Abstract: A cooling system for an aircraft includes an air intake, a heat exchanger configured to receive air passing into the air intake when the aircraft is operating at Mach speed, and configured to receive compressed refrigerant from a first compressor at a first pressure, an evaporator positioned within the aircraft and configured to receive heated air from a compartment within the aircraft, at least one of an expansion device and an expansion machine, and the compressed refrigerant rejects heat in the heat exchanger to the air, expands in the at least one of the expansion device and the expansion machine, and receives heat in the evaporator from the heated air.

Abstract: A thermal management system includes a closed dynamic cooling circuit, and a closed first steady-state cooling circuit. Each circuit has its own compressor, heat rejection exchanger, and expansion device. A thermal energy storage (TES) system is configured to receive a dynamic load and thermally couple the dynamic cooling circuit and the first steady-state cooling circuit. The dynamic cooling circuit is configured to cool the TES to fully absorb thermal energy received by the TES when a dynamic thermal load is ON, and the steady-state cooling circuit is configured to cool the TES when the dynamic thermal load is OFF.

Abstract: A cooling system for an aircraft includes a first cooling circuit having a first evaporator and a second evaporator, and a second cooling circuit having a third evaporator and a fourth evaporator. One of the first and second cooling circuits includes a first set of valves arranged to direct refrigerant through a first cooling sub-circuit, a second cooling sub-circuit, or both the first and second cooling sub-circuits based on ambient conditions. Two of the evaporators are installed on a first side of the aircraft, and the other two of the four evaporators are installed on a second side of the aircraft opposite the first side, and the first and second cooling circuits reject heat, via a heat exchanger, from their respective cooling circuit to air passing into an engine of the aircraft.

Abstract: A cooling system includes a first heat exchanger, an evaporator coupled to a thermal load of an aircraft. first and second cooling circuits coupled to the heat exchanger, the first and second cooling circuits selectable via a set of cooling circuit valves that are arranged to direct a refrigerant through the first circuit, the second circuit, or both the first and second circuits based on air passing through the first heat exchanger at ambient conditions of the aircraft, and a receiver configured to accumulate reserve refrigerant to provide flexibility in system operation as the cooling system operates in sub-critical, trans-critical, and super-critical modes of operation.

Abstract: A multi-evaporator cooling system includes a compressor circuit that generates multiple levels of evaporating pressures, the circuit comprising at least one compressor configured to compress a refrigerant to a first pressure, a heat exchanger configured to receive the compressed refrigerant from the at least one compressor and cool the compressed refrigerant, a first evaporator circuit configured to receive the compressed refrigerant from the heat exchanger, expand the compressed refrigerant to a second pressure that is lower than the first pressure, and return the refrigerant to the compressor circuit, and a second evaporator circuit configured to receive the compressed refrigerant from the heat exchanger, expand the compressed refrigerant to a third pressure that is lower than the second pressure, and return the refrigerant to the compressor circuit.

Abstract: An aircraft power and propulsion system includes an air compressor, a heat rejection heat exchanger, a combustor positioned to receive compressed air from the air compressor as a core stream and provide thrust to the aircraft, and a closed-loop s-CO2 system. The closed-loop s-CO2 system includes carbon dioxide as a working fluid, receives power from the combustor, and rejects heat via the heat rejection heat exchanger to a cooling stream. The closed-loop system s-CO2 configured to provide power to a fan that provides the cooling stream and thrust, and power to the air compressor and at least one auxiliary load.

Abstract: A power and propulsion system includes an air compressor, a combustor positioned to receive compressed air from the air compressor as a core stream, and a closed-loop system having carbon dioxide as a working fluid that receives heat from the combustor and rejects heat to a cooling stream. The closed-loop system configured to provide power to a fan that provides the cooling stream, and to one or more distributed propulsors that provide thrust to an aircraft.

Abstract: A cooling system for an aircraft includes an air intake, a heat exchanger configured to receive air passing into the air intake when the aircraft is operating at Mach speed, and configured to receive compressed refrigerant from a first compressor at a first pressure, an evaporator positioned within the aircraft and configured to receive heated air from a compartment within the aircraft, at least one of an expansion device and an expansion machine, and the compressed refrigerant rejects heat in the heat exchanger to the air, expands in the at least one of the expansion device and the expansion machine, and receives heat in the evaporator from the heated air.

Abstract: A gas turbine engine includes a shaft comprising a first compressor, a fan assembly, and a power circuit that provides power to the shaft in a closed-loop system. An inner housing houses at least a portion of the shaft, the first compressor for compressing a core stream of air, and a combustor. A baffle encloses a portion of the inner housing and forms a first air passageway therebetween. A nacelle encloses a portion of the baffle and forms a second air passageway therebetween. A heat exchanger is positioned in the second air passageway that rejects heat from the power circuit into a heat rejection stream of air passing through the second air passageway. Air is accelerated as streams in parallel and via the fan assembly as the core stream into the inner housing, as a bypass flow stream of air through the first volume, and as the heat rejection stream.

