Raman Scattering Studies of Combustion

Abstract

–The need for spatially and temporally well-resolved non-perturbing measurement techniques for modern combustion systems has stimulated development of various new methods for sensing the physical and chemical conditions. Strong requirements are imposed upon new potential techniques by the specific needs of combustion science and technology, such as the necessity to probe rapidly fluctuating, luminous hot flows which can contain more than one phase. Furthermore, the proven capabilities for some of these applicat ions of presentday probes, such as thermocouples, hot wires, gas sampling apparatus, etc., lead to the conclusion that new combustion sensors should be developed for experimental conditions for which present probes are clearly not adequate or for which they cannot survive. Raman scattering is described here as a candidate measurement technique which can satisfy many of the needs of combustion experiments, but which must be applied with care and discretion in order to avoid disadvantages arising from its low intensity. Basic measurement principles and applications are described, and alternate stronger scattering processes are mentioned.