Abstract: A gas turbine engine includes a compressor section and a turbine section operably coupled to the compressor section. The gas turbine engine further includes a means for selectively releasing a cooling fluid flow produced at a cryogenic temperature and a plumbing system in fluid communication with the means for selectively releasing the cooling fluid flow. The plumbing system is configured to route the cooling fluid flow to one or more of the compressor section and the turbine section.

Abstract: An engine-driven cryogenic cooling system for an aircraft includes a first air cycle machine, a second air cycle machine, and a means for condensing a chilled air stream into liquid air for an aircraft use. The first air cycle machine includes a plurality of components operably coupled to a gearbox of a gas turbine engine and configured to produce a cooling air stream based on a first engine bleed source of the gas turbine engine. The second air cycle machine is operable to output the chilled air stream at a cryogenic temperature based on a second engine bleed source cooled by the cooling air stream of the first air cycle machine.

Abstract: A cryogenic cooling system for an aircraft includes a first air cycle machine, a second air cycle machine, and a means for collecting liquid air. The first air cycle machine is operable to output a cooling air stream based on a first air source. The second air cycle machine is operable to output a chilled air stream at a cryogenic temperature based on a second air source cooled by the cooling air stream of the first air cycle machine. An output of the second air cycle machine is provided to the means for collecting liquid air.

Abstract: A rotor dynamics adjustment system includes a rotor system with at least one compressor section and at least one turbine section operably coupled to a shaft. The rotor dynamics adjustment system also includes one or more rotor system sensors configured to collect a plurality of sensor data from the rotor system, an electric motor operably coupled to the rotor system, and a controller. The controller is operable to monitor the one or more rotor system sensors while the rotor system is rotating. A dynamic motion of the rotor system is characterized based on the sensor data from the one or more rotor system sensors. A damping correction torque is determined to diminish the dynamic motion of the rotor system. The electric motor is commanded to apply the damping correction torque to the rotor system.

Abstract: A compressor surge control system includes a rotor system with at least one compressor section and at least one turbine section operably coupled to a shaft. The compressor surge control system also includes one or more rotor system sensors configured to collect a plurality of sensor data from the rotor system, an electric motor operably coupled to the rotor system, and a controller. The controller is operable to monitor the one or more rotor system sensors while the rotor system is rotating. The controller determines whether the plurality of sensor data from the one or more rotor system sensors is indicative of an early-stage compressor surge oscillation. A surge control torque is determined to diminish the early-stage compressor surge oscillation of the rotor system. The electric motor is commanded to apply the surge control torque to the rotor system.

Abstract: An engine system for an aircraft includes a first gas turbine engine, a first core turning system, a second gas turbine engine, and a second core turning system. The engine system also includes a controller operable to shutdown the first gas turbine engine responsive to determining that the aircraft has landed and operate in the second gas turbine engine in a taxi mode while using the first core turning system to cool the first gas turbine engine. The controller is further operable to shutdown the second gas turbine engine and disable the first core turning system based on a power-down condition, restart the first gas turbine engine and use the second core turning system to cool the second gas turbine engine based on a restart condition, and complete cooling of the second gas turbine prior to restarting the second gas turbine engine.

Abstract: A gas generator has at least one compressor rotor, at least one gas generator turbine rotor and a combustion section. A fan drive turbine is positioned downstream of a path of the products of combustion having passed over the at least one gas generator turbine rotor. The fan drive turbine drives a shaft and the shaft engages gears to drive at least three fan rotors.

Abstract: An engine system for an aircraft includes a first gas turbine engine, a first core turning system, a second gas turbine engine, and a second core turning system. The engine system also includes a controller operable to shutdown the first gas turbine engine responsive to determining that the aircraft has landed and operate in the second gas turbine engine in a taxi mode while using the first core turning system to cool the first gas turbine engine. The controller is further operable to shutdown the second gas turbine engine and disable the first core turning system based on a power-down condition, restart the first gas turbine engine and use the second core turning system to cool the second gas turbine engine based on a restart condition, and complete cooling of the second gas turbine prior to restarting the second gas turbine engine.

Abstract: A thermoelectric conditioning arrangement may comprise a first antenna/splitter configured to transmit a power & control signal, a second antenna/splitter configured to receive the power & control signal, a waveguide coupled between the first antenna/splitter and the second antenna/splitter, wherein the power & control signal is guided from the first antenna/splitter to the second antenna/splitter via the waveguide, a power converter configured to receive the power & control signal from the second antenna/splitter and generate a direct current (DC) signal, and a thermoelectric cooler (TEC) configured to receive the DC signal from the power converter.

