Sharpe, G.J. (2008) Effect of thermal expansion on the linear stability of planar premixed flames for a simple chain-branching model: The high activation energy asymptotic limit. Combustion Theory and Modelling, 12 (4). pp. 717-738. ISSN 1364-7830Full text available as:
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The linear stability of freely propagating, adiabatic, planar premixed ames is investigated in the context of a simple chain-branching chemistry model consisting of a chain-branching reaction step and a completion reaction step. The role of chain-branching is governed by a crossover temperature. Hydrodynamic effects, induced by thermal expansion, are taken into account and the results compared and contrasted with those from a previous purely thermal-di�usive constant density linear stability study. It is shown that when thermal expansion is properly accounted for, a region of stable ames predicted by the constant density model disappears, and instead the ame is unstable to a long-wavelength cellular instability. For a pulsating mode, however, thermal expansion is shown to have only a weak e�ect on the critical fuel Lewis number required for instability. These e�ects of thermal expansion on the two-step chain-branching ame are shown to be qualitatively similar to those on the standard one-step reaction model. Indeed, as found by constant density studies, in the limit that the chain-branching crossover temperature tends to the adiabatic ame temperature, the two-step model can be described to leading order by the one-step model with a suitably de�ned e�ective activation energy.
|Copyright, Publisher and Additional Information:||© 2008 Taylor & Francis. This is an author produced version of a paper published in 'Combustion Theory and Modelling'. Uploaded in accordance with the publisher's self-archiving policy.|
|Keywords:||Thermal expansion, planar premixed flames|
|Institution:||The University of Leeds|
|Academic Units:||The University of Leeds > Faculty of Engineering (Leeds) > School of Mechanical Engineering (Leeds) > Institute of Engineering Thermofluids, Surfaces & Interfaces (iETSI) (Leeds)|
|Depositing User:||Mrs Fiona Slade|
|Date Deposited:||15 Jan 2010 16:30|
|Last Modified:||19 Sep 2013 16:20|
|Publisher:||Taylor & Francis|