Flame kernel generation and propagation in turbulent partially premixed hydrocarbon jet

Handle URI:
http://hdl.handle.net/10754/564911
Title:
Flame kernel generation and propagation in turbulent partially premixed hydrocarbon jet
Authors:
Mansour, Mohy S.; Elbaz, Ayman M.; Zayed, M. F.
Abstract:
Flame development, propagation, stability, combustion efficiency, pollution formation, and overall system efficiency are affected by the early stage of flame generation defined as flame kernel. Studying the effects of turbulence and chemistry on the flame kernel propagation is the main aim of this work for natural gas (NG) and liquid petroleum gas (LPG). In addition the minimum ignition laser energy (MILE) has been investigated for both fuels. Moreover, the flame stability maps for both fuels are also investigated and analyzed. The flame kernels are generated using Nd:YAG pulsed laser and propagated in a partially premixed turbulent jet. The flow field is measured using 2-D PIV technique. Five cases have been selected for each fuel covering different values of Reynolds number within a range of 6100-14400, at a mean equivalence ratio of 2 and a certain level of partial premixing. The MILE increases by increasing the equivalence ratio. Near stoichiometric the energy density is independent on the jet velocity while in rich conditions it increases by increasing the jet velocity. The stability curves show four distinct regions as lifted, attached, blowout, and a fourth region either an attached flame if ignition occurs near the nozzle or lifted if ignition occurs downstream. LPG flames are more stable than NG flames. This is consistent with the higher values of the laminar flame speed of LPG. The flame kernel propagation speed is affected by both turbulence and chemistry. However, at low turbulence level chemistry effects are more pronounced while at high turbulence level the turbulence becomes dominant. LPG flame kernels propagate faster than those for NG flame. In addition, flame kernel extinguished faster in LPG fuel as compared to NG fuel. The propagation speed is likely to be consistent with the local mean equivalence ratio and its corresponding laminar flame speed. Copyright © Taylor & Francis Group, LLC.
KAUST Department:
Clean Combustion Research Center
Publisher:
Informa UK Limited
Journal:
Combustion Science and Technology
Issue Date:
23-Apr-2014
DOI:
10.1080/00102202.2014.883850
Type:
Article
ISSN:
00102202
Sponsors:
This work is financially supported by the joint project between Cairo University, Egypt, and North Carolina State University, USA. The project title is "Computational and Experimental Studies of Turbulent Premixed Flame Kernels." The project ID is 422.
Appears in Collections:
Articles; Clean Combustion Research Center

Full metadata record

DC FieldValue Language
dc.contributor.authorMansour, Mohy S.en
dc.contributor.authorElbaz, Ayman M.en
dc.contributor.authorZayed, M. F.en
dc.date.accessioned2015-08-04T07:24:54Zen
dc.date.available2015-08-04T07:24:54Zen
dc.date.issued2014-04-23en
dc.identifier.issn00102202en
dc.identifier.doi10.1080/00102202.2014.883850en
dc.identifier.urihttp://hdl.handle.net/10754/564911en
dc.description.abstractFlame development, propagation, stability, combustion efficiency, pollution formation, and overall system efficiency are affected by the early stage of flame generation defined as flame kernel. Studying the effects of turbulence and chemistry on the flame kernel propagation is the main aim of this work for natural gas (NG) and liquid petroleum gas (LPG). In addition the minimum ignition laser energy (MILE) has been investigated for both fuels. Moreover, the flame stability maps for both fuels are also investigated and analyzed. The flame kernels are generated using Nd:YAG pulsed laser and propagated in a partially premixed turbulent jet. The flow field is measured using 2-D PIV technique. Five cases have been selected for each fuel covering different values of Reynolds number within a range of 6100-14400, at a mean equivalence ratio of 2 and a certain level of partial premixing. The MILE increases by increasing the equivalence ratio. Near stoichiometric the energy density is independent on the jet velocity while in rich conditions it increases by increasing the jet velocity. The stability curves show four distinct regions as lifted, attached, blowout, and a fourth region either an attached flame if ignition occurs near the nozzle or lifted if ignition occurs downstream. LPG flames are more stable than NG flames. This is consistent with the higher values of the laminar flame speed of LPG. The flame kernel propagation speed is affected by both turbulence and chemistry. However, at low turbulence level chemistry effects are more pronounced while at high turbulence level the turbulence becomes dominant. LPG flame kernels propagate faster than those for NG flame. In addition, flame kernel extinguished faster in LPG fuel as compared to NG fuel. The propagation speed is likely to be consistent with the local mean equivalence ratio and its corresponding laminar flame speed. Copyright © Taylor & Francis Group, LLC.en
dc.description.sponsorshipThis work is financially supported by the joint project between Cairo University, Egypt, and North Carolina State University, USA. The project title is "Computational and Experimental Studies of Turbulent Premixed Flame Kernels." The project ID is 422.en
dc.publisherInforma UK Limiteden
dc.subjectFlame kernelen
dc.titleFlame kernel generation and propagation in turbulent partially premixed hydrocarbon jeten
dc.typeArticleen
dc.contributor.departmentClean Combustion Research Centeren
dc.identifier.journalCombustion Science and Technologyen
dc.contributor.institutionMechanical Power Engineering Department, Cairo University, Cairo, Egypten
dc.contributor.institutionMechanical Power Engineering Department, Helwan University, Ain Helwan, Egypten
kaust.authorElbaz, Ayman M.en
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