Cellular instabilities and self-acceleration of outwardly propagating spherical flames

摘要: Using a recently developed constant and high-pressure combustion chamber, an experimental study wasconducted on several aspects of cellular instabilities outwardly propagating spherical premixed flames. Propane/air hydrogen/oxygen/nitrogen flames different concentrations under elevated pressures were used to systematically identify the influences thermal expansion ratio, flame thickness, global activation energy, mixture Lewis number, stretch rate generation hydrodynamic diffusional-thermal cells over surface. In particular, it was demonstrated that instability is greatly enhanced with increasing pressure hence decreasing although influence can also be moderated by progressively important three-body termination reactions as increases. The onset examined in light theory Bechtold Matalon, satisfactory qualitative acceptable quantitative comparisons observed. found self-accelerating, including those are diffusionally unstable, fractal dimensions between 2.20 2.25.