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

Abstract

In a systematic investigation under well-defined flame conditions, dynamic light scattering (DLS) was applied to the determination of soot particle radii with the aim of examining the suitability of this technique for accurate soot particle sizing. In particular, flat premixed methane–, propane–, ethene–, 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, soot volume fraction and particle number density were determined; also, the temperature was measured at each flame condition. In comparison to absorption techniques, attractive features of DLS are its independence of the particle 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 evaluation of the potential of DLS as a complement to other soot diagnostic techniques.