Systems and methods for reducing the pressure of a first pressurized fluid, thereby reducing the temperature of the pressurized fluid, and utilization of the reduced-pressure and temperature fluid to cool a second fluid. Such an approach can enable a reduction in the size and weight of a hydraulic system, utilize waste energy in a system, and/or minimize electrical power requirements of a system, among other benefits.

A fan assembly is provided. The fan assembly includes a fan, a fan casing circumscribing the fan, and a fan casing heating system in thermal communication with the fan casing. The fan includes a hub, and a plurality of fan blades extending from the hub. Each fan blade of the plurality of fan blades terminates at a respective blade tip. A clearance gap is defined between the fan casing and the blade tips. The fan casing heating system is configured to apply heat to the fan casing when the fan is operating in a first operational mode, and remove the applied heat when the fan transitions into a second operational mode.

Disclosed is an air pump for a fuel cell that utilizes a speed-reduction traction drive so that a low speed electric motor can be used to drive a high-speed rotodynamic compressor. The rotodynamic compressor is an efficient air pump, but operates at high speeds that would require a specialized high-speed electric motor. The speed-reduction traction drive couples to the compressor and provides a low-speed output that is connected to a lower speed electric motor.

An air conditioning system for an aircraft is provided. The air conditioning system includes a first rotating component and a second rotating component. The first rotating component includes a compressor and a turbine. The compressor pressurizes a first medium. The first turbine receives a mixture of a second medium and a pressurized form of the first medium. The second rotating component includes a fan.

An airplane is provided. The airplane includes a first medium, a second medium, and an air conditioning. The air conditioning system includes a first turbine, a compressor, and a mixing point. The compressor is located upstream of the turbine in a flow path of the first medium. The mixing point is a location at which the first medium mixes with the second medium. The mixing point is downstream of the compressor and upstream of the turbine.

An air cycle machine for an environmental control system for an aircraft is provided. The air cycle machine includes a compressor configured to compress a first medium, a turbine configured to receive second medium, a mixing point downstream of the compressor and downstream of the turbine; and a shaft mechanically coupling the compressor and the turbine.

An airplane is provided. The airplane includes a compressing device. The compressing device includes a turbine with a first inlet and a second inlet. The turbine provides energy by expanding mediums. The first inlet is configured to receive a first medium of the mediums. The second inlet is configured to receive a second medium of the mediums. The compressing device includes a compressor and a motor. The compressor receives a first energy derived from the first and second mediums being expanded across the turbine during a first mode of the compressing device, receives a second energy derived from the first medium being expanded across the turbine during a second mode of the compressing device, and compresses the second medium in accordance with the first mode or the second mode. The motor provides a supplementary energy to the compressor

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.

A turbocharger includes a two-stage serial compressor having a first impeller and a second impeller affixed to a shaft and arranged in series for a two-stage compression of air, an exhaust gas-driven turbine having a turbine wheel affixed to the shaft, and an electric motor mounted on the shaft for assisting the turbine in rotatably driving the compressor.