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dc.contributor.authorGuiberti, Thibault
dc.contributor.authorBoyette, Wesley
dc.contributor.authorMasri, Assaad R.
dc.contributor.authorRoberts, William L.
dc.date.accessioned2019-01-29T11:30:24Z
dc.date.available2019-01-29T11:30:24Z
dc.date.issued2019-01-26
dc.identifier.citationGuiberti TF, Boyette WR, Masri AR, Roberts WL (2019) Detachment mechanisms of turbulent non-premixed jet flames at atmospheric and elevated pressures. Combustion and Flame 202: 219–227. Available: http://dx.doi.org/10.1016/j.combustflame.2019.01.019.
dc.identifier.issn0010-2180
dc.identifier.doi10.1016/j.combustflame.2019.01.019
dc.identifier.urihttp://hdl.handle.net/10754/630959
dc.description.abstractThe stability limits of a turbulent flame in a practical combustor are important characteristics that influence its performance. The mechanisms controlling the stability limits of turbulent non-premixed flames are examined here in the canonical configuration of a fuel jet in co-flow air. This study focuses on the conditions leading to the detachment of flames from the injector nozzle by means of an experimental parametric study in which pressure (1 ≤ P ≤ 10 bar), fuel (methane and ethane), nozzle wall thickness (t = 0.20 mm, 0.58 mm, and 0.89 mm), jet velocity (0.5 ≤ Uj ≤ 16.5 m s−1), and co-flow velocity (Uc = 0.3 m s−1, 0.6 m s−1, and 0.9 m s−1) are varied. It is shown that the mechanism leading to detachment depends on the ratio of the nozzle wall thickness to the laminar flame thickness. If this ratio is smaller than 3, the nozzle is “thin” and type I detachment occurs (flame base stability lifting). In this case, the detachment velocity decreases with pressure and is proportional to the laminar burning velocity. If the ratio is larger than 3, the nozzle is “thick” and type II detachment occurs (local flame extinction lifting). Then, the detachment velocity is controlled by the extinction strain rate. Experiments also show that the Kolmogorov scale of turbulence regulates local flame extinction and type II detachment and a model is proposed to predict detachment for any fuel, pressure, and nozzle wall thickness using the computed extinction strain rate and the Kolmogorov time scale. Finally, the data show that elevating pressure allows stabilizing attached non-premixed jet flames with high Reynolds numbers without the need for complex stabilization strategies such as pilot flames, swirl, or oxygen/hydrogen enrichment. Pressure allows studying flame/turbulence interactions at Reynolds numbers relevant to practical applications while conserving simple configurations amenable to diagnostics and modeling.
dc.description.sponsorshipThe research reported in this publication was supported by funding from King Abdullah University of Science and Technology (KAUST).
dc.publisherElsevier BV
dc.relation.urlhttps://www.sciencedirect.com/science/article/pii/S0010218019300379?via%3Dihub
dc.rightsNOTICE: this is the author’s version of a work that was accepted for publication in Combustion and Flame. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Combustion and Flame, [, , (2019-01-26)] DOI: 10.1016/j.combustflame.2019.01.019 . © 2019. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/
dc.rights.urihttp://creativecommons.org/licenses/by-nc-nd/4.0/
dc.subjectJet flame
dc.subjectElevated pressure
dc.subjectDetachment
dc.subjectLift-off
dc.subjectLocal extinction
dc.subjectKolmogorov scale
dc.titleDetachment mechanisms of turbulent non-premixed jet flames at atmospheric and elevated pressures
dc.typeArticle
dc.contributor.departmentClean Combustion Research Center
dc.contributor.departmentMechanical Engineering Program
dc.contributor.departmentPhysical Science and Engineering (PSE) Division
dc.contributor.departmenthigh-pressure combustion (HPC) Research Group
dc.identifier.journalCombustion and Flame
dc.eprint.versionPost-print
dc.contributor.institutionSchool of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, NSW 2006 Australia.
kaust.personGuiberti, Thibault
kaust.personBoyette, Wesley
kaust.personRoberts, William L.
refterms.dateFOA2019-01-29T11:42:19Z
dc.date.published-online2019-01-26
dc.date.published-print2019-04


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NOTICE: this is the author’s version of a work that was accepted for publication in Combustion and Flame. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Combustion and Flame, [, , (2019-01-26)] DOI: 10.1016/j.combustflame.2019.01.019 . © 2019. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/
Except where otherwise noted, this item's license is described as NOTICE: this is the author’s version of a work that was accepted for publication in Combustion and Flame. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Combustion and Flame, [, , (2019-01-26)] DOI: 10.1016/j.combustflame.2019.01.019 . © 2019. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/