Flow instability in laminar jet flames driven by alternating current electric fields

Handle URI:
http://hdl.handle.net/10754/622293
Title:
Flow instability in laminar jet flames driven by alternating current electric fields
Authors:
Kim, Gyeong Taek; Park, Daegeun ( 0000-0002-6658-2096 ) ; Cha, Min Suk ( 0000-0003-4059-3421 ) ; Park, Jeong; Chung, Suk-Ho ( 0000-0001-8782-312X )
Abstract:
The effect of electric fields on the instability of laminar nonpremixed jet flames was investigated experimentally by applying the alternating current (AC) to a jet nozzle. We aimed to elucidate the origin of the occurrence of twin-lifted jet flames in laminar jet flow configurations, which occurred when AC electric fields were applied. The results indicated that a twin-lifted jet flame originated from cold jet instability, caused by interactions between negative ions in the jet flow via electron attachment as O +e→O when AC electric fields were applied. This was confirmed by conducting systematic, parametric experiment, which included changing gaseous component in jets and applying different polarity of direct current (DC) to the nozzle. Using two deflection plates installed in parallel with the jet stream, we found that only negative DC on the nozzle could charge oxygen molecules negatively. Meanwhile, the cold jet instability occurred only for oxygen-containing jets. A shedding frequency of jet stream due to AC driven instability showed a good correlation with applied AC frequency exhibiting a frequency doubling. However, for the applied AC frequencies over 80Hz, the jet did not respond to the AC, indicating an existence of a minimum flow induction time in a dynamic response of negative ions to external AC fields. Detailed regime of the instability in terms of jet velocity, AC voltage and frequency was presented and discussed. Hypothesized mechanism to explain the instability was also proposed.
KAUST Department:
Clean Combustion Research Center; Physical Sciences and Engineering (PSE) Division
Citation:
Kim GT, Park DG, Cha MS, Park J, Chung SH (2016) Flow instability in laminar jet flames driven by alternating current electric fields. Proceedings of the Combustion Institute. Available: http://dx.doi.org/10.1016/j.proci.2016.09.015.
Publisher:
Elsevier BV
Journal:
Proceedings of the Combustion Institute
Issue Date:
13-Oct-2016
DOI:
10.1016/j.proci.2016.09.015
Type:
Article
ISSN:
1540-7489
Appears in Collections:
Articles; Physical Sciences and Engineering (PSE) Division; Clean Combustion Research Center

Full metadata record

DC FieldValue Language
dc.contributor.authorKim, Gyeong Taeken
dc.contributor.authorPark, Daegeunen
dc.contributor.authorCha, Min Suken
dc.contributor.authorPark, Jeongen
dc.contributor.authorChung, Suk-Hoen
dc.date.accessioned2017-01-02T09:08:24Z-
dc.date.available2017-01-02T09:08:24Z-
dc.date.issued2016-10-13en
dc.identifier.citationKim GT, Park DG, Cha MS, Park J, Chung SH (2016) Flow instability in laminar jet flames driven by alternating current electric fields. Proceedings of the Combustion Institute. Available: http://dx.doi.org/10.1016/j.proci.2016.09.015.en
dc.identifier.issn1540-7489en
dc.identifier.doi10.1016/j.proci.2016.09.015en
dc.identifier.urihttp://hdl.handle.net/10754/622293-
dc.description.abstractThe effect of electric fields on the instability of laminar nonpremixed jet flames was investigated experimentally by applying the alternating current (AC) to a jet nozzle. We aimed to elucidate the origin of the occurrence of twin-lifted jet flames in laminar jet flow configurations, which occurred when AC electric fields were applied. The results indicated that a twin-lifted jet flame originated from cold jet instability, caused by interactions between negative ions in the jet flow via electron attachment as O +e→O when AC electric fields were applied. This was confirmed by conducting systematic, parametric experiment, which included changing gaseous component in jets and applying different polarity of direct current (DC) to the nozzle. Using two deflection plates installed in parallel with the jet stream, we found that only negative DC on the nozzle could charge oxygen molecules negatively. Meanwhile, the cold jet instability occurred only for oxygen-containing jets. A shedding frequency of jet stream due to AC driven instability showed a good correlation with applied AC frequency exhibiting a frequency doubling. However, for the applied AC frequencies over 80Hz, the jet did not respond to the AC, indicating an existence of a minimum flow induction time in a dynamic response of negative ions to external AC fields. Detailed regime of the instability in terms of jet velocity, AC voltage and frequency was presented and discussed. Hypothesized mechanism to explain the instability was also proposed.en
dc.publisherElsevier BVen
dc.subjectElectric fielden
dc.subjectJet flow instabilityen
dc.subjectTwin jet flameen
dc.titleFlow instability in laminar jet flames driven by alternating current electric fieldsen
dc.typeArticleen
dc.contributor.departmentClean Combustion Research Centeren
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
dc.identifier.journalProceedings of the Combustion Instituteen
dc.contributor.institutionInterdisciplinary Program of Biomechanical Engineering, Pukyong National University, Busan, Republic of Koreaen
kaust.authorPark, Daegeunen
kaust.authorCha, Min Suken
kaust.authorChung, Suk-Hoen
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