Enstrophy transport conditional on local flow topologies in different regimes of premixed turbulent combustion

Handle URI:
http://hdl.handle.net/10754/625478
Title:
Enstrophy transport conditional on local flow topologies in different regimes of premixed turbulent combustion
Authors:
Papapostolou, Vassilios; Wacks, Daniel H.; Chakraborty, Nilanjan; Klein, Markus; Im, Hong G. ( 0000-0001-7080-1266 )
Abstract:
Enstrophy is an intrinsic feature of turbulent flows, and its transport properties are essential for the understanding of premixed flame-turbulence interaction. The interrelation between the enstrophy transport and flow topologies, which can be assigned to eight categories based on the three invariants of the velocity-gradient tensor, has been analysed here. The enstrophy transport conditional on flow topologies in turbulent premixed flames has been analysed using a Direct Numerical Simulation database representing the corrugated flamelets (CF), thin reaction zones (TRZ) and broken reaction zones (BRZ) combustion regimes. The flame in the CF regime exhibits considerable flame-generated enstrophy, and the dilatation rate and baroclinic torque contributions to the enstrophy transport act as leading order sink and source terms, respectively. Consequently, flow topologies associated with positive dilatation rate values, contribute significantly to the enstrophy transport in the CF regime. By contrast, enstrophy decreases from the unburned to the burned gas side for the cases representing the TRZ and BRZ regimes, with diminishing influences of dilatation rate and baroclinic torque. The enstrophy transport in the TRZ and BRZ regimes is governed by the vortex-stretching and viscous dissipation contributions, similar to non-reacting flows, and topologies existing for all values of dilatation rate remain significant contributors.
KAUST Department:
Clean Combustion Research Center
Citation:
Papapostolou V, Wacks DH, Chakraborty N, Klein M, Im HG (2017) Enstrophy transport conditional on local flow topologies in different regimes of premixed turbulent combustion. Scientific Reports 7. Available: http://dx.doi.org/10.1038/s41598-017-11650-x.
Publisher:
Springer Nature
Journal:
Scientific Reports
Issue Date:
11-Sep-2017
DOI:
10.1038/s41598-017-11650-x
Type:
Article
ISSN:
2045-2322
Sponsors:
N.C. and D.H.W. are grateful to EPSRC and N8/ARCHER. HGI was sponsored by KAUST and made use of the resources of the KAUST Supercomputing Laboratory and computer clusters.
Additional Links:
https://www.nature.com/articles/s41598-017-11650-x
Appears in Collections:
Articles; Clean Combustion Research Center

Full metadata record

DC FieldValue Language
dc.contributor.authorPapapostolou, Vassiliosen
dc.contributor.authorWacks, Daniel H.en
dc.contributor.authorChakraborty, Nilanjanen
dc.contributor.authorKlein, Markusen
dc.contributor.authorIm, Hong G.en
dc.date.accessioned2017-09-20T06:02:14Z-
dc.date.available2017-09-20T06:02:14Z-
dc.date.issued2017-09-11en
dc.identifier.citationPapapostolou V, Wacks DH, Chakraborty N, Klein M, Im HG (2017) Enstrophy transport conditional on local flow topologies in different regimes of premixed turbulent combustion. Scientific Reports 7. Available: http://dx.doi.org/10.1038/s41598-017-11650-x.en
dc.identifier.issn2045-2322en
dc.identifier.doi10.1038/s41598-017-11650-xen
dc.identifier.urihttp://hdl.handle.net/10754/625478-
dc.description.abstractEnstrophy is an intrinsic feature of turbulent flows, and its transport properties are essential for the understanding of premixed flame-turbulence interaction. The interrelation between the enstrophy transport and flow topologies, which can be assigned to eight categories based on the three invariants of the velocity-gradient tensor, has been analysed here. The enstrophy transport conditional on flow topologies in turbulent premixed flames has been analysed using a Direct Numerical Simulation database representing the corrugated flamelets (CF), thin reaction zones (TRZ) and broken reaction zones (BRZ) combustion regimes. The flame in the CF regime exhibits considerable flame-generated enstrophy, and the dilatation rate and baroclinic torque contributions to the enstrophy transport act as leading order sink and source terms, respectively. Consequently, flow topologies associated with positive dilatation rate values, contribute significantly to the enstrophy transport in the CF regime. By contrast, enstrophy decreases from the unburned to the burned gas side for the cases representing the TRZ and BRZ regimes, with diminishing influences of dilatation rate and baroclinic torque. The enstrophy transport in the TRZ and BRZ regimes is governed by the vortex-stretching and viscous dissipation contributions, similar to non-reacting flows, and topologies existing for all values of dilatation rate remain significant contributors.en
dc.description.sponsorshipN.C. and D.H.W. are grateful to EPSRC and N8/ARCHER. HGI was sponsored by KAUST and made use of the resources of the KAUST Supercomputing Laboratory and computer clusters.en
dc.publisherSpringer Natureen
dc.relation.urlhttps://www.nature.com/articles/s41598-017-11650-xen
dc.rightsThis article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.en
dc.rights.urihttp://creativecommons.org/licenses/by/4.0/en
dc.titleEnstrophy transport conditional on local flow topologies in different regimes of premixed turbulent combustionen
dc.typeArticleen
dc.contributor.departmentClean Combustion Research Centeren
dc.identifier.journalScientific Reportsen
dc.eprint.versionPublisher's Version/PDFen
dc.contributor.institutionUniversity of Newcastle, School of Mechanical and Systems Engineering, Newcastle, NE1 7RU, UK.en
dc.contributor.institutionDurham University, School of Engineering and Computing Sciences, Durham, DH1 3LE, UK.en
dc.contributor.institutionUniversity of Newcastle, School of Mechanical and Systems Engineering, Newcastle, NE1 7RU, UK. nilanjan.chakraboty@ncl.ac.uk.en
dc.contributor.institutionUniversität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, München, 85577, Neubiberg, Germany.en
kaust.authorIm, Hong G.en
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