UNIQUE OPTICAL HIGH TEMPERATURE SENSORS FOR TURBINE ENGINES

ACCURATE MEASUREMENT OF TURBINE ENGINE TEMPERATURES UNDER ACTUAL OPERATING CONDITIONS REMAINS A MAJOR TECHNICAL CHALLENGE DUE TO THE HARSH ENGINE ENVIRONMENT. RELIABLE HIGH TEMPERATURE DATA WILL RESULT IN IMPROVED ENGINE DESIGNS AND PERFORMANCE. TACAN WILL STUDY TWO VERSIONS OF A NEW OPTICAL SENSOR UTILIZING RARE EARTH MATERIALS WITH HIGH TEMPERATURE LIGHT GUIDES. ONE SENSOR WILL USE THERMOGRAPHIC PHOSPHORS ADHERED TO THE END OF CERAMIC WAVEGUIDES. THIS DESIGN CONCEPT ELIMINATES THE LINE-OF-SIGHT AND ATTENUATION PROBLEMS PRESENT IN THE CURRENT TECHNIQUE OF APPLYING PHOSPHORS TO ENGINE SURFACES AND TRANSMITTING THE EXCITATION AND SIGNAL BEAMS ACROSS FREE SPACE OR THROUGH COMBUSTION GASES. THE SECOND SENSOR VERSION REPLACES THE EXCITATION LIGHT SOURCE AND ITS OPTICS TRAIN WITH A RADIOISOTOPE LOCATED IN THE SENSOR HEAD. BASED ON OUR EXPERIENCE WITH HIGH TEMPERATURE MATERIALS AND FIBER OPTIC SENSORS, WE EXPECT TO SHOW THE FEASIBILITY OF OUR APPROACH TO OBTAIN REPRODUCIBLE AND ACCURATE ENGINE TEMPERATURE DATA WITHOUT PERTURBINE FLOWS OR REQUIRING COMPONENT TRENCHING. THE SENSORS WHICH RESULT FROM OUR RESEARCH WILL COMPLEMENT EXISTING FIBER OPTIC TEMPERATURE SENSORS AND WILL FIND APPLICATIONS IN UNIQUE ENVIRONMENTS. OUR RESEARCH WILL ALSO LEAD TO THE DEVELOPMENT OF SELF-LUMINOUS MATERIALS WHICH CAN BE USED IN PAINTS AND MARKINGS.