the waves, reducing the sheltered region on the leeward side of the wave and the turbulence above the wave crest compared with non-breaking waves at similar steepness. At the higher gas flow rate the effect of active wave breaking is found to be small, and the main geometrical properties of the waves are found to dominate the evolution of the separated flow region.</description><identifier>ISSN: 0022-1120</identifier><identifier>EISSN: 1469-7645</identifier><identifier>DOI: 10.1017/jfm.2019.660</identifier><language>eng</language><publisher>Cambridge: Cambridge University Press</publisher><subject>Aerodynamics ; Air flow ; Breaking waves ; Flow rates ; Flow separation ; Flow velocity ; Fluid dynamics ; Friction ; Gas flow ; Inertia ; Liquid phases ; Particle image velocimetry ; Phase velocity ; Pipe flow ; Simulation ; Slopes ; Stabilizing ; Statistical analysis ; Statistical methods ; Temperature ; Turbulence ; Two phase flow ; Velocity ; Velocity distribution ; Vorticity ; Water waves ; Wave breaking ; Wave crest ; Wave crests</subject><ispartof>Journal of fluid mechanics, 2019-11, Vol.878, p.796-819</ispartof><rights>2019 Cambridge University Press</rights><rights>info:eu-repo/semantics/openAccess</rights><lds50>peer_reviewed</lds50><oa>free_for_read</oa><woscitedreferencessubscribed>false</woscitedreferencessubscribed><citedby>FETCH-LOGICAL-c292t-197e5d770eeddcc43caa2693b478613e3671edf93252553e7519f3b46e400063</citedby><cites>FETCH-LOGICAL-c292t-197e5d770eeddcc43caa2693b478613e3671edf93252553e7519f3b46e400063</cites><orcidid>0000-0003-2105-991X</orcidid></display><links><openurl>$$Topenurl_article</openurl><openurlfulltext>$$Topenurlfull_article</openurlfulltext><thumbnail>$$Tsyndetics_thumb_exl</thumbnail><link.rule.ids>230,314,780,784,885,26567,27924,27925</link.rule.ids></links><search><creatorcontrib>Vollestad, P.</creatorcontrib><creatorcontrib>Ayati, A. A.</creatorcontrib><creatorcontrib>Jensen, A.</creatorcontrib><title>Experimental investigation of intermittent airflow separation and microscale wave breaking in wavy two-phase pipe flow</title><title>Journal of fluid mechanics</title><description>We perform an experimental analysis of co-current, stratified wavy pipe flow, with the aim of investigating the effect of small scale wave breaking (microscale breaking) on the airflow. Particle image velocimetry is applied simultaneously in the gas and liquid phases. Active wave breaking is identified by high levels of vorticity on the leeward side of individual waves, and the statistics of the airflow above breaking and non-breaking waves are extracted from the gas-phase velocity fields. Keeping the liquid superficial velocity constant ( $U_{sl}=0.1~\text{m}~\text{s}^{-1}$ ), we consider two experimental cases of different gas flow rates. The lowest flow rate ( $U_{sg}=1.85~\text{m}~\text{s}^{-1}$ ) is slightly higher than the onset of microscale breaking, while the higher flow rate ( $U_{sg}=2.20~\text{m}~\text{s}^{-1}$ ) is within the regime where wave breaking is observed to be frequent, and the root-mean-square interface elevation $\unicode[STIX]{x1D702}_{rms}$ is independent of gas flow rate. Results show that for the lowest gas flow rate considered, active wave breaking has a stabilizing effect on the airflow above the waves, reducing the sheltered region on the leeward side of the wave and the turbulence above the wave crest compared with non-breaking waves at similar steepness. At the higher gas flow rate the effect of active wave breaking is found to be small, and the main geometrical properties of the waves are found to dominate the evolution of the separated flow region.