A Direct Numerical Simulation study of a turbulent lifted flame in hot oxidizer

Shahram Karami, Evatt R. Hawkes, Mohsen Talei

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4 Citations (Scopus)

Abstract

This paper presents a Direct Numerical Simulation (DNS) study of the stabilisation of a turbulent lifted flame in hot oxidizer, a problem of practical significance in diesel engines, gas turbines, and recirculating industrial burners. A slot jet of fuel issuing into a hot co-flow oxidizer stream is simulated using a single-step chemistry model and assuming unity Lewis number. A jet Reynolds number of 5,300 was enabled by the use of scalable high-order numerical methods and highly parallel computation. The basic structure of the flame is described noting features of the flame base and trailing premixed and diffusion flames. The flame base is studied to determine whether the stabilisation is due auto-ignition, premixed flame propagation, or another mechanism. The flame index (FI) is used to distinguish non-premixed flames from premixed flames close to the flame base. The time evolution of temperature, reaction rate and scalar dissipation rate along with iso-lines of appropriate temperature and most reactive mixture fraction are analysed to identify the flame base. It is concluded that the flame base exists on the outer boundary of the jet and consists of mainly non-premixed flames followed by a vigorous trailing rich premixed flame region inside the jet.

Original languageEnglish
Title of host publicationProceedings of the 18th Australasian Fluid Mechanics Conference, AFMC 2012
PublisherAustralasian Fluid Mechanics Society
ISBN (Electronic)9780646583730
Publication statusPublished - 2012
Externally publishedYes
EventAustralasian Fluid Mechanics Conference 2012 - University of Tasmania (Newnham Campus), Launceston, Australia
Duration: 3 Dec 20127 Dec 2012
Conference number: 18th
http://www.18afmc.com.au/

Conference

ConferenceAustralasian Fluid Mechanics Conference 2012
Abbreviated titleAFMC 2012
CountryAustralia
CityLaunceston
Period3/12/127/12/12
OtherThe 18th AFMC is to be the 1st of a series which will be held every 2 years by The Australasian Fluid Mechanics Society.
Internet address

Cite this

Karami, S., Hawkes, E. R., & Talei, M. (2012). A Direct Numerical Simulation study of a turbulent lifted flame in hot oxidizer. In Proceedings of the 18th Australasian Fluid Mechanics Conference, AFMC 2012 Australasian Fluid Mechanics Society.