Abstract: A nozzle assembly for a gas turbine engine and methods for assembling a nozzle assembly are provided. In one example aspect, the nozzle assembly includes an outer wall and an inner wall radially spaced from the outer wall. The outer wall defines a plurality of mounting openings spaced circumferentially from one another. The inner wall defines a plurality of mounting openings spaced circumferentially from one another. The mounting openings defined by the inner wall are positioned circumferentially between adjacent mounting openings defined by the outer wall. The nozzle assembly includes vanes that are inserted through the mounting openings of the outer wall in a radially inward direction and vanes that are inserted through the mounting openings of the inner wall in a radially outward direction in an alternating manner.

Abstract: A method for operating a hybrid-electric propulsion system of an aircraft is provided. The hybrid-electric propulsion system includes a gas turbine engine having a high pressure system, a low pressure system, and an electric machine coupled to one of the high pressure system or low pressure system. The method includes receiving data indicative of an actual or anticipated in-flight shutdown of the gas turbine engine; and adding power to the gas turbine engine through the electric machine in response to receiving data indicative of the actual or anticipated in-flight shutdown of the gas turbine engine.

Abstract: A method is provided for operating a hybrid-electric propulsion system of an aircraft. The hybrid-electric propulsion system includes a gas turbine engine having a high pressure system, a low pressure system, an electric machine coupled to at least one of the high pressure system or low pressure system, and an energy storage unit. The method includes operating the electric machine as an electric generator to charge the energy storage unit during a flight operation of the aircraft; switching the gas turbine engine to an electric operating mode during or after a landing operation of the aircraft; driving a system of the gas turbine engine using power from the energy storage unit while in the electric operating mode to provide or assist with providing ground operations the aircraft.

Abstract: A heat management system for a turbomachine may include a first heat exchanger configured and arranged to receive a first fluid stream from a first duct, a second heat exchanger configured and arranged to receive the first fluid stream after discharging from the first heat exchanger, and a second duct fluidly communicating with the first duct between the first heat exchanger and the second heat exchanger to introduce a second fluid stream from the second duct to the first duct. A method of cooling fluid streams may include directing a first fluid stream from a first duct across or through a first heat exchanger, directing the first fluid stream across or through a second heat exchanger after discharging from the first heat exchanger, and directing a second fluid stream from a second duct to the first duct, with the second duct fluidly communicating with the first duct between the first heat exchanger and the second heat exchanger.

Abstract: An aspect of the present disclosure is directed to a system for reducing thermal gradient at a heat engine. The heat engine includes a rotor assembly with a rotor disk and a seal assembly is provided. An interfacing structure at least partially surrounds the rotor assembly at the seal assembly. The seal assembly and the interfacing structure together form a first cavity defining a first environmental condition and a second cavity defining a second environmental condition. A fluid supply manifold is connected to the rotor assembly and is extended at least partially along a radial direction from the first cavity to an outlet opening in thermal communication with the rotor disk of the rotor assembly.

Abstract: A gas turbine engine assembly includes a turbomachine including a compressor section, a combustion section, and a turbine section in serial flow order; a fuel delivery system operable with the combustion section of the turbomachine for providing fuel to the combustion section of the turbomachine; and an air cycle assembly including an air cycle machine and a heat exchanger, the air cycle machine in airflow communication with the compressor section of the turbomachine and the heat exchanger in airflow communication with the air cycle machine. The gas turbine engine assembly also includes a thermal transfer bus thermally coupling the heat exchanger of the air cycle assembly to the fuel delivery system for transferring heat from the air cycle machine to the fuel delivery system.

Abstract: A heat exchanger apparatus includes: a shell extending over a flow length from an inlet at a upstream end to an outlet at a downstream end, and defining a first flowpath for a first fluid; a structure disposed within the shell defining a second flowpath for a second fluid; at least one secondary inlet in the shell disposed downstream from the upstream end; and a nozzle disposed downstream of the inlet.

Abstract: A nozzle assembly for a gas turbine engine and methods for assembling a nozzle assembly are provided. In one example aspect, the nozzle assembly includes an outer wall and an inner wall radially spaced from the outer wall. The outer wall defines a plurality of mounting openings spaced circumferentially from one another. The inner wall defines a plurality of mounting openings spaced circumferentially from one another. The mounting openings defined by the inner wall are positioned circumferentially between adjacent mounting openings defined by the outer wall. The nozzle assembly includes vanes that are inserted through the mounting openings of the outer wall in a radially inward direction and vanes that are inserted through the mounting openings of the inner wall in a radially outward direction in an alternating manner.

Abstract: A method and apparatus for a turbine engine having a compressor section, combustion section, and a turbine section in an axial flow arrangement with a cooling circuit in fluid communication with at least one of the compressor section, combustion section, or turbine section. The method and apparatus further including separating particles from a cooling air that flows through the cooling circuit.

Abstract: An ejector assembly includes a primary nozzle in fluid communication with a primary fluid inlet, a secondary nozzle in fluid communication with a secondary fluid inlet, the primary nozzle being oriented concentrically within the secondary nozzle and the secondary nozzle having a venturi downstream of the primary nozzle, and the primary nozzle having a variable cross-sectional area.

Abstract: A heat exchanger and heat exchanger core are provided. The heat exchanger core includes a plurality of columnar passages extending between an inlet plenum of the heat exchanger core and an outlet plenum of the heat exchanger core, the columnar passages formed monolithically in a single fabrication process.

