Cellular structures on premixed flames in a uniform laminar flow
These results show a good qualitative agreement with the model of a threefold instability mechanism. The marginal stability is crossed when the strength of the hydrodynamic instability is increased following an increase in the normal flame speed. The critical velocity is lowered by decreasing the Lewis number due to the destabilizing influence of transverse mass fluxes. As expected, the critical wavelength is principally related to the critical flame speed and does not vary significantly from one fuel to another. This analysis has also led to a good estimation of the behavior of stable flame fronts in a weakly turbulent flow /11/.
However, the quantitative discrepancy evident in figure 8 may result from an over-simplification of the chemical kinetic scheme in the model (overall one-step reaction), from finite size effects in the burner or even from the neglect of non linear effects which appear as soon as the threshold is crossed /12/.
KeywordsEquivalence Ratio Flame Front Marginal Stability Lewis Number Premix Flame
Unable to display preview. Download preview PDF.
- 1-.A. Smithells and H. Ingle, “The structure and chemistry of flames“; J. Chem. Soc. 61, 204 (1892).Google Scholar
- 2-.W.B. Bush, F.E. Fendell, “Asymptotic analysis of laminar flame propagation for general Lewis number”, Combustion Sci. and Techn., 1, 421–428 (1970)Google Scholar
- 3-.L. Landau, “on the theory of slow combustion”. Acta Physico-chimica URSS, 19, 77–85 (1944)Google Scholar
- 4-.L. Landau, E. Lifchitz, “Mécanique des Fluides”, ed.Mir, Moscou (1971).Google Scholar
- 5-.P. Pelcé, P. Clavin, “Influence of hydrodynamics and diffusion upon the stability limits of laminar premixed flames”, J. Fluid Mech., 124, 218–237 (1982)Google Scholar
- 6-.J. Quinard, G. Searby, L. Boyer, “The stability limits and critical size of structures in premixed flames”. To appear in the proceedings of the 9th ICODERS, Poitiers (1983)Google Scholar
- 7-.L. Boyer, G. Searby, J. Quinard, “Some recent applications of Laser Tomography in combustion”. Proceedings of the XV ICHMT Symposium on Heat and Mass Transfer Measurement Techniques. Dubrovnik (1983) to appear.Google Scholar
- 9-.P. Clavin, C. Nicoli, “Effect of the heat-losses on the limits of stability of premixed flames propagating downwards“ to appear in Comb. and Flame.Google Scholar
- 10-.P. Clavin, P. Garcia, “The influence of the temperature dependence of diffusivities on the dynamics of flame fronts; J. Mécanique Théo. et Appl. 2, 245–263 (1983)Google Scholar
- 12-.P. Pelcé, “Influence du champ de pesanteur sur la propagation d'un front de flamme courbé dans un tube”, Colloque de Mécanique appliquée, Ecole INRIA — CEA — EDF, Session combustion (18–21 oct. 83).Google Scholar