</description><subject>Aerodynamics</subject><subject>Air flow</subject><subject>Breaking waves</subject><subject>Flow rates</subject><subject>Flow separation</subject><subject>Flow velocity</subject><subject>Fluid dynamics</subject><subject>Friction</subject><subject>Gas flow</subject><subject>Inertia</subject><subject>Liquid phases</subject><subject>Particle image velocimetry</subject><subject>Phase velocity</subject><subject>Pipe flow</subject><subject>Simulation</subject><subject>Slopes</subject><subject>Stabilizing</subject><subject>Statistical analysis</subject><subject>Statistical methods</subject><subject>Temperature</subject><subject>Turbulence</subject><subject>Two phase flow</subject><subject>Velocity</subject><subject>Velocity distribution</subject><subject>Vorticity</subject><subject>Water waves</subject><subject>Wave breaking</subject><subject>Wave crest</subject><subject>Wave crests</subject><issn>0022-1120</issn><issn>1469-7645</issn><fulltext>true</fulltext><rsrctype>article</rsrctype><creationdate>2019</creationdate><recordtype>article</recordtype><sourceid>3HK</sourceid><recordid>eNo1kEtPwzAQhC0EEqVw444lrqT47eaIKl5SJS69W26yKS5JHGy3pf8eR4XTSrOzo50PoVtKZpRQ_bhtuhkjtJwpRc7QhApVFloJeY4mhDBWUMrIJbqKcUsI5aTUE7R__hkguA76ZFvs-j3E5DY2Od9j32QhQehcSnmPrQtN6w84wmDDyWL7GneuCj5WtgV8sHvA6wD2y_WbfDwKR5wOvhg-bQQ8uAHwmHGNLhrbRrj5m1O0enleLd6K5cfr--JpWVSsZKmgpQZZa00A6rqqBK-sZarka6HninLgSlOom5IzyaTkoCUtm7xVIAghik_R3Sm2Ci736k3vgzWUzCUzWsy1zo77k2MI_nuXy5ut34U-_2QYl5xIJoTIrof_HB9jgMYMmZkNx5xlRvQmozcjepPR81_mAXd0</recordid><startdate>20191110</startdate><enddate>20191110</enddate><creator>Vollestad, P.</creator><creator>Ayati, A. A.</creator><creator>Jensen, A.</creator><general>Cambridge University Press</general><scope>AAYXX</scope><scope>CITATION</scope><scope>3V.</scope><scope>7TB</scope><scope>7U5</scope><scope>7UA</scope><scope>7XB</scope><scope>88I</scope><scope>8FD</scope><scope>8FE</scope><scope>8FG</scope><scope>8FK</scope><scope>8G5</scope><scope>ABJCF</scope><scope>ABUWG</scope><scope>AEUYN</scope><scope>AFKRA</scope><scope>ARAPS</scope><scope>AZQEC</scope><scope>BENPR</scope><scope>BGLVJ</scope><scope>BHPHI</scope><scope>BKSAR</scope><scope>C1K</scope><scope>CCPQU</scope><scope>DWQXO</scope><scope>F1W</scope><scope>FR3</scope><scope>GNUQQ</scope><scope>GUQSH</scope><scope>H8D</scope><scope>H96</scope><scope>HCIFZ</scope><scope>KR7</scope><scope>L.G</scope><scope>L6V</scope><scope>L7M</scope><scope>M2O</scope><scope>M2P</scope><scope>M7S</scope><scope>MBDVC</scope><scope>P5Z</scope><scope>P62</scope><scope>PCBAR</scope><scope>PQEST</scope><scope>PQQKQ</scope><scope>PQUKI</scope><scope>PTHSS</scope><scope>Q9U</scope><scope>S0W</scope><scope>3HK</scope><orcidid>https://orcid.org/0000-0003-2105-991X</orcidid></search><sort><creationdate>20191110</creationdate><title>Experimental investigation of intermittent airflow separation and microscale wave breaking in wavy two-phase pipe flow</title><author>Vollestad, P. ; Ayati, A. A. ; Jensen, A.</author></sort><facets><frbrtype>5</frbrtype><frbrgroupid>cdi_FETCH-LOGICAL-c292t-197e5d770eeddcc43caa2693b478613e3671edf93252553e7519f3b46e400063</frbrgroupid><rsrctype>articles</rsrctype><prefilter>articles</prefilter><language>eng</language><creationdate>2019</creationdate><topic>Aerodynamics</topic><topic>Air flow</topic><topic>Breaking waves</topic><topic>Flow rates</topic><topic>Flow separation</topic><topic>Flow velocity</topic><topic>Fluid dynamics</topic><topic>Friction</topic><topic>Gas flow</topic><topic>Inertia</topic><topic>Liquid phases</topic><topic>Particle image velocimetry</topic><topic>Phase velocity</topic><topic>Pipe flow</topic><topic>Simulation</topic><topic>Slopes</topic><topic>Stabilizing</topic><topic>Statistical analysis</topic><topic>Statistical methods</topic><topic>Temperature</topic><topic>Turbulence</topic><topic>Two phase flow</topic><topic>Velocity</topic><topic>Velocity distribution</topic><topic>Vorticity</topic><topic>Water waves</topic><topic>Wave breaking</topic><topic>Wave crest</topic><topic>Wave crests</topic><toplevel>peer_reviewed</toplevel><toplevel>online_resources</toplevel><creatorcontrib>Vollestad, P.