Local Strain Rate and Curvature Dependences of Scalar Dissipation Rate Transport in Turbulent Premixed Flames: A Direct Numerical Simulation Analysis
The statistical behaviours of the instantaneous scalar dissipation rate Nc of reaction progress variable c in turbulent premixed flames have been analysed based on three-dimensional direct numerical simulation data of freely propagating statistically planar flame and V-flame configurations with diff...
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| Language: | English |
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Wiley
2014-01-01
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| Series: | Journal of Combustion |
| Online Access: | http://dx.doi.org/10.1155/2014/280671 |
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| author | Y. Gao N. Chakraborty N. Swaminathan |
| author_facet | Y. Gao N. Chakraborty N. Swaminathan |
| author_sort | Y. Gao |
| collection | DOAJ |
| description | The statistical behaviours of the instantaneous scalar dissipation rate Nc of reaction progress variable c in turbulent premixed flames have been analysed based on three-dimensional direct numerical simulation data of freely propagating statistically planar flame and V-flame configurations with different turbulent Reynolds number Ret. The statistical behaviours of Nc and different terms of its transport equation for planar and V-flames are found to be qualitatively similar. The mean contribution of the density-variation term T1 is positive, whereas the molecular dissipation term (-D2) acts as a leading order sink. The mean contribution of the strain rate term T2 is predominantly negative for the cases considered here. The mean reaction rate contribution T3 is positive (negative) towards the unburned (burned) gas side of the flame, whereas the mean contribution of the diffusivity gradient term (D) assumes negative (positive) values towards the unburned (burned) gas side. The local statistical behaviours of Nc, T1, T2, T3, (-D2), and f(D) have been analysed in terms of their marginal probability density functions (pdfs) and their joint pdfs with local tangential strain rate aT and curvature km. Detailed physical explanations have been provided for the observed behaviour. |
| format | Article |
| id | doaj-art-a995e8593b8d4bdfa25a63322a5d206a |
| institution | OA Journals |
| issn | 2090-1968 2090-1976 |
| language | English |
| publishDate | 2014-01-01 |
| publisher | Wiley |
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| series | Journal of Combustion |
| spelling | doaj-art-a995e8593b8d4bdfa25a63322a5d206a2025-08-20T02:23:06ZengWileyJournal of Combustion2090-19682090-19762014-01-01201410.1155/2014/280671280671Local Strain Rate and Curvature Dependences of Scalar Dissipation Rate Transport in Turbulent Premixed Flames: A Direct Numerical Simulation AnalysisY. Gao0N. Chakraborty1N. Swaminathan2School of Mechanical and Systems Engineering, Newcastle University, Claremont Road, Newcastle-Upon-Tyne NE1 7RU, UKSchool of Mechanical and Systems Engineering, Newcastle University, Claremont Road, Newcastle-Upon-Tyne NE1 7RU, UKCambridge University Engineering Department, Trumpington Street, Cambridge CB2 1PZ, UKThe statistical behaviours of the instantaneous scalar dissipation rate Nc of reaction progress variable c in turbulent premixed flames have been analysed based on three-dimensional direct numerical simulation data of freely propagating statistically planar flame and V-flame configurations with different turbulent Reynolds number Ret. The statistical behaviours of Nc and different terms of its transport equation for planar and V-flames are found to be qualitatively similar. The mean contribution of the density-variation term T1 is positive, whereas the molecular dissipation term (-D2) acts as a leading order sink. The mean contribution of the strain rate term T2 is predominantly negative for the cases considered here. The mean reaction rate contribution T3 is positive (negative) towards the unburned (burned) gas side of the flame, whereas the mean contribution of the diffusivity gradient term (D) assumes negative (positive) values towards the unburned (burned) gas side. The local statistical behaviours of Nc, T1, T2, T3, (-D2), and f(D) have been analysed in terms of their marginal probability density functions (pdfs) and their joint pdfs with local tangential strain rate aT and curvature km. Detailed physical explanations have been provided for the observed behaviour.http://dx.doi.org/10.1155/2014/280671 |
| spellingShingle | Y. Gao N. Chakraborty N. Swaminathan Local Strain Rate and Curvature Dependences of Scalar Dissipation Rate Transport in Turbulent Premixed Flames: A Direct Numerical Simulation Analysis Journal of Combustion |
| title | Local Strain Rate and Curvature Dependences of Scalar Dissipation Rate Transport in Turbulent Premixed Flames: A Direct Numerical Simulation Analysis |
| title_full | Local Strain Rate and Curvature Dependences of Scalar Dissipation Rate Transport in Turbulent Premixed Flames: A Direct Numerical Simulation Analysis |
| title_fullStr | Local Strain Rate and Curvature Dependences of Scalar Dissipation Rate Transport in Turbulent Premixed Flames: A Direct Numerical Simulation Analysis |
| title_full_unstemmed | Local Strain Rate and Curvature Dependences of Scalar Dissipation Rate Transport in Turbulent Premixed Flames: A Direct Numerical Simulation Analysis |
| title_short | Local Strain Rate and Curvature Dependences of Scalar Dissipation Rate Transport in Turbulent Premixed Flames: A Direct Numerical Simulation Analysis |
| title_sort | local strain rate and curvature dependences of scalar dissipation rate transport in turbulent premixed flames a direct numerical simulation analysis |
| url | http://dx.doi.org/10.1155/2014/280671 |
| work_keys_str_mv | AT ygao localstrainrateandcurvaturedependencesofscalardissipationratetransportinturbulentpremixedflamesadirectnumericalsimulationanalysis AT nchakraborty localstrainrateandcurvaturedependencesofscalardissipationratetransportinturbulentpremixedflamesadirectnumericalsimulationanalysis AT nswaminathan localstrainrateandcurvaturedependencesofscalardissipationratetransportinturbulentpremixedflamesadirectnumericalsimulationanalysis |