Concentration measurement in a transient gas jet using laser induced fluorescence method

Instantaneous measurement of density distribution as cross section of jet, in particular is very effective to understand direct factors, eq. scale or uniformity of mixture, which affect combustion performance. Using laser induced fluorescence, mixture spreading process of intermittent unsteady jet flow was measured, and transformed into visual image of instantaneous concentration distribution of jet at its cross section. Quantitative measuring method of density distribution in jet was thus established. In thus study, the following effects and problems of the concentration process to get concentration image from fluorescence image, such as: linearity between concentration and fluorescence emission, temperature and the kind of ambient gas effects on fluorescence, induced laser absorption and fluorescence extinction by fluorescence gas, are discussed.