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.

One embodiment includes a multistage infrared suppression exhaust system for an aircraft, including: a stage one including a first exhaust conduit to receive a first exhaust air flow at a first temperature-pressure product T.sub.1P.sub.1, a second exhaust conduit to receive a second exhaust air flow at a second temperature-pressure product T.sub.2P.sub.2, and a flow integrator mechanically configured to mix the first exhaust air flow with the second exhaust air flow in an integration chamber while preventing back flow into the second exhaust conduit; and a stage two including a stage two cooling airflow to cool the mixed first and second exhaust air flows.

One embodiment includes a multistage infrared suppression exhaust system for an aircraft, including: a stage one including a first exhaust conduit to receive a first exhaust air flow at a first temperature-pressure product T.sub.1P.sub.1, a second exhaust conduit to receive a second exhaust air flow at a second temperature-pressure product T.sub.2P.sub.2, and a flow integrator mechanically configured to mix the first exhaust air flow with the second exhaust air flow in an integration chamber while preventing back flow into the second exhaust conduit; and a stage two including a stage two cooling airflow to cool the mixed first and second exhaust air flows.

An aircraft system includes a turbine engine having a compressor, a combustor having an inlet and an outlet, and a turbine having an inlet portion and an outlet portion. An auxiliary power unit (APU) is operatively connected to the turbine engine. The APU includes a compressor portion, a generator, and a turbine portion. The compressor portion is operatively connected to the turbine portion through the generator. A source of cryogenic fluid is operatively connected to the turbine engine and the APU. A heat exchange member includes an inlet section operatively connected to the source of cryogenic fluid, a first outlet section operatively connected to the turbine engine and a second outlet section operatively connected to the compressor portion.

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.

An engine-driven cryogenic cooling system for an aircraft includes a first air cycle machine, a second air cycle machine, and a means for condensing a chilled air stream into liquid air for an aircraft use. The first air cycle machine includes a plurality of components operably coupled to a gearbox of a gas turbine engine and configured to produce a cooling air stream based on a first engine bleed source of the gas turbine engine. The second air cycle machine is operable to output the chilled air stream at a cryogenic temperature based on a second engine bleed source cooled by the cooling air stream of the first air cycle machine.

An engine-driven cryogenic cooling system for an aircraft includes a first air cycle machine, a second air cycle machine, and a means for condensing a chilled air stream into liquid air for an aircraft use. The first air cycle machine includes a plurality of components operably coupled to a gearbox of a gas turbine engine and configured to produce a cooling air stream based on a first engine bleed source of the gas turbine engine. The second air cycle machine is operable to output the chilled air stream at a cryogenic temperature based on a second engine bleed source cooled by the cooling air stream of the first air cycle machine.

A system comprises a gas turbine engine. The gas turbine engine has a flow diffuser system, a combustor, a modified compressor section, and a turbine coupled to a shaft. The system includes a low pressure intercooled compressor, a high pressure intercooled compressor, a recuperator, and a compressed air storage tank. The compressed air storage tank is in selective fluid communication with the low pressure intercooled compressor via the high pressure intercooled compressor, and the recuperator. The high pressure intercooled compressor is configured to selectively receive compressed air from the low pressure intercooled compressor and is further configured to selectively compress the compressed air to a highly compressed air for storage in the compressed air storage tank. Each of the compressed air storage tank and the low pressure intercooled compressor is selectively and fluidly coupled to the gas turbine engine.

A system comprises a gas turbine engine. The gas turbine engine has a flow diffuser system, a combustor, a modified compressor section, and a turbine coupled to a shaft. The system includes a low pressure intercooled compressor, a high pressure intercooled compressor, a recuperator, and a compressed air storage tank. The compressed air storage tank is in selective fluid communication with the low pressure intercooled compressor via the high pressure intercooled compressor, and the recuperator. The high pressure intercooled compressor is configured to selectively receive compressed air from the low pressure intercooled compressor and is further configured to selectively compress the compressed air to a highly compressed air for storage in the compressed air storage tank. Each of the compressed air storage tank and the low pressure intercooled compressor is selectively and fluidly coupled to the gas turbine engine.

Waste heat management systems are described. The waste heat management systems include a turbine engine having a compressor section, a combustor section, a turbine section, and a nozzle. The compressor section, the combustor section, the turbine section, and the nozzle define a core flow path that expels through the nozzle. The waste heat management systems also include an auxiliary power unit (APU) system and a waste heat recovery system operably connected to the APU system. The APU system is integrated into a working fluid flow path of the waste heat recovery system.