Abstract: A system and method that comprises an air cycle machine, a flow of bleed air, at least one heat exchanger, and an inlet configured to supply the flow of the bleed air is provided. The bleed air flows from a source to mix with recirculated air in accordance with a high pressure mode or a recirculation chilling mode. The system and method also can also utilize the recirculated air flowing from the chamber to drive or maintain the air cycle machine in accordance with the above modes.

Abstract: A computer-implemented method for designing a built-in test is described. The method includes receiving, via a processor, a subsystem model including system parameters for a heat exchanger, wherein each of the system parameters includes a sensor variance; determining, via the processor, a test design vector based on one or more of the system parameters; and designing, via the processor, the built-in test based on the test design vector.

Abstract: An environmental control system includes an air cycle machine. The air cycle machine includes a compressor section with a compressor inlet and a compressor outlet, and a first turbine section with a first turbine inlet and a first turbine outlet. The environmental control system further includes a first turbine bypass shutoff valve positioned at the first turbine inlet. The first turbine bypass shutoff valve is configured to shut off the flow of air to the first turbine inlet.

Abstract: A distributed control system includes a local feedback controller, a sensor, and a controller. The local feedback controller is in communication with an actuator arranged to control a position of a valve associated with a conduit. The sensor is arranged to provide a signal indicative of at least one of a pressure, flow rate, and a temperature of a fluid within the conduit to the local feedback controller. The controller is programmed to provide a target control reference to the local feedback controller.

Abstract: A system and method that comprises an air cycle machine, a flow of bleed air, at least one heat exchanger, and an inlet configured to supply the flow of the bleed air is provided. The bleed air directly flows from a source to mix with recirculated air downstream of a compressor of the air cycle machine in accordance with a high pressure mode or a recirculation chilling mode. The system and method can also utilize the recirculated air flowing from the chamber to drive or maintain the air cycle machine in accordance with the above modes.

Abstract: A system and method that comprises an air cycle machine, a flow of bleed air, at least one heat exchanger, and an inlet configured to supply the flow of the bleed air is provided. The bleed air directly flows from a source to either a compressor of the air cycle machine or the at least one heat exchanger in accordance with a high pressure, low pressure, or pressure boost operation mode. The system and method also can also utilize recirculated air flowing from the chamber to drive or maintain the air cycle machine in accordance with the above modes.

Abstract: A matched venturi assembly is provided and includes a venturi component configured to provide for fluid communication between an inlet and an outlet, sensors coupled to the venturi component and configured to generate readings of characteristics of fluid flows proceeding through the venturi component and a venturi controller, which is receptive of the readings from the sensors. The venturi controller is configured to interpret the readings and is trimmable in a test phase where fluid flows with known characteristics are flown through the venturi component and interpretations of the readings are calibrated in accordance with differences between the readings and the known characteristics.

Abstract: A computer-implemented method for designing a built-in test is described. The method includes receiving, via a processor, a subsystem model including system parameters for a heat exchanger, wherein each of the system parameters includes a sensor variance; determining, via the processor, a test design vector based on one or more of the system parameters; and designing, via the processor, the built-in test based on the test design vector.

Abstract: A system and method that comprises an air cycle machine, a flow of bleed air, at least one heat exchanger, and an inlet configured to supply the flow of the bleed air is provided. The bleed air directly flows from a source to either a compressor of the air cycle machine or the at least one heat exchanger in accordance with a high pressure, low pressure, or pressure boost operation mode. The system and method also can also utilize recirculated air flowing from the chamber to drive or maintain the air cycle machine in accordance with the above modes.

Abstract: A system and method that comprises an air cycle machine, a flow of bleed air, at least one heat exchanger, and an inlet configured to supply the flow of the bleed air is provided. The bleed air directly flows from a source to mix with recirculated air downstream of a compressor of the air cycle machine in accordance with a high pressure mode or a recirculation chilling mode. The system and method can also utilize the recirculated air flowing from the chamber to drive or maintain the air cycle machine in accordance with the above modes.

Abstract: A system and method that comprises an air cycle machine, a flow of bleed air, at least one heat exchanger, and an inlet configured to supply the flow of the bleed air is provided. The bleed air flows from a source to mix with recirculated air in accordance with a high pressure mode or a recirculation chilling mode. The system and method also can also utilize the recirculated air flowing from the chamber to drive or maintain the air cycle machine in accordance with the above modes.

Abstract: An environmental control system includes an air cycle machine. The air cycle machine includes a compressor section with a compressor inlet and a compressor outlet, and a first turbine section with a first turbine inlet and a first turbine outlet. The environmental control system further includes a first turbine bypass shutoff valve positioned at the first turbine inlet. The first turbine bypass shutoff valve is configured to shut off the flow of air to the first turbine inlet.

Abstract: An active airflow control system for an aircraft includes an air conditioning system, an air conditioning controller configured to control operation of the air conditioning system, a plurality of flow control devices in fluid communication with the air conditioning system and in signal communication with the air conditioning controller, wherein the plurality of flow control devices are configured to increase and decrease an amount of air flowing therethrough in response to receiving a controlling signal from the air conditioning controller, and a plurality of zones in fluid communication with the air conditioning system, wherein each zone of the plurality of zones is a pressurized zone of the aircraft, and wherein each zone of the plurality of zones is in fluid communication with at least one flow control device of the plurality of flow control devices.

Abstract: An electronic control for an air conditioning system is provided. The system includes first and second air conditioning packs located in the air craft remote from one another. Each pack includes a pack controller in the same location as the pack. The pack controllers produce operating instruction signals to the packs for instructing the packs to produce conditioned air in response to a reference signal. A supervisory controller is centrally located in aircraft, preferably in the electronics equipment bay, and is connected to each of the pack controllers. The supervisory controller produces the reference signal to the pack controllers. In addition to controlling the operation of the packs, the pack controllers preferably include prognostics for monitoring the packs and diagnosing problems. The distributed electronic controllers of the present invention utilized for the packs may similarly be applied to the zone trim system and the engine air bleed valves.