Abstract: An embodiment of an engine assembly includes a combustion turbine engine having at least a first compressor spool, a first turbine spool, a first shaft connecting the first compressor spool and the first turbine spool, and a combustor disposed in a working gas flow path between the first compressor spool and the first turbine spool. A first controller is programmed with a surge map, and configured to operate the combustion turbine engine in a range extending between a first suppressed idle mode, a second base idle mode, and a maximum takeoff power rating mode. An idle speed suppressor includes at least one idle assist motor connected to the first shaft of the combustion turbine engine.

Abstract: A propulsion system for an aircraft including at least two main gas turbine engines and a plurality of dedicated boundary layer ingestion fans. The propulsion system is arranged such that a combined thrust produced by the boundary layer ingestion fans is less than 20 percent of a total thrust of the main engines and the boundary layer ingestion fans. The boundary layer ingestion fans are controllable and selectively turned off at lower speeds.

Abstract: A compressor surge control system includes a rotor system with at least one compressor section and at least one turbine section operably coupled to a shaft. The compressor surge control system also includes one or more rotor system sensors configured to collect a plurality of sensor data from the rotor system, an electric motor operably coupled to the rotor system, and a controller. The controller is operable to monitor the one or more rotor system sensors while the rotor system is rotating. The controller determines whether the plurality of sensor data from the one or more rotor system sensors is indicative of an early-stage compressor surge oscillation. A surge control torque is determined to diminish the early-stage compressor surge oscillation of the rotor system. The electric motor is commanded to apply the surge control torque to the rotor system.

Abstract: A rotor dynamics adjustment system includes a rotor system with at least one compressor section and at least one turbine section operably coupled to a shaft. The rotor dynamics adjustment system also includes one or more rotor system sensors configured to collect a plurality of sensor data from the rotor system, an electric motor operably coupled to the rotor system, and a controller. The controller is operable to monitor the one or more rotor system sensors while the rotor system is rotating. A dynamic motion of the rotor system is characterized based on the sensor data from the one or more rotor system sensors. A damping correction torque is determined to diminish the dynamic motion of the rotor system. The electric motor is commanded to apply the damping correction torque to the rotor system.

Abstract: A cryogenic cooling system for an aircraft includes a first air cycle machine, a second air cycle machine, and a means for collecting liquid air. The first air cycle machine is operable to output a cooling air stream based on a first air source. The second air cycle machine is operable to output a chilled air stream at a cryogenic temperature based on a second air source cooled by the cooling air stream of the first air cycle machine. An output of the second air cycle machine is provided to the means for collecting liquid air.

Abstract: A drive arrangement for an aircraft comprises a pair of propulsor units each having a fan and a fan shaft for driving the fan. A core engine has a turbine driving a core engine shaft. A mechanical connection connects the core engine shaft to drive the fan shafts for each of the propulsor units. An aircraft also has such an arrangement.

Abstract: A thermoelectric conditioning arrangement may comprise a first antenna/splitter configured to transmit a power & control signal, a second antenna/splitter configured to receive the power & control signal, a waveguide coupled between the first antenna/splitter and the second antenna/splitter, wherein the power & control signal is guided from the first antenna/splitter to the second antenna/splitter via the waveguide, a power converter configured to receive the power & control signal from the second antenna/splitter and generate a direct current (DC) signal, and a thermoelectric cooler (TEC) configured to receive the DC signal from the power converter.

Abstract: A propulsion system for an aircraft comprises at least two main gas turbine engines and a plurality of dedicated boundary layer ingestion fans. An aircraft is also disclosed.

Abstract: A gas turbine engine is provided that includes a core flow path to direct a core stream flow. A common flow path is outboard of the core flow path, where the common flow path directs both a second stream flow and a third stream flow. Another gas turbine engine is provided that includes an outer case structure around a central longitudinal engine axis. An intermediate case structure is inboard of the outer case structure, where the intermediate case structure and the outer case structure direct both a third stream flow and a second stream flow. An inner case structure is inboard of the intermediate case structure, where the inner case structure and the intermediate case structure direct a core stream flow.

Abstract: A gas turbine engine comprises an outer nacelle. A nose cone is spaced radially inward of the outer nacelle. The nose cone defines a particle separator for directing an outer air flow and an inner airflow. The inner airflow is directed through a core inlet to a compressor. The engine further comprises a drive gear system for driving at least one propeller. A variable pitch control system may alter a pitch angle of the at least one propeller. Some of the outer air flow is directed to at least one of the drive gear system and the pitch control system.

Abstract: A gas generator has at least one compressor rotor, at least one gas generator turbine rotor and a combustion section. A fan drive turbine is positioned downstream of a path of the products of combustion having passed over the at least one gas generator turbine rotor. The fan drive turbine drives a shaft and the shaft engages gears to drive at least three fan rotors.