Influence of Flame on Phase Doppler Anemometry

Abstract

The objective of the present study is to clarify the influence of a flame on phase-Doppler-anemometry (PDA) and to discuss quantitatively the accuracy of droplet size and velocity measurement using a polystyrene particle with a known size and a Bunsen burner placed on the optical path of PDA to simulate the variation of the refractive index of a combusting field. It was found that the fluctuation of the flame significantly influences the measured values, especially those of size, and some scattering of data was observed, while the measured mean diameter obtained in these experiments had little difference depending on the existence of a flame in front of the PDA optics or not. Furthermore, we tried to elucidate the cause of errors by comparing the scatter of measured size with the displacement of incident laser beams. As a result, it was found that the displacement of the laser beams is related to errors caused by the interference of the flame on the optical path of PDA.