Dynamic light scattering in sooting premixed atmospheric-pressure methane-, propane-, ethene-, and propene-oxygen flames

In a systematic investigation under well-defined flame conditions, dynamic light scattering (DLS) was applied to the determination of soot particle ra dii with the aim of examining the suitability of this technique for accurat e soot particle sizing. In particular, flat premixed methane-, propane-, et hene-, and propene-oxygen flames at atmospheric pressure were investigated, and particle sizes were obtained as a function of stoichiometry and height above the burner surface. In combination with absorption measurements, soo t volume fraction and particle number density were determined; also, the te mperature was measured at each flame condition. In comparison to absorption techniques, attractive features of DLS are its independence of the particl e refractive index and its insensitivity to fluorescence interference; also , it offers spatial resolution. In principle, additional information on the particle size distribution as well as on the global shape of the particles may be obtained from DLS experiments. This study is therefore an evaluatio n of the potential of DLS as a complement to other soot diagnostic techniqu es. (C) 1999 by The Combustion Institute.