FFT method of dynamic light scattering for particle size diagnostics in luminous flames

Abstract Time correlation spectroscopy was used to measure the size of luminous particles in situ in wick flames and in candle flames containing particle sizes for which little information has been available. The time correlation function of scattered light from the particle in the scattering volume is related to diffusion due to the micro-Brownian motion of the particles. The fluctuation term directly related to the dynamic light scattering was emphasized by improving the observation system. The particle diffusion constants in the luminous area of kerosene lamp and candle flames were about 9–12 × 10 −9 and 5–8 × 10 −9 m 2 /s, respectively. The particle size estimation can be related to the diffusion constant using kinetic or hydrodynamic relations.