Abstract: A heat exchanger includes an inlet plenum chamber, an outlet plenum chamber fluidly coupled to the inlet plenum chamber, and a plurality of intermediate plenum chambers disposed downstream from the inlet plenum chamber and upstream from the outlet plenum chamber. The plurality of intermediate plenum chambers includes a first intermediate plenum chamber, at least one tube bundle, and a first bypass valve fluidly coupled to the first intermediate plenum chamber. The first bypass valve is configured to control fluid flow rate from the first intermediate plenum chamber to the outlet plenum chamber.

Abstract: A gas turbine engine having a waste heat recovery system is provided. The 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 exhaust section including a primary exhaust flowpath and a waste heat recovery flowpath parallel to the primary exhaust flowpath; and the waste heat recovery system includes a heat source exchanger positioned in thermal communication with a first portion of the waste heat recovery flowpath.

Abstract: In an embodiment, a heat exchanger includes a monolithic body that includes a first substrate, a second substrate, a third substrate, and a plurality of partial height fins. The second substrate is arranged parallel to and spaced from the first substrate, thereby defining a first fluid flow path. The third substrate is arranged parallel to and spaced from the second substrate opposite the first substrate, thereby defining a second fluid flow path. The plurality of partial height fins extend from one of the second substrate and the third substrate toward the other of the second substrate or the third substrate, wherein a terminal edge of each partial height fin is at least partially spaced from the other of the second substrate or the third substrate.

Abstract: A heat exchange system for a gas turbine engine includes a first heat exchanger that defines a first heat source flowpath, a second heat exchanger that defines a second heat source flowpath, and a coolant fluid circuit. The coolant fluid circuit defines a first coolant flowpath that extends through the first heat exchanger and is in thermal communication with the first heat source flowpath, and a second coolant flowpath that extends through the second heat exchanger and is in thermal communication with the second heat source flowpath. The first coolant flowpath and the second coolant flowpath are arranged in a parallel flow configuration.

Abstract: A gas turbine engine is provided, having a turbomachine and a rotor assembly driven by the turbomachine and operable at a first blade passing frequency (f1) greater than or equal to 2,500 hertz and less than or equal to 5,000 hertz during a high power operating condition; a heat exchanger positioned within an annular duct and extending substantially continuously along the circumferential direction, wherein an effective transmission loss (ETL) for the heat exchanger positioned within the annular duct is between 5 decibels and 1 decibels for a high power operating condition, and wherein the heat exchanger comprises a heat transfer section defining an acoustic length (Li), and wherein an Operational Acoustic Reduction Ratio (OARR) is greater than or equal to 0.75 to achieve the ETL at the high power operating condition, the OARR equal to: sin ? ? ( 2 × ? × f 1 a 1 × L i ) 2 wherein a1 is equal to 13,200 inches per second during the high power operating condition.

Abstract: A passive flow modulation device for a machine defining an axial direction and a radial direction, the passive flow modulation device including: a first ring with a first coefficient of thermal expansion; a second ring disposed coaxially with the first ring and positioned at least partially inward of the first ring along the radial direction, spaced from the first ring along the axial direction, or both, the first ring, the second ring, or both defining at least in part one or more passages, the second ring with a second coefficient of thermal expansion that is less than the first coefficient of thermal expansion to passively modulate a size of the one or more passages during operation.

Abstract: A system for energy conversion that includes a propulsion system, a fuel circuit, a combustion device, a turbine, and a load device. The fuel circuit is in fluid communication with a fuel tank and a fuel flow control device that separates a flow of fuel into a first portion and a second portion. The combustion device receives a flow of oxidizer and the second portion of fuel to generate combustion gases. The turbine receives the combustion gases from the combustion device via a fluid circuit. The load device is operably coupled to the turbine via a driveshaft and is configured to receive torque from the driveshaft.

Abstract: A method and structure for thermal management for a vehicle is provided. The method includes extracting a flow of compressed fluid from a compressor section of a propulsion system in which the flow of compressed fluid includes a pressure parameter, and generating an output torque via expanding at least a portion of the flow of compressed fluid across a turbine operably connected to a driveshaft. The turbine is positioned downstream of the compressor section and upstream of a cooling system.

