Abstract: The gas turbine engine can have an air mover configured for generating a flow of air around a rotation axis; a surface extending around the rotation axis delimiting a passage for the flow of air downstream of the air mover; an electric machine disposed within the passage and coupled to the air mover; a coolant circuit having: an evaporator circumferentially disposed around at least part of the electric machine and in thermal communication therewith; a condenser having a surface cooler circumferentially disposed at least partially around the surface and in thermal communication therewith; a first conduit fluidly connecting an upper region of the evaporator to an upper region of the condenser; and a second conduit fluidly connecting a lower region of the condenser to a lower region of the evaporator; and a coolant fluid in the coolant circuit.

Abstract: The aircraft can have a first engine secured to a first wing on a first side of a fuselage, and a second engine secured to a second wing on a second side of the fuselage, the second wing having a proximal end secured to the fuselage, and a distal end extending away from the fuselage. While operating the first engine, compressed gas can be conveyed from the first engine to a thrust generating device located at the distal end of the second wing.

Abstract: An electric fan for producing thrust to propel an aircraft is disclosed. The electric fan comprises a stator, a fan rotor rotatably mounted relative to the stator and an electric motor mounted to the stator and drivingly engaged with the fan rotor to cause rotation of the fan rotor relative to the stator. The fan rotor comprises an annular body defining a flow passage therethrough and a plurality of fan blades disposed in the flow passage and mounted for common rotation with the annular body about a fan rotation axis. The electric motor has a motor rotation axis that differs from the fan rotation axis.

Abstract: The gas turbine engine can have an air mover configured for generating a flow of air around a rotation axis; a surface extending around the rotation axis delimiting a passage for the flow of air downstream of the air mover; an electric machine disposed within the passage and coupled to the air mover; a coolant circuit having: an evaporator circumferentially disposed around at least part of the electric machine and in thermal communication therewith; a condenser having a surface cooler circumferentially disposed at least partially around the surface and in thermal communication therewith; a first conduit fluidly connecting an upper region of the evaporator to an upper region of the condenser; and a second conduit fluidly connecting a lower region of the condenser to a lower region of the evaporator; and a coolant fluid in the coolant circuit.

Abstract: An electric fan for producing thrust to propel an aircraft is disclosed. The electric fan comprises a stator, a fan rotor rotatably mounted relative to the stator and an electric motor mounted to the stator and drivingly engaged with the fan rotor to cause rotation of the fan rotor relative to the stator. The fan rotor comprises an annular body defining a flow passage therethrough and a plurality of fan blades disposed in the flow passage and mounted for common rotation with the annular body about a fan rotation axis. The electric motor has a motor rotation axis that differs from the fan rotation axis.

Abstract: The aircraft can have a first engine secured to a first wing on a first side of a fuselage, and a second engine secured to a second wing on a second side of the fuselage, the second wing having a proximal end secured to the fuselage, and a distal end extending away from the fuselage. While operating the first engine, compressed gas can be conveyed from the first engine to a thrust generating device located at the distal end of the second wing.

Abstract: A gas turbine engine system includes a boost compressor configured to compress air; a combustor in which the compressed air is mixed with fuel and ignited to generate a stream of combustion gases; and a turbine configured to extract energy from the combustion gases, the turbine being drivingly coupled to the boost compressor and to an output shaft via a differential gearbox configured to apportion an input torque from the turbine between a first output torque applied to the output shaft and a second output torque applied to the boost compressor.

Abstract: An engine assembly for an aircraft, including an internal combustion engine having a liquid coolant system in fluid communication with a heat exchanger, an exhaust duct in fluid communication with air passages of the heat exchanger, a fan in fluid communication with the exhaust duct for driving a cooling air flow through the air passages of the heat exchanger and into the exhaust duct, and an intermediate duct in fluid communication with an exhaust of the engine and having an outlet positioned within the exhaust duct downstream of the fan and upstream of the outlet of the exhaust duct. The outlet of the intermediate duct is spaced inwardly from a peripheral wall of the exhaust duct. The engine assembly may be configured as an auxiliary power unit. A method of discharging air and exhaust gases in an auxiliary power unit having an internal combustion engine is also discussed.

Abstract: A hybrid gas-electric turbine engine for turboprop or turboshaft applications is disclosed together with associated methods. In various embodiments disclosed herein, the turbine engine comprises a turbine configured to be driven by a flow of combustion gas; a turbine shaft configured to be driven by the turbine and transfer power to a load coupled to the turbine engine and an electric motor configured to transfer power to the load coupled to the turbine engine. The rotor may have a rotor axis of rotation that is radially offset from a shaft axis of rotation of the turbine shaft. In some embodiments, the electric motor may be a multi-rotor electric motor.

Abstract: A gas turbine engine system includes a boost compressor configured to compress air; a combustor in which the compressed air is mixed with fuel and ignited to generate a stream of combustion gases; and a turbine configured to extract energy from the combustion gases, the turbine being drivingly coupled to the boost compressor and to an output shaft via a differential gearbox configured to apportion an input torque from the turbine between a first output torque applied to the output shaft and a second output torque applied to the boost compressor.

