Abstract: A gas turbine engine includes a compressor section, a combustion section, a turbine section, and an exhaust section in serial flow order and together defining a core air flowpath. The gas turbine engine also includes a turbine rear frame extending through the core air flowpath at a location downstream of the turbine section and defining a leading edge within the core air flowpath. The gas turbine engine also includes a waste heat recovery system operable to separate, at or upstream of the leading edge of the turbine rear frame, a core airflow exiting the turbine section into a primary exhaust airflow and a waste heat recovery airflow. The waste heat recovery system comprises a heat source exchanger positioned to receive the waste heat recovery airflow.

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 thermal management system including a fluid flow mechanism. The fluid flow mechanism includes an electric machine. A conduit is formed through the electric machine allowing a heat transfer fluid to flow therethrough. The fluid flow mechanism includes a flow device configured to provide a first portion of the heat transfer fluid to a first heat exchange circuit and a second portion of heat transfer fluid to a second heat exchange circuit. The conduit is in fluid communication with the second heat exchange circuit.

Abstract: A pump system to pressurize a fluid within a closed loop transport bus is disclosed herein. The example of the pump system disclosed herein includes a pump, including an impeller, to increase kinetic energy of a fluid flowing through the impeller; an electric motor, including a rotor shaft connected to the impeller, to provide torque to the rotor shaft; a first bearing to support the rotor shaft at a first operational speed range, the first bearing coupled to an inner race; a second bearing to support the rotor shaft at a second operational speed range, the rotor shaft coupled to an outer race; and one or more sprag elements configured to: engage the inner race with the outer race at the first operational speed range; and disengage the inner race from the outer race at the second operational speed range.

Abstract: A gas turbine engine assembly includes a gas turbine engine with a combustion section, a fuel delivery system, and a thermal energy management system. The fuel delivery assembly provides a fuel to the combustion section of the gas turbine engine. The thermal energy management system includes a thermal transport bus, a heat source heat exchanger, and a heat sink heat exchanger. The thermal transport bus has a portion of the fuel configured to flow therethrough. The fuel is disposed as a heat exchange fluid of the thermal energy management system. The heat source heat exchanger is in thermal communication with the flow of fuel through the transport bus. The heat sink heat exchanger is in thermal communication with the flow of fuel through the transport bus.

Abstract: A method is provided for operating a thermal management system of a gas turbine engine. The method includes: operating the gas turbine engine to start-up the gas turbine engine; receiving data indicative of a state of a thermal transport bus of the thermal management system using a sensor, the state of the thermal transport bus including a phase of a thermal fluid within the thermal transport bus; and starting a pump of a pump assembly in response to receiving data indicative of the state of the thermal transport bus of the thermal management system, the pump in fluid communication 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 fuel oxygen reduction unit is provided that includes an inlet fuel line and an outlet fuel line; an oxygen transfer assembly in fluid communication with the inlet fuel line, the outlet fuel line, and a stripping gas flowpath for reducing an amount of oxygen in an inlet fuel flow through the inlet fuel line using a stripping gas flow through the stripping gas flowpath; a catalyst in communication with the stripping gas flowpath at a location downstream of the oxygen transfer assembly, the catalyst configured to reduce an oxygen content of the stripping gas flow through the stripping gas flowpath; and a recuperative heat exchanger in airflow communication with the stripping gas flowpath at a location downstream of the catalyst and upstream of the catalyst for exchanging heat from the stripping gas flow flowing from the catalyst with the stripping gas flow flowing through the recuperative heat exchanger at the location upstream of the catalyst.

Abstract: A thermal management system for transferring heat between fluids includes a thermal transport bus through which a heat exchange fluid flows. Additionally, the system includes a heat source heat exchanger arranged along the bus such that heat is added to the fluid flowing through the heat source heat exchanger. Moreover, the system includes a plurality of heat sink heat exchangers arranged along the bus such that heat is removed from the fluid flowing through the plurality of heat sink heat exchangers. Furthermore, the system includes a bypass conduit fluidly coupled to the bus such that the bypass conduit allows the fluid to bypass one of the heat source heat exchanger or one of the heat sink heat exchangers. In addition, the system includes a valve configured to control a flow of the fluid through the bypass conduit based on a pressure of the fluid within the bus.

