Local extinction and reignition in a turbulent lifted flame

Shahram Karami, Mohsen Talei, Evatt R. Hawkes

Research output: Chapter in Book/Report/Conference proceedingConference PaperOtherpeer-review

Abstract

Direct numerical simulation (DNS) was used to analyse local extinction and reignition in a lifted turbulent flame. The edge flame propagation velocity appears to be dependent on the scalar dissipation rate consistent with previous experimental and numerical studies. This dependency is analysed with a model proposed for laminar triple flames, showing a good agreement for moderate scalar dissipation rates and an under- and over-predictions of the DNS results in very low and high scalar dissipation rates, respectively. These discrepancies are then explained based on the model’s assumptions. The extinction and reignition are also analysed separately where the distinction is made based on the average hole diameter. It is revealed that during the extinction process, the edge flame is primarily a nonpremixed flame and propagation velocity reduces in a non-linear manner as scalar dissipation rate increases. In the reignition process, the flame experiences a wide range of premixed and non-premixed modes and the edge propagation velocity, conditionally averaged on the scalar dissipation rate decreases linearly when the scalar dissipation rate increases.
Original languageEnglish
Title of host publicationAustralian Combustion Symposium 2015 Proceedings
EditorsYi Yang, Negel Smith
Place of PublicationMelbourne Vic Australia
PublisherThe Combustion Institute - Australian and New Zealand Section
Pages168-171
Number of pages4
Publication statusPublished - Dec 2015
Externally publishedYes
EventAustralian Combustion Symposium 2015 - University of Melbourne, Melbourne, Australia
Duration: 7 Dec 20159 Dec 2015

Conference

ConferenceAustralian Combustion Symposium 2015
CountryAustralia
CityMelbourne
Period7/12/159/12/15

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