A gas turbine engine includes a compressor section having a first compressor and a second compressor and a turbine section having a first turbine and a second turbine. The first compressor is connected to the first turbine via a first shaft and the second compressor is connected to the second turbine via a second shaft. A motor connected to the first shaft such that rotational energy generated by the motor is translated to the first shaft. A power distribution system connects the motor to a stored power system including at least one of an energy storage unit and a supplementary power unit. The power distribution system is configured to provide power from the stored power system to the motor.

An aircraft cooling device for cooling a fluid in a fluid supply and/or drainage device of an aircraft in flight, the aircraft cooling device being configured as a skin component for the aircraft, the skin component including an integrated ply of one or more hollow fibers, each hollow fiber being configured for conducting the fluid from one end portion to another end portion of the hollow fiber such that the fluid supply and/or drainage device is enabled to pump the fluid through the one or more hollow fibers when in fluid connection with ply.

An aircraft cooling device for cooling a fluid in a fluid supply and/or drainage device of an aircraft in flight, the aircraft cooling device being configured as a skin component for the aircraft, the skin component including an integrated ply of one or more hollow fibers, each hollow fiber being configured for conducting the fluid from one end portion to another end portion of the hollow fiber such that the fluid supply and/or drainage device is enabled to pump the fluid through the one or more hollow fibers when in fluid connection with ply.

A fuel cell system having at least one fuel cell with an external surface; and one or more of audio, image, or strain sensors external to the fuel cell surface, configured for detecting a change in the external surface of the fuel cell indicative of a fault condition. The at last one sensor may include a visual camera, an IR camera, an IR detector, or a UV-responsive camera, or an ultrasound transducer, a piezoelectric sensor and a vibration sensor, or a surface acoustic wave detector, or a mass spectrometer.

A fuel cell system having at least one fuel cell with an external surface; and one or more of audio, image, or strain sensors external to the fuel cell surface, configured for detecting a change in the external surface of the fuel cell indicative of a fault condition. The at last one sensor may include a visual camera, an IR camera, an IR detector, or a UV-responsive camera, or an ultrasound transducer, a piezoelectric sensor and a vibration sensor, or a surface acoustic wave detector, or a mass spectrometer.

A fuel cell system includes: a gas turbine having a combustion chamber and a turbine; a hydrogen fuel cell configured to generate electrical energy from input air and input hydrogen; an air flow path for providing air from a source of fresh air as input air to the fuel cell and to the combustion chamber; and a closed hydrogen loop for providing hydrogen from a liquid or compressed hydrogen source to the fuel cell and to the combustion chamber. The system further includes: a hydrogen recirculation loop receiving hydrogen from the liquid or compressed hydrogen source and hydrogen used by the fuel cell to provide cooled used hydrogen, The hydrogen recirculation loop combines the cooled used hydrogen with hydrogen from the liquid or compressed hydrogen source to provide to the fuel cell as the input hydrogen.

A fuel cell system includes: a gas turbine having a combustion chamber and a turbine; a hydrogen fuel cell configured to generate electrical energy from input air and input hydrogen; an air flow path for providing air from a source of fresh air as input air to the fuel cell and to the combustion chamber; and a closed hydrogen loop for providing hydrogen from a liquid or compressed hydrogen source to the fuel cell and to the combustion chamber. The system further includes: a hydrogen recirculation loop receiving hydrogen from the liquid or compressed hydrogen source and hydrogen used by the fuel cell to provide cooled used hydrogen, The hydrogen recirculation loop combines the cooled used hydrogen with hydrogen from the liquid or compressed hydrogen source to provide to the fuel cell as the input hydrogen.

A method is provided for operating a propulsion system having a gas turbine engine and a fuel cell assembly. The fuel cell assembly includes a fuel cell. The method includes: receiving gas composition data of output products from the fuel cell; and controlling operation of the fuel cell assembly, the gas turbine engine, or both in response to the received gas composition data of the output products from the fuel cell.

A method is provided for operating a propulsion system having a gas turbine engine and a fuel cell assembly. The fuel cell assembly includes a fuel cell. The method includes: receiving gas composition data of output products from the fuel cell; and controlling operation of the fuel cell assembly, the gas turbine engine, or both in response to the received gas composition data of the output products from the fuel cell.

A fuel cell thermal management system and method for aerodynamic vehicles (such as aircraft) having propulsion systems powered by hydrogen fuel cells. The system and method reduce the overall amount of energy required to operate a propulsion system, which in turn reduces cooling requirements and improves efficiency. A cabin air reuse system uses cabin exhaust air as input air for the fuel cell. Because the cabin exhaust air is compressed, this saves the work involved in compressing air for input to the fuel cell.