An aircraft propulsion system is disclosed and includes a first gas turbine engine including a first input shaft driving a first gear system, a first fan driven by the first gear system, a first generator supported on the first input shaft and a fan drive electric motor providing a drive input to the first fan, a second gas turbine engine including a second input shaft driving a second gear system, a second fan driven by the second gear system, a second generator supported on the second input shaft and a second fan drive electric motor providing a drive input to the second fan and a controller controlling power output from each of the first and second generators and directing the power output between each of the first and second fan drive electric motors.

An aircraft propulsion system comprises a gas turbine engine arranged to provide propulsive thrust and a fuel cell system having an air input port, the aircraft propulsion system being configured such that air from a compressor of the gas turbine engine is provided to the air input port during operation of the aircraft propulsion system. The fuel cell system is able to provide appreciable electrical power at altitude without the need for a dedicated compressor.

A gas turbine propulsion system includes a shroud that defines a fluid flow path. A gas turbine engine in the fluid flow path includes a compressor, a combustor downstream from the compressor, and a turbine downstream from the combustor. An electric generator in the fluid flow path defined by the shroud includes a rotor coaxially aligned with the turbine. A propulsor is upstream from the gas turbine engine, and an electric motor is operably coupled to the propulsor to rotate the propulsor. The propulsor is rotationally isolated from the gas turbine engine so that the propulsor rotates independently from operation of the gas turbine engine.

A twin-engine system includes a gas turbine engine comprising a core and a first output shaft drivable by the core. An electric engine has an electric motor configured to drive a second output shaft. A reduction gear box (RGB) has an RGB input drivingly engaged to both the first output shaft and the second output shaft. The RGB has an RGB output to provide rotational output to a rotatable load.

A system includes a first electric motor that when in operation imparts rotation to a fan stage of an engine. The system also includes a combustion section of the engine comprising a combustor that when in operation generates combustion gas through ignition of fuel and compressed air. The system further includes a turbine of the engine coupled to a shaft of the engine, wherein the turbine when in operation receives the combustion gas from the combustion section and imparts rotation to the shaft using the combustion gas.

A hybrid hydrogen-electric and hydrogen turbine engine and system is disclosed. The hydrogen-electric system has an air inlet, a hydrogen fuel source, a fuel cell stack, and a motor assembly disposed in electrical communication with the fuel cell stack. The hydrogen turbine system has an air intake in fluid communication with the air inlet of the hydrogen-electric system, a combustion chamber in fluid communication with the air intake and the hydrogen fuel source of the hydrogen-electric system, the combustion chamber configured to mix air received from the air intake with hydrogen received from the hydrogen fuel source, and a turbine driven by energy received from the combustion chamber. The hydrogen-electric system and the hydrogen turbine system cooperate with one another to generate the output power of the hybrid hydrogen engine system.

A system includes a gas turbine engine of an aircraft, the gas turbine engine having a low speed spool, a high speed spool, and a combustor. The system also includes a low spool motor configured to augment rotational power of the low speed spool and a high spool motor configured to augment rotational power of the high speed spool. The system further includes a controller configured to cause fuel flow. The controller is configured to control a thrust response of the gas turbine engine to a thrust target between zero and a thrust level to move the aircraft during engine start and during engine idle. The controller is also configured to control the low spool motor to drive rotation of the low speed spool responsive to a thrust command while the controller does not command fuel flow to the combustor.

A system includes a gas turbine engine of an aircraft, the gas turbine engine having a low speed spool, a high speed spool, and a combustor. The system also includes a low spool motor configured to augment rotational power of the low speed spool and a high spool motor configured to augment rotational power of the high speed spool. The system further includes a controller configured to cause fuel flow. The controller is configured to control a thrust response of the gas turbine engine to a thrust target between zero and a thrust level to move the aircraft during engine start and during engine idle. The controller is also configured to control the low spool motor to drive rotation of the low speed spool responsive to a thrust command while the controller does not command fuel flow to the combustor.

An integrated hydrogen-electric engine including an air compressor system, a hydrogen fuel source, a fuel cell stack, a heat exchanger, an elongated shaft, and a motor assembly. The heat exchanger is disposed in fluid communication with the hydrogen fuel source and the fuel cell stack. The elongated shaft supports the air compressor system, the fuel cell stack and the heat exchanger. The motor assembly is disposed in electrical communication with the fuel cell stack.

A system configured to compress air to be used by a power generation system includes a first compressor stage configured to be driven by exhaust air from the power generation system and a second compressor stage configured to be driven by electrical power generated by the power generation system.