Abstract: A fuel system is provided for an aircraft having a fuel source. The fuel system includes a fuel oxygen reduction unit defining a liquid fuel supply path, a stripping gas supply path, a liquid fuel outlet path, and a stripping gas return path, wherein the stripping gas return path is in airflow communication with the fuel source.

Abstract: A fuel delivery system for a gas turbine engine includes a fuel source; a draw pump downstream of the fuel source for generating a liquid fuel flow from the fuel source; a main fuel pump downstream of the draw pump; and a fuel oxygen reduction unit downstream of the draw pump and upstream of the main fuel pump.

Abstract: A thermal management system of a gas turbine engine, the thermal management system including: a thermal transport bus configured to have a heat exchange fluid flowing therethrough and including a pump including a plurality of bearings; an auxiliary thermal bus in thermal communication with the plurality of bearings; and an auxiliary heat exchanger in thermal communication with the auxiliary thermal bus.

Abstract: A fuel oxygen reduction unit assembly for a fuel system is provided. The fuel oxygen reduction unit assembly includes: a fuel oxygen reduction unit located downstream from the fuel source and defining a stripping gas flowpath and a liquid fuel flowpath, the fuel oxygen reduction unit comprising a means for transferring an amount of oxygen from a liquid fuel flow through the liquid fuel flowpath to a gas flow through the stripping gas flowpath; and an oxygen conversion unit in flow communication with the stripping gas flowpath configured to extract a flow of oxygen from a gas flow through the stripping gas flowpath, the oxygen conversion unit defining an oxygen outlet configured to provide the extracted flow of oxygen to an external system.

Abstract: A fuel delivery system for a gas turbine engine includes a fuel tank; a draw pump downstream of the fuel tank for generating a liquid fuel flow from the fuel tank; a main fuel pump downstream of the draw pump; and a fuel oxygen conversion unit downstream of the draw pump and upstream of the main fuel pump. The fuel oxygen conversion unit includes a stripping gas line; a contactor in fluid communication with the stripping gas line and the draw pump for forming a fuel/gas mixture; and a dual separator pump in fluid communication with the contactor for receiving the fuel/gas mixture and separating the fuel/gas mixture into a stripping gas flow and the liquid fuel flow at a location upstream of the main fuel pump.

Abstract: A fuel oxygen reduction unit for an engine is provided. The fuel oxygen reduction unit includes an inlet fuel line; a stripping gas source; a contactor selectively in fluid communication with the stripping gas source, the inlet fuel line, or both to form a fuel/gas mixture; and a separator that receives the fuel/gas mixture, the separator configured to separate the fuel/gas mixture into an outlet stripping gas flow and an outlet fuel flow; wherein a flow of stripping gas passes through the fuel oxygen reduction unit a single time.

Abstract: A gas turbine engine includes a turbomachine and a thermal management system. The thermal management system includes a heat source heat exchanger configured to collect heat from the turbomachine during operation; a heat sink heat exchanger; and a thermal transport bus having a heat exchange fluid configured to flow therethrough at a pressure within an operational pressure range. The thermal management system defines an operational temperature range for the heat exchange fluid, the operational temperature range having a lower temperature limit less than about zero degrees Fahrenheit at a pressure within the operational pressure range and an upper temperature limit of at least about 1000 degrees Fahrenheit at a pressure within the operational pressure range.

Abstract: A fan assembly for a gas turbine engine includes a fan disk, a trunnion, a fan blade, and a counterweight assembly. The fan disk is configured to rotate about an axial centerline of the gas turbine engine when installed in the gas turbine engine. The trunnion is mounted to the fan disk and defines a slot extending through a portion of the trunnion. The fan blade defines a pitch axis and is rotatably attached to the fan disk about its pitch axis through the trunnion. The counterweight assembly includes a link arm extending to the trunnion and an engagement device mounted to the link arm that is disposed to move through the slot of the trunnion.

Abstract: A method of regulating pressure in a thermal transport bus of a gas turbine engine, the method including: operating the gas turbine engine with the thermal transport bus having an intermediary heat exchange fluid flowing therethrough, the thermal transport bus including one or more heat source heat exchangers and one or more heat sink heat exchangers in thermal communication through the intermediary heat exchanger fluid; and adjusting a flow volume of the thermal transport bus using a variable volume device in fluid communication with the thermal transport bus in response to a pressure change associated with the thermal transport bus.

Abstract: A fuel oxygen reduction unit for an engine is provided. The fuel oxygen reduction unit includes an inlet fuel line; a stripping gas source; a contactor selectively in fluid communication with the stripping gas source, the inlet fuel line, or both to form a fuel/gas mixture; and a separator that receives the fuel/gas mixture, the separator configured to separate the fuel/gas mixture into an outlet stripping gas flow and an outlet fuel flow; wherein a flow of stripping gas passes through the fuel oxygen reduction unit a single time.

Abstract: A fan assembly for a gas turbine engine includes a fan disk, a trunnion, an actuation device, a fan blade, and a counterweight assembly. The trunnion is mounted to the fan disk. The actuation device is operably coupled to the trunnion. The fan blade is rotatably attached to the fan disk. The counterweight assembly includes a link arm, a lever arm, a hinge, and a counterweight. The link arm is connected to the trunnion, to the actuation device, or to both. The link arm is configured to drive rotation of the trunnion relative to the fan disk. The hinge is pivotably connected to the lever arm. The lever arm is connected to the link arm and is disposed to rotate about a connection point of the lever arm and the hinge. The counterweight is mounted to the lever arm at a location spaced from the hinge.