Abstract: An apparatus, system, and method for a gas turbine engine may include a sectioned heat exchanger. A heat exchanger may include an inlet manifold configured to receive a working fluid. A plurality of circuits including at least first and second circuits configured to transfer heat with respect to the working fluid. Each of the circuits may have a circuit inlet valve, a circuit heat exchange channel, and a circuit outlet valve. The heat exchanger may further include an outlet manifold configured to pass the working fluid to an outlet. The heat exchanger may include a first sensor configured to measure of first parameter of the first circuit and a second sensor configured to measure a second parameter of at least one of the outlet and the second circuit. A controller may be configured to selectively isolate at least one of the plurality of circuits based on a pressure difference between the first and second parameters.

Abstract: A gas turbine engine includes a first shaft coupled to a first turbine and a first compressor, a second shaft coupled to a second turbine and a second compressor, and a third shaft coupled to a third turbine and a fan assembly. The turbine engine includes a heat rejection heat exchanger configured to reject heat from a closed loop system with air passed from the fan assembly, and a combustor positioned to receive compressed air from the second compressor as a core stream. The closed-loop system includes the first, second, and third turbines and the first compressor and receives energy input from the combustor.

Abstract: A cooling system includes a heat exchanger through which a refrigerant flows, and which rejects heat to a fluid, an evaporator, a first circuit having an expansion device, a second circuit having an expansion machine coupled to a compressor, and a set of valves arranged to direct the refrigerant through the first circuit, the second circuit, or both the first and second circuits based on ambient conditions.

Abstract: A cooling system includes a main refrigerant circuit that includes a compressor, a heat rejection heat exchanger, one of an expander and an expansion device, at least one evaporator coupled to a thermal load, and a suction accumulator. A charge management circuit includes a charge management receiver configured in parallel with the compressor and the heat rejection heat exchanger. A controller is configured to accumulate and discharge reserve refrigerant to and from the charge management receiver to provide flexibility in system operation as refrigerant in the main refrigerant circuit operates in sub-critical, trans-critical, and super-critical modes of operation.

Abstract: A cooling system for an aircraft includes an air intake, an expansion device, and an evaporator. A first heat exchanger receives air passing into the air intake when the aircraft is operating at elevation, and receives the refrigerant from a first compressor at a first pressure. A second compressor receives the refrigerant from the first heat exchanger and compresses the refrigerant to a second pressure that is greater than the first pressure. A second heat exchanger receives the refrigerant from the second compressor. The first and second compressors are configured the first and second compressors are configured to operate at pressures that avoid temperature differences between the refrigerant and the air within each of the first and second heat exchangers below a set restriction.

Abstract: A gas turbine engine includes a shaft having a first air compressor coupled thereto, a combustor positioned to receive compressed air from the first compressor, and a power source coupled to the shaft, the power source powered by a working fluid other than the compressed air.

Abstract: A cooling system includes a first heat exchanger for cooling a refrigerant, an expander configured to receive the refrigerant from the first heat exchanger at least one compressor configured to compress the refrigerant, an ejector configured to receive the refrigerant from the expander as a motive stream that evacuates and compresses the refrigerant from an evaporator, and a liquid separator coupled to an output of the ejector and configured to provide liquid refrigerant to an evaporator loop and vapor refrigerant to the at least one compressor. The evaporator loop includes an expansion device positioned to expand the liquid refrigerant from the liquid separator, and the evaporator configured to receive the refrigerant from the expansion device, heat the refrigerant from a heat load, and pass the refrigerant to the ejector.

Abstract: A multi-evaporator cooling system includes a compressor circuit that generates multiple levels of evaporating pressures, the circuit comprising at least one compressor configured to compress a refrigerant to a first pressure, a heat exchanger configured to receive the compressed refrigerant from the at least one compressor and cool the compressed refrigerant, a first evaporator circuit configured to receive the compressed refrigerant from the heat exchanger, expand the compressed refrigerant to a second pressure that is lower than the first pressure, and return the refrigerant to the compressor circuit, and a second evaporator circuit configured to receive the compressed refrigerant from the heat exchanger, expand the compressed refrigerant to a third pressure that is lower than the second pressure, and return the refrigerant to the compressor circuit.

Abstract: A cooling system includes a heat exchanger through which a refrigerant flows, and which rejects heat to a fluid, an evaporator, a first circuit having an expansion device, a second circuit having an expansion machine coupled to a compressor, and a set of valves arranged to direct the refrigerant through the first circuit, the second circuit, or both the first and second circuits based on ambient conditions.

Abstract: A cooling system for an aircraft includes a first cooling circuit having a first evaporator and a second evaporator, and a second cooling circuit having a third evaporator and a fourth evaporator. One of the first and second cooling circuits includes a first set of valves arranged to direct refrigerant through a first cooling sub-circuit, a second cooling sub-circuit, or both the first and second cooling sub-circuits based on ambient conditions. Two of the evaporators are installed on a first side of the aircraft, and the other two of the four evaporators are installed on a second side of the aircraft opposite the first side, and the first and second cooling circuits reject heat, via a heat exchanger, from their respective cooling circuit to air passing into an engine of the aircraft.

Abstract: A cooling system includes a first heat exchanger, an evaporator coupled to a thermal load of an aircraft. first and second cooling circuits coupled to the heat exchanger, the first and second cooling circuits selectable via a set of cooling circuit valves that are arranged to direct a refrigerant through the first circuit, the second circuit, or both the first and second circuits based on air passing through the first heat exchanger at ambient conditions of the aircraft, and a receiver configured to accumulate reserve refrigerant to provide flexibility in system operation as the cooling system operates in sub-critical, trans-critical, and super-critical modes of operation.