Formative Diagnosis of NO & Soot by LIF & LLS Methods of YAG Laser

Abstract

An experimental study was made of two-dimensional visualization on soot particles and NO in steady and unsteady flames by laser sheet. The soot volume fraction are obtained from the scattered light intensity of the soot by LLS (laser-light scattered) method, since the relation between the light intensity and the soot volume fraction by light attenuation method is determined quantitatively. And NO distribution was measured by planar laser-induced fluorescence (LIF) method. It was found that the soot volume fraction lay within the limits of 10-7 and 10-5 (cm3/cm3), and had maxima at the inside of ribbon flame front. The reaction of soot decomposition became actively with the eddy break down over the downstream. The distribution NO and flame temperature showed a similar tendency. LIF intensity of NO agreed relatively with the NO concentration of the sampling gas measured by chemiluminescence method.