Abstract: A high efficiency hydrogen fuel system for an aircraft at high altitude which utilizes compressors to compress air to a sufficiently high pressure for the fuel cell. Liquid hydrogen is compressed and then utilized in heat exchangers to cool the compressed air, maintaining the air at a temperature low enough for the fuel cell. The hydrogen is also used to cool the fuel cell as it is also depressurized prior to its entry in the fuel cell cycle. A water condensation system allows for water removal from the airstream to reduce impacts to the atmosphere. The hydrogen fuel system may be used with VTOL aircraft, which may allow them to fly at higher elevations. The hydrogen fuel system may be used with other subsonic and supersonic aircraft, such as with asymmetric wing aircraft.

Abstract: A slanted heat exchange system and method for use in aerodynamic vehicle and for transferring heat between a coolant and a fluid. In some examples, the aerodynamic vehicle is an aircraft, and the fluid is air. The slanted heat exchange system and method include a slanted heat exchanger that is slanted relative to a channel direction just before the slanted heat exchanger. The slanted heat exchanger has an increased frontal surface area while still preserving a relatively compact cross-sectional area when viewed from the front. An array of inlet turning vanes both diffuse and slow down the fluid while also turning the fluid to enter the slanted heat exchanger approximately perpendicular to the slanted heat exchanger. This mitigates turning losses and reduces any pressure drop across the heat exchanger. In some examples, an array of outlet turning vanes turns and accelerates the fluid exiting the slanted heat exchanger.

Abstract: A variable-geometry cooling airflow management system and method for managing the cooling of a fuel cell on an aerodynamic vehicle (such as an aircraft). The cooling management is achieved by providing a conduit having a fan, radiator, and variable-geometry openings (such as variable-geometry inlet and variable-geometry outlet) at the conduit ends. Heat from the fuel cell is transferred to a coolant, which then flows through the radiator in the conduit. Cooling airflow passes over the radiator to provide fuel cell cooling. The amount of cooling airflow over the radiator is adjusted by varying the size of the variable-geometry inlet, the variable-geometry outlet, or both. Adjustments are made based on the operational parameters of the aircraft such as airspeed and flight configuration. A fan also may be located in the conduit, a speed of which is varied by the control system based on the operational parameters of the aircraft.

Abstract: A fuel cell system includes a hydrogen expansion system comprising an aeolipile, and a heat exchanger for receiving and expanding hydrogen received from a supply of hydrogen, for provision to the aeolipile. A generator coupled to the aeolipile may generate electrical power from operation of the aeolipile. The hydrogen leaving the aeolipile may be returned to the heat exchanger to transfer heat to the hydrogen received from the supply of hydrogen.

Abstract: An aircraft includes a fuel cell system including a fuel cell powered by hydrogen received from a supply of hydrogen, and a propulsion unit including a conduit through which a flow of air is propelled. A first heat exchanger transfers heat from the fuel cell to a coolant fluid located in a coolant loop, and a second heat exchanger is located in the conduit for heating the air passing through the conduit by transferring heat to the air from the coolant fluid via the second heat exchanger. This configuration serves to cool the fuel cell while increasing the efficiency of the propulsion unit.

Abstract: A fuel cell system includes a fuel cell for receiving hydrogen from a supply of hydrogen. The system comprises a heat exchanger for transferring heat to the hydrogen from a coolant fluid located in a cooling loop. The cooling loop comprises a number of cooling cores located in a conduit that supplies air to the fuel cell. A compressor compresses air cooled by the cooling cores to provide compressed air to the fuel call. The cooling cores may be de-iced by a coolant fluid that has been warmed by operation of the fuel cell. Fuel cell system efficiency can be increased by cooling the air to be supplied to the fuel cell before or after compressing it.

