Turbine Exhaust Gas Temperature (EGT) Sensor Development: FBG-Based Sensing using Sapphire Optical Fibers

EGT measurement in gas-turbine engines is considered a key parameter for optimizing fuel economy and PHM systems.Currently, direct EGT measurements made on turbine modules are limited due to the ultra high temperature (UHT) environment. Accurate EGT measurements and durable sensors are of specific importance for high-performance military turbine engines.optoXense will develop a new FBG-based EGT sensor system, which involves fiberoptic sensing technology developed for operation in UHT conditions using sapphire fibers instead of the silica fibers to raise the operating temperatures to 1600C.Phase-I development includes: (a) producing a minimally intrusive EGT sensor based on silica fibers but with UHT housing materials, to account for actual deployment conditions, (b) demonstrating a development path to prove viability of FBG temperature sensing with sapphire fibers, (c) conducting laboratory tests and verification, and (d) developing a plan for engine test cell experiments, and a path for commercial application of the technology.In Phase-II, optoXense will implement singlemode (SM) sapphire fibers for hosting FBG temperature sensors and produce the associated UHT optomechanical coupling to standard SM optical fiber for routing outside the UHT zones.optoXense will also demonstrate the sensor ruggedness, precision, accuracy, and frequency response in a representative engine test facility.