A parametric study of AC electric field-induced toroidal vortex formation in laminar nonpremixed coflow flames

Handle URI:
http://hdl.handle.net/10754/623453
Title:
A parametric study of AC electric field-induced toroidal vortex formation in laminar nonpremixed coflow flames
Authors:
Xiong, Yuan ( 0000-0001-5328-3487 ) ; Chung, Suk-Ho ( 0000-0001-8782-312X ) ; Cha, Min Suk ( 0000-0003-4059-3421 )
Abstract:
This study presents an experimental work investigating the controlling parameters on the formation of an electrically-induced inner toroidal vortex (ITV) near a nozzle rim in small, laminar nonpremixed coflow flames, when an alternating current is applied to the nozzle. A systematic parametric study was conducted by varying the flow parameters of the fuel and coflowing-air velocities, and the nozzle diameter. The fuels tested were methane, ethylene, ethane, propane, n-butane, and i-butane, each representing different ion-generation characteristics and sooting tendencies. The results showed that the fluid dynamic effects on ITV formation were weak, causing only mild variation when altering flow velocities. However, increased fuel velocity resulted in increased polycyclic aromatic hydrocarbon (PAH) formation, which promoted ITV formation. When judging the ITV-formation tendency based on critical applied voltage and frequency, it was qualitatively well correlated with the PAH concentration and the relative location of PAHs to the nozzle rim. The sooting tendency of the fuels did not affect the results much. A change in the nozzle diameter highlighted the importance of the relative distance between the PAH zone and the nozzle rim, indicating the role of local electric-field intensity on ITV formation. Detailed onset conditions, characteristics of near-nozzle flow patterns, and PAH distributions are also discussed.
KAUST Department:
Clean Combustion Research Center
Citation:
Xiong Y, Chung SH, Cha MS (2017) A parametric study of AC electric field-induced toroidal vortex formation in laminar nonpremixed coflow flames. Combustion and Flame 182: 142–149. Available: http://dx.doi.org/10.1016/j.combustflame.2017.04.013.
Publisher:
Elsevier BV
Journal:
Combustion and Flame
Issue Date:
2-May-2017
DOI:
10.1016/j.combustflame.2017.04.013
Type:
Article
ISSN:
0010-2180
Sponsors:
The research reported in this publication was supported by Competitive Research Funding from King Abdullah University of Science and Technology (KAUST).
Additional Links:
http://www.sciencedirect.com/science/article/pii/S0010218017301475
Appears in Collections:
Articles; Clean Combustion Research Center

Full metadata record

DC FieldValue Language
dc.contributor.authorXiong, Yuanen
dc.contributor.authorChung, Suk-Hoen
dc.contributor.authorCha, Min Suken
dc.date.accessioned2017-05-09T12:54:46Z-
dc.date.available2017-05-09T12:54:46Z-
dc.date.issued2017-05-02en
dc.identifier.citationXiong Y, Chung SH, Cha MS (2017) A parametric study of AC electric field-induced toroidal vortex formation in laminar nonpremixed coflow flames. Combustion and Flame 182: 142–149. Available: http://dx.doi.org/10.1016/j.combustflame.2017.04.013.en
dc.identifier.issn0010-2180en
dc.identifier.doi10.1016/j.combustflame.2017.04.013en
dc.identifier.urihttp://hdl.handle.net/10754/623453-
dc.description.abstractThis study presents an experimental work investigating the controlling parameters on the formation of an electrically-induced inner toroidal vortex (ITV) near a nozzle rim in small, laminar nonpremixed coflow flames, when an alternating current is applied to the nozzle. A systematic parametric study was conducted by varying the flow parameters of the fuel and coflowing-air velocities, and the nozzle diameter. The fuels tested were methane, ethylene, ethane, propane, n-butane, and i-butane, each representing different ion-generation characteristics and sooting tendencies. The results showed that the fluid dynamic effects on ITV formation were weak, causing only mild variation when altering flow velocities. However, increased fuel velocity resulted in increased polycyclic aromatic hydrocarbon (PAH) formation, which promoted ITV formation. When judging the ITV-formation tendency based on critical applied voltage and frequency, it was qualitatively well correlated with the PAH concentration and the relative location of PAHs to the nozzle rim. The sooting tendency of the fuels did not affect the results much. A change in the nozzle diameter highlighted the importance of the relative distance between the PAH zone and the nozzle rim, indicating the role of local electric-field intensity on ITV formation. Detailed onset conditions, characteristics of near-nozzle flow patterns, and PAH distributions are also discussed.en
dc.description.sponsorshipThe research reported in this publication was supported by Competitive Research Funding from King Abdullah University of Science and Technology (KAUST).en
dc.publisherElsevier BVen
dc.relation.urlhttp://www.sciencedirect.com/science/article/pii/S0010218017301475en
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, [, , (2017-05-02)] DOI: 10.1016/j.combustflame.2017.04.013 . © 2017. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/en
dc.subjectElectric fielden
dc.subjectNonpremixed flameen
dc.subjectToroidal vortexen
dc.subjectPolycyclic aromatic hydrocarbons, Ionic winden
dc.titleA parametric study of AC electric field-induced toroidal vortex formation in laminar nonpremixed coflow flamesen
dc.typeArticleen
dc.contributor.departmentClean Combustion Research Centeren
dc.identifier.journalCombustion and Flameen
dc.eprint.versionPost-printen
kaust.authorXiong, Yuanen
kaust.authorChung, Suk-Hoen
kaust.authorCha, Min Suken
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