An air cycle machine includes a compressor in fluid communication with a load cooling heat exchanger, a first valve and a first turbine connecting the compressor to the load cooling heat exchanger, and a second valve and a second turbine. The second valve and the second turbine connect the compressor to the load cooling heat exchanger and connected in parallel with the first valve and the first turbine between the compressor and the load cooling heat exchanger. Air cycle machine systems and methods of controlling air flow through air cycle machines are also described.

An air cycle machine includes a compressor in fluid communication with an output conduit, a first turbine operably connected to the compressor and fluidly coupling the compressor with the output conduit, a second turbine operably connected to the compressor and fluidly coupling the compressor with the output conduit, and a valve. The valve couples the compressor with the output conduit and has an open position and a closed position. In the open position the first turbine and the second turbine are fluidly connected in parallel between the compressor and the output conduit. In the closed position the first turbine is fluidly connected in series with the second turbine between the compressor and the output conduit. Air cycle machine systems and methods of controlling flow in air cycle machines are also described.

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 compute 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.

Disclosed is a cooling circuit for cooling a heat load in an aircraft system, having: a compressor; a turbine connected to the compressor by a shaft, the turbine configured to drive the compressor via the shaft when RAM air pressure into a turbine inlet is above a first threshold; and a motor connected to the shaft configured to drive the compressor when RAM air pressure at the turbine inlet is below the first threshold to cause the compressor to draw air into the turbine inlet, through the turbine, a heat exchanger in fluid communication with the heat load, the compressor, and out of a compressor outlet.

A heat exchanger for cooling a component includes a heat transfer chamber containing a heated substance having a first density and a liquid coolant having a second density. The heat exchanger can also include a circulation circuit that recirculates the heated substance through the heat transfer chamber for mixing with the liquid coolant.

A refrigeration system can include a main flow circuit configured to flow a refrigerant therethrough and a heat input disposed in the main flow circuit and configured to receive heat and transfer the heat to the refrigerant in the main flow circuit to output heated refrigerant flow. The system can include a passive pump disposed in the main flow circuit downstream of the heat input configured to receive the heated refrigerant flow from the heat input and to use the heated refrigerant flow to generate a vacuum at a pump port and a condenser disposed in the main flow circuit downstream of the passive pump for receiving flow from the passive pump. The condenser can be configured to receive heat from the heated refrigerant flow and reject heat to cool the heated refrigerant flow to output partially cooled refrigerant flow. An outlet of the condenser can be upstream of the heat input.

An environmental control system (ECS) for an aircraft includes at least one cooling turbine, and a turbine bypass valve disposed fluidly upstream of the at least one cooling turbine. The turbine bypass valve is configured to direct a first portion of an ECS output airflow to a first air load at a first pressure via a first outlet passage, and direct a second portion of the ECS output airflow across a cooling turbine of the at least one cooling turbine and to a second air load at a second pressure lower than the first pressure for cooling thereof.

The system can include an on-board thermal management subsystem. The system 100 can optionally include an off-board (extravehicular) infrastructure subsystem. The on-board thermal management subsystem can include: a battery pack, one or more fluid loops, and an air manifold. The system 100 can additionally or alternatively include any other suitable components.

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 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.