A method is provided during which an aircraft powerplant is provided. The aircraft powerplant includes a combustor and a water recovery system. The water recovery system includes a condenser and a reservoir. Fuel is combusted within the combustor to provide combustion products. Water is extracted from the combustion products using the condenser. The water recovery system is operated in one of a plurality of modes based on likelihood of contrail formation. The modes include a first mode and a second mode, where the water is collected within the reservoir during the first mode, and where the water passes through the water recovery system during the second mode.

The present disclosure provides systems and methods for processing ammonia. The system may comprise one or more reactor modules configured to generate hydrogen from a source material comprising ammonia. The hydrogen generated by the one or more reactor modules may be used to provide additional heating of the reactor modules (e.g., via combustion of the hydrogen), or may be provided to one or more fuel cells for the generation of electrical energy.

A method of operating a fuel system for a vehicle having an engine, the fuel system comprising a fuel delivery system, the fuel delivery system including a liquid hydrogen delivery assembly and a regulator assembly, the regulator assembly having a buffer tank, the method including: providing a first flow of hydrogen fuel from a liquid hydrogen fuel tank through the liquid hydrogen delivery assembly to the regulator assembly, wherein providing the first flow of hydrogen fuel includes pumping the first flow of hydrogen fuel through the liquid hydrogen delivery assembly using a pump at a first fuel flowrate; receiving data indicative of a commanded fuel flowrate to the engine, wherein the commanded fuel flowrate is higher than the first fuel flowrate; and providing stored hydrogen fuel from a gaseous fuel storage to the engine.

A fuel system can include a first fuel circuit, a second fuel circuit, and an inert gas purge system operatively connected to both the first fuel circuit and the second fuel circuit to purge at least a portion of either or both of the first and/or second fuel circuit. The first fuel can be a liquid fuel and the second fuel can be a gaseous fuel. The first fuel circuit can include a first fuel manifold configured to fluidly communicate a first fuel supply with at least one dual fuel nozzles downstream of the first fuel manifold.

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 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 turbo-expanding cracking assembly includes a plurality of stages each including a rotating blade coupled to an output shaft and a fixed stator, at least one heat exchanger configured to transfer heat to an ammonia containing fuel flow, and a catalyst that is configured to decompose an ammonia containing fuel flow into a flow containing hydrogen (H2).

A turbo-expanding cracking assembly includes a plurality of stages each including a rotating blade coupled to an output shaft and a fixed stator, at least one heat exchanger configured to transfer heat to an ammonia containing fuel flow, and a catalyst that is configured to decompose an ammonia containing fuel flow into a flow containing hydrogen (H2).

Aircraft propulsion systems include a fan shaft connected to a fan, the fan shaft defining a centerline axis of the aircraft propulsion system, one or more offset cores arranged at an angle to the centerline axis, the one or more offset cores each comprising a hydrogen burning combustor, a centerline cavity defined along the centerline axis, and a heat exchanger arranged within the centerline cavity. In operation, a portion of air is directed from the fan into the centerline cavity to provide a first working fluid to the heat exchanger within the centerline cavity.

Aircraft propulsion systems include a fan shaft connected to a fan, the fan shaft defining a centerline axis of the aircraft propulsion system, one or more offset cores arranged at an angle to the centerline axis, the one or more offset cores each comprising a hydrogen burning combustor, a centerline cavity defined along the centerline axis, and a heat exchanger arranged within the centerline cavity. In operation, a portion of air is directed from the fan into the centerline cavity to provide a first working fluid to the heat exchanger within the centerline cavity.