An environmental control system of an aircraft includes a ram air circuit including a ram air shell having at least one heat exchanger positioned therein, at least one dehumidification system arranged in fluid communication with the ram air circuit, a compressing device arranged in fluid communication with the ram air circuit and the dehumidification system, and an expansion device arranged in fluid communication with the ram air circuit and the at least one dehumidification system.

A pressurization system includes a first compressor that receives a ram air, a fan air, or engine air; a first turbine that is on a common shaft with the first compressor and wherein the first turbine receives an engine air; a main heat exchanger downstream of the first compressor and the first turbine; an internal environment suitable for human occupants and downstream of the main heat exchanger; a second turbine downstream of the internal environment; the second turbine may be on the common shaft with the first compressor and first turbine; or a generator downstream of the second turbine; a motor downstream of the generator; and wherein the motor drives the first compressor.

Air conditioning system for a cabin 6 of an aircraft, the air conditioning system 1 including a pressurized air source 2, a ram air duct 3, an air amplifier 4 and a heat exchanger 5. The air amplifier 4 includes an inlet 41 for work air, a slot 42 suitable for letting the work air exit the air amplifier, and a main fluid zone 43. The inlet 41 is in fluid communication with the pressurized air source 2 and the slot 42 is arranged in fluid communication with the ram air duct 3, in such a way that the work air exiting from the slot 42 produces a suction effect in the ambient air in such a way that this ambient air flows along the ram air duct 3. The air amplifier 4 is arranged so that the ambient air is forced by the suction effect to pass from the inlet 51 to the outlet 52 of the cold side of the heat exchanger 5.

A method for depressurizing a cabin of an aircraft on the ground from the outer side of the aircraft using a depressurizing system including a venting valve which can be actuated between open and closed positions by means of a shutter and which is connected in fluid terms to a vacuum pump and to a pressure tap port of the aircraft which is connected to a protection valve against excess pressure in the cabin. The method includes fluidly connecting the venting valve to the pressure tap port, the shutter being in the open position, moving the shutter to the closed position thereof and activating the vacuum pump to generate a reduced pressure in the region of the pressure tap port.

According to one embodiment, a ram air fan inlet shroud for a ram air fan assembly of an aircraft is provided. The ram air fan inlet shroud including: a shroud portion extending outwardly from a conical portion, the conical portion providing a transition between a central portion and an inner ram air fan hub interface portion, the conical portion including a plurality of inner cooling holes, a diameter of each of the plurality of inner cooling holes is about 0.406 inches (1.031 cm); and a recessed portion located between the inner ram air fan hub interface portion and an outer ram air fan hub interface portion, the recessed portion including a plurality of outer cooling holes.

A system for providing active flow control in an aircraft having a gas turbine engine. The system includes an environmental control system that includes a cabin blower system having a compressor operable to compress a fluid delivered by a fan section of the gas turbine engine to generate a pressurised fluid for use by the environmental control system. The environmental control system is fluidicly connected to an active flow control system via a fluid supply line, for allowing the pressurised fluid generated by the compressor to be supplied to the active flow control system so that it can be ejected from the aircraft across an exterior surface of a movable control element of the aircraft.

An auxiliary power unit for an aircraft, having a compressor, an intercooler including first conduit(s) having an inlet in fluid communication with the compressor outlet and second conduit(s) configured for circulation of a coolant therethrough, an engine core having an inlet in fluid communication with an outlet of the first conduit(s), and a bleed conduit in fluid communication with the outlet of the first conduit(s) through a bleed air valve. The auxiliary power unit may include a generator in driving engagement with the shaft of the engine core to provide electrical power for the aircraft. A method of providing compressed air and electrical power to an aircraft is also discussed.

An environmental control system of an aircraft includes a compressing device having a compressor configured to receive a first flow of a medium and a turbine configured to receive the first flow of the medium and a distinct second flow of the medium. A dehumidification system is arranged in fluid communication with the turbine. A valve is configured to divert the second flow around the turbine and an inlet port is arranged in fluid communication with the compressor, the turbine, and the dehumidification system.

An aircraft comprising a main engine to provide a supply of bleed air, an APU housing within an APU compartment and having an APU bleed valve, an APU bleed air duct connecting main engine with the APU, and a bleed air heating system for the APU compartment comprising an auxiliary pipeline connecting the APU bleed air duct with the APU compartment, a temperature sensor, an auxiliary pipeline valve to control the discharge of bleed air into the APU compartment, and a temperature controller configured to establish a heating operation mode, when the sensed temperature falls below a minimum temperature threshold value, and a standby operation mode, when the sensed temperature surpasses a maximum temperature threshold value. The temperature controller operates the main engine and the valves to establish these operation modes.

A system of pressure control for an environment to be pressurized includes a controller configured to calculate an environment leakage effective area CdALEAK according to: CdALEAK=f(Pc, Tc, Pa, WLEAK) wherein Pc is an environment pressure; Tc is an environment temperature; Pa is an ambient pressure outside of the environment; WLEAK=WECSWOFVWAPU; wherein WECS=air pressure inflow into the environment; WOFV=air pressure outflow to ambient that is outside of the environment; WAPU=f(Tin, Pin, APURPM, Flowfuel); wherein Tin=inlet temperature to a power source; Pin=inlet pressure to the power source; APURPM=rotational speed of the power source; Flowfuel=power source fuel flow. A processor is in communication with the controller and configured to compare a current CdALEAK value with a control limit; wherein the control limit is based on historical CdALEAK values.