Gas turbine combustors pose many modeling and design difficulties. This has created an urgent need for experimental research using laser diagnostics to validate and refine computer design models of combustors. In this paper, key practical problems, limitations, and our operational experience with laser diagnostic systems for gas turbine combustion research are described.
It is found that unavailability of a good LDA seeder design and an unambiguous particle bias correction scheme present the main obstacles to using LDA in gas turbine combustor measurements. The practical problems of the Raman/Rayleigh system, particularly above 1200 K are high background luminosity, beam steering due to unmixedness, and high Poisson uncertainty in temperature and concentration measurements. The integration of LDA-Raman systems is beset by optical and data acquisition difficulties. Therefore, considerable work is still required to make the applications of advanced laser diagnostics to measurements in a practical gas turbine combustor a reality.