Development of an Optical Fiber Type of Fluctuation Concentration Measuring System of Multiple Species by the Light Absorption Spectrometric Method

Abstract

For the purpose of investigating the mixing process and reacting diffusion of multiple species in turbulent flows, a system of measuring the simultaneous concentration fluctuation of each species is developed using the light absorption spectrometric technique. This system makes it possible to measure instantaneous concentration of three species, which have light absorption bands between visible and near-infrared rays (wavelength 300∼2000 nm). An optical glass fiber with the diameter of 0.5 mm is used to introduce the light into a sampling part whose volume is about 4×10^-4 cc. The quantitative measurements are documented in a turbu1ent jet of the mixture of two species with the premixed ratio of 1.0. The measured concentration fluctuation properties for each species show good agreements with the past data, so it is ascertained that the present system enables one to measure simultaneously the concentration of two species.