Abstract: Sound-attenuating heat exchangers and methods of exchanging heat and attenuating sound within sound-attenuating heat exchangers. The sound-attenuating heat exchangers include a base region, which defines a first base side and a second base side, and a plurality of elongate fluid conduits, which are at least partially defined by the base region and configured to contain a cooled fluid stream. The sound-attenuating heat exchangers also include a plurality of heat transfer-enhancing structures, which extend from the first base side and are configured to exchange thermal energy with a cooling fluid stream, and a sound-attenuating region, which extends from the second base side. The sound-attenuating region includes a plurality of resonator cells configured to attenuate sound and a plurality of resonator cell openings. Each resonator cell opening opens from a corresponding resonator cell toward the plurality of heat transfer-enhancing structures.

Abstract: A blocker door assembly for use in a gas turbine includes a panel, a core integrally formed with the panel, and a plurality of mounting structures extending from at least one of the panel and the core. The plurality of mounting structures are integrally formed with the core and the panel such that the panel, the core, and the mounting structures are co-molded from a thermoplastic material.

Abstract: An example system for providing mechanical power to an aircraft accessory with a turbine engine, where the turbine engine includes a low-speed spool and a high-speed spool, includes an accessory gearbox disposed between the low-speed spool and the high-speed spool and a clutch disposed within or external to the accessory gearbox. The accessory gearbox is configured to drive the aircraft accessory, and the clutch is configured to enable either the high-speed spool or the low-speed spool to provide mechanical power to the aircraft accessory via the accessory gearbox.

Abstract: Shape memory alloy (SMA) actuators and thermal management systems including the same. An SMA actuator includes an SMA lifting tube and a process fluid conduit configured to convey a process fluid through the SMA lifting tube. The SMA actuator assumes a conformation that is based on the temperature of the process fluid. The SMA lifting tube includes a first end and a second end configured to translate relative to the first end at least partially along a lateral direction. A thermal management system is configured to regulate a temperature of a process fluid. The thermal management system includes a heat exchanger that at least partially defines a heat transfer region, a process fluid conduit configured to convey the process fluid through the heat transfer region, and an actuator assembly including the SMA actuator. The actuator assembly is configured to selectively position the heat exchanger within a thermal management fluid flow.

Abstract: An example system for providing mechanical power to an aircraft accessory with a turbine engine, where the turbine engine includes a low-speed spool and a high-speed spool, includes an accessory gearbox disposed between the low-speed spool and the high-speed spool and a clutch disposed within or external to the accessory gearbox. The accessory gearbox is configured to drive the aircraft accessory, and the clutch is configured to enable either the high-speed spool or the low-speed spool to provide mechanical power to the aircraft accessory via the accessory gearbox.

Abstract: A system (166) for transferring mechanical power in a turbine engine (150/151) including a low pressure spool (162) and a high pressure spool (156) includes a power transfer unit (168) coupled between an output shaft (172) of the low pressure spool (162) and a drive shaft (174) of the high pressure spool (156) to mechanically link the low pressure spool (162) to the high pressure spool (156), and a clutch (170) coupled to the power transfer unit (168), wherein the clutch (170) is configured to transfer power produced from the low pressure spool (162) to the high pressure spool (156).

Abstract: Shape memory alloy (SMA) actuators and thermal management systems including the same. An SMA actuator includes an SMA lifting tube and a process fluid conduit configured to convey a process fluid through the SMA lifting tube. The SMA actuator assumes a conformation that is based on the temperature of the process fluid. The SMA lifting tube includes a first end and a second end configured to translate relative to the first end at least partially along a lateral direction. A thermal management system is configured to regulate a temperature of a process fluid. The thermal management system includes a heat exchanger that at least partially defines a heat transfer region, a process fluid conduit configured to convey the process fluid through the heat transfer region, and an actuator assembly including the SMA actuator. The actuator assembly is configured to selectively position the heat exchanger within a thermal management fluid flow.

Abstract: A compact inlet design including a single bulkhead and/or an acoustic panel extending into nacelle lip region for noise reduction.

Abstract: A thermal management system includes a heat exchanger and a housing that receives the heat exchanger. The heat exchanger defines a heat transfer region within which thermal exchange occurs between a process fluid and a thermal management fluid. The thermal management system further includes a process fluid conduit to convey the process fluid through the heat transfer region and an actuator assembly configured to position the heat exchanger relative to the housing. The actuator assembly is configured to selectively assume a position between a stowed position and a deployed position. When the actuator assembly is in the deployed position, the heat transfer region extends within a flow of the thermal management fluid such that the process fluid flow flows in heat exchange relation with the thermal management fluid flow. In some such embodiments, the actuator assembly automatically transitions between the stowed position and the deployed position.

Abstract: A shape memory alloy (SMA) actuator includes an SMA lifting tube that extends between a first end and a second end and that is configured to be in thermal communication with a process fluid during operative use of the SMA actuator. The SMA actuator is configured to assume a conformation among a plurality of conformations defined between and including a first conformation and a second conformation based, at least in part, on the temperature of the process fluid that is in thermal communication with the SMA lifting tube. The SMA lifting tube is configured such that the second end translates relative to the first end at least partially along a lateral direction that is at least substantially perpendicular to at least a portion of the SMA lifting tube between the first end and the second end as the SMA actuator transitions between the first conformation and the second conformation.

