A heat exchanger (HEX) for cooling air in a gas turbine engine is provided. An adjustable damper is provided. The adjustable damper may be for damping a movement of the HEX relative to the gas turbine engine. An adjustable damper may comprise: a first tube; a second tube located at least partially within the first tube; a housing coupled to the second tube; a moveable member, the moveable member comprising a contacting surface in contact with the second tube; an adjusting member adjustably coupled to the housing; and a spring member located between the moveable member and the adjusting member, the spring member configured to at least one of compress or decompress in response to adjusting member moving relative to the housing.

A heat exchanger (HEX) for cooling air in a gas turbine engine is provided. An adjustable damper is provided. The adjustable damper may be for damping a movement of the HEX relative to the gas turbine engine. An adjustable damper may comprise: a first tube; a second tube located at least partially within the first tube; a housing coupled to the second tube; a moveable member, the moveable member comprising a contacting surface in contact with the second tube; an adjusting member adjustably coupled to the housing; and a spring member located between the moveable member and the adjusting member, the spring member configured to at least one of compress or decompress in response to adjusting member moving relative to the housing.

Gas turbine engine including a nacelle and an engine core within the nacelle. The engine core defines a principal rotational axis along its length. The engine core and nacelle define a bypass passage therebetween. The gas turbine engine further includes a cooling system including a cooling duct, which duct defines an inlet for receiving bypass air from the bypass passage at an upstream location and an outlet for discharging the bypass air at a downstream location. The cooling duct extends, relative to the principal axis, axially and circumferentially around a section of the engine core. The cooling duct comprises: first portion that extends at least axially relative to the principal rotational axis; second portion downstream of the first portion that extends circumferentially around the engine core relative to the principal rotational axis; and third portion downstream of second portion that extends at least axially relative to the principal rotational axis.

A system for modulating air flow in a gas turbine engine is provided. The system may include a seal wall comprising an opening, a seal door configured to slideably engage the seal wall, and an actuator configured to move the seal door over the opening. In various embodiments, the system may include a surface forward of the seal door. The seal door may be configured to seal a passage through the surface and the opening of the seal wall. A track may be disposed under the seal door. The track may comprise cobalt. Rollers may be coupled to the seal door with the rollers on the track. The seal door may comprise a nickel-chromium alloy. A sync ring may be coupled to the seal door. The actuator may be coupled through the sync ring to the seal door.

A system for modulating air flow in a gas turbine engine is provided. The system may include a seal wall comprising an opening, a seal door configured to slideably engage the seal wall, and an actuator configured to move the seal door over the opening. In various embodiments, the system may include a surface forward of the seal door. The seal door may be configured to seal a passage through the surface and the opening of the seal wall. A track may be disposed under the seal door. The track may comprise cobalt. Rollers may be coupled to the seal door with the rollers on the track. The seal door may comprise a nickel-chromium alloy. A sync ring may be coupled to the seal door. The actuator may be coupled through the sync ring to the seal door.

Gas turbine engines are described. The gas turbine engines include a compressor section, a combustor section, a turbine section, a nozzle section, wherein the compressor section, the combustor section, the turbine section, and the nozzle section define a core flow path that expels through the nozzle section, and a waste heat recovery system. The waste heat recovery system includes a heat recovery heat exchanger arranged at the nozzle section, wherein the heat recovery heat exchanger is arranged within the nozzle section such that the heat recovery heat exchanger occupies less than an entire area of an exhaust area of the nozzle section and a heat rejection heat exchanger arranged to reduce a temperature of a working fluid of the waste heat recovery system.

Gas turbine engines are described. The gas turbine engines include a compressor section, a combustor section, a turbine section, a nozzle section, wherein the compressor section, the combustor section, the turbine section, and the nozzle section define a core flow path that expels through the nozzle section, and a waste heat recovery system. The waste heat recovery system includes a heat recovery heat exchanger arranged at the nozzle section, wherein the heat recovery heat exchanger is arranged within the nozzle section such that the heat recovery heat exchanger occupies less than an entire area of an exhaust area of the nozzle section and a heat rejection heat exchanger arranged to reduce a temperature of a working fluid of the waste heat recovery system.

A method is provided during which an aircraft powerplant is provided. The aircraft powerplant includes a combustor and a water recovery system. The water recovery system includes a condenser and a reservoir. Fuel is combusted within the combustor to provide combustion products. Water is extracted from the combustion products using the condenser. The water recovery system is operated in one of a plurality of modes based on likelihood of contrail formation. The modes include a first mode and a second mode, where the water is collected within the reservoir during the first mode, and where the water passes through the water recovery system during the second mode.

A gas turbine engine includes: a fan that is arranged in front of a compressor and rotates in association with a rotating shaft; a casing including an inner shell accommodating the compressor, a combustor, and a turbine, and an outer shell arranged such that a bypass passage through which part of air supplied by the fan flows exists between the inner shell and the outer shell; bearings arranged inside the inner shell; an oil mist generator that is arranged outside the outer shell and generates oil mist by mixing oil with compressed air extracted through an extraction port of the compressor; an air pipe through which the compressed air extracted from the compressor is guided to the oil mist generator; and an oil mist pipe through which the oil mist generated by the oil mist generator is guided to the bearings. At least one of the air pipe and the oil mist pipe includes a heat exchanger that is arranged in the bypass passage and is cooled by the air flowing through the bypass passage.

A lubricating oil circuit of a turbomachine includes a distribution valve that distributes an oil flow rate among a first heat exchanger and a bypass duct, connected to an oil duct, which is connected to an heat exchanger positioned against a turbomachine fuel passage duct, and includes a gearbox of a rotation speed reducer that lowers a rotational speed of a first rotary fan shaft of the turbomachine relative to a rotational speed of a second low-pressure compressor rotary shaft of the turbomachine or of a second low-pressure turbine rotary shaft of the turbomachine, and a regulation device. The regulation device includes a local regulation loop that generates an oil flow rate distribution control signal and regulates an oil temperature of the oil duct on a temperature setpoint, and a global regulation loop that generates the temperature setpoint as a function of the temperature and of the temperature setpoint.