Abstract: A hydrogen circulation system for use with a fuel cell stack includes a supply line for receiving hydrogen gas from a supply of hydrogen, a fuel cell for receiving hydrogen gas from the supply line, an excess hydrogen line for receiving excess hydrogen from the fuel cell, and a turbocharger coupled to the excess hydrogen line and the supply line, to receive excess hydrogen from the excess hydrogen line, compress it, and return it to the supply line, the turbocharger being powered in use by hydrogen gas from the supply line.

Abstract: A high efficiency hydrogen fuel system for an aircraft at high altitude which utilizes compressors to compress air to a sufficiently high pressure for the fuel cell. Liquid hydrogen is compressed and then utilized in heat exchangers to cool the compressed air, maintaining the air at a temperature low enough for the fuel cell. The hydrogen is also used to cool the fuel cell as it is also depressurized prior to its entry in the fuel cell cycle. A water condensation system allows for water removal from the airstream to reduce impacts to the atmosphere. The hydrogen fuel system may be used with VTOL aircraft, which may allow them to fly at higher elevations. The hydrogen fuel system may be used with other subsonic and supersonic aircraft, such as with asymmetric wing aircraft.

Abstract: A high efficiency hydrogen fuel system for an aircraft at high altitude which utilizes compressors to compress air to a sufficiently high pressure for the fuel cell. Liquid hydrogen is compressed and then utilized in heat exchangers to cool the compressed air, maintaining the air at a temperature low enough for the fuel cell. The hydrogen is also used to cool the fuel cell as it is also depressurized prior to its entry in the fuel cell cycle. A water condensation system allows for water removal from the airstream to reduce impacts to the atmosphere. The hydrogen fuel system may be used with VTOL aircraft, which may allow them to fly at higher elevations. The hydrogen fuel system may be used with other subsonic and supersonic aircraft, such as with asymmetric wing aircraft.

Abstract: A high efficiency hydrogen fuel system for an aircraft at high altitude which utilizes compressors to compress air to a sufficiently high pressure for the fuel cell. Liquid hydrogen is compressed and then utilized in heat exchangers to cool the compressed air, maintaining the air at a temperature low enough for the fuel cell. The hydrogen is also used to cool the fuel cell as it is also depressurized prior to its entry in the fuel cell cycle. A water condensation system allows for water removal from the airstream to reduce impacts to the atmosphere. The hydrogen fuel system may be used with VTOL aircraft, which may allow them to fly at higher elevations. The hydrogen fuel system may be used with other subsonic and supersonic aircraft, such as with asymmetric wing aircraft.

Abstract: A high efficiency hydrogen fuel system for an aircraft at high altitude which utilizes compressors to compress air to a sufficiently high pressure for the fuel cell. Liquid hydrogen is compressed and then utilized in heat exchangers to cool the compressed air, maintaining the air at a temperature low enough for the fuel cell. The hydrogen is also used to cool the fuel cell as it is also depressurized prior to its entry in the fuel cell cycle. A water condensation system allows for water removal from the airstream to reduce impacts to the atmosphere. The hydrogen fuel system may be used with VTOL aircraft, which may allow them to fly at higher elevations. The hydrogen fuel system may be used with other subsonic and supersonic aircraft, such as with asymmetric wing aircraft.

Abstract: A high efficiency hydrogen fuel system for an aircraft at high altitude which utilizes compressors to compress air to a sufficiently high pressure for the fuel cell. Liquid hydrogen is compressed and then utilized in heat exchangers to cool the compressed air, maintaining the air at a temperature low enough for the fuel cell. The hydrogen is also used to cool the fuel cell as it is also depressurized prior to its entry in the fuel cell cycle. A water condensation system allows for water removal from the airstream to reduce impacts to the atmosphere. The hydrogen fuel system may be used with VTOL aircraft, which may allow them to fly at higher elevations. The hydrogen fuel system may be used with other subsonic and supersonic aircraft, such as with asymmetric wing aircraft.

