Disclosed is an air cycle machine (ACM) having: a turbine; a compressor; a compressor shaft connected to the compressor and configured to receive rotational energy from a gearbox; and a turbine shaft connected to the turbine and configured to provide rotational energy to the gearbox; wherein the turbine shaft and the compressor shaft operate at different rotational speeds.

An aircraft installation of a pneumatic system of an aircraft with different compressed air sources for supplying pressurized air to air consumer equipment. Either an air bleed system, electrical compressors, or a combination thereof may perform such supplying of compressed air depending on the aircraft operation condition, for instance the flight altitude or specific flight phases. Also, a turbofan engine, and a method for supplying compressed air to air consumer equipment are disclosed.

The auxiliary duct can branch radially outwardly from the bypass duct, have a proximal end fluidly connecting the bypass duct and a distal end, a valve can be activatable to selectively open and close the auxiliary passage, and a structure can protrude partially from the auxiliary duct into the auxiliary passage, the structure spaced apart from the proximal end, between the proximal end and the valve, the structure generating lesser pressure losses when flow in the auxiliary passage is directed towards the distal end than when the flow is directed towards the proximal end.

A system includes a first fluid flow path configured to condition a pressurized medium and deliver the pressurized medium to one or more loads. The first fluid flow path including an air cycle machine. A second fluid flow path is configured to circulate a working fluid. The second fluid flow path includes a heat exchanger thermally coupled to the first fluid flow path. Within the heat exchanger, heat extracted from the pressurized medium is transferred to the working fluid. The second fluid flow path additionally includes a turbine operably coupled to the air cycle machine, a condenser, and a pump operable to circulate the working fluid through at least a portion of the second fluid flow path. The turbine is rotationally driven by expanding the working fluid across the turbine.

A dual entry turbine of a compression device includes a housing having a first inlet and a second inlet, and a first outlet and a second outlet. A turbine impeller is arranged within the housing. The turbine impeller has a first gas path and a second gas path. A first flow path extends from the first inlet to the first outlet via the first gas path and a second flow path extends from the second inlet to the second outlet via the second gas path. The first flow path and the second flow path being fluidly separate from one another.

An auxiliary power unit for an aircraft. It includes an air compressor coupled to an air-drawing device for drawing in air from outside the aircraft, the compressor supplying compressed air to a manifold. The manifold is configured to supply air to an environmental control system and a start-up module of at least one propulsion system of the aircraft running on hydrogen. The manifold is also configured to supply air to a fuel cell stack arranged to provide an electric generation function configured to power non-propulsive systems of the aircraft, the fuel cell stack also being supplied with hydrogen from a tank supplying hydrogen to the at least one propulsion system of the aircraft.

A method for heating an unpressurized aircraft includes receiving a desired air temperature, calculating a target duct air temperature based on the desired air temperature, determining an actual duct air temperature via a duct air temperature sensor, calculating a target modulation of one or more ram air valves based on a difference between the target duct air temperature and the actual duct air temperature, modulating one or more of the ram air valves based on the target modulation, introducing a bleed air from a turbine engine to a heat exchanger, introducing a temperature control air from one of the one or more ram air valves to the heat exchanger for cooling the bleed air to provide a temperature-controlled air, mixing the temperature-controlled air from the heat exchanger with an ejector ram air in an ejector, and providing air from the ejector to an occupied compartment of the unpressurized aircraft.

A system includes a concentration sensor, a flow sensor, and a controller. The concentration sensor is configured to measure a concentration of a contaminant in a cabin of an aircraft. The flow sensor is configured to measure a flow rate of air into the cabin. The controller is configured to determine whether a concentration measurement of the contaminant in the cabin exceeds a first concentration threshold. The controller is configured to, in response to determining that the concentration measurement does not exceed the first concentration threshold, control the flow rate of air into the cabin based on a flow rate setpoint. The controller is configured to, in response to determining that the concentration measurement exceeds the first concentration threshold, control the flow rate of air into the cabin based on a flow rate setpoint and a correction factor that is based on a flow sensor tolerance.

A cold regulating valve for a heat exchanger system of an aircraft propulsion system, where the cold regulating valve includes an open frame which delimits an opening, two shutters with an external convex shape slidably mounted on the open frame between a closed position and an open position, a mechanism linked to the shutters and mobile between a first position and a second position, and wherein the mechanism moves the shutters from the closed position to the open position when it moves from the first position to the second position and vice versa, and an actuator acting on the mechanism to move it from the first position to the second position and vice versa. The specific embodiment of the cold regulating valve generates a low drag when the shutters are in a closed position.

An environmental control system comprising that utilizes recirculation air. The environmental control system includes an inlet configured to supply bleed air at a first energy from a source to the environmental control system, where the environmental control system supplies the bleed air at a second energy to a chamber. The environmental control system also includes an air cycle machine comprising a compressor and a turbine, where the air cycle machine receives the recirculation air from the chamber and the recirculation air is bleed air at a third energy flowing from the chamber to the air cycle machine.