Abstract: A gas turbine engine includes a compressor section and a turbine section together defining a core air flowpath. Additionally, a rotary component is rotatable with at least a portion of the compressor section and at least a portion of the turbine section. An electric machine is mounted coaxially with the rotary component and positioned at least partially inward of the core air flowpath along a radial direction of the gas turbine engine. A cavity wall defines at least in part a buffer cavity surrounding at least a portion of the electric machine to thermally insulate the electric machine, e.g., from the relatively high temperatures within the core air flowpath.

Abstract: A heat engine comprising a compressor providing a flow of compressed air from a core flowpath of the heat engine; a cooled cooling air (CCA) heat exchanger system to which the flow of compressed air is provided from the compressor; a coolant supply system providing a flow of coolant to the CCA heat exchanger in thermal communication with the flow of compressed air at the CCA heat exchanger, in which the coolant supply system and CCA heat exchanger together define a CCA circuit through which the compressed air flows in thermal communication with the coolant; and a hot section disposed downstream of the compressor section along the core flowpath through which combustion gases flow, in which the hot section defines a secondary flowpath through which the flow of compressed air from the CCA heat exchanger is provided.

Abstract: A method of regulating pressure in a thermal transport bus of a gas turbine engine, the method including: operating the gas turbine engine with the thermal transport bus having an intermediary heat exchange fluid flowing therethrough, the thermal transport bus including one or more heat source heat exchangers and one or more heat sink heat exchangers in thermal communication through the intermediary heat exchanger fluid; and adjusting a flow volume of the thermal transport bus using a variable volume device in fluid communication with the thermal transport bus in response to a pressure change associated with the thermal transport bus.

Abstract: A thermal management system is provided for incorporation into a gas turbine engine, wherein the gas turbine engine, the aircraft, or both define a vertical direction. The thermal management system including: a thermal transport bus having a thermal fluid flowing therethrough; a plurality of heat source exchangers in thermal communication with the thermal fluid in the thermal transport bus; and a pump assembly in flow communication with the thermal transport bus, the pump assembly including: a pump; and a pump protection device positioned below the pump along the vertical direction.

Abstract: A propulsion system for an aircraft having an aft end is provided herein. The propulsion system can include an electric propulsion engine defining a central axis. The electric propulsion engine can include an electric motor, a fan rotatable about the central axis of the electric propulsion engine by the electric motor, a bearing supporting rotation of the fan, and a thermal management system. The thermal management system can include a lubrication oil circulation assembly for providing the bearing with lubrication oil. The lubrication oil circulation assembly can be driven independently of a shaft of the electric propulsion engine.

Abstract: A fan assembly for a gas turbine engine includes a fan disk, a trunnion, an actuation device, a fan blade, and a counterweight assembly. The trunnion is mounted to the fan disk. The actuation device is operably coupled to the trunnion. The fan blade is rotatably attached to the fan disk. The counterweight assembly includes a link arm, a lever arm, a hinge, and a counterweight. The link arm is connected to the trunnion, to the actuation device, or to both. The link arm is configured to drive rotation of the trunnion relative to the fan disk. The hinge is pivotably connected to the lever arm. The lever arm is connected to the link arm and is disposed to rotate about a connection point of the lever arm and the hinge. The counterweight is mounted to the lever arm at a location spaced from the hinge.

Abstract: A heat engine comprising a compressor providing a flow of compressed air from a core flowpath of the heat engine; a cooled cooling air (CCA) heat exchanger system to which the flow of compressed air is provided from the compressor; a coolant supply system providing a flow of coolant to the CCA heat exchanger in thermal communication with the flow of compressed air at the CCA heat exchanger, in which the coolant supply system and CCA heat exchanger together define a CCA circuit through which the compressed air flows in thermal communication with the coolant; and a hot section disposed downstream of the compressor section along the core flowpath through which combustion gases flow, in which the hot section defines a secondary flowpath through which the flow of compressed air from the CCA heat exchanger is provided.

Abstract: A method of regulating pressure in a thermal transport bus of a gas turbine engine, the method including: operating the gas turbine engine with the thermal transport bus having an intermediary heat exchange fluid flowing therethrough, the thermal transport bus including one or more heat source heat exchangers and one or more heat sink heat exchangers in thermal communication through the intermediary heat exchanger fluid; and adjusting a flow volume of the thermal transport bus using a variable volume device in fluid communication with the thermal transport bus in response to a pressure change associated with the thermal transport bus.

Abstract: A method of detecting an airflow fault condition in a gas turbine engine, the method including: operating the gas turbine engine with a thermal transport bus having an intermediary heat exchange fluid flowing therethrough; determining a performance characteristic of the intermediary heat exchange fluid in the thermal transport bus is outside of a predetermined range, wherein the performance characteristic includes a temperature, a pressure, a flowrate, or a combination thereof; and indicating an airflow fault condition in response to determining the performance characteristic is outside of the predetermined range.