Tip opening of premixed bunsen flames: Extinction with negative stretch and local Karlovitz number

Handle URI:
http://hdl.handle.net/10754/564133
Title:
Tip opening of premixed bunsen flames: Extinction with negative stretch and local Karlovitz number
Authors:
Vu, Tranmanh; Cha, Min Suk ( 0000-0003-4059-3421 ) ; Lee, Byeongjun; Chung, Suk-Ho ( 0000-0001-8782-312X )
Abstract:
The characteristics of tip openings in premixed bunsen flames have been studied experimentally by measuring OH radicals from laser-induced fluorescence and tip curvatures from chemiluminescent images. Results showed that the tip opening occurred at a constant equivalence ratio and was independent of the jet velocity in propane/air mixtures. The observation of a local extinction phenomenon of the negatively stretched flame due to the flame curvature could not be consistently explained based on flame stretch or the Karlovitz number, since they varied appreciably with the jet velocity. The concept of the local Karlovitz number (KaL) was introduced, which is defined as the ratio of the characteristic reaction time in the normal direction for a stretched flame to the characteristic flow time in the tangential direction for the stretched flame. The local Karlovitz number maintained a constant value under tip opening conditions, irrespective of the jet velocity. Tip opening occurred at a reasonably constant local Karlovitz number of about ~1.72 when the nitrogen dilution level in propane and n-butane fuels was varied.
KAUST Department:
Clean Combustion Research Center; Physical Sciences and Engineering (PSE) Division; Mechanical Engineering Program; Combustion and Laser Diagnostics Laboratory
Publisher:
Elsevier BV
Journal:
Combustion and Flame
Issue Date:
Apr-2015
DOI:
10.1016/j.combustflame.2014.11.022
Type:
Article
ISSN:
00102180
Sponsors:
Research reported in this publication was supported by Competitive Research Funding from King Abdullah University of Science and Technology (KAUST).
Appears in Collections:
Articles; Physical Sciences and Engineering (PSE) Division; Mechanical Engineering Program; Clean Combustion Research Center

Full metadata record

DC FieldValue Language
dc.contributor.authorVu, Tranmanhen
dc.contributor.authorCha, Min Suken
dc.contributor.authorLee, Byeongjunen
dc.contributor.authorChung, Suk-Hoen
dc.date.accessioned2015-08-03T12:33:32Zen
dc.date.available2015-08-03T12:33:32Zen
dc.date.issued2015-04en
dc.identifier.issn00102180en
dc.identifier.doi10.1016/j.combustflame.2014.11.022en
dc.identifier.urihttp://hdl.handle.net/10754/564133en
dc.description.abstractThe characteristics of tip openings in premixed bunsen flames have been studied experimentally by measuring OH radicals from laser-induced fluorescence and tip curvatures from chemiluminescent images. Results showed that the tip opening occurred at a constant equivalence ratio and was independent of the jet velocity in propane/air mixtures. The observation of a local extinction phenomenon of the negatively stretched flame due to the flame curvature could not be consistently explained based on flame stretch or the Karlovitz number, since they varied appreciably with the jet velocity. The concept of the local Karlovitz number (KaL) was introduced, which is defined as the ratio of the characteristic reaction time in the normal direction for a stretched flame to the characteristic flow time in the tangential direction for the stretched flame. The local Karlovitz number maintained a constant value under tip opening conditions, irrespective of the jet velocity. Tip opening occurred at a reasonably constant local Karlovitz number of about ~1.72 when the nitrogen dilution level in propane and n-butane fuels was varied.en
dc.description.sponsorshipResearch reported in this publication was supported by Competitive Research Funding from King Abdullah University of Science and Technology (KAUST).en
dc.publisherElsevier BVen
dc.subjectExtinctionen
dc.subjectFlame curvatureen
dc.subjectLocal Karlovitz numberen
dc.subjectNegative stretchen
dc.subjectPremixed flameen
dc.titleTip opening of premixed bunsen flames: Extinction with negative stretch and local Karlovitz numberen
dc.typeArticleen
dc.contributor.departmentClean Combustion Research Centeren
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
dc.contributor.departmentMechanical Engineering Programen
dc.contributor.departmentCombustion and Laser Diagnostics Laboratoryen
dc.identifier.journalCombustion and Flameen
dc.contributor.institutionSchool of Mechanical Engineering, Yeungnam UniversityGyeongsan, South Koreaen
kaust.authorCha, Min Suken
kaust.authorChung, Suk-Hoen
kaust.authorVu, Tranmanhen
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