Abstract: Provided are fluid exchange apparatuses and methods of exchanging fluids between streams. Exemplary fluid exchange apparatus includes a first interleaved pathway with a plurality of first passages, and a second interleaved pathway with a plurality of second passages, in which the plurality of first passages and the plurality of second passages interleave with one another. Exemplary methods include directing a first fluid through a first interleaved pathway of a fluid exchange apparatus and directing a second fluid through a second interleaved pathway of a fluid exchange apparatus. The first fluid may flow from an upstream portion of a first duct into the first interleaved pathway and may discharge into a downstream portion of the second duct. The second fluid may flow from an upstream portion of the second duct into the second interleaved pathway and may discharge into a downstream portion of the first duct.

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.

Abstract: A gas supply system is provided herein. The gas supply system includes a fuel oxygen reduction unit having a circuit defining a gas flowpath for a flow of a stripping gas. A reservoir is in selective fluid communication with the fuel oxygen reduction unit and is configured to store a portion of the stripping gas from the circuit. The reservoir is further configured to be in selective fluid communication with the fuel system component when installed in a vehicle to provide the stored portion of the stripping gas to the fuel system component in response to detection of a purge condition.

Abstract: A pericritical fluid system for a thermal management system associated with a turbine engine may include one or more sensors configured to generate sensor outputs corresponding to one or more phase properties of a pericritical fluid flowing through a cooling circuit of the thermal management system, and a controller configured to generate control commands configured to control one or more controllable components of the thermal management system based at least in part on the sensor outputs. The one or more sensors may include one or more phase detection sensors, such as an acoustic sensor.

Abstract: An aircraft propulsion system and computing system are provided. The propulsion system includes a low pressure (LP) spool and a core engine having a high pressure (HP) spool. A frame is positioned in serial flow arrangement between an HP turbine and an LP turbine. The frame includes an inter-turbine burner including a strut forming an outlet opening into a core flowpath of the propulsion system. A first fuel system is configured to flow a liquid fuel to a combustion section for generating first combustion gases. A second fuel system is configured to flow a gaseous fuel to the core flowpath via the inter-turbine burner for generating second combustion gases. The propulsion system forms a rated power output ratio of the core engine and the inter-turbine burner with the LP spool between 1.5 and 5.7.

Abstract: A shaft power transfer system includes a first mechanical clutch mechanism operably coupling a high-pressure shaft to a low-pressure shaft. The first mechanical clutch mechanism transfers power from the high-pressure shaft to the low-pressure shaft at a predefined first speed transient condition. The system further includes a second mechanical clutch mechanism that operably couples the low-pressure shaft to the high-pressure shaft. The second mechanical clutch mechanism transfers power from the low-pressure shaft to the high-pressure shaft at a predefined second speed transient condition where the predefined first speed transient condition is different than the predefined second speed transient condition.

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 gas turbine engine defines a working air flowpath and includes an electrical system having an electric machine coupled to the rotary component at least partially inward of the working air flowpath along the radial direction and an electric bus electrically coupled to the electric machine. The electric bus includes an electric line extending through the working air flowpath within or downstream of a turbine section. The engine further includes a cooling system including a cooling fluid supply line and a cooling fluid return line, wherein a portion of the electric line extending though the working air flowpath is substantially embedded within the cooling fluid supply line, and wherein a portion of the cooling fluid supply line extending though the working air flowpath is substantially embedded within the cooling fluid return line.

Abstract: A method is provided of controlling a cooled cooling air system for an aeronautical gas turbine engine. The method includes: receiving data indicative of an ambient condition of the aeronautical gas turbine engine, data indicative of a deterioration parameter of the aeronautical gas turbine engine, data indicative of an operating condition of the aeronautical gas turbine engine, or a combination thereof; and modifying a cooling capacity of the cooled cooling air system in response to the received data indicative of the ambient condition of the aeronautical gas turbine engine, data indicative of the deterioration parameter of the aeronautical gas turbine engine, data indicative of an operating condition of the aeronautical gas turbine engine, or the combination thereof.

Abstract: A system for energy conversion that includes a propulsion system, a fuel circuit, a combustion device, a turbine, and a load device. The fuel circuit is in fluid communication with a fuel tank and a fuel flow control device that separates a flow of fuel into a first portion and a second portion. The combustion device receives a flow of oxidizer and the second portion of fuel to generate combustion gases. The turbine receives the combustion gases from the combustion device via a fluid circuit. The load device is operably coupled to the turbine via a driveshaft and is configured to receive torque from the driveshaft.

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 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.