A propulsion system includes a system for producing electricity that supplies electricity to at least one electric motor to which is mechanically coupled a propeller situated near a first longitudinal end of a nacelle that houses at least the system for producing electricity and the at least one electric motor. An air circulation channel, which receives a heat exchanger provided to allow the system for producing electricity to be cooled, extends inside the nacelle from a first end of the air circulation channel situated at the first longitudinal end of the nacelle. A part of the air circulation channel that is contiguous with its first end is delimited by an outer surface of cylindrical shape that surrounds the longitudinal axis of the nacelle.

A fuel cell power system including at least one fuel cell, a ram air system and a cooling circuit in which coolant is intended to circulate for regulating a temperature of the at least one fuel cell. The cooling circuit comprises a ram air heat exchanger in the ram air system and the ram air system comprises a nozzle. The fuel cell power system further comprises a water tank and the fuel cell power system is arranged to flow water from the water tank to the ram air system so as to spray water in ram air via the nozzle. Thus, dimensioning of the ram air system which includes the ram air heat exchanger is reduced.

A fuel cell to provide a higher power density. The fuel cell can be produced by 3D printing in ceramic and has an improved power density by virtue of its spiral shape. In order to better extract the energy generated by the fuel cell, an interconnector sheet can be fastened positively to fastening knobs of the fuel cell by holding eyes. In addition, the interconnector sheet can be fixed by glass solder.

Power management method and system for an unmanned air vehicle, wherein the unmanned air vehicle comprises a plurality of power demanding subsystems and a plurality of power sources. The invention establishes mission oriented fixed parameters. A fuzzy logic power management unit, comprised in the system, automatically calculates and assigns priorities for delivering power to the subsystems. It also automatically calculates and assigns amounts of power delivered to each subsystem and automatically decides which of the power sources to deliver power to which subsystem. The fuzzy logic power management system calculates and assigns the priorities and loads in function of a plurality of internal variables, external variables and the mission oriented fixed parameters.

A method for generating electrical energy by a fuel cell system operated with a reformate gas is provided. According to this method, a fuel cell system is provided. The fuel cell system has a first reactor and a second reactor. A gas separation unit is also provided. A portion of a first fuel gas is fed to the gas separation unit. A target gas including N.sub.2 or CO.sub.2 is separated by the gas separation unit. The separated target gas is fed into a protective housing of the fuel cell system. An H.sub.2-enriched tail gas formed in the gas separation unit is fed as a second fuel gas for operation of the fuel cell.

Autonomous trolleys include an integrated power source, which energy can be utilized for integrated trolley systems such as a wheel assist module, heating module, and cooling module. The power source may include a fuel cell system or a rechargeable electrical energy storage device or a combination thereof. The rechargeable electrical energy storage device can be charged by any other power source, including a fuel cell system. The trolley can also be equipped with a fuel tank for easy and safe refueling of a fuel cell system.

Methods and systems for a full-scale vertical takeoff and landing manned or unmanned aircraft, having an all-electric, low-emission or zero-emission lift and propulsion system, an integrated ‘highway in the sky’ avionics system for navigation and guidance, a tablet-based motion command, or mission planning system to provide the operator with ‘drive by wire’ style direction control, and automatic on-board-capability to provide traffic awareness, weather display and collision avoidance. Automatic computer monitoring by a programmed triple-redundant digital autopilot computer controls each motor-controller and motor to produce pitch, bank, yaw and elevation, while simultaneously restricting the flight regime that the pilot can command, to protect the pilot from inadvertent potentially harmful acts that might lead to loss of control, or loss of vehicle stability. By using the results of the state measurements to inform motor control commands, the methods and systems contribute to the operational simplicity, reliability and safety of the vehicle.

The application provides an autonomous refueling vehicle for a hydrogen-electric aircraft, which includes two or more wings. The wings are provided with one or more removable electric propulsion pods. The autonomous refueling vehicle includes a hydrogen refueling module adapted to connect to the propulsion pods and to a hydrogen source. The autonomous refueling vehi-cle includes also includes a propulsion pod handling device, which is adapted to remove the propulsion pod from the wings and to position the propulsion pods on the hydrogen refueling module such that the propulsion pods are connected to the hy-drogen refueling module. The autonomous refueling vehicle is also adapted to autonomously move itself to the hydrogen source to allow the hydrogen refueling module to removably connect to the hydrogen source for refueling of the propulsion pods.

The technology relates to techniques for an aquatic energy discharge system for an energy storage system of an aircraft. An aquatic energy discharge system can include an energy storage system, a pair of electrodes coupled to the energy storage system, and a water detection system configured to detect a water landing. The electrodes can be configured to submerge in a body of water after the aircraft has landed in the body of water, and cause a hydrolysis reaction that drains energy from the energy storage system in response to the water detection system detecting the water landing. A method of discharging an energy storage system of an aircraft can include detecting that an aircraft (or portion thereof) has landed in a body of water, and discharging the energy storage system by powering a hydrolysis reaction using a pair of electrodes.

An aircraft comprising a structure comprising a leakproof tank delimited by walls, of which at least one is in contact with the air outside the aircraft, and filled partly with a two-phase heat-transfer fluid, a fuel cell that is passed through by a heat-transfer fluid, and a line which takes the heat-transfer fluid at an output of the fuel cell and which reintroduces this heat-transfer fluid at an input of the fuel cell. The line passes through the leakproof tank immersed in the heat-transfer fluid in liquid phase.