Abstract: A gas turbine engine includes a fan assembly, a turbomachine defining in part a working gas flowpath, the gas turbine engine defining a bypass passage over the turbomachine, a core cowl, and a heat exchanger assembly including a heat exchanger and a heat exchanger cowl defining a cooling air flowpath extending between a flowpath inlet in airflow communication with the bypass passage to receive a cooling airflow from the bypass passage and a flowpath outlet in airflow communication with the bypass passage to exhaust the cooling airflow back to the bypass passage, the heat exchanger positioned within the cooling air flowpath, the cooling air flowpath comprising a diffusion section located between the flowpath inlet and the heat exchanger.

Abstract: A gas turbine engine is provided. The gas turbine engine includes: a fan; a turbomachine drivingly coupled to the fan and defining in part a working gas flowpath, the gas turbine engine defining a bypass passage over the turbomachine, the turbomachine defining an annular cooling passage extending between a CP inlet and a CP outlet, the CP inlet in airflow communication with the working gas flowpath and the CP outlet in airflow communication with the bypass passage; and a variable bleed assembly including a variable bleed duct extending between a VB inlet and a VB outlet, the VB inlet in airflow communication with the working gas flowpath at a location downstream of the CP inlet and the VB outlet in airflow communication with the annular cooling passage for urging an airflow through the cooling passage.

Abstract: A turbine engine includes a fan including a fan rotor assembly having a plurality of fan blades coupled to a fan disk, a fan frame that supports the fan, and a fan speed sensor system. The fan speed sensor system includes one or more fan speed sensors that sense a fan speed of the fan. The one or more fan speed sensors are positioned to sense the fan rotor assembly. A method of operating the turbine engine includes rotating the fan rotor assembly, sensing rotation of the fan rotor assembly with the one or more fan speed sensors, determining the fan speed of the fan based on the rotation of the fan rotor assembly, and controlling one or more components of the turbine engine based on the fan speed of the fan.

Abstract: A turbine engine has a longitudinal centerline axis. The turbine engine includes a fan, a turbo-engine, and a unidirectional brake. The fan includes a plurality of fan blades that rotate in a first direction about the longitudinal centerline axis. The turbo-engine includes a combustor that combusts compressed air and fuel to generate combustion gases and a low-pressure turbine including a low-pressure shaft. The low-pressure turbine receives the combustion gases to rotate the low-pressure turbine. The fan is coupled to the low-pressure shaft such that rotation of the low-pressure shaft causes the fan to rotate in the first direction. A unidirectional brake is coupled to the low-pressure shaft to prevent rotation of the low-pressure shaft and, thus, the fan in a second direction opposite the first direction.

Abstract: Truss-braced wing aircraft engine mounting and associated systems are disclosed. An example aircraft includes a fuselage including a central structural section, a wing extending from the fuselage, a truss extending from the central structural section and coupled to the wing, a pylon coupled to the central structural section, and an engine coupled to the pylon, wherein the pylon is positioned at an angle substantially 45 degrees from a horizontal plane and a vertical plane.

Abstract: A gas turbine engine includes a fan, a turbomachine comprising a compressor section, a combustion section, and a turbine section arranged in serial flow order and defining in part a working gas flowpath, the compressor section including a frame and defining a cavity forward of the frame, the compressor section further comprising a booster disposed in the working gas flowpath including a vane in fluid communication with the working gas flowpath and the cavity, the gas turbine engine defining a bypass passage over the turbomachine, and a heat exchanger disposed at least partially in the cavity, wherein the heat exchanger is in fluid communication with the booster in the working gas flowpath and is in fluid communication with the bypass passage.

Abstract: A gas turbine engine includes a fan assembly, a turbo-engine encased within a turbo-engine cowl structure, a nacelle, and a thrust reverser system arranged, at least in part, in the nacelle. The turbo-engine includes a low-pressure compressor, a high-pressure compressor, an inter-compressor frame structure between the low-pressure compressor and the high-pressure compressor and including an outer frame portion having a cowl door engagement member on an upstream side of the outer frame portion, and a plurality of cowl doors defining the turbo-engine cowl structure. Each cowl door includes an inter-compressor frame engagement portion that engages with the cowl door engagement member of the inter-compressor frame structure, and a plurality of thrust reverser drag link connectors arranged on an outer side of the cowl door and arranged between the upstream side of the inter-compressor frame structure and a downstream side of the inter-compressor frame structure.

Abstract: A heat exchanger positioned within an annular duct of a gas turbine engine is provided. The heat exchanger extends substantially continuously along the circumferential direction and defining a heat exchanger height equal to at least 10% of a duct height. An effective transmission loss (ETL) for the heat exchanger positioned within the annular duct is between 5 decibels and 1 decibels for an operating condition of the gas turbine engine. The heat exchanger includes 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 operating condition.

Abstract: A gas turbine engine includes a fan assembly, a turbomachine defining in part a working gas flowpath, the gas turbine engine defining a bypass passage over the turbomachine, a core cowl, and a heat exchanger assembly including a heat exchanger and a heat exchanger cowl defining a cooling air flowpath extending between a flowpath inlet in airflow communication with the bypass passage to receive a cooling airflow from the bypass passage and a flowpath outlet in airflow communication with the bypass passage to exhaust the cooling airflow back to the bypass passage, the heat exchanger positioned within the cooling air flowpath, the cooling air flowpath comprising a diffusion section located between the flowpath inlet and the heat exchanger.

