Flame Propagation and Fractal Dimension in a Concentric Double Cylinders Apparatus

Abstract

The aim of this study is to estimate the flame fractal dimensions of methane/air mixtures by experimentally measuring the apparent flame-propagation velocities. In this study, we used an apparatus consisting of two concentric cylinders. It was found that the larger the cylinder size, i.e. the flame scale, is, (i) the more the number of wrinkles of flame is, (ii) the faster the apparent flame-propagation velocity is, and (iii) the values of flame fractal dimension are varied from 1.3 to 2.0. It was also found that the fractal dimension increases with a decrease in equivalence ratio, which is likely because of the effect of preferential diffusion and/or the change in the Lewis number.