Abstract: An auxiliary power unit includes a load compressor configured to generate compressed air for an environmental control system of an aircraft; a gas turbine engine drivingly coupled to the load compressor; and a conduit establishing fluid communication between the load compressor and an injection location in a gas path of the gas turbine engine to direct at least some of the compressed air generated by the load compressor to the injection location, the injection location being upstream of a turbine of the gas turbine engine.

Abstract: An electric fan for producing thrust to propel an aircraft is disclosed. The electric fan comprises a stator, a fan rotor rotatably mounted relative to the stator and an electric motor mounted to the stator and drivingly engaged with the fan rotor to cause rotation of the fan rotor relative to the stator. The fan rotor comprises an annular body defining a flow passage therethrough and a plurality of fan blades disposed in the flow passage and mounted for common rotation with the annular body about a fan rotation axis. The electric motor has a motor rotation axis that differs from the fan rotation axis.

Abstract: An exhaust system for a gas turbine engine, such as an APU, comprises a pressure vessel having an annular wall circumscribing an exhaust plenum. The annular wall is composed of an arrangement of individual tubes assembled side-by-side around a central axis of the exhaust plenum. The tubes are fed with pressurized cooling air, such as P3 air. A heat exchanger in heat transfer relationship with the exhaust gases flowing through the exhaust plenum receives air from the tubes. The heat transferred from the exhaust gases to the air circulated through the heat exchanger may be used to provide pre-heated air to the engine combustor.

Abstract: An engine assembly for an aircraft, including an internal combustion engine having a liquid coolant system in fluid communication with a heat exchanger, an exhaust duct in fluid communication with air passages of the heat exchanger, a fan in fluid communication with the exhaust duct for driving a cooling air flow through the air passages of the heat exchanger and into the exhaust duct, and an intermediate duct in fluid communication with an exhaust of the engine and having an outlet positioned within the exhaust duct downstream of the fan and upstream of the outlet of the exhaust duct. The outlet of the intermediate duct is spaced inwardly from a peripheral wall of the exhaust duct. The engine assembly may be configured as an auxiliary power unit. A method of discharging air and exhaust gases in an auxiliary power unit having an internal combustion engine is also discussed.

Abstract: An exhaust system for a gas turbine engine, such as an APU, comprises a pressure vessel having an annular wall circumscribing an exhaust plenum. The annular wall is composed of an arrangement of individual tubes assembled side-by-side around a central axis of the exhaust plenum. The tubes are fed with pressurized cooling air, such as P3 air. A heat exchanger in heat transfer relationship with the exhaust gases flowing through the exhaust plenum receives air from the tubes. The heat transferred from the exhaust gases to the air circulated through the heat exchanger may be used to provide pre-heated air to the engine combustor.

Abstract: A hybrid gas-electric turbine engine for turboprop or turboshaft applications is disclosed together with associated methods. In various embodiments disclosed herein, the turbine engine comprises a turbine configured to be driven by a flow of combustion gas; a turbine shaft configured to be driven by the turbine and transfer power to a load coupled to the turbine engine and an electric motor configured to transfer power to the load coupled to the turbine engine. The rotor may have a rotor axis of rotation that is radially offset from a shaft axis of rotation of the turbine shaft. In some embodiments, the electric motor may be a multi-rotor electric motor.

Abstract: A fan blade platform assembly comprises a plate insert shaped and dimensioned to span a gap formed between the opposed facing platforms of adjacent fan blades of a turbo fan engine. The plate insert can be retained in engagement under arresting shoulders provided on the adjacent fan blades by a spring force exerted by a spring insert held captive and in contact between the plate insert and an outer surface of the fan hub.

Abstract: A fan blade anti-fretting insert is described whereby to reduce wear between the root portion of a fan blade and the root slot of the rotor fan hub of a turbo fan engine to which the fan blade are secured. The anti-fretting insert can be formed of a composite spring material having a memory and is dimensioned and shaped to be fitted between the fan blade platform and the outer surface portion of the rotor fan hub between adjacent fan blades, whereby to apply a pushing force against the platform and consequently to the fan blades secure thereto thereby applying a resulting pulling force on the root portion of the fan blades to prevent rocking of the root portion in their root slots formed in the rotor fan hub.

Abstract: A single oil nozzle unit is mounted in a bearing compartment of a gas turbine engine for providing multiple individual jets for the individual bearing components in the bearing compartment.

Abstract: A fan blade anti-fretting insert is described whereby to reduce wear between the root portion of a fan blade and the root slot of the rotor fan hub of a turbo fan engine to which the fan blade are secured. The anti-fretting insert can be formed of a composite spring material having a memory and is dimensioned and shaped to be fitted between the fan blade platform and the outer surface portion of the rotor fan hub between adjacent fan blades, whereby to apply a pushing force against the platform and consequently to the fan blades secure thereto thereby applying a resulting pulling force on the root portion of the fan blades to prevent rocking of the root portion in their root slots formed in the rotor fan hub.