Abstract: A thermal management system including a fluid flow mechanism. The fluid flow mechanism includes an electric machine. A conduit is formed through the electric machine allowing a heat transfer fluid to flow therethrough. The fluid flow mechanism includes a flow device configured to provide a first portion of the heat transfer fluid to a first heat exchange circuit and a second portion of heat transfer fluid to a second heat exchange circuit. The conduit is in fluid communication with the second heat exchange circuit.

Abstract: A fuel oxygen reduction unit is provided for reducing an oxygen content of a flow of liquid fuel to an engine. The fuel oxygen reduction unit includes: a stripping gas supply line for providing a flow of stripping gas; a contactor defining a liquid fuel inlet, a stripping gas inlet and a fuel/gas mixture outlet, the stripping gas supply line in airflow communication with the stripping gas inlet; a means for modulating the flow of stripping gas through the stripping gas supply line; and a controller operable with the means for modulating the flow of stripping gas through the stripping gas supply line to modulate the flow of stripping gas through the stripping gas supply line in response to an engine operability parameter.

Abstract: A thermal management system for transferring heat between fluids includes a thermal transport bus through which a heat exchange fluid flows. Additionally, the system includes a heat source heat exchanger arranged along the bus such that heat is added to the fluid flowing through the heat source heat exchanger. Moreover, the system includes a plurality of heat sink heat exchangers arranged along the bus such that heat is removed from the fluid flowing through the plurality of heat sink heat exchangers. Furthermore, the system includes a bypass conduit fluidly coupled to the bus such that the bypass conduit allows the fluid to bypass one of the heat source heat exchanger or one of the heat sink heat exchangers. In addition, the system includes a valve configured to control a flow of the fluid through the bypass conduit based on a pressure of the fluid within the bus.

Abstract: A gas turbine engine assembly includes a gas turbine engine with a combustion section, a fuel delivery system, and a thermal energy management system. The fuel delivery assembly provides a fuel to the combustion section of the gas turbine engine. The thermal energy management system includes a thermal transport bus, a heat source heat exchanger, and a heat sink heat exchanger. The thermal transport bus has a portion of the fuel configured to flow therethrough. The fuel is disposed as a heat exchange fluid of the thermal energy management system. The heat source heat exchanger is in thermal communication with the flow of fuel through the transport bus. The heat sink heat exchanger is in thermal communication with the flow of fuel through the transport bus.

Abstract: A vapor cycle system for cooling components includes a refrigeration circuit through which a mass of a refrigerant flows. The refrigeration circuit, in turn, includes a compressor, a first condenser, a second condenser fluidly coupled to the first condenser in series or in parallel, an expansion valve, and an evaporator. Furthermore, the system includes a refrigerant charge control device configured to increase or decrease the mass of the refrigerant flowing through the refrigeration circuit.

Abstract: A propulsion engine for an aeronautical vehicle defines a radial direction and a cooling air flowpath. The propulsion engine includes a power source; and a fan including a fan blade rotatable by the power source and extending generally along the radial direction, the fan blade defining an inlet, an outlet, and a cooling air passage extending between the inlet and the outlet and in airflow communication with the cooling air flowpath, the inlet being positioned inward from the outlet along the radial direction to provide a cooling airflow through the cooling air flowpath.

Abstract: A propulsion engine for an aeronautical vehicle defines a radial direction and a cooling air flowpath. The propulsion engine includes a power source; and a fan including a fan blade rotatable by the power source and extending generally along the radial direction, the fan blade defining an inlet, an outlet, and a cooling air passage extending between the inlet and the outlet and in airflow communication with the cooling air flowpath, the inlet being positioned inward from the outlet along the radial direction to provide a cooling airflow through the cooling air flowpath.

Abstract: A thermal management system for an aircraft is provided. The thermal management system may comprise a first vapor compression circuit, a second vapor compression circuit, and an intercooler. The first vapor compression circuit may define a first flowpath for fluid compression, condensation, expansion, and evaporation. The second vapor compression circuit may define a second flowpath for fluid compression, condensation, expansion, and evaporation. The intercooler may be disposed in cascading thermal communication between the first vapor compression circuit and the second vapor compression circuit. Generally, heat generated by the aircraft may be transferred to the first vapor compression circuit during aircraft operation.