FIBEROPTIC PROBE FOR LASER-INDUCED FLUORESCENCE MEASUREMENTS OF THE FUEL-AIR DISTRIBUTION IN GAS-TURBINE COMBUSTORS

A fiber-optic probe has been developed for spatially and temporally re solved measurements of the equivalence ratio in actual gas-turbine com bustors. The measurement is based on laser-induced fluorescence, where acetone is used as a fluorescence seed. The effects of acetoin concen tration, temperature, and pressure on the fluorescence signal have bee n characterized in a steady flow test cell at temperatures (up to 400 degrees C) and pressures (up to 12 atm) representative of real-gas-tur bine combustors. The capabilities of the fiber-optic probe have been d emonstrated by making measurements in a turbulent axisymmetric airjet. Under typical measurement conditions it has been shown that the mean and rms fluctuation of the equivalence ratio can be determined with an accuracy of better than +/- 5%.