Turbulent Non-Premixed Flames Stabilized on Double-Slit Curved Wall-Jet Burner with Simultaneous OH-Planar Laser-Induced Fluorescence and Particle Image Velocimetry Measurements

Handle URI:
http://hdl.handle.net/10754/566185
Title:
Turbulent Non-Premixed Flames Stabilized on Double-Slit Curved Wall-Jet Burner with Simultaneous OH-Planar Laser-Induced Fluorescence and Particle Image Velocimetry Measurements
Authors:
Mansour, Morkous S. ( 0000-0002-5002-1403 ) ; Chung, Suk-Ho ( 0000-0001-8782-312X )
Abstract:
A double-slit curved wall-jet (CWJ) burner utilizing a Coanda effect by supplying fuel and air as annular-inward jets over a curved surface was employed to investigate the stabilization characteristics and structure of propane/air turbulent non-premixed flames with varying global equivalence ratio and Reynolds number. Simultaneous time-resolved measurements of particle image velocimetry (PIV) and planar laser-induced fluorescence (PLIF) of OH radicals were conducted. The burner showed a potential of stable and non-sooting operation for relatively large fuel loading and overall rich conditions. Mixing characteristics in cold flow were first examined using an acetone fluorescence technique, indicating substantial transport between the fuel and air by exhibiting appreciable premixing conditions. PIV measurements revealed that the flow field consisted of a wall-jet region leading to a recirculation zone through flow separation, an interaction jet region resulting from the collision of annular-inward jets, followed by a merged-jet region. The flames were stabilized in the recirculation zone and, in extreme cases, only a small flame seed remained in the recirculation zone. Together with the collision of the slit jets in the interaction jet region, the velocity gradients in the shear layers at the boundaries of the annular jets generate the turbulence. Turbulent mean and rms velocities were influenced by the presence of the flame, particularly in the recirculation zone. Flames with a high equivalence ratio were found to be more resistant to local extinction and exhibited a more corrugated and folded nature, particularly at high Reynolds numbers. For flames with a low equivalence ratio, local quenching and re-ignition processes maintained flames in the merged jet region, revealing a strong intermittency, which was substantiated by the increased principal strain rates for these flames. © 2015 Taylor & Francis Group, LLC.
KAUST Department:
Clean Combustion Research Center; Mechanical Engineering Program; Physical Sciences and Engineering (PSE) Division; Combustion and Laser Diagnostics Laboratory
Publisher:
Informa UK Limited
Journal:
Combustion Science and Technology
Issue Date:
29-Apr-2015
DOI:
10.1080/00102202.2015.1042103
Type:
Article
ISSN:
0010-2202; 1563-521X
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.authorMansour, Morkous S.en
dc.contributor.authorChung, Suk-Hoen
dc.date.accessioned2015-08-12T09:31:36Zen
dc.date.available2015-08-12T09:31:36Zen
dc.date.issued2015-04-29en
dc.identifier.issn0010-2202en
dc.identifier.issn1563-521Xen
dc.identifier.doi10.1080/00102202.2015.1042103en
dc.identifier.urihttp://hdl.handle.net/10754/566185en
dc.description.abstractA double-slit curved wall-jet (CWJ) burner utilizing a Coanda effect by supplying fuel and air as annular-inward jets over a curved surface was employed to investigate the stabilization characteristics and structure of propane/air turbulent non-premixed flames with varying global equivalence ratio and Reynolds number. Simultaneous time-resolved measurements of particle image velocimetry (PIV) and planar laser-induced fluorescence (PLIF) of OH radicals were conducted. The burner showed a potential of stable and non-sooting operation for relatively large fuel loading and overall rich conditions. Mixing characteristics in cold flow were first examined using an acetone fluorescence technique, indicating substantial transport between the fuel and air by exhibiting appreciable premixing conditions. PIV measurements revealed that the flow field consisted of a wall-jet region leading to a recirculation zone through flow separation, an interaction jet region resulting from the collision of annular-inward jets, followed by a merged-jet region. The flames were stabilized in the recirculation zone and, in extreme cases, only a small flame seed remained in the recirculation zone. Together with the collision of the slit jets in the interaction jet region, the velocity gradients in the shear layers at the boundaries of the annular jets generate the turbulence. Turbulent mean and rms velocities were influenced by the presence of the flame, particularly in the recirculation zone. Flames with a high equivalence ratio were found to be more resistant to local extinction and exhibited a more corrugated and folded nature, particularly at high Reynolds numbers. For flames with a low equivalence ratio, local quenching and re-ignition processes maintained flames in the merged jet region, revealing a strong intermittency, which was substantiated by the increased principal strain rates for these flames. © 2015 Taylor & Francis Group, LLC.en
dc.publisherInforma UK Limiteden
dc.subjectDouble-slit curved wall-jet (CWJ) burneren
dc.subjectFlame extinctionen
dc.subjectOH-planar laser-induced fluorescence (OH-PLIF)en
dc.subjectParticle image velocimetry (PIV)en
dc.subjectStrain rateen
dc.subjectTurbulent non-premixed flameen
dc.titleTurbulent Non-Premixed Flames Stabilized on Double-Slit Curved Wall-Jet Burner with Simultaneous OH-Planar Laser-Induced Fluorescence and Particle Image Velocimetry Measurementsen
dc.typeArticleen
dc.contributor.departmentClean Combustion Research Centeren
dc.contributor.departmentMechanical Engineering Programen
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
dc.contributor.departmentCombustion and Laser Diagnostics Laboratoryen
dc.identifier.journalCombustion Science and Technologyen
kaust.authorMansour, Morkous S.en
kaust.authorChung, Suk-Hoen
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