Fiber Optic Microprobes for Total Temperature and Pressure

Luna Innovations proposes to develop innovative micro-miniature high-frequency probes, based on Luna Innovations patented EFPI fiber-optic transducer technology, for total temperature and total pressure measurement. Very small probes are needed formeasuring the inlet temperature distortions introduced during testing of gas turbines used to simulate hot gas ingestion. STOVL operation increases the chance of hot gas ingestion, to which new lean burn combustor designs are much more sensitive. Thefiber-optic sensor to be developed will easily meet the needs of frequency response and minimum blockage, as well as being Electromagnetic Interference resistant, require fewer connections and can be multiplexed. During the Phase I development effort,Luna Innovations will concentrate on numerical modeling of the aerodynamics and the thermodynamics of a transducer for total temperature measurement. Luna Innovations expertise in miniature fiber optic sensors will be utilized to design and develophousings meeting the 1/16in diameter requirement. All design studies and analysis will also be preformed with the incorporation of the pressure sensor kept in mind. The Phase II effort will then focus on the integration of a pressure sensor into the totaltemperature probe for a hybrid probe, as well as the development of the support electronics and algorithms. As engine efficiency of commercial engines are improved and emissions are reduced by new lean combustor designs, the ingestion of hot gases duringtaxi and takeoff will become much more important to model and test to mitigate the effects on the stability of the combustion. It is anticipated that this technology will find use in every gas turbine test facility, enabling performance improvements andemissions reduction. Luna Innovations is certain that this technology will push state of the art for aero-probes and will be enabling technology for the VAATE and Joint Strike Fighter programs, and is certain that the military and commercial industry willembrace the developed technology and implementation will be widespread.