Stabilization and structure of N-heptane flame on CWJ-spray burner with kHZ SPIV and OH-PLIF

Handle URI:
http://hdl.handle.net/10754/576856
Title:
Stabilization and structure of N-heptane flame on CWJ-spray burner with kHZ SPIV and OH-PLIF
Authors:
Mansour, Morkous S. ( 0000-0002-5002-1403 ) ; Al Khesho, Issam; Chung, Suk-Ho ( 0000-0001-8782-312X )
Abstract:
A curved wall-jet (CWJ) burner was employed to stabilize turbulent spray flames that utilized a Coanda effect by supplying air as annular-inward jet over a curved surface, surrounding an axisymmetric solid cone fuel spray. The stabilization characteristics and structure of n-heptane/air turbulent flames were investigated with varying fuel and air flow rates and the position of pressure atomizer (L). High-speed planar laser-induced fluorescence (PLIF) of OH radicals delineated reaction zone contours and simultaneously stereoscopic particle image velocimetry (SPIV) quantified the flow field features, involving turbulent mixing within spray, ambient air entrainment and flame-turbulence interaction. High turbulent rms velocities were generated within the recirculation zone, which improved the flame stabilization. OH fluorescence signals revealed a double flame structure near the stabilization edge of lifted flame that consisted of inner partially premixed flame and outer diffusion flame front. The inner reaction zone is highly wrinkled and folded due to significant turbulent mixing between the annular-air jet and the fuel vapor generated from droplets along the contact interface of this air jet with the fuel spray. Larger droplets, having higher momentum are able to penetrate the inner reaction zone and then vaporized in the low-speed hot region bounded by these reaction zones; this supports the outer diffusion flame. Frequent local extinctions in the inner reaction zone were observed at low air flow rate. As flow rate increases, the inner zone is more resistant to local extinction despite of its high wrinkling and corrugation degree. However, the outer reaction zone exhibits stable and mildly wrinkled features irrespective of air flow rate. The liftoff height increases with the air mass flow rate but decreases with L.
KAUST Department:
Clean Combustion Research Center
Citation:
Stabilization and structure of N-heptane flame on CWJ-spray burner with kHZ SPIV and OH-PLIF 2015 Experimental Thermal and Fluid Science
Publisher:
Elsevier BV
Journal:
Experimental Thermal and Fluid Science
Issue Date:
31-Aug-2015
DOI:
10.1016/j.expthermflusci.2015.08.019
Type:
Article
ISSN:
08941777
Additional Links:
http://linkinghub.elsevier.com/retrieve/pii/S0894177715002307
Appears in Collections:
Articles; Clean Combustion Research Center

Full metadata record

DC FieldValue Language
dc.contributor.authorMansour, Morkous S.en
dc.contributor.authorAl Khesho, Issamen
dc.contributor.authorChung, Suk-Hoen
dc.date.accessioned2015-09-06T14:10:02Zen
dc.date.available2015-09-06T14:10:02Zen
dc.date.issued2015-08-31en
dc.identifier.citationStabilization and structure of N-heptane flame on CWJ-spray burner with kHZ SPIV and OH-PLIF 2015 Experimental Thermal and Fluid Scienceen
dc.identifier.issn08941777en
dc.identifier.doi10.1016/j.expthermflusci.2015.08.019en
dc.identifier.urihttp://hdl.handle.net/10754/576856en
dc.description.abstractA curved wall-jet (CWJ) burner was employed to stabilize turbulent spray flames that utilized a Coanda effect by supplying air as annular-inward jet over a curved surface, surrounding an axisymmetric solid cone fuel spray. The stabilization characteristics and structure of n-heptane/air turbulent flames were investigated with varying fuel and air flow rates and the position of pressure atomizer (L). High-speed planar laser-induced fluorescence (PLIF) of OH radicals delineated reaction zone contours and simultaneously stereoscopic particle image velocimetry (SPIV) quantified the flow field features, involving turbulent mixing within spray, ambient air entrainment and flame-turbulence interaction. High turbulent rms velocities were generated within the recirculation zone, which improved the flame stabilization. OH fluorescence signals revealed a double flame structure near the stabilization edge of lifted flame that consisted of inner partially premixed flame and outer diffusion flame front. The inner reaction zone is highly wrinkled and folded due to significant turbulent mixing between the annular-air jet and the fuel vapor generated from droplets along the contact interface of this air jet with the fuel spray. Larger droplets, having higher momentum are able to penetrate the inner reaction zone and then vaporized in the low-speed hot region bounded by these reaction zones; this supports the outer diffusion flame. Frequent local extinctions in the inner reaction zone were observed at low air flow rate. As flow rate increases, the inner zone is more resistant to local extinction despite of its high wrinkling and corrugation degree. However, the outer reaction zone exhibits stable and mildly wrinkled features irrespective of air flow rate. The liftoff height increases with the air mass flow rate but decreases with L.en
dc.language.isoenen
dc.publisherElsevier BVen
dc.relation.urlhttp://linkinghub.elsevier.com/retrieve/pii/S0894177715002307en
dc.rightsNOTICE: this is the author’s version of a work that was accepted for publication in Experimental Thermal and Fluid Science. 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 Experimental Thermal and Fluid Science, 31 August 2015. DOI: 10.1016/j.expthermflusci.2015.08.019en
dc.subjectTurbulent spray flameen
dc.subjectCWJ burneren
dc.subjectFlame structureen
dc.subjectSPIVen
dc.subjectOH-PLIFen
dc.titleStabilization and structure of N-heptane flame on CWJ-spray burner with kHZ SPIV and OH-PLIFen
dc.typeArticleen
dc.contributor.departmentClean Combustion Research Centeren
dc.identifier.journalExperimental Thermal and Fluid Scienceen
dc.eprint.versionPost-printen
dc.contributor.institutionDepartment of Mechanical Engineering, Helwan University, Cairo, Egypten
dc.contributor.affiliationKing Abdullah University of Science and Technology (KAUST)en
kaust.authorMansour, Morkous S.en
kaust.authorAl Khesho, Issamen
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