Abstract: A shape memory alloy (SMA) actuated aerostructure operable to dynamically change shape according to flight conditions is disclosed. Deformable structures are actuated by SMA actuators that are coupled to face sheets of the deformable structures. Actuating the SMA actuators produces complex shape changes of the deformable structures by activating shape changes of the SMA actuators. The SMA actuators are actuated via an active or passive temperature change based on operating conditions. The SMA actuated aerostructure can be used for morphable nozzles such as a variable area fan nozzle and/or a variable geometry chevron of a jet engine to reduce engine noise during takeoff without degrading fuel burn during cruise.

Abstract: A system and method is provided that improves the under frequency response of gas turbines by providing a fast-response power augmentation system. The system includes a tank storing a blended mixture of motive fuel such as ethanol or methanol and demineralized water in a predetermined ratio that is provided as a diluent to be injected into the compressor bellmouth, the Compressor Discharge Chamber (CDC), and/or the combustion system via one to three dedicated circuits. To achieve the instantaneous injection of the diluent at the correct pressure and for the appropriate duration to meet the needs of the gas turbine Grid compliance mandate, an accumulator is used as the motive force to drive the augmentation fluid in the dedicated circuits. The injected diluent is microprocessor controlled to either be simultaneous into all three circuits or is sequenced based on a determination of the best turbine control and performance.

Abstract: The invention relates to a turbomachine thermomechanical part forming a body of revolution about a longitudinal axis, and including at least one abradable ring for a labyrinth seal. In characteristic manner, the abradable ring is made up of angular sectors that present different stiffnesses between adjacent pairs of sectors. The invention is applicable to a compressor, a turbine, or to a rotor and stator assembly.

Abstract: A turbine overspeed control system for use with a gas turbine engine of a gas turbine electrical powerplant. The overspeed control system preferably comprises a first and second overspeed control subsystem. When an overspeed condition of the gas turbine engine is detected, the first overspeed control subsystem acts to remove air from a combustion section of the engine, while the second overspeed control subsystem operates to alter the angle at which an incoming flow of air is supplied to a compressor turbine located therein. The result of operating the first and/or second overspeed control subsystem is a reduction in the speed of the gas turbine engine that is much more rapid than can be accomplished by simply shutting off a fuel supply thereto.

Abstract: A microprocessor-based control system for a gas turbine electrical powerplant the microprocessor-based control system controls the startup, operation, and shutdown of the gas turbine electric powerplant. The microprocessor-based control system of the present invention dispenses with the need to utilize relays, timers, or other control hardware. Rather, the microprocessor-based control system employs software that replaces the control hardware, and directly reads the inputs, calculates the control actions, and writes the outputs. The microprocessor-based control system is also in electrical communication with an overspeed control system, provided to ensure that a runaway condition of the gas turbine engine does not occur should the gas turbine engine become disconnected from the speed reducer (gearbox) or generator. Sensors are used to monitor multiple operating conditions of the powerplant.

Abstract: A control system for selectively adjusting effective flow areas of an aircraft engine exhaust nozzle to change operational characteristics of the nozzle. The control system includes a chamber having a hollow interior, a plurality of outlet passages extending from the hollow interior of the chamber to sites within the exhaust nozzle, and an adjustable inlet extending from a pressurized air source to the hollow interior of the chamber for delivering a jet of pressurized air to the chamber. The inlet is adjustable to direct pressurized air to selected one or more outlet passages for the delivery of air via the one or more outlets to corresponding one or more sites within the exhaust nozzle, thereby to change the operational characteristics of the nozzle.

Abstract: A pressure controlled pintle is employed in combination with a throttling quid, gel, or hybrid engine to provide a constant pressure and variable thrust from a single operating engine. As the propellants are throttled back and the chamber pressure drops, the pintle moves and closes the gap between the pintle and nozzle throat, thereby lowering the throat area and re-establishing the design chamber pressure related to pintle spring tension. By retaining the design pressure over a wide thrust range, the engine efficiency remains at the design value. This eliminates the drop of Isp due to pressure and keeps the cost of the system reasonable because only one engine is required. When a higher thrust is desired, a throttling valve in an injector increases the propellant flow rate, which causes a higher pressure in the combustion chamber. The constant pressure actuator moves the pintle to open the nozzle throat, which reduces the pressure to the design value. The design value may not be optimum.

Abstract: Apparatus for sensing and transmitting physical intelligence is disclosed. In one embodiment the intelligence is transmittable from the sensing device to a remotely positioned, intelligence processing unit. The apparatus taught has particular applicability to gas turbine engine control systems requiring the encoding and transmission of accurate physical intelligence from a hostile environment to the remotely positioned intelligence processing unit. Techniques employing time sequencing through a fiber optic circuit of the transmitted intelligence to reduce the size, weight and complexity of the apparatus are developed.