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The Structure And Stability Of Expanding And Converging Near-Stoichiometric Flames, Raymond Addabbo

Dissertations

The stability of expanding and converging premixed flames is investigated theoretically. These configurations are inherently unsteady and represent simple examples of positively (expanding) and negatively (converging) stretched flames. A new model is employed in this study that incorporates both hydrodynamic and diffusional-thermal effects. The model expands earlier works by incorporating variable transport properties, variations in the mixture strength and a more realistic dependence on viscosity.

The expanding flame is shown to remain stable at small radii provided the thermal diffusivity exceeds the mass diffusivity of the deficient reactant. However, once the flame achieves a critical size, a cellular instability appears, …