Propagation of symmetric and non-symmetric premixed flames in narrow channels: Influence of conductive heat-losses

• Published in: Combustion and flame Vol. 161; no. 4; pp. 927 - 936
• Main Authors: Kurdyumov, Vadim N., Jiménez, Carmen
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Inc 01.04.2014; Elsevier
• Subjects: Applied sciences; Channels; Combustion; Combustion instabilities; Combustion. Flame; Discontinuity; Energy; Energy. Thermal use of fuels; Exact sciences and technology; Flow rate; Heat exchange; Laminar flow; Mathematical analysis; Miscellaneous; Non-symmetric flames; Premixed flame dynamics; Premixed flames; Theoretical studies. Data and constants. Metering; Premixed flame dynamics; Combustion instabilities; Non-symmetric flames; Combustion instability; Diffusion flame; Propagation; Premixed flame; Heat loss
• ISSN: 0010-2180; 1556-2921
• DOI: 10.1016/j.combustflame.2013.10.002

Two-dimensional symmetric and non-symmetric premixed flames propagating in a narrow channel subject to a Poiseuille flow are investigated within the context of a diffusive-thermal model. Attention is focussed on the impact of the flame-wall heat exchange on the structure and stability of flames. It is found that an increase in the heat-losses leads to a discontinuity of the steady-state response curves: for Le<1 the flame extinguishes inside a finite interval of flow rate values while for Le>1 the flame cannot exist for flow rates larger or smaller than some critical values. Linear stability analysis of two-dimensional steady-state flames is also performed. It is shown that for symmetric flames with low Lewis number the heat-losses produce a stabilization effect while for flames with high Lewis number the increase in heat-losses tends to flame destabilization, producing oscillatory (symmetric or non-symmetric) behavior.