</creatorcontrib><creatorcontrib>Ayati, A. A.</creatorcontrib><creatorcontrib>Jensen, A.</creatorcontrib><collection>CrossRef</collection><collection>ProQuest Central (Corporate)</collection><collection>Mechanical &amp; Transportation Engineering Abstracts</collection><collection>Solid State and Superconductivity Abstracts</collection><collection>Water Resources Abstracts</collection><collection>ProQuest Central (purchase pre-March 2016)</collection><collection>Science Database (Alumni Edition)</collection><collection>Technology Research Database</collection><collection>ProQuest SciTech Collection</collection><collection>ProQuest Technology Collection</collection><collection>ProQuest Central (Alumni) (purchase pre-March 2016)</collection><collection>Research Library (Alumni Edition)</collection><collection>Materials Science &amp; Engineering Collection</collection><collection>ProQuest Central (Alumni)</collection><collection>ProQuest One Sustainability</collection><collection>ProQuest Central</collection><collection>Advanced Technologies &amp; Aerospace Collection</collection><collection>ProQuest Central Essentials</collection><collection>AUTh Library subscriptions: ProQuest Central</collection><collection>Technology Collection</collection><collection>ProQuest Natural Science Collection</collection><collection>Earth, Atmospheric &amp; Aquatic Science Collection</collection><collection>Environmental Sciences and Pollution Management</collection><collection>ProQuest One Community College</collection><collection>ProQuest Central</collection><collection>ASFA: Aquatic Sciences and Fisheries Abstracts</collection><collection>Engineering Research Database</collection><collection>ProQuest Central Student</collection><collection>Research Library Prep</collection><collection>Aerospace Database</collection><collection>Aquatic Science &amp; Fisheries Abstracts (ASFA) 2: Ocean Technology, Policy &amp; Non-Living Resources</collection><collection>SciTech Premium Collection (Proquest) (PQ_SDU_P3)</collection><collection>Civil Engineering Abstracts</collection><collection>Aquatic Science &amp; Fisheries Abstracts (ASFA) Professional</collection><collection>ProQuest Engineering Collection</collection><collection>Advanced Technologies Database with Aerospace</collection><collection>ProQuest Research Library</collection><collection>ProQuest Science Journals</collection><collection>ProQuest Engineering Database</collection><collection>Research Library (Corporate)</collection><collection>ProQuest Advanced Technologies &amp; Aerospace Database</collection><collection>ProQuest Advanced Technologies &amp; Aerospace Collection</collection><collection>Earth, Atmospheric &amp; Aquatic Science Database</collection><collection>ProQuest One Academic Eastern Edition (DO NOT USE)</collection><collection>ProQuest One Academic</collection><collection>ProQuest One Academic UKI Edition</collection><collection>Engineering Collection</collection><collection>ProQuest Central Basic</collection><collection>DELNET Engineering &amp; Technology Collection</collection><collection>NORA - Norwegian Open Research Archives</collection><jtitle>Journal of fluid mechanics</jtitle></facets><delivery><delcategory>Remote Search Resource</delcategory><fulltext>fulltext</fulltext></delivery><addata><au>Vollestad, P.</au><au>Ayati, A. A.</au><au>Jensen, A.