Abstract: Aircraft engines include a turbine engine comprising a compressor section, a burner section, and a turbine section arranged along a shaft, with a core flow path through the turbine engine such that exhaust from the burner section passes through the turbine section, a condensing assembly arranged downstream of the turbine section of the turbine engine along the core flow path, and an exhaust compressor arranged downstream of the condensing assembly along the core flow path. The condensing assembly is configured to reduce a mass flow of the exhaust compressor by condensing water vapor from the core flow and removing liquid water from the core flow.

Abstract: An engine system includes a turbine engine including a compressor section, a combustor section having a burner, a turbine section, and a nozzle in an open-loop configuration. The engine system also includes a bottom-cycle apparatus and an exhaust heat exchanger downstream of the turbine section of the turbine engine configured to reject heat from the turbine engine to the bottoming-cycle apparatus and create a cooled turbine exhaust in the turbine engine. The engine system further includes an exhaust compressor arranged downstream of the exhaust heat exchanger and upstream of the nozzle of the turbine engine configured to compress the cooled turbine exhaust stream and increase a pressure of the cooled turbine exhaust stream prior to exiting the nozzle of the turbine engine.

Abstract: A powertrain system of an aircraft includes one or more electrical components to provide electrical power to one or more electrical loads of the aircraft. The system further includes a rechargeable cryogenic heat sink containing a volume of cryogenic cooling material. The cryogenic heat sink is configured to cool the one or more electrical components. A method of operating a powertrain system of an aircraft includes generating thermal energy at one or more electrical components of the powertrain system, fluidly connecting a cryogenic heat sink to the one or more electrical components, and cooling the one or more electrical components via a volume of cryogenic cooling material of the cryogenic heat sink.

Abstract: A powerplant is provided that includes an engine and a water recovery system. The engine includes an engine combustor, an engine turbine, a flowpath and a fluid delivery system. The flowpath extends out of the engine combustor and through the engine turbine. The fluid delivery system includes a hydrogen reservoir and an oxygen reservoir. The hydrogen reservoir is configured to store fluid hydrogen as liquid hydrogen. The oxygen reservoir is configured to store fluid oxygen as liquid oxygen. The fluid delivery system is configured to provide the fluid hydrogen and the fluid oxygen for combustion within the engine combustor to produce combustion products within the flowpath. The water recovery system is configured to extract water from the combustion products. The water recovery system is configured to provide the water to a component of the powerplant.

Abstract: A powerplant is provided that includes an engine and a water recovery system. The engine includes an engine combustor, an engine turbine, a flowpath and a fluid delivery system. The flowpath extends out of the engine combustor and through the engine turbine. The fluid delivery system includes a hydrogen reservoir and an oxygen reservoir. The hydrogen reservoir is configured to store fluid hydrogen as liquid hydrogen. The oxygen reservoir is configured to store fluid oxygen as liquid oxygen. The fluid delivery system is configured to provide the fluid hydrogen and the fluid oxygen for combustion within the engine combustor to produce combustion products within the flowpath. The water recovery system is configured to extract water from the combustion products. The water recovery system is configured to provide the water to a component of the powerplant.

Abstract: A disclosed drive assembly for an auxiliary power unit includes a first drive shaft driven by an auxiliary power unit, a second drive shaft driven by a first electric motor, a differential gear system including a ring gear driven by the second drive shaft, a and planet gears supported within a carrier attached to the ring gear. The first drive shaft and an output shaft are coupled to the planet gears and a generator is driven by the output shaft. The electric motor and the auxiliary power unit combine to drive the output shaft.

Abstract: Techniques for determining a fan spool speed value associated with a hybrid electric gas engine (“engine”) are described herein. For example, a method includes generating a first fan spool speed value based on a base extraction amount. The method further includes generating a change in the first fan spool speed value based on a flight condition and a change in extraction amount. The method further includes generating a second fan spool speed value based on the extraction amount and an augmentation value for intersection of a combustion instability and burner pressure limit. The method further includes generating a second change in the second fan spool speed value based on the flight condition and the change in extraction amount. The method further includes determining a final fan spool speed value and operating the engine at the final fan spool speed value.

Abstract: 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.

Abstract: Aircraft engines include a burner section and a turbine section arranged along a shaft, wherein an exhaust from the burner section is directed through the turbine section to drive rotation of the turbine section and a core flow path passes through the burner section and then the turbine section. A condenser assembly is arranged downstream of the turbine section along the core flow path. A cryogenic fuel source is configured to supply fuel to the burner section along a fuel line passing through the condenser assembly and the fuel within the fuel line is configured to pick up heat from the exhaust from the burner section and condense water therefrom.