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An assessment of large eddy simulations of premixed flames propagating past repeated obstacles
journal contribution
posted on 2009-11-20, 15:13 authored by Sreenivasa Rao Gubba, Salah Ibrahim, Weeratunge MalalasekeraWeeratunge Malalasekera, Assaad R. MasriThis paper presents an assessment of Large Eddy Simulations in calculating the
structure of turbulent premixed flames propagating past solid obstacles. One objective
of the present study is to evaluate the LES simulations and identify the drawbacks in
accounting the chemical reaction rate. Another objective is to analyse the flame
structure and to calculate flame speed, generated overpressure at different time intervals
following ignition of a stoichiometric propane/air mixture. The combustion chamber has
built-in repeated solid obstructions to enhance the turbulence level and hence increase
the flame propagating speed. Various numerical tests have also been carried out to
determine the regimes of combustion at different stages of the flame propagation. These
have been identified from the calculated results for the flow and flame characteristic
parameters. It is found that the flame lies within the ‘thin reaction zone’ regime which
supports the use of the laminar flamelet approach for modelling turbulent premixed
flames. A sub-model to calculate the model coefficient in the algebraic flame surface
density model is implemented and examined. It is found that the LES predictions are
slightly improved due to the calculation of model coefficient by using sub-model.
Results are presented and discussed in this paper are for the flame structure, position,
speed, generated pressure and the regimes of combustion during all stages of flame
propagation from ignition to venting. The calculated results are validated against
available experimental data.
History
School
- Mechanical, Electrical and Manufacturing Engineering
Citation
GUBBA, S.R... et al, 2009. An assessment of large eddy simulations of premixed flames propagating past repeated obstacles. Combustion Theory and Modelling, 13(3), pp.513-540.Publisher
© Taylor & FrancisVersion
- AM (Accepted Manuscript)
Publication date
2009Notes
This article was published in the journal, Combustion Theory and Modelling [© Taylor & Francis]. The definitive version is available from: http://dx.doi.org/10.1080/13647830902928532ISSN
1741-3559;1364-7830Language
- en