Abstract: A compact inlet design including a single bulkhead and/or an acoustic panel extending into nacelle lip region for noise reduction. The compact inlet is used with a low power fluid ice protection system capable of preventing ice build-up on the acoustic panel in the nacelle lip region.

Abstract: A shape memory alloy (SMA) actuator includes an SMA lifting tube that extends between a first end and a second end and that is configured to be in thermal communication with a process fluid during operative use of the SMA actuator. The SMA actuator is configured to assume a conformation among a plurality of conformations defined between and including a first conformation and a second conformation based, at least in part, on the temperature of the process fluid that is in thermal communication with the SMA lifting tube. The SMA lifting tube is configured such that the second end translates relative to the first end at least partially along a lateral direction that is at least substantially perpendicular to at least a portion of the SMA lifting tube between the first end and the second end as the SMA actuator transitions between the first conformation and the second conformation.

Abstract: A thermal management system includes a heat exchanger and a housing that receives the heat exchanger. The heat exchanger defines a heat transfer region within which thermal exchange occurs between a process fluid and a thermal management fluid. The thermal management system further includes a process fluid conduit to convey the process fluid through the heat transfer region and an actuator assembly configured to position the heat exchanger relative to the housing. The actuator assembly is configured to selectively assume a position between a stowed position and a deployed position. When the actuator assembly is in the deployed position, the heat transfer region extends within a flow of the thermal management fluid such that the process fluid flow flows in heat exchange relation with the thermal management fluid flow. In some such embodiments, the actuator assembly automatically transitions between the stowed position and the deployed position.

Abstract: A system (166) for transferring mechanical power in a turbine engine (150/151) including a low pressure spool (162) and a high pressure spool (156) includes a power transfer unit (168) coupled between an output shaft (172) of the low pressure spool (162) and a drive shaft (174) of the high pressure spool (156) to mechanically link the low pressure spool (162) to the high pressure spool (156), and a clutch (170) coupled to the power transfer unit (168), wherein the clutch (170) is configured to transfer power produced from the low pressure spool (162) to the high pressure spool (156).

Abstract: A blocker door assembly for use in a gas turbine engine includes a facesheet including a plurality of openings to facilitate noise attenuation and a body portion coupled to the facesheet. The body portion includes a backsheet integrally formed with a honeycomb core, wherein the body portion is molded from a thermoplastic material.

Abstract: A blocker door assembly for use in a gas turbine includes a panel, a core integrally formed with the panel, and a plurality of mounting structures extending from at least one of the panel and the core. The plurality of mounting structures are integrally formed with the core and the panel such that the panel, the core, and the mounting structures are co-molded from a thermoplastic material.

Abstract: Thermal management systems incorporating shape memory alloy (SMA) actuators and related methods. A thermal management system includes a heat transfer region, a process fluid conduit, a thermal management fluid conduit, and an SMA actuator assembly. The SMA actuator assembly includes an SMA element coupled to an actuation element, which is configured to assume a position among a plurality of positions defined between a restrictive position and an open position. The position of the actuation element is based, at least in part, on a conformation of the SMA element. A method of passively regulating a temperature of a process fluid includes conveying a process fluid stream in heat exchange relation with an SMA element, transitioning the SMA element to assume a conformation, flowing each of the process fluid stream and a thermal management fluid stream through a heat transfer region, and modulating a flow rate of the thermal management fluid stream.

Abstract: Bleed air systems for use with aircraft and related methods are disclosed. An example apparatus includes a compressor having a compressor inlet, a compressor outlet, and a first drive shaft. The compressor outlet is to be fluidly coupled to a system of an aircraft that receives pressurized air, and the compressor inlet is to receive bleed air from a low-pressure compressor of an engine of the aircraft. The example apparatus includes a gearbox operatively coupled to the first drive shaft to drive the compressor. The gearbox is to be operatively coupled to and powered by a second drive shaft extending from the engine. The example apparatus also includes a clutch disposed between the first drive shaft and the gearbox to selectively disconnect the first drive shaft from the gearbox.

Abstract: A compression molding assembly for molding a honeycomb core, including a plurality of cells defined by a plurality of walls, of a blocker door is provided. The compression molding assembly includes a ram plate comprising a plurality of openings defined therethrough and a plurality of core inserts coupled to the ram plate such that the plurality of core inserts are configured to form the honeycomb core of the blocker door. Each core insert is removably coupled with a respective opening of the plurality of openings such that each core insert is configured to form a respective cell of the plurality of cells.

Abstract: Thermal management systems incorporating shape memory alloy (SMA) actuators and related methods. A thermal management system includes a heat transfer region, a process fluid conduit, a thermal management fluid conduit, and an SMA actuator assembly. The SMA actuator assembly includes an SMA element coupled to an actuation element, which is configured to assume a position among a plurality of positions defined between a restrictive position and an open position. The position of the actuation element is based, at least in part, on a conformation of the SMA element. A method of passively regulating a temperature of a process fluid includes conveying a process fluid stream in heat exchange relation with an SMA element, transitioning the SMA element to assume a conformation, flowing each of the process fluid stream and a thermal management fluid stream through a heat transfer region, and modulating a flow rate of the thermal management fluid stream.