An airplane is provided. The airplane includes a first medium at a first pressure, a second medium at a second pressure, a third medium at a third pressure; and an air conditioning system. The air conditioning system includes a compressor, a first heat exchanger configured to transfer heat from the first medium to the third medium, a second heat exchanger configured to reject heat from the first medium, a third heat exchanger configured to reject heat from the second medium, a first turbine configured to receive the first medium, and a second turbine configured to receive the second medium.

An airplane is provided. The airplane includes a first medium at a first pressure, a second medium at a second pressure, a third medium at a third pressure; and an air conditioning system. The air conditioning system includes a compressor, a first heat exchanger configured to transfer heat from the first medium to the third medium, a second heat exchanger configured to reject heat from the first medium, a third heat exchanger configured to reject heat from the second medium, a first turbine configured to receive the first medium, and a second turbine configured to receive the second medium.

An air cycle machine is provided. The air cycle machine can be included an environmental control system of an aircraft. The air cycle machine can include a turbine comprising a plurality of inlet gas flow paths, a compressor driven by the turbine from a shaft, and a fan driven by the turbine from the shaft.

An air cycle machine is provided. The air cycle machine can be included an environmental control system of an aircraft. The air cycle machine can include a turbine comprising a plurality of inlet gas flow paths, a compressor driven by the turbine from a shaft, and a fan driven by the turbine from the shaft.

The low pressure turbine includes a rotor, an outer casing, a plurality of stages of rotor blades, and a plurality of stages of stator vanes. The rotor includes a longitudinal centerline. The outer casing circumscribes the rotor. The plurality of stages of rotor blades is disposed on a radially outer surface of the rotor in a serial flow arrangement. The plurality of stages of stator vanes is disposed on a radially inner surface of the outer casing in a serial flow arrangement. Each stage of the plurality of stages of stator vanes precedes a stage of rotor blades. The last stage of rotor blades of the plurality of stages of rotor blades includes a low swirl outlet rotor blade stage.

The low pressure turbine includes a rotor, an outer casing, a plurality of stages of rotor blades, and a plurality of stages of stator vanes. The rotor includes a longitudinal centerline. The outer casing circumscribes the rotor. The plurality of stages of rotor blades is disposed on a radially outer surface of the rotor in a serial flow arrangement. The plurality of stages of stator vanes is disposed on a radially inner surface of the outer casing in a serial flow arrangement. Each stage of the plurality of stages of stator vanes precedes a stage of rotor blades. The last stage of rotor blades of the plurality of stages of rotor blades includes a low swirl outlet rotor blade stage.

A system includes a compressor having a compressor inlet, a turbine having a plurality of stages disposed within a turbine casing, and a turbine extraction gas (TEG) heating system. The turbine is configured to drive the compressor via expansion of combustion products through the plurality of stages. The TEG heating system includes a turbine gas extraction system coupled to the turbine casing and to the compressor inlet. The turbine gas extraction system is configured to receive a portion of the combustion products as a turbine extraction gas (TEG) from the turbine. The TEG is received through the turbine casing, the TEG heating system is configured to supply a heated flow to the compressor inlet, and the heated flow includes the TEG.

The rotor assembly can have a first disc having a first body extending circumferentially and radially around the axis, a first set of circumferentially distributed blades protruding radially from the first disc, and a male spline extending axially relative the first body, the male spline extending around and along the axis, and a second disc having a second body extending circumferentially and radially around the axis, a second set of circumferentially distributed blades protruding radially from the second disc, and a female spline extending around and along the axis, the female spline receiving the male spline in a spline engagement.

A fixture for an electro-chemical machining (ECM) electrode is provided. The fixture may include a clamp having a shape and size configured to selectively engage in at least a portion of a selected dovetail slot of a plurality of dovetail slots in a turbine wheel. An electrode mount positions an electrode head relative to the clamp such that the electrode head operatively engages a portion of the selected dovetail slot for electro-chemical machining of the portion. The fixture's electrode may act as a cathode for the ECM process. The fixture allows for ECM on site without removing a turbine wheel from a turbomachine.

A fixture for an electro-chemical machining (ECM) electrode is provided. The fixture may include a clamp having a shape and size configured to selectively engage in at least a portion of a selected dovetail slot of a plurality of dovetail slots in a turbine wheel. An electrode mount positions an electrode head relative to the clamp such that the electrode head operatively engages a portion of the selected dovetail slot for electro-chemical machining of the portion. The fixture's electrode may act as a cathode for the ECM process. The fixture allows for ECM on site without removing a turbine wheel from a turbomachine.