</au><format>journal</format><genre>article</genre><ristype>JOUR</ristype><atitle>Experimental investigation of intermittent airflow separation and microscale wave breaking in wavy two-phase pipe flow</atitle><jtitle>Journal of fluid mechanics</jtitle><date>2019-11-10</date><risdate>2019</risdate><volume>878</volume><spage>796</spage><epage>819</epage><pages>796-819</pages><issn>0022-1120</issn><eissn>1469-7645</eissn><abstract>We perform an experimental analysis of co-current, stratified wavy pipe flow, with the aim of investigating the effect of small scale wave breaking (microscale breaking) on the airflow. Particle image velocimetry is applied simultaneously in the gas and liquid phases. Active wave breaking is identified by high levels of vorticity on the leeward side of individual waves, and the statistics of the airflow above breaking and non-breaking waves are extracted from the gas-phase velocity fields. Keeping the liquid superficial velocity constant ( $U_{sl}=0.1~\text{m}~\text{s}^{-1}$ ), we consider two experimental cases of different gas flow rates. The lowest flow rate ( $U_{sg}=1.85~\text{m}~\text{s}^{-1}$ ) is slightly higher than the onset of microscale breaking, while the higher flow rate ( $U_{sg}=2.20~\text{m}~\text{s}^{-1}$ ) is within the regime where wave breaking is observed to be frequent, and the root-mean-square interface elevation $\unicode[STIX]{x1D702}_{rms}$ is independent of gas flow rate. Results show that for the lowest gas flow rate considered, active wave breaking has a stabilizing effect on the airflow above the waves, reducing the sheltered region on the leeward side of the wave and the turbulence above the wave crest compared with non-breaking waves at similar steepness. At the higher gas flow rate the effect of active wave breaking is found to be small, and the main geometrical properties of the waves are found to dominate the evolution of the separated flow region.</abstract><cop>Cambridge</cop><pub>Cambridge University Press</pub><doi>10.1017/jfm.2019.660</doi><tpages>24</tpages><orcidid>https://orcid.org/0000-0003-2105-991X</orcidid><oa>free_for_read</oa></addata></record>
fulltext fulltext
identifier ISSN: 0022-1120
ispartof Journal of fluid mechanics, 2019-11, Vol.878, p.796-819
issn 0022-1120
1469-7645
language eng
recordid cdi_cristin_nora_10852_74877
source NORA - Norwegian Open Research Archives; Cambridge University Press
subjects Aerodynamics
Air flow
Breaking waves
Flow rates
Flow separation
Flow velocity
Fluid dynamics
Friction
Gas flow
Inertia
Liquid phases
Particle image velocimetry
Phase velocity
Pipe flow
Simulation
Slopes
Stabilizing
Statistical analysis
Statistical methods
Temperature
Turbulence
Two phase flow
Velocity
Velocity distribution
Vorticity
Water waves
Wave breaking
Wave crest
Wave crests
title Experimental investigation of intermittent airflow separation and microscale wave breaking in wavy two-phase pipe flow
url http://sfxeu10.hosted.exlibrisgroup.com/loughborough?ctx_ver=Z39.88-2004&ctx_enc=info:ofi/enc:UTF-8&ctx_tim=2025-01-07T19%3A51%3A30IST&url_ver=Z39.88-2004&url_ctx_fmt=infofi/fmt:kev:mtx:ctx&rfr_id=info:sid/primo.exlibrisgroup.com:primo3-Article-proquest_crist&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.genre=article&rft.atitle=Experimental%20investigation%20of%20intermittent%20airflow%20separation%20and%20microscale%20wave%20breaking%20in%20wavy%20two-phase%20pipe%20flow&rft.jtitle=Journal%20of%20fluid%20mechanics&rft.au=Vollestad,%20P.&rft.date=2019-11-10&rft.volume=878&rft.spage=796&rft.epage=819&rft.pages=796-819&rft.issn=0022-1120&rft.eissn=1469-7645&rft_id=info:doi/10.1017/jfm.2019.660&rft_dat=%3Cproquest_crist%3E2353052444%3C/proquest_crist%3E%3Cgrp_id%3Ecdi_FETCH-LOGICAL-c292t-197e5d770eeddcc43caa2693b478613e3671edf93252553e7519f3b46e400063%3C/grp_id%3E%3Coa%3E%3C/oa%3E%3Curl%3E%3C/url%3E&rft_id=info:oai/&rft_pqid=2353052444&rft_id=info:pmid/&rfr_iscdi=true