The invention concerns an aircraft propulsion system comprising at least one member (1, 3, 4, 8) in contact with a turbulent flow of a stream (F), characterised in that said member is covered, at least partially, by a piezoelectric structure (S) such as a piezoelectric film, said structure (S) comprising a grooved structure (5, 6, 7, 9) comprising a series of grooves, in contact with the flow of the stream, the grooves extending in the direction of flow of the stream, the grooved structure comprising at least one geometric parameter (h, s, w) configured to adapt depending on at least one parameter of the flow of the stream and/or an operating point of the propulsion system and/or an engine speed of the propulsion system.

A system and method for controlling boundary layer transition for a high-speed vehicle are disclosed. The method includes determining a location of onset of boundary-layer transition that naturally develops during high-speed flight of the high-speed vehicle, and providing a pair of flow control strips at a surface/wall/skin of the high-speed vehicle such that the boundary-layer transition is delayed or prevented during high-speed flight of the high-speed vehicle. The delayed or prevented locations of the transition result in a change in the high-speed boundary layer during the high-speed flight of the high-speed vehicle. The change in the high-speed boundary layer transition affects skin friction drag, aero-thermodynamic heating, and pressure fluctuations in the boundary layer of the high-speed vehicle.

A method of generating a pressure wave proximate an airflow surface and altering airflow to promote a localized lowering of skin friction over the airflow surface is described herein. A series of pressure waves may be configured to create a virtual riblet to control turbulent vortices in a boundary layer adjacent to the airflow surface creating a virtual riblet. The pressure waves may be configured to prevent disruption of the flow of air relative to at least one of a step or a gap associated with the airflow surface. The pressure wave generating system may be comprised of at least one of a thermoacoustic material, a piezoelectric material and a semiconductor material, and a microelectric circuit.

Systems and method for active control of stationary vortices for aerodynamic structures are disclosed herein. In one embodiment, a method for active control of vortices over a solid surface includes: generating vortices proximate to the solid surface; sensing locations of vortices by printed skin sensors; and maintaining the vortices in their fixed spanwise positions with respect to the solid surface by actuation of printed skin actuators.

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.

An aeroseal comprises a substantially straight portion having a first engagement end and a second engagement end opposite the first engagement end. The aeroseal also comprises a first engagement extension extending transversely from the first engagement end of the substantially straight portion and having a distal end. The aeroseal further comprises a second engagement extension extending transversely from the second engagement end of the substantially straight portion and having a distal end. The aeroseal also comprises a substantially curved portion interconnecting the distal end of the first engagement extension and the distal end of the second engagement extension to form an acute angle between the first and second engagement extensions and facing away from the substantially straight portion.

A plasma plate is used to minimize drag of a fluid flow over an exposed surface. The plasma plate includes a series of plasma actuators positioned on the surface. Each plasma actuator is made of a dielectric separating a first electrode exposed to a fluid flow and a second electrode separated from the fluid flow under the dielectric. A pulsed direct current power supply provides a first voltage to the first electrode and a second voltage to the second electrode. The series of plasma actuators is operably connected to a bus which distribute powers and is positioned to minimize flow disturbances. The plasma actuators are arranged into a series of linear rows such that a velocity component is imparted to the fluid flow.

A system for slowing down the speed of flying objects by applying electrodynamic and aerodynamic braking forces. The system is comprised of plurality of stubs, where each stub is made of dielectric material surrounded by metal foil and another metal foil is inserted in the middle of the stub, where the outer metal foil and the inner metal foil are isolated from each other, so that they form a capacitor. Each stub is stored in a barrel before being used. When activated, the stubs are stretched from the barrel as a tail behind the flying object. The area of the stub generates aerodynamic drag. The stub capacitor is charged by a generator so that free electrons are present in the outer metal layer of the stub. The electric field produced by these charges interacts with ions in the atmosphere.

Enhanced high-speed aircraft performance, including increased lift/drag ratio, from localized high-temperature speed of sound increases, and associated systems and methods are disclosed. A representative method for operating a vehicle includes, while a lifting body of the vehicle is immersed in a gas, heating the gas in a target volume sufficiently to increase the speed of sound in the gas relative to the speed of sound in the gas outside the target volume. The target volume can be positioned adjacent to, forward of, and/or along a pressure surface of the lifting body.

A hypersonic aircraft includes one or more leading edge assemblies that are designed to cool the leading edge of certain portions of the hypersonic aircraft that are exposed to high thermal loads, such as extremely high temperatures and/or thermal gradients. Specifically, the leading edge assemblies may include an outer wall tapered to a leading edge or stagnation point. A coolant supply may be in fluid communication with at least one fluid passageway that passes through the outer wall to deliver a flow of cooling fluid to the stagnation point. In addition, a nose cover is positioned at least partially over or within the at least one fluid passageway and is formed from a material that ablates or melts when the leading edge is exposed to a predetermined critical temperature, the nose cover being configured for restricting the flow of coolant until the nose cover is ablated or melted away.