Abstract

In almost all combustion systems the liquid fuel is injected into the combustor as a spray. Spray formation, vaporization, and mixing with the oxidizer determine the quality of the combustion process and thereby the amount of unwanted emissions. A laser diagnostic is needed which can monitor these processes in order to optimize them. Especially the distributions of vaporized fuel and of oxidizer are of interest including regions where liquid fuel is coexisting. A well-known method to discriminate between different phases of the fuel is the exciplex fluorescence technique developed by Melton and Verdieck [1]. Quantitative results are difficult to obtain if oxygen, the oxidizer in almost all combustion systems, is present. Another technique is based on the fluorescence of acetone which is practically independent of its phase. Phase discrimination is done by using the huge difference in molecular density [2]. The high absorption coefficient for the used UV light prevented saturation of the CCD camera by liquid droplets.

© 1998 Optical Society of America