Aircraft environmental control systems having electrically powered ram circuit fans are described herein. An example environmental control system includes an air cycle machine to produce cabin air for a cabin of the aircraft. The air cycle machine includes a turbine and a heat exchanger. The environmental control system also includes a ram circuit. The heat exchanger is disposed in the ram circuit. The environmental control system further includes a fan in the ram circuit to control air flow through the ram circuit and across the heat exchanger, an electric motor, and an overrunning clutch operatively coupled between the turbine and the electric motor to enable the turbine to drive the fan during a first mode of operation and to enable the electric motor to drive the fan during a second mode of operation.

Aircraft systems including a pressurized fuel tank containing a pressurized fuel, a turbo expander configured to receive the pressurized fuel from the fuel tank, the turbo expander configured to decrease a pressure of the pressurized fuel to generate low pressure fuel having pressure less than the pressurized fuel, a fuel-to-air heat exchanger configured to receive the low pressure fuel from the turbo expander as a first working fluid and air as a second working fluid, the heat exchanger configured to cool the air and warm the fuel, an aircraft cabin configured to receive the cooled air, and a fuel consumption system configured to consume the fuel to generate power.

A flow management system for delivering air to a heat load of an aircraft includes a cover having an opening for receiving and directing an airflow, and a duct defining a non-linear fluid flow path. The fluid flow path operably couples the opening and the heat load. A configuration of the fluid flow path reduces a velocity of the airflow therein while minimizing a pressure drop of the airflow.

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 method, apparatus, system, and computer program product for managing pumps in an aircraft. Flight information about an operation of the pumps in a pump package in the aircraft is received by a computer system. The flight information is received from the aircraft. A number of times that an abnormal switching occurred for the pumps within a window of consecutive flights is determined by the computer system when the abnormal switching is identified from the flight information. A set of actions is performed by the computer system when the abnormal switching occurred a number of times for the pumps within the window of consecutive flights that exceeds a set of thresholds for the abnormal switching that is considered healthy for the pumps.

A passenger cabin air distribution system includes a ventilation system and an ejector-diffuser. The ventilation system is operable to provide a conditioned air. The ejector-diffuser is positioned to receive a flow of the conditioned air from the ventilation system. The ejector-diffuser includes an induction unit and a diffuser section. The induction unit includes a secondary inlet in communication with a cabin air from a passenger cabin and is configured to mix the flow of the conditioned air with an induced flow of the cabin air into a mixed air. The diffuser section includes a discharge to eject the mixed air to the passenger cabin. The diffuser section is shaped to provide for efficient mixing with low backpressure in order to maintain the low motive pressure in the nozzle.

An aircraft includes: a cockpit, the inside of which is pressurized; equipment which is at least partially disposed on the outside of the cockpit (external space) where the pressure is lower than the inside of the cockpit (internal space); a forced air delivery mechanism which discharges air from a peripheral space of the equipment on the outside of the cockpit by an exhaust fan to supply a branch flow divided from a main flow of air-conditioning exhaust, which has air-conditioned the inside of the cockpit, as cooling air to the equipment; and a natural air delivery mechanism which uses a differential pressure between the inside of the cockpit and the outside of the cockpit to supply air inside the cockpit as cooling air to the equipment through a ventilation opening putting in communication the peripheral space and the inside of the cockpit with one another.

A removable battery to provide motive power for an aircraft includes a battery frame and removable, interchangeable battery modules. Each of the battery modules defines module common space through which liquid heat transfer fluid flows during charging of the battery when the battery is removed from the aircraft and through which air as a heat transfer fluid flows during discharge of the battery, as during flight. The module common space also defines a combustion conduit to convey heated air and products of combustion safely outside the battery in the event of a cell fire during flight. The removable battery frame is a structural component of the aircraft.

A vehicle is provided including a structure including a skin defining an outside surface exposed to ambient cooling flow and an inside surface. The structure includes a first structural member extending from the inside surface of the skin and a second structural member extending from the inside surface of the skin; and a thermal management system including a heat exchanger assembly positioned adjacent to, and in thermal communication with, the inside surface of the skin, the heat exchanger assembly positioned at least partially between the first and second structural members of the structure.

A power electronics cooling system includes a ram air fan with one or more blades and a ram air fan motor connected via an output shaft. The ram air fan draws in air and passes it across a heat exchanger to cool one or more cooling liquids. One or more pumps pressurize and pump the cooling liquids to various electronic components, including one or more motor controllers. The pumps may be mechanically or electrically coupled to the output shaft of the ram air fan, such that the motor of the ram air fan provides energy to the pumps.