Abstract: A turbine engine assembly includes a core engine generating a high energy gas flow that is expanded through a turbine section, a hydrogen fuel system supplying hydrogen fuel to a combustor through a fuel flow path, a condenser extracting water from the high energy gas flow, an evaporator inputting thermal energy into the water extracted by the condenser to generate a steam flow, and at least one superheater receiving the steam flow from the evaporator and input thermal energy for heating the steam flow. The steam flow from the at least one superheater is injected into the core flow path upstream of the turbine section.

Abstract: A gas turbine engine includes a core engine that includes a core flow path where air is compressed in a compressor section, communicated to a combustor section, mixed with an ammonia based fuel and ignited to generate a high energy combusted gas flow that is expanded through a turbine section. The turbine section is mechanically coupled to drive the compressor section. An ammonia flow path communicates an ammonia flow to the combustor section. A cracking device is disposed in the ammonia flow path. The cracking device is configured to decompose the ammonia flow into a fuel flow containing hydrogen (H2). At least one heat exchanger is upstream of the cracking device that provides thermal communication between the ammonia flow and a working fluid flow such that the ammonia fluid flow accepts thermal energy from the working fluid flow.

Abstract: A turbofan engine has an engine case and a gaspath through the engine case. A fan has a circumferential array of fan blades. The engine further has a compressor, a combustor, a gas generating turbine, and a low pressure turbine section. A speed reduction mechanism couples the low pressure turbine section to the fan. A bypass area ratio is greater than about 6.0. The low pressure turbine section airfoil count to bypass area ratio is below about 170.

Abstract: Propulsion systems for aircraft include a fan and a low pressure turbine operably coupled to a first shaft, a low pressure compressor and an intermediate pressure turbine operably coupled to a second shaft, and a high pressure compressor and a high pressure turbine operably coupled to a third shaft. A burner is arranged between the high pressure compressor and the high pressure turbine, with a main flow path defined through the propulsion system. A hydrogen fuel system is configured to supply hydrogen fuel to the burner. A condenser is arranged along the main flow path and configured to extract water from exhaust from the burner. An evaporator is arranged along the main flow path and configured to receive a portion of the water to generate steam which is injected into the main flow path upstream from the evaporator.

Abstract: Aircraft engines and methods of operation include a core assembly having 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 core condenser is arranged downstream of the turbine section of the core assembly along the core flow path, the core condenser being configured to condense water from the core flow path. A refrigeration system is operably coupled to the core condenser and configured to direct a cold stream flow path into thermal interaction with the core flow path at the core condenser and configured to control a delta temperature at which heat exchange occurs between the core flow path and the cold stream flow path.

Abstract: An aircraft propulsion system includes a fan section that includes a fan shaft that is rotatable about a fan axis. The fan shaft includes a fan gear. The aircraft propulsion system also includes a boost turbine engine that includes a first output shaft that includes a first gear that is coupled to the fan gear. The boost turbine engine has a first maximum power capacity. The aircraft propulsion system further includes a cruise gas turbine engine that includes a second output shaft that includes a second gear that is coupled to the fan gear. The cruise turbine engine has a second maximum power capacity that is less than the first maximum power capacity of the boost turbine engine. The fan section produces a thrust that corresponds to power input through the fan gear from the boost turbine engine and the cruise turbine engine.

Abstract: A gas turbine engine includes a core engine that includes a core flow path where air is compressed in a compressor section, communicated to a combustor section, mixed with an ammonia based fuel and ignited to generate a high energy combusted gas flow that is expanded through a turbine section. The turbine section is mechanically coupled to drive the compressor section. An ammonia flow path communicates an ammonia flow to the combustor section. A cracking device is disposed in the ammonia flow path. The cracking device is configured to decompose the ammonia flow into a fuel flow containing hydrogen (H2). At least one heat exchanger is upstream of the cracking device that provides thermal communication between the ammonia flow and a working fluid flow such that the ammonia fluid flow accepts thermal energy from the working fluid flow.

Abstract: Aircraft propulsion systems and aircraft are described. The aircraft propulsion systems include aircraft systems having at least one hydrogen tank and an aircraft-systems heat exchanger and engine systems having at least a main engine core, a high pressure pump, a hydrogen-air heat exchanger, and an expander, wherein the main engine core comprises a compressor section, a combustor section having a burner, and a turbine section. Hydrogen is supplied from the at least one hydrogen tank through a hydrogen flow path, passing through the aircraft-systems heat exchanger, the high pressure pump, the hydrogen-air heat exchanger, and the expander, prior to being injected into the burner for combustion.

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: Aircraft propulsion systems including a closed loop-supercritical fluid system having a turbine, a cooler heat exchanger, a compressor, and a recovery heat exchanger arranged along a closed-loop flow path of a supercritical fluid. A shaft is operably coupled to the turbine and configured to be rotationally driven by the turbine. A fan is configured to generate thrust, the fan operably coupled to the shaft to be rotationally driven by the shaft. A burner is configured to combust a fuel and air from the fan to generate a combusted gas and supply said combusted gas to the recovery heat exchanger of the closed loop-supercritical fluid system and out an exhaust nozzle.

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: 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 for an aircraft. This powerplant includes an engine and an energy 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 is configured to provide fluid hydrogen and fluid oxygen for combustion within the engine combustor to produce combustion products within the flowpath. The energy recovery system includes an energy recovery system condenser, an energy recovery system pump, an energy recovery system evaporator and an energy recovery system turbine. The energy recovery system pump is configured to pump liquid water from the energy recovery system condenser to the energy recovery system evaporator.

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: 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: 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: 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.

Abstract: A propulsor includes a propulsor body and a prop assembly in rotational communication with the propulsor body. The prop assembly includes a plurality of prop blades configured for rotation about an axial centerline of the propulsor. The plurality of prop blades are rotatable between a deployed position and a stowed position. The propulsor further includes at least one linkage having a first linkage end and a second linkage end. The first linkage end of the at least one linkage is rotatably mounted to the propulsor body and the second linkage end is configured to be rotatably mounted to an aircraft body. The propulsor further includes a first motor coupled to the at least one linkage and configured to rotate the at least one linkage relative to the propulsor body between a first rotational position and a second rotational position.

Abstract: Turbine engine systems are described. The turbine engine systems include a combustor arranged along a core flow path of the turbine engine, a cryogenic fuel tank configured to supply a fuel to the combustor, a fuel supply line having a first flow supply line and a second flow supply line, the first flow supply line fluidly connecting the cryogenic fuel tank to the combustor through a first core flow path heat exchanger, and the second flow supply line fluidly connecting the cryogenic fuel tank to the combustor through a second core flow path heat exchanger, and a flow controller arranged along the fuel supply line and configured to respectively control a flow of fuel into the first flow supply line and the second flow supply line.