HIGH-TEMPERATURE PHOSPHOR THERMOMETRY OF ROTATING TURBINE-BLADES

Remote-temperature sensing using thermal phosphors is being developed as a nonintrusive technique for monitoring and analyzing the high-temperature, highly corrosive environments of turbomachinery. Proof-ofprinciple tests were conducted on phosphor-coated turbine blades that were rotating at low speeds and were immersed in a jet fuel flame. A pulsed nitrogen laser produced fluorescence from the applied phosphor. A simple optical scheme collected this emission, and a digital oscilloscope extracted from the signal the temperature-dependent decay rate. Measured temperatures ranged from 700-1000°C. These were comparable with values indicated by a pyrometer. Time-dependent temperature measurements demonstrated the transient capabilities of the thermophosphor technique. This is only the second time the phosphor technique has been implemented in a flame environment. The previous work involved a water-cooled object near 150°C. The current test was at a much higher temperature and incorporated a rotating object as well. The data provide important information for designing a thermophosphor system for future real-engine testing. © 1990 American Institute of Aeronautics and Astronautics, Inc., All rights reserved.