An engine comprises an air intake arrangement configured to receive air; a heat exchanger arrangement arranged downstream of the air intake arrangement, configured to cool the air, and comprising a plurality of heat exchanger modules; and one or more turbomachinery components configured to receive cooled air from the heat exchanger arrangement. The plurality of heat exchanger modules are arranged to be generally centred on and to be arranged along a longitudinal axis of the engine. At least one of the plurality of heat exchanger modules is arranged to at least partially overlap with at least one other one of the plurality of heat exchanger modules relative to the longitudinal axis of the engine.

A propulsion system for an aircraft includes an engine having a central axis. A cowl surrounds the engine and includes a cowl lip. A compression ramp is spaced away from the cowl lip. An inlet is formed by the cowl lip and the compression ramp. The compression ramp is non-planar. The compression ramp is movable relative to the cowl lip to vary compression of an inlet airflow through the inlet.

A hypersonic vehicle has a body, a control surface, and a hypersonic air-breathing engine. The engine includes a converging inlet having a fixed cowling having a first cross-sectional area and a throat having a second cross-sectional area. A flow restrictor is movable between a stowed position and a fully deployed position. The flow restrictor has a third cross-sectional area that is smaller than the first cross-sectional area, such that a consistent gap is formed between a periphery of the flow restrictor and an inner surface of the cowling with the flow restrictor in the fully deployed position and the difference between the first cross-sectional area and the third cross-sectional area is approximately equal to the second cross-sectional area.

A device for a variable and adaptable diverterless bump engine inlet of an aircraft comprises a flexible inlet, a mechanism to change the shape of the flexible inlet, and a processing unit to control the mechanism. The flexible inlet of the device includes a plurality of edges attached partly to a fuselage skin and partly to an engine inlet duct. With this device, the shape of the flexible inlet can be controlled according to the flight conditions, and hence the engine air intake will perform more efficient at all speeds while fulfilling requirements for less radar visibility.

A flight vehicle has an engine that includes air inlet, an isolator (or diffuser) downstream of the air inlet, and a combustor downstream of the isolator. The isolator includes a bulged region that has at least one dimension, perpendicular to the direction of the air flow from the inlet to the combustor, that is at a local maximum, larger than comparable isolator dimensions both upstream and downstream of the bulged region. The bulged region stabilizes shocks within the isolator, and facilitates flow mixing. The flow diversion of high energy flow around the outermost walls of the bulged section into the center of the flow at the aft end of the isolator, increases mixing of the flow, and results in a more consistent flow profile entering the combustor over a wide range of flight conditions (Mach, altitude, angle-of-attack, yaw) and throttle settings.

A flight vehicle has a propulsion system that includes an air inlet, an isolator (or diffuser) downstream of the air inlet, and a combustor downstream of the isolator. The isolator includes an obstruction that protrudes inwardly from an inner wall of the isolator, into the flow channel in which air flows through the isolator. The obstruction diverts the flow to either side of it. Downstream of the obstruction the flow on either side of the obstruction comes together again, leading to mixing of the flow, for example including mixing of low energy and boundary layer flow with high energy flow. This mixing of flow may make for a more uniform flow at the exit of the isolator. In addition the obstruction may help fix the location of shocks within the isolator, providing longer flow mixing length in the isolator.

A gas turbine engine includes a gas generator with at least one compressor rotor, at least one gas generator turbine rotor and a combustion section. There is a duct located downstream of the gas generator. The duct is configured to move between a first position and a second position. A fan drive turbine is positioned downstream of a path of the products of combustion and passes over at least one gas generator turbine rotor when the duct is in the first position. The fan drive turbine is for driving a shaft and the shaft is for engaging gears to drive at least two fan rotors. An augmentor section is positioned downstream of a path of products of combustion and passes over at least one gas generator turbine rotor when the duct is in second position.

A high efficiency hydrogen fuel system for an aircraft at high altitude which utilizes compressors to compress air to a sufficiently high pressure for the fuel cell. Liquid hydrogen is compressed and then utilized in heat exchangers to cool the compressed air, maintaining the air at a temperature low enough for the fuel cell. The hydrogen is also used to cool the fuel cell as it is also depressurized prior to its entry in the fuel cell cycle. A water condensation system allows for water removal from the airstream to reduce impacts to the atmosphere. The hydrogen fuel system may be used with VTOL aircraft, which may allow them to fly at higher elevations. The hydrogen fuel system may be used with other subsonic and supersonic aircraft, such as with asymmetric wing aircraft.

An air inlet for a flight vehicle engine includes at least one fin, at least partially upstream of a throat of the engine. The fin protrudes into a flow channel, extending beyond a boundary layer into the main airstream in the inlet. The fin causes mixing in the flow, bringing high-momentum flow into areas of the flow channel containing low-momentum flow by aggregating the boundary layer and causing it to lift from the surface. The fin may have a width and/or height that varies along its length in the flow direction, which may allow it to shape the flow around it in predictable ways, without resulting in excessive drag.

An apparatus for suppressing shock-induced separation of high speed airflow from a relatively low-energy boundary layer. The apparatus may include an actuator or array of actuators configured to alternately inhale and exhale fluid and positioned to alternately inhale fluid from and exhale fluid into a boundary layer of a fluid mass flowing along the wall. The actuator may be positioned to inhale fluid from a boundary layer separation bubble induced by a supersonic shock wave propagated in the fluid mass.