Gas turbines with turbine inlet temperatures of 2500 to 3000 F are planned for the future. A critical element of the advanced controls needed for a turbine of this type is the turbine inlet temperature sensor to protect vital engine hardware and the registration of gas temperature for power controls. The paper discusses the requirements for high temperature sensor advancements, since currently developed sensors have short life, slow response, and are not sufficiently accurate. Considerable discussion is devoted to the capabilities of two different types of thermocouples and a radiation pyrometer to sense turbine hardware. Innovative concepts, such as a gas collimator lens, the use of fiber optics to avoid environmental test temperature, effects of combustion gases on radiant intensity, and emissivity changes on indicated temperature are discussed.
High temperatures and rotative speeds of future U. S. Army aircraft propulsion systems will impose increasingly severe operating requirements on oil-lubricated engine bearings and associated seals. Accordingly, air-lubricated bearings are being investigated as a possible approach to alleviating the lubrication problems. This paper presents the results of design and performance studies, as well as bearing component tests, relative to applying air bearings to a two-shaft, 3.5-lb/sec turboshaft engine. The test results verify that air bearings can carry the maximum loads imposed by flight and landing conditions, and can survive the sliding contacts associated with 15,000 engine start/stop cycles. Incentives for pursuing the air-bearing approach are identified, as are also the development and problem areas.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.