Direct numerical simulation of a turbulent lifted flame: Stabilisation mechanism

S. Karami, E. R. Hawkes, M. Talei, H. Yu

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

A turbulent lifted slot-jet flame is studied using direct numerical simulation (DNS). A single step chemistry model is employed with a mixture-fraction dependent activation energy to quantitatively reproduce the dependence of laminar burning rate on equivalence ratio that is typical of hydrocarbon fuels. It is observed that the leading flame edge exhibits a single branch close to the stoichiometric mixture fraction iso-surface, rather than a tribrachial structure. The flame edge has a complex, highly convoluted structure suggesting it can burn at speeds that are much faster than SL. There is no evidence of a rich inner premixed flame or detached diffusion flame islands, in contrast with the observation in the previous DNS studies of hydrogen flames. On average, the streamwise velocity balances the streamwise flame propagation, confirming that flame propagation is the basic stabilisation mechanism. The analysis of the flow and propagation velocities reveal an elliptical pattern of flame motion around the average stabilisation point. Visualisation of the flame suggests that this motion is connected with the passage of large eddies.

Original languageEnglish (US)
Title of host publicationProceedings of the 19th Australasian Fluid Mechanics Conference, AFMC 2014
PublisherAustralasian Fluid Mechanics Society
ISBN (Electronic)9780646596952
StatePublished - 2014
Event19th Australasian Fluid Mechanics Conference, AFMC 2014 - Melbourne, Australia
Duration: Dec 8 2014Dec 11 2014

Publication series

NameProceedings of the 19th Australasian Fluid Mechanics Conference, AFMC 2014

Other

Other19th Australasian Fluid Mechanics Conference, AFMC 2014
CountryAustralia
CityMelbourne
Period12/8/1412/11/14

ASJC Scopus subject areas

  • Fluid Flow and Transfer Processes

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  • Cite this

    Karami, S., Hawkes, E. R., Talei, M., & Yu, H. (2014). Direct numerical simulation of a turbulent lifted flame: Stabilisation mechanism. In Proceedings of the 19th Australasian Fluid Mechanics Conference, AFMC 2014 (Proceedings of the 19th Australasian Fluid Mechanics Conference, AFMC 2014). Australasian Fluid Mechanics Society.