Abstract: A rotor assembly for an engine, comprising: a rotor, supported on bearings for axial rotation, a rotor portion forming a compression passage extending outwards from the axis, gases entering the rotor through inlets at the axis and flowing outwards through the compression passage; a combustion chamber supported within the compression passage near the maximum radius of the rotor having a closed outer end and combustion chamber gases inlets through which gases enter the combustion chamber, each combustion chamber having a fuel inlet, and; one or more expansion passages in fluidic connection with and extending radially inwards from the combustion chamber within a compression passage and fluidically connecting at or near the rotor axis to a combustion gas outlet tube that extends along the rotor axis, combustion gases created by combustion of fuel with inlet gases within the combustion chamber expanding as they flow inwards through the expansion passage.

Abstract: A thermodynamic machine, comprising: a rotor, configured to rotate about a rotor axis, a working fluid circulation path and a coolant fluid path formed within the rotor, the coolant fluid path fluidically isolated from the working fluid circulation path, the working fluid circulation path spanning radially from the rotor axis to close to the periphery of the rotor; a working fluid circulation drive configured to drive the circulation of a working fluid about the working fluid circulation path; at least one working fluid cooler heat exchanger formed as part of the working fluid circulation path and the coolant fluid path, in use coolant fluid passing through the working fluid cooler heat exchanger to transfer heat from the working fluid to the coolant fluid, and; a working fluid heater in the working fluid circulation path configured to heat a working fluid circulating around the working fluid circulation path.

Abstract: A rotor assembly for an engine, comprising: a rotor, supported on bearings for axial rotation, a rotor portion forming a compression passage extending outwards from the axis, gases entering the rotor through inlets at the axis and flowing outwards through the compression passage; a combustion chamber supported within the compression passage near the maximum radius of the rotor having a closed outer end and combustion chamber gases inlets through which gases enter the combustion chamber, each combustion chamber having a fuel inlet, and; one or more expansion passages in fluidic connection with and extending radially inwards from the combustion chamber within a compression passage and fluidically connecting at or near the rotor axis to a combustion gas outlet tube that extends along the rotor axis, combustion gases created by combustion of fuel with inlet gases within the combustion chamber expanding as they flow inwards through the expansion passage.

Abstract: A thermodynamic machine, comprising: a rotor, configured to rotate about a rotor axis, a working fluid circulation path and a coolant fluid path formed within the rotor, the coolant fluid path fluidically isolated from the working fluid circulation path, the working fluid circulation path spanning radially from the rotor axis to close to the periphery of the rotor; a working fluid circulation drive configured to drive the circulation of a working fluid about the working fluid circulation path; at least one working fluid cooler heat exchanger formed as part of the working fluid circulation path and the coolant fluid path, in use coolant fluid passing through the working fluid cooler heat exchanger to transfer heat from the working fluid to the coolant fluid, and; a working fluid heater in the working fluid circulation path configured to heat a working fluid circulating around the working fluid circulation path.

Abstract: A reciprocator restraint assembly for a Z-crank axial piston machine is described. The assembly includes two gimbal arms each linked together at gimbal link joint that intersect at a point T. Point T lying in a medial plane M being defined as the plane passing through the point of coincidence of the crank and crankshaft axes to which the line that bisects the crank angle is normal. Each of the gimbal arms is pivotally mounted at an identical distance L from point T. A cylinder gimbal is pivotally mounted from the cylinder cluster and a reciprocator gimbal is pivotally mounted from the reciprocator. The reciprocator gimbal pivot axis is equidistant from point X and T as is the cylinder gimbal pivot axis.

Abstract: A recipricator restraint assembly for a Z-crank axial piston machine is described. The assembly includes two gimbal arms each linked together at gimbal link joint that intersect at a point T. Point T lying in a medial plane M being defined as the plane passing through the point of coincidence of the crank and crankshaft axes to which the line that bisects the crank angle is normal. Each of the gimbal arms is pivotally mounted at an identical distance L from point T. A cylinder gimbal is pivotally mounted from the cylinder cluster and a recipricator gimbal is pivotally mounted from the recipricator. The recipricator gimbal pivot axis is equidistant from point X and T as is the cylinder gimbal pivot axis.