The effect of Lewis number variation on combustion waves in a model with chain-branching reaction

Autor:	Geoff Mercer, A. V. Kolobov, A. A. Polezhaev, Vladimir Gubernov, Harvinder S. Sidhu
Rok vydání:	2008
Předmět:	Premixed flame Hopf bifurcation Chemistry Applied Mathematics Thermodynamics Geometry General Chemistry Combustion Flame speed Lewis number Physics::Fluid Dynamics symbols.namesake symbols Physics::Chemical Physics Adiabatic process Dimensionless quantity Linear stability
Zdroj:	Journal of Mathematical Chemistry. 44:816-830
ISSN:	1572-8897 0259-9791
Popis:	In this paper we investigate the linear stability and properties of the travelling premixed combustion waves in a model with two-step chain-branching reaction mechanism in the adiabatic limit in one spatial dimension. It is shown that the Lewis number for fuel has a significant effect on the properties and stability of premixed flames, whereas the Lewis number for the radicals has only quantitative (but not qualitative) effect on the combustion waves. We demonstrate that when the Lewis number for fuel is less than unity the flame speed is unique and is a monotonically decreasing function of the dimensionless activation energy. The combustion wave is stable and exhibits extinction for finite values of activation energy as the flame speed decreases to zero. For fuel Lewis number greater than unity the flame speed is a double-valued function. The slow solution branch is shown to be unstable whereas the fast solution branch is either stable or exhibits the onset of pulsating instabilities via the Hopf bifurcation. The evolution of these instabilities leads to flame extinction.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::7ca7f609c10f192af6adea669ede74a2 https://doi.org/10.1007/s10910-008-9363-x Zobrazit plný text záznamu Plný text ve formátu PDF