Abstract: 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 a turbo expander. The main engine core includes 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 turbo expander, prior to being injected into the burner for combustion. The turbo expander includes a rotor separated into a first expander portion and a second expander portion arranged about an output shaft and the output shaft is operably connected to a generator configured to generate electrical power.

Abstract: Aircraft engine systems include a core assembly having at least a burner section and a fuel cell configured to generate electrical power. A cryogenic fuel source is configured to supply a fuel through a fuel supply line to each of the burner section and the fuel cell for reaction to generate the electrical power. A system controller is configured to direct fuel to each of the combustor section and the fuel cell. The controller determines if an amount of fuel in the fuel supply line is in excess of that necessary for operation of the core assembly and, based on a determination that excess fuel is present, the controller is configured to direct at least a portion of the excess fuel from the fuel supply line to the fuel cell to generate the electrical power.

Abstract: A heat exchanger for heat exchange between a first fluid and a second fluid has a plurality of tube sections, each having; an interior for passing the first fluid; an exterior for exposure to the second fluid; a first leg; a second leg; and a turn joining the first leg to the second leg. A has: fiber members passing between legs of the tube sections; and an end plate.

Abstract: A propulsion system for an aircraft includes a gas generating core engine that generates an exhaust gas flow that is expanded through a turbine section. A power turbine engine is forward of the core engine and is coupled to drive a propulsor. A hydrogen fuel system supplies hydrogen fuel to the combustor through a fuel flow path. A condenser extracts water from the exhaust gas flow. A water separator is in communication with the condenser and directs the extracted water to a water storage tank. An evaporator receives a portion of the water that is extracted by the condenser and generates a steam flow. The steam flow is injected into the core flow path upstream of the turbine section.

Abstract: A turbofan gas turbine engine includes, among other things, a fan section, a core engine, a bypass passage, and a bypass ratio defined as the volume of air passing into the bypass passage compared to the volume of air passing into the core engine, the bypass ratio being greater than or equal to 10. A gear arrangement drives the fan section. A compressor section includes a low pressure compressor section and a high pressure compressor section. A turbine section drives the gear arrangement. An overall pressure ratio is provided by the combination of a pressure ratio across the low pressure compressor section and a pressure ratio across the high pressure compressor section, and greater than 40. The pressure ratio across the high pressure compressor section is between 7 and 15, and the pressure ratio across the low pressure compressor section is between 4 and 8.

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 propulsion system includes a core engine generating a high energy gas flow, a condenser configured to extract water from the high energy gas flow and an evaporator transforming the extracted water into a steam flow. The steam flow is injected into a core flow path of the core engine increase mass flow.

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 propulsion system for an aircraft includes a gas generating core engine that generates an exhaust gas flow that is expanded through a turbine section. A power turbine engine is forward of the core engine. A propulsor is coupled to the power turbine. A hydrogen fuel system supplies hydrogen fuel to the combustor through a fuel flow path. A condenser extracts water from the exhaust gas flow. An evaporator receives a portion of the water that is extracted by the condenser and generates a steam flow. The steam flow is injected into the core flow path upstream of the turbine section. An inlet duct communicates an inlet airflow to the compressor section aft at a location aft of the turbine section. An exhaust duct routes exhaust gas flow through the condenser and into thermal communication with a water flow of water extracted in the condenser in the evaporator.

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: 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: 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: 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.