Abstract: A gas turbine engine includes a combustion section and a compressor section, the compressor section including a high pressure compressor. The high pressure compressor includes an aft-most compressor stage and an upstream compressor stage, each of the aft-most compressor stage and the upstream compressor stage including a rotor disk. The gas turbine engine also includes a high pressure spool assembly, the high pressure spool assembly including a rotor disk, and an airflow member extending from the rotor disk of the high pressure spool assembly to the rotor disk of the upstream compressor stage of the high pressure compressor to define in part a compressor cooling air passage outward of the airflow member along a radial direction.

Abstract: A heat management system for a turbomachine may include a first heat exchanger configured and arranged to receive a first fluid stream from a first duct, a second heat exchanger configured and arranged to receive the first fluid stream after discharging from the first heat exchanger, and a second duct fluidly communicating with the first duct between the first heat exchanger and the second heat exchanger to introduce a second fluid stream from the second duct to the first duct. A method of cooling fluid streams may include directing a first fluid stream from a first duct across or through a first heat exchanger, directing the first fluid stream across or through a second heat exchanger after discharging from the first heat exchanger, and directing a second fluid stream from a second duct to the first duct, with the second duct fluidly communicating with the first duct between the first heat exchanger and the second heat exchanger.

Abstract: A gas turbine engine includes a turbomachine including a compressor section, a combustion section, a turbine section, and an exhaust section arranged in serial flow order and together defining at least in part a core air flowpath. The gas turbine engine also includes a thermal management system including a flowpath heat exchanger coupled to, or integrated into, one or more components of the compressor section, the combustion section, the turbine section, or the exhaust section such that the flowpath heat exchanger is directly thermally coupled to an airflow through the core air flowpath.

Abstract: An aspect of the present disclosure is directed to a rotor assembly for a turbine engine. The rotor assembly includes an airfoil assembly and a hub to which the airfoil assembly is attached. A wall assembly defines a first cavity and a second cavity between the airfoil assembly and the hub. The first cavity and the second cavity are at least partially fluidly separated by the wall assembly. The first cavity is in fluid communication with a flow of first cooling fluid and the second cavity is in fluid communication with a flow of second cooling fluid different from the first cooling fluid.

Abstract: Heat exchangers, heat exchanger systems, and hypersonic vehicles are provided. For example, a heat exchanger is provided that comprises a first chamber for receipt of a flow of cool fluid and a second chamber for receipt of a flow of hot fluid. The heat exchanger further comprises a buffer fluid flowpath for circulation of a buffer fluid therethrough. The buffer fluid circulates within the buffer fluid flowpath disposed between the first chamber and the second chamber to transfer heat from the hot fluid to the cool fluid. In certain embodiments, a hypersonic vehicle comprises such a heat exchanger, and the cool fluid is cryogenic or near-cryogenic fuel of the hypersonic vehicle and the hot fluid is engine bleed air from a hypersonic propulsion engine of the vehicle.

Abstract: Flow paths and boundary layer restart features are provided. For example, a flow path comprises a flow path wall defining an inner flow path surface and an asymmetric notch defined in the flow path wall. The asymmetric notch comprises a first surface and a second surface and is asymmetric about a first line extending through an intersection of the first and second surfaces. Further, a flow boundary layer restart feature comprises a first surface extending inward with respect to a flow path surface of a flow path and a second surface extending inward with respect to the flow path surface. The second surface is asymmetric with respect to the first surface such that the first and second surfaces define an asymmetric notch. Additionally, a flow path wall may comprise an asymmetric notch that includes a flow expansion angle and a flow contraction angle that are unequal.

Abstract: A heat management system for a turbomachine may include a first heat exchanger configured and arranged to receive a first fluid stream from a first duct, a second heat exchanger configured and arranged to receive the first fluid stream after discharging from the first heat exchanger, and a hatch configured to provide fluid communication from a second duct to the first duct so as to introduce a second fluid stream from the second duct to the first duct. A method of cooling fluid streams may include directing a first fluid stream from a first duct across or through a first heat exchanger, directing the first fluid stream across or through a second heat exchanger after discharging from the first heat exchanger, and directing a second fluid stream from a second duct to the first duct, with the second fluid stream flowing through a hatch configured to provide fluid communication from the second duct to the first duct.

Abstract: A vehicle is provided including a structure including a skin defining an outside surface exposed to ambient cooling flow and an inside surface. The structure includes a first structural member extending from the inside surface of the skin and a second structural member extending from the inside surface of the skin; and a thermal management system including a heat exchanger assembly positioned adjacent to, and in thermal communication with, the inside surface of the skin, the heat exchanger assembly positioned at least partially between the first and second structural members of the structure.

Abstract: A heat exchanger is provided that can include furcating unit cells coupled with each other. Each of the unit cells can be elongated along an axis and include a sidewall that defines annular ring openings on opposite ends of the unit cell along the axis. The sidewall also can define undulating annular rings between the annular ring openings and axially separated from each other along the axis. The sidewall can further define angled openings into the unit cell both above and below each of the undulating annular rings. At least a first opening of the annular ring openings and the angled openings can be configured to be an inlet to receive a first fluid into the unit cell and at least a second opening of the annular ring openings and the angled openings configured to be an outlet through which the first fluid exits the unit cell.