Dinesh_Comb T and M .pdf (1.44 MB)
Download file

Identification and analysis of instability in non-premixed swirling flames using LES

Download (1.44 MB)
journal contribution
posted on 20.11.2009, 14:33 by K.K.J. Ranga-Dinesh, K.W. Jenkins, M.P. Kirkpatrick, Weeratunge MalalasekeraWeeratunge Malalasekera
Large eddy simulations (LES) of turbulent non-premixed swirling flames based on the Sydney swirl burner experiments under different flame characteristics are used to uncover the underlying instability modes responsible for the centre jet precession and large scale recirculation zone. The selected flame series known as SMH flames have a fuel mixture of methane-hydrogen (50:50 by volume). The LES solves the governing equations on a structured Cartesian grid using a finite volume method, with turbulence and combustion modelling based on the localised dynamic Smagorinsky model and the steady laminar flamelet model respectively. The LES results are validated against experimental measurements and overall the LES yields good qualitative and quantitative agreement with the experimental observations. Analysis showed that the LES predicted two types of instability modes near fuel jet region and bluff body stabilized recirculation zone region. The Mode I instability defined as cyclic precession of a centre jet is identified using the time periodicity of the centre jet in flames SMH1 and SMH2 and the Mode II instability defined as cyclic expansion and collapse of the recirculation zone is identified using the time periodicity of the recirculation zone in flame SMH3. Finally frequency spectra obtained from the LES are found to be in good agreement with the experimentally observed precession frequencies.

History

School

  • Mechanical, Electrical and Manufacturing Engineering

Citation

RANGA-DINESH, K.K.J., ....et al., 2009. Identification and analysis of instability in non-premixed swirling flames using LES. Combustion Theory and Modelling, 13 (6), pp.947–971.

Publisher

© Taylor & Francis

Version

AM (Accepted Manuscript)

Publication date

2009

Notes

This article was accepted for publication in the journal, Combustion Theory and Modelling, [© Taylor & Francis] and the definitive version is available at: http://dx.doi.org/10.1080/13647830903295899

ISSN

1364-7830;1741-3559

Language

en