A cryogenic cooling system for an aircraft includes a first air cycle machine, a second air cycle machine, and a means for collecting liquid air. The first air cycle machine is operable to output a cooling air stream based on a first air source. The second air cycle machine is operable to output a chilled air stream at a cryogenic temperature based on a second air source cooled by the cooling air stream of the first air cycle machine. An output of the second air cycle machine is provided to the means for collecting liquid air.

A compressed air energy storage system may have an accumulator and a thermal storage subsystem having a cold storage chamber for containing a supply of granular heat transfer, a hot storage chamber and at least a first mixing chamber in the gas flow path and having an interior in which the compressed gas contacts the granular heat transfer particles at a mixing pressure that is greater than the cold storage pressure and the hot storage pressure and a conveying system operable to selectably move the granular heat transfer particles from the cold storage chamber, through the first mixing chamber and into the hot storage chamber, and vice versa.

In one aspect of the present disclosure, there is provided a gas turbine engine. The gas turbine engine includes a primary gas path having, in fluid series communication: an air inlet, a compressor fluidly connected to the air inlet, a combustor fluidly connected to an outlet of the compressor, and a turbine section fluidly connected to an outlet of the combustor section. In embodiments, a hydrogen expansion turbine is in fluid communication to receive hydrogen from the gaseous hydrogen outlet of the heat exchanger. In certain embodiments, the gas turbine engine includes a heat exchanger having a gas conduit fluidly connected to the primary gas path, and a fluid conduit in fluid isolation from the gas conduit and in thermal communication with the gas conduit.

A heat exchanger array includes a first row of heat exchangers, a second row of heat exchangers, and side curtains. The first row heat exchangers are spaced apart to define first gaps. The second row heat exchangers are spaced apart to define second gaps and are positioned downstream of and staggered from the first row heat exchangers such that the second row heat exchangers are aligned with the first gaps and the first row heat exchangers are aligned with the second gaps. Each side curtain is in close proximity to a first row heat exchanger and a second row heat exchanger. The side curtains define a neck region upstream of and aligned with each first row heat exchanger and each second row heat exchanger. Each neck region has a neck area that is less than a frontal area of the heat exchanger with which it is aligned.

An aircraft power plant comprising novel air management features for high-power fuel cell applications, the features combine supercharging and turbocharging elements with air and hydrogen gas pathways, utilize novel airflow concepts and provide for much stronger integration of various fuel cell drive components.

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 ground-based cryogenic cooling system includes a means for cooling an airflow and producing chilled air responsive to a power supply. A liquid air condensate pump system is operable to condense the chilled air into liquid air and urge the liquid air through a feeder line. A cryogenic cartridge includes a coupling interface configured to detachably establish fluid communication with the feeder line and a cryogenic liquid reservoir configured to store the liquid air under pressure. The cryogenic cartridge can be coupled to a cryogenic liquid distribution system on an aircraft. The liquid air can be selectively released from the cryogenic cartridge through the cryogenic liquid distribution system for an aircraft use.

A turbofan engine assembly including a compressor, an intermittent internal combustion engine having an inlet in fluid communication with an outlet of the compressor through at least one first passage of an intercooler, a turbine having an inlet in fluid communication with an outlet of the intermittent internal combustion engine, the turbine compounded with the intermittent internal combustion engine, a bypass duct surrounding the intermittent internal combustion engine, compressor and turbine, and a fan configured to propel air through the bypass duct and through an inlet of the compressor, wherein the intercooler is located in the bypass duct, the intercooler having at least one second passage in heat exchange relationship with the at least one first passage, the at least one second passage in fluid communication with the bypass duct.

A combined cycle heat engine (10). The engine (10) comprises a first gas turbine engine (11) comprising a first air compressor (14), a first combustion system (16, 20) and a first turbine system (18, 22), and a second gas turbine engine (32) comprising a second air compressor (36) and a second turbine system (40). The engine further comprises a heat exchanger (38) configured to transfer heat from an exhaust of the first turbine system (18, 22) to compressed air from the second air compressor (36). The first combustion system comprises a first combustor (16) provided downstream of the first air compressor (14) and upstream of the first turbine system (18, 22), and a second combustor (20) downstream of a first turbine section (18) of the first turbine system and upstream of a second turbine section (22) of the first turbine system.

A system for an aircraft includes an engine bleed source of a gas turbine engine. The system also includes a means for chilling an engine bleed air flow from the engine bleed source to produce a chilled working fluid. The system further includes a means for providing the chilled working fluid for an aircraft use.