Flame front surface characteristics in turbulent premixed propane/air combustion

摘要: The characteristics of the flame front surfaces in turbulent premixed propane/air flames were investigated. Flame images obtained using laser-induced fluorescence (LIF) OH and Mie scattering on two Bunsen–type burners 11.2-mm 22.4-mm diameters. Nondimensional turbulence intensity, u′/SL, was varied from 0.9 to 15, Reynolds number, based integral length scale, 40 467. Approximately 100 recorded for each experimental condition. Fractal parameters (fractal dimension, inner outer cutoffs) corresponding standard deviations determined by analysis caliper technique. fractal dimensions derived are almost identical. However, cutoffs consistently higher than those scattering. self-similar region wrinkling is about a decade all studied. In nondimensional intensity range 1 it found that mean dimension 2.2 does not show any dependence intensity. This contradicts findings previous studies showed asymptotically reaches 2.35–2.37 when u′/SL exceeds 3. It shown reason this discrepancy image method used studies. Examples given inadequacy circle extraction images. so far, studies, capable correctly predicting burning velocity available area closure model.