An aircraft electrical system including: a first DC power bus and a fuel cell assembly including a first fuel cell group, wherein the first fuel cell group is electrically coupled directly to the first DC power bus without a voltage converter to provide a first power output to the first DC power bus.

A power source for an aircraft having an engine, the power source including: a fuel cell assembly configured to be integrated into the engine, the fuel cell assembly including: a first fuel cell group; and a second fuel cell group, wherein during a first operating condition of the power source the fuel cell assembly is configured to provide a first power output from the first fuel cell group and the second fuel cell group and during a second operating condition is further configured to provide a second power output from the first fuel cell group, the second power output being different than the first power output.

A turbine engine system includes aircraft systems including at least one hydrogen fuel tank, engine systems comprising a compressor section, a combustor section having a burner, and a turbine section, and a hydrogen fuel flow supply line configured to supply hydrogen fuel from the at least one hydrogen fuel tank into the burner for combustion. The turbine engine system has a bypass ratio between 5 to 20.

Systems and methods of aircraft thrust management are provided. For example, a propulsion system for an aircraft comprises a fuel cell assembly comprising a fuel cell, a turbomachine, and a controller comprising memory and one or more processors. The memory stores instructions that, when executed by the one or more processors, cause the propulsion system to perform operations including receiving data indicative of a propulsion system thrust discrepancy and modifying an output of the fuel cell in response to receiving data indicative of the propulsion system thrust discrepancy. Modifying the fuel cell output may include modifying output products, an electrical power output, or both of the fuel cell to balance the thrust provided by the propulsion system.

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.

A propulsion system comprising a nacelle with an air channel along a longitudinal direction, an electric motor whose output drives a propeller, and a fuel cell, comprising a core outside the air channel, open channels, each of which has an inlet and an outlet opening in the air channel, and, for each open channel, a fuel chamber, an electrolyte between the open channel and the fuel chamber, a cathode, and an anode, each open channel having an inlet surface area which is less than the surface area of an intermediate area between the inlet and the outlet, the surface area of the outlet being smaller than the surface area of the intermediate area. Such a system makes it possible to have the fuel cell close to the electric motor, thereby reducing the lengths of the electrical conductors between them, and consequently improving the operation of the fuel cell.

A fuselage heat exchanger having channels for dissipating waste heat generated by fuel cells that power unmanned aerial vehicles (UAVs) or drones. A heat exchanger built into the fuselage can dissipate such waste heat. Coolant flowing through channels embedded within an aircraft fuselage panel dissipates heat to airflow around the outer surface of the fuselage.

A power distribution controller for a hybrid aircraft is configured to continuously: obtain a state-of-charge (SoC) measurement for a battery of the hybrid aircraft; obtain a fuel level measurement for a secondary energy source of the hybrid aircraft; receive a control input indicating one of a throttle level or an operating mode for one or more motors of the hybrid aircraft; calculate a ratio of energy to source from each of the battery and the secondary energy source in order to operate the one or more motors of the hybrid aircraft based on the control input, the SoC measurement, and the fuel level measurement; and transmit a control signal that causes energy to be apportioned from the battery and the secondary energy source to the one or more motors based on the determined ratio.

A method of operating an aircraft includes providing a fuel cell system to power the aircraft, providing an airflow path through the fuel cell system, sensing a change mass air flow rate supplied to a compressor of the fuel cell system, and at least one of adjusting a restriction of airflow entering the airflow path in response to the sensed change in mass air flow rate, adjusting a restriction of airflow exiting the airflow path in response to the sensed change in mass air flow rate, and adjusting an air scoop to gather a different amount of air into the airflow path. A method of operating an aircraft includes sensing a change in ambient pressure supplied to an airflow path and adjusting a restriction of airflow exiting the airflow path in response to a sensed change in ambient pressure.

Aircraft propulsion systems and aircraft having such propulsion systems are described. The aircraft propulsion systems include a fan, a motor operably connected to the fan by a drive shaft, and an aircraft power generation system operably coupled to the motor to drive rotation of the fan through the drive shaft, wherein the aircraft power generation system comprises a fuel cell configured to generate at least 1 MW of electrical power.