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Characteristics of Propagating Tribrachial Flames in Counterflow  

Ko, Young-Sung (Korea Aerospace Research Institute)
Chung, Tae-Man (School of Mechanical and Aerospace Engineering, Seoul National University)
Chung, Suk-Ho (School of Mechanical and Aerospace Engineering, Seoul National University)
Publication Information
Journal of Mechanical Science and Technology / v.16, no.12, 2002 , pp. 1710-1718 More about this Journal
Abstract
The effect of fuel concentration gradient on the propagation characteristics of tribrachial (or triple) flames has been investigated experimentally in both two-dimensional and axisymmetric counterflows. The gradient at the stoichiometric location was controlled by the equivalence ratios at the two nozzles; one of which is maintained rich, while the other lean. Results show that the displacement speed of tribrachial flames in the two-dimensional counterflow decreases with fuel concentration gradient and has much larger speed than the maximum speed predicted previously in two-dimensional mixing layers. From an analogy with premixed flame propagation, this excessively large displacement speed can be attributed to the flame propagation with respect to burnt gas. Corresponding maximum speed in the limit of small mixture fraction gradient was estimated and the curvefit of the experimental data substantiates this limiting speed. As mixture fraction gradient approaches zero, a transition occurs, such that the propagation speed of tribrachial flame approaches stoichiometric laminar burning velocity with respect to burnt gas. Similar results have been obtained for tribrachial flames propagating in axisymmetric counterflow.
Keywords
Propagation Speed; Tribrachial Flame; Counterflow;
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1 Buckmaster, J. and Matalon, M., 1988, 'Anomalous Lewis Number Effects in Tribrachial Flames,' Proc. Combust. Inst., Vol. 22, pp. 1527-1535
2 Cha, M. S. and Chung, S. H., 1996, 'Characteristics of Lifted Flames in Nonpremixed Turbulent Confined Jets,' Proc. Combust. Inst., Vol. 26, pp. 121-128
3 Chung, S. H. and Lee, B. J., 1991, 'On the Characteristics of Laminar Lifted Flames in a Nonpremixed Jet,' Combust. Flame, Vol. 86, pp. 62-72   DOI   ScienceOn
4 Lee S. D. and Chung S. H., 1994, 'On the Structure and Extinction of Interacting Lean Methane Air Premixed Flames,' Combust. Flame, Vol. 98, pp.80-92   DOI   ScienceOn
5 Lockett, R. D., Boulanger, B., Harding, S. C. and Greenhalgh, D. A., 1999, 'The Structure and Stability of the Laminar Counter-flow Partially Premixed Methane/Air Triple Flame,' Combust. Flame, Vol. 119, pp. 109-120   DOI   ScienceOn
6 Mielenz, O., Schlottmann, F. and Rogg, B., 1999, 'Experimental Investigations of Laminar Triple Flames and Triplet Flames in Strained Flow Fields,' Seventeenth ICDERS, Paper no. 215
7 Phillips, H., 1965, 'Flame in a Buoyant Methane Layer,' Proc. Combust. Inst., Vol. 10, pp. 1277-1283
8 Plessing, T., Terhoeven, P., Peters, N. and Mansour, M. S., 1998, 'An Experimental and Numerical Study of a Laminar Triple Flame,' Combust. Flame, Vol. 115, pp. 335-353   DOI   ScienceOn
9 Ruetsch, G. R., Vervisch, L. and Linan, A., 1995, 'Effects of Heat Release on Triple Flames,' Phys. Fluids, Vol. 7, pp. 1447-1454   DOI   ScienceOn
10 Daou, J. and Linan, A., 1998, 'The Role of Unequal Diffusivities in Ignition and Extinction Fronts in Strained Mixing Layers,' Combust. Theory Modelling, Vol. 2, pp.449-477   DOI   ScienceOn
11 Im, H. G. and Chen, J. H., 1999, 'Structure and Propagation of Triple Flames in Partially Premixed Hydrogen-air Mixtures,' Combust. Flame, Vol. 119, pp. 436-454   DOI   ScienceOn
12 Veynante, D., Vervisch, L., Poinsot, T., Linan A. and Ruetsch, G., 1994, 'Triple Flame Struc ture and Diffusion Flame Stabilization,' Proceedings of the Summer Program, Center for Turbu lence Research, pp.55-73
13 Dold, J. W., 1989, 'Flame Propagation in a Nonuniform Mixture: Analysis of a Slowly Varying Triple Flame,' Combust. Flame, Vol. 76, pp.71-88   DOI   ScienceOn
14 Domingo, P. and Vervisch, L., 1996, 'Triple Flames and Partially premixed Combustion in Autoignition of Non-premixed Turbulent Mixtures,' Proc. Combust. Inst., Vol. 26, pp.233-240
15 Law, C. K., 1993, in Reduced Kinetic Mechanism for Application in Combustion Systems (N. Peters and B. Rogg, Eds.), Lecture Notes, in Physics Series m15, Springer-Verlag, Berlin, pp. 15-26
16 Lee, B. J., Kim, J. S. and Chung, S. H., 1994, 'Effect of Dilution of the Liftoff of Nonpremixed Jet Flames,' Proc. Combust. Inst., Vol. 25, pp.1175-1181
17 Echekki, T, Chen, J. H., 1998, 'Structure and Propagation of Methanol-Air Triple Flames,' Combust. Flame, Vo. 114, pp.231-245   DOI   ScienceOn
18 Ghosal, S. and Vervisch, L., 2000, 'Theoretical and Numerical Study of a Symmetrical Triple Flame using the Parabolic Flame Path Approximation,' J. Fluid Mech., Vol. 415, pp.227-260   DOI   ScienceOn
19 Kioni, P. N., Rogg, B., Bray, K. N. C. and Linan, A., 1993, 'Flame Spread in Laminar Mixing Layers: The Triple Flame,' Combust. Flame, Vol. 95, pp. 276-290   DOI   ScienceOn
20 Kioni, P. N., Bray, K. N. C., Greenhalgh, D. A., Rogg, B., 1999, 'Experimental and Numerical Studies of a Triple Flame,' Combust. Flame, Vol. 116, pp. 192-206   DOI   ScienceOn
21 Ko, Y. S. and Chung, S. H., 1999, 'Propagation of Unsteady Tribrachial Flames in Laminar Non-premixed Jets,' Combust. Flame, Vol. 118, pp.151-163   DOI   ScienceOn
22 Smooke, M. D., 1982, 'Solution of BurnerStabilized Premixed Laminar Flame by Boun dary Value Methods,' J. Computat. Phys., Vol 48, pp. 72 -105   DOI   ScienceOn
23 Lee, B. J., Cha, M. S. and Chung, S. H., 1997, 'Characteristics of Laminar Lifted Flames in a Partially Premixed Jets,' Combust. Sci. Technol., Vol. 127, pp. 55-70   DOI
24 Lee, B. J. and Chung, S. H., 1997, 'Stabilization of Lifted Tribrachial Flames in a Laminar Nonpremixed Jet,' Combust. Flame, Vol. 109, pp.163-172   DOI   ScienceOn