Direct Numerical Simulations of NOx formation in spatially developing turbulent premixed Bunsen flames with mixture inhomogeneity

Handle URI:
http://hdl.handle.net/10754/625559
Title:
Direct Numerical Simulations of NOx formation in spatially developing turbulent premixed Bunsen flames with mixture inhomogeneity
Authors:
Luca, Stefano; Attili, Antonio; Bisetti, Fabrizio
Abstract:
Direct Numerical Simulation of three-dimensional spatially developing turbulent methane/air flames are performed. Four flames are simulated; they differ for the level of premixing of the fuel inlet: one has a fully premixed inlet, the other three have a partially premixed inlet that mimic a common injection strategy in stationary gas turbines. The jet consist of a methane/air mixture with global equivalence ratio ɸ = 0.7 and temperature of 800 K. The simulations are performed at 4 atm. The inlet velocity field and the fuel/air fields were extracted from a fully developed turbulent channel simulation. Chemistry is treated with a new skeletal chemical mechanism consisting of 33 species developed specifically for the DNS. The data are analyzed to study possible influences of partial premixing on the flame structure and the combustion efficiency. The results show that increasing the level of partial premixing, the fluctuations of heat release rate increase, due to the richer and leaner pockets of mixture in the flame, while the conditional mean decreases. Increasing the level of partial premixing, the peak of NO and the range of NO values for a given temperature increase. An analysis of NO production is performed categorizing the different initiation steps in the Ndecomposition through four pathways: thermal, prompt, NNH and NO. Different behaviour with respect to laminar flames is found for the NNH pathway suggesting that turbulence influences this pathway of formation of NO.
KAUST Department:
Clean Combustion Research Center; Mechanical Engineering Program
Citation:
Luca S, Attili A, Bisetti F (2017) Direct Numerical Simulations of NOx formation in spatially developing turbulent premixed Bunsen flames with mixture inhomogeneity. 55th AIAA Aerospace Sciences Meeting. Available: http://dx.doi.org/10.2514/6.2017-0603.
Publisher:
American Institute of Aeronautics and Astronautics
Journal:
55th AIAA Aerospace Sciences Meeting
Conference/Event name:
55th AIAA Aerospace Sciences Meeting
Issue Date:
5-Jan-2017
DOI:
10.2514/6.2017-0603
Type:
Conference Paper
Sponsors:
Research reported in this publication was supported by the King Abdullah University of Science and Technology (KAUST). The authors acknowledge valuable support from KAUST Supercomputing Laboratory (KSL) in the form of computational time on the CRAY XC40 “Shaheen”.
Additional Links:
https://arc.aiaa.org/doi/10.2514/6.2017-0603
Appears in Collections:
Conference Papers; Mechanical Engineering Program; Clean Combustion Research Center

Full metadata record

DC FieldValue Language
dc.contributor.authorLuca, Stefanoen
dc.contributor.authorAttili, Antonioen
dc.contributor.authorBisetti, Fabrizioen
dc.date.accessioned2017-10-03T12:49:25Z-
dc.date.available2017-10-03T12:49:25Z-
dc.date.issued2017-01-05en
dc.identifier.citationLuca S, Attili A, Bisetti F (2017) Direct Numerical Simulations of NOx formation in spatially developing turbulent premixed Bunsen flames with mixture inhomogeneity. 55th AIAA Aerospace Sciences Meeting. Available: http://dx.doi.org/10.2514/6.2017-0603.en
dc.identifier.doi10.2514/6.2017-0603en
dc.identifier.urihttp://hdl.handle.net/10754/625559-
dc.description.abstractDirect Numerical Simulation of three-dimensional spatially developing turbulent methane/air flames are performed. Four flames are simulated; they differ for the level of premixing of the fuel inlet: one has a fully premixed inlet, the other three have a partially premixed inlet that mimic a common injection strategy in stationary gas turbines. The jet consist of a methane/air mixture with global equivalence ratio ɸ = 0.7 and temperature of 800 K. The simulations are performed at 4 atm. The inlet velocity field and the fuel/air fields were extracted from a fully developed turbulent channel simulation. Chemistry is treated with a new skeletal chemical mechanism consisting of 33 species developed specifically for the DNS. The data are analyzed to study possible influences of partial premixing on the flame structure and the combustion efficiency. The results show that increasing the level of partial premixing, the fluctuations of heat release rate increase, due to the richer and leaner pockets of mixture in the flame, while the conditional mean decreases. Increasing the level of partial premixing, the peak of NO and the range of NO values for a given temperature increase. An analysis of NO production is performed categorizing the different initiation steps in the Ndecomposition through four pathways: thermal, prompt, NNH and NO. Different behaviour with respect to laminar flames is found for the NNH pathway suggesting that turbulence influences this pathway of formation of NO.en
dc.description.sponsorshipResearch reported in this publication was supported by the King Abdullah University of Science and Technology (KAUST). The authors acknowledge valuable support from KAUST Supercomputing Laboratory (KSL) in the form of computational time on the CRAY XC40 “Shaheen”.en
dc.publisherAmerican Institute of Aeronautics and Astronauticsen
dc.relation.urlhttps://arc.aiaa.org/doi/10.2514/6.2017-0603en
dc.titleDirect Numerical Simulations of NOx formation in spatially developing turbulent premixed Bunsen flames with mixture inhomogeneityen
dc.typeConference Paperen
dc.contributor.departmentClean Combustion Research Centeren
dc.contributor.departmentMechanical Engineering Programen
dc.identifier.journal55th AIAA Aerospace Sciences Meetingen
dc.conference.date2017-01-09 to 2017-01-13en
dc.conference.name55th AIAA Aerospace Sciences Meetingen
dc.conference.locationGrapevine, TX, USAen
dc.contributor.institutionInstitute for Combustion Technology, RWTH Aachen University, Aachen, 52056, , Germanyen
dc.contributor.institutionDepartment of Aerospace Engineering and Engineering Mechanics, The University of Texas at Austin, Austin, TX, 78712, , United Statesen
kaust.authorLuca, Stefanoen
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