Abstract: A gas turbine engine comprising: a fan assembly comprising a fan; a turbomachine drivingly coupled to the fan and comprising a compressor section, a combustion section, and a turbine section arranged in serial flow order and defining in part a working gas flowpath, the gas turbine engine defining a bypass passage over the turbomachine, the turbomachine defining an annular cooling passage extending between a CP inlet and a CP outlet, the CP inlet in airflow communication with the working gas flowpath, the bypass passage, or both; an accessory system; a heat exchanger positioned in thermal communication with the annular cooling passage at a location between the CP inlet and the CP outlet, the heat exchanger in thermal communication with the accessory system; and a bleed cooling system defining a BC inlet in airflow communication with the annular cooling passage at a location between the CP inlet and the CP outlet.

Abstract: A heat exchanger positioned within an annular duct of a gas turbine engine is provided. The heat exchanger extends substantially continuously along the circumferential direction and defining a heat exchanger height equal to at least 10% of a duct height. An effective transmission loss (ETL) for the heat exchanger positioned within the annular duct is between 5 decibels and 1 decibels for an operating condition of the gas turbine engine. The heat exchanger includes 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 operating condition.

Abstract: A gas turbine engine including: a fan assembly comprising a fan; and a turbomachine drivingly coupled to the fan and including a compressor section, a combustion section, and a turbine section arranged in serial flow order and defining in part a working gas flowpath, the gas turbine engine defining a bypass passage over the turbomachine; the turbomachine further including a heat exchanger and defining an annular cooling passage extending between an inlet and an outlet, the inlet in airflow communication with the working gas flowpath at a location upstream of the compressor section and the outlet in airflow communication with the bypass passage, the heat exchanger in thermal communication with an airflow through the cooling passage.

Abstract: A thermal management system includes a thermal circuit having a thermal transport bus with a thermal fluid flowing therethrough. The thermal transport bus includes first and second bus segments. First and second thermal loads are on the first and second bus segments, respectively, and have different first and second inlet temperature requirements. The thermal management system includes a plurality of heat exchangers in thermal communication with the first and second thermal loads. The heat exchangers include a first heat exchanger and one or more second heat exchangers. The first heat exchanger is on one of the first or second bus segments for rejecting heat to engine fuel. The thermal fluid is split between each of the first and second bus segments such that only a portion of the thermal fluid flows through the first heat exchanger to accommodate the different first and second inlet temperature requirements.

Abstract: A thermal management system includes a thermal circuit having a thermal transport bus with a thermal fluid flowing therethrough. The thermal transport bus includes first and second bus segments. First and second thermal loads are on the first and second bus segments, respectively, and have different first and second inlet temperature requirements. The thermal management system includes a plurality of heat exchangers in thermal communication with the first and second thermal loads. The heat exchangers include a first heat exchanger and one or more second heat exchangers. The first heat exchanger is on one of the first or second bus segments for rejecting heat to engine fuel. The thermal fluid is split between each of the first and second bus segments such that only a portion of the thermal fluid flows through the first heat exchanger to accommodate the different first and second inlet temperature requirements.

Abstract: An engine includes a gearbox coupled to a first element and a second element. The engine may include a first speed sensor positioned on an input side of the gearbox, the first speed sensor operable to detect a first speed of the first element. The engine may further include a second speed sensor positioned on an output side of the gearbox, the second speed sensor operable to detect a second speed of the second element. The engine includes a controller comprising a processor and a memory coupled to the processor. The processor may be configured to receive data from the first speed sensor and the second speed sensor. The processor is also configured to detect a trigger event based on the data from the first speed sensor and the data from the second speed sensor. Upon detecting the trigger event, the processor communicates a command to an engine operational system.

Abstract: A heat exchanger positioned within an annular duct of a gas turbine engine is provided. The heat exchanger extends substantially continuously along the circumferential direction and defining a heat exchanger height equal to at least 10% of a duct height. An effective transmission loss (ETL) for the heat exchanger positioned within the annular duct is between 5 decibels and 1 decibels for an operating condition of the gas turbine engine. The heat exchanger includes 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 operating condition.

Abstract: A turbine engine has a longitudinal centerline axis. The turbine engine includes a fan, a turbo-engine, and a unidirectional brake. The fan includes a plurality of fan blades that rotate in a first direction about the longitudinal centerline axis. The turbo-engine includes a combustor that combusts compressed air and fuel to generate combustion gases and a low-pressure turbine including a low-pressure shaft. The low-pressure turbine receives the combustion gases to rotate the low-pressure turbine. The fan is coupled to the low-pressure shaft such that rotation of the low-pressure shaft causes the fan to rotate in the first direction. A unidirectional brake is coupled to the low-pressure shaft to prevent rotation of the low-pressure shaft and, thus, the fan in a second direction opposite the first direction.

Abstract: A gas turbine engine is provided. The gas turbine engine includes: a fan; a turbomachine drivingly coupled to the fan and defining in part a working gas flowpath, the gas turbine engine defining a bypass passage over the turbomachine, the turbomachine defining an annular cooling passage extending between a CP inlet and a CP outlet, the CP inlet in airflow communication with the working gas flowpath and the CP outlet in airflow communication with the bypass passage; and a variable bleed assembly including a variable bleed duct extending between a VB inlet and a VB outlet, the VB inlet in airflow communication with the working gas flowpath at a location downstream of the CP inlet and the VB outlet in airflow communication with the annular cooling passage for urging an airflow through the cooling passage.

Abstract: A gas turbine engine including: a fan assembly comprising a fan; and a turbomachine drivingly coupled to the fan and including a compressor section, a combustion section, and a turbine section arranged in serial flow order and defining in part a working gas flowpath, the gas turbine engine defining a bypass passage over the turbomachine; the turbomachine further including a heat exchanger and defining an annular cooling passage extending between an inlet and an outlet, the inlet in airflow communication with the working gas flowpath at a location upstream of the compressor section and the outlet in airflow communication with the bypass passage, the heat exchanger in thermal communication with an airflow through the cooling passage.