Instability and electrical response of small laminar coflow diffusion flames under AC electric fields: Toroidal vortex formation and oscillating and spinning flames

Handle URI:
http://hdl.handle.net/10754/626972
Title:
Instability and electrical response of small laminar coflow diffusion flames under AC electric fields: Toroidal vortex formation and oscillating and spinning flames
Authors:
Xiong, Yuan ( 0000-0001-5328-3487 ) ; Chung, Suk-Ho ( 0000-0001-8782-312X ) ; Cha, Min Suk ( 0000-0003-4059-3421 )
Abstract:
Dynamical and electrical responses of a small coflow diffusion flame were investigated by applying a high-voltage alternating current (AC), to a fuel jet nozzle. High-speed imaging and electrical diagnostics were adopted to capture flame dynamics and electrical signals, such as voltage (V ), frequency (f ) and current (I ). In the V -f domain of 0-5kV and 0-5kHz, AC-driven instabilities, resulting in various flame modes such as an oscillation, pinch-off and spinning of flames were identified. Characteristic frequency of each mode was determined and a visualization of near-nozzle flow structures suggested a close causality of initial counter-rotating vortices (inner and outer toroidal vortices - ITV and OTV), to the other observed flame. An axisymmetric ITV shedding was identified within oscillating and pinch-off modes, while asymmetric ITV shedding was identified with the spinning mode. Integrated electric power over several AC periods correlated well with variation in the flame surface area for these instabilities, demonstrating that measured electric power is a potential indicator of combustion instabilities in electric-field-assisted combustion.
KAUST Department:
Clean Combustion Research Center; Physical Sciences and Engineering (PSE) Division; Mechanical Engineering Program
Citation:
Xiong Y, Chung SH, Cha MS (2017) Instability and electrical response of small laminar coflow diffusion flames under AC electric fields: Toroidal vortex formation and oscillating and spinning flames. Proceedings of the Combustion Institute 36: 1621–1628. Available: http://dx.doi.org/10.1016/j.proci.2016.06.022.
Publisher:
Elsevier BV
Journal:
Proceedings of the Combustion Institute
Issue Date:
24-Jun-2016
DOI:
10.1016/j.proci.2016.06.022
Type:
Article
ISSN:
1540-7489
Sponsors:
King Abdullah University of Science and Technology
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.authorXiong, Yuanen
dc.contributor.authorChung, Suk-Hoen
dc.contributor.authorCha, Min Suken
dc.date.accessioned2018-02-01T07:25:00Z-
dc.date.available2018-02-01T07:25:00Z-
dc.date.issued2016-06-24en
dc.identifier.citationXiong Y, Chung SH, Cha MS (2017) Instability and electrical response of small laminar coflow diffusion flames under AC electric fields: Toroidal vortex formation and oscillating and spinning flames. Proceedings of the Combustion Institute 36: 1621–1628. Available: http://dx.doi.org/10.1016/j.proci.2016.06.022.en
dc.identifier.issn1540-7489en
dc.identifier.doi10.1016/j.proci.2016.06.022en
dc.identifier.urihttp://hdl.handle.net/10754/626972-
dc.description.abstractDynamical and electrical responses of a small coflow diffusion flame were investigated by applying a high-voltage alternating current (AC), to a fuel jet nozzle. High-speed imaging and electrical diagnostics were adopted to capture flame dynamics and electrical signals, such as voltage (V ), frequency (f ) and current (I ). In the V -f domain of 0-5kV and 0-5kHz, AC-driven instabilities, resulting in various flame modes such as an oscillation, pinch-off and spinning of flames were identified. Characteristic frequency of each mode was determined and a visualization of near-nozzle flow structures suggested a close causality of initial counter-rotating vortices (inner and outer toroidal vortices - ITV and OTV), to the other observed flame. An axisymmetric ITV shedding was identified within oscillating and pinch-off modes, while asymmetric ITV shedding was identified with the spinning mode. Integrated electric power over several AC periods correlated well with variation in the flame surface area for these instabilities, demonstrating that measured electric power is a potential indicator of combustion instabilities in electric-field-assisted combustion.en
dc.description.sponsorshipKing Abdullah University of Science and Technologyen
dc.publisherElsevier BVen
dc.subjectAlternating currenten
dc.subjectIonic winden
dc.subjectJet diffusion flameen
dc.subjectToroidal vortexen
dc.titleInstability and electrical response of small laminar coflow diffusion flames under AC electric fields: Toroidal vortex formation and oscillating and spinning flamesen
dc.typeArticleen
dc.contributor.departmentClean Combustion Research Centeren
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
dc.contributor.departmentMechanical Engineering Programen
dc.identifier.journalProceedings of the Combustion Instituteen
kaust.authorXiong, Yuanen
kaust.authorChung, Suk-Hoen
kaust.authorCha, Min Suken
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