An aircraft is provided and includes a fuselage including a top and a tail, a main rotor apparatus disposed at the top of the fuselage, which rotates one or more rotors to generate lift, and an active flow control (AFC) system. The AFC system includes plasma actuators configured to generate plasma at a location adjacent to the main rotor apparatus and/or at the tail of the fuselage.

A highly-conformal, pliable thin electromagnetic (EM) skin for altering at least one electromagnetic property of a surface includes a pliable thin film, and sub-wavelength elements incorporated into and/or on the pliable thin film which are smaller in scale than the wavelengths of electromagnetic radiation they are intended to influence. The electromagnetic skin readily conforms to contours of a surface to which it attaches or otherwise adheres to. Such electromagnetic skin can be used to cover various surface and platforms on equipment, walls, vehicles, and aircraft to change the electromagnetic properties of such surfaces to achieve certain functions that are not achievable with simple ground plane surfaces. The EM skin may be judiciously configured to alter at least one electromagnetic property of the surface by blocking, absorbing, enhancing, and/or bending waves of electromagnetic radiation.

A method is provided for generating a region of plasma in a gaseous atmosphere that includes argon. A laser beam from a Ti:sapphire laser is directed into the gaseous atmosphere such that a portion of the argon along the laser beam is ionized. Microwave energy is directed into the ionized region of the laser beam to generate a plasma.

An airfoil article including a composite skin having a first surface and a second surface opposite first surface, forming a leading edge. The leading edge is during use subjected to an airflow meeting the leading edge at stagnation points. The leading edge includes an elongated member. The outer surface of the elongated member is arranged flush with the first surface of the composite skin such that an essentially smooth aerodynamic surface of the leading edge is formed. The elongated member is adapted to serve as an erosion protection of the leading edge and to function as an electrode of a plasma generating system.

An improved high-voltage AC power supply energizes and regulates plasma actuators for aerodynamic flow control. Such plasma actuators are used, for example, on aerodynamic surfaces, wind turbine blades, and the like for vehicle control, drag or noise reduction, or efficient power generation. Various embodiments of the power supply are small, compact, lightweight, portable, modular, self-contained in its own housing, easily replaceable and swappable, autonomous, self-cooling, and/or gangable in series or parallel to provide any desired control authority over the selected surface. In some embodiments, the parameters for the plasma electronics can be manually selected and pre-programmed for a specific application, while in preferred embodiments, the plasma electronics can automatically identify the appropriate parameters and self-tune the performance of the plasma actuators.

An assembly for arrangement to the surface of an aerodynamic profile comprises an array of actuators, which are designed as piezo actuators and plasma actuators.

A method and apparatus may comprise a first number of layers of a flexible material, a second number of layers of a dielectric material, a first electrode attached to a surface layer in the first number of layers, and a second electrode attached to a second layer in one of the first number of layers and the second number of layers. The first number of layers may be interspersed with the second number of layers. The first electrode may be configured to be exposed to air. The first electrode and the second electrode may be configured to form a plasma in response to a voltage.

A surface plasma actuator includes a conducting wire attached to a surface of a target object and electrically insulated from the target object. Surface plasma is generated along a neighborhood of the conducting wire by applying a pulse voltage between the conducting wire and a conductive portion on a side of the target object. An induced gas flow is generated by the surface plasma.

A method and system delay the laminar-to-turbulent transition of a supersonic or hypersonic boundary layer flow moving in a flow direction over a surface. For supersonic boundary layer flow, oblique first-mode instability waves present in the boundary layer and propagating at an oblique angle relative to the flow direction cause a laminar-to-turbulent transition in the boundary layer flow. These instability waves have a wavelength associated therewith in a direction perpendicular to the flow direction. Flow disruptors are used to generate modulations within the boundary layer flow wherein a wavelength of the modulations along the direction perpendicular to the flow direction is less than one-half of the wavelength of the instability waves. For hypersonic boundary layer flow, the flow disruptors generate modulations within the boundary layer flow wherein the wavelength of the modulations is less than streak spacing for optimal transient growth or, equivalently, in the range of one to two times the boundary layer thickness.

The present disclosure presents systems and methods for dynamic stall control in aircrafts. One such method involves positioning one or more counter-flow point embedded electrode plasma actuator devices on an edge of an airfoil of an aircraft, wherein a counter-flow point embedded electrode plasma actuator device comprises at least a first electrode that is unexposed and embedded under a surface of the airfoil and a second electrode positioned on or in a top surface of the airfoil; and/or activating the one or more counter-flow point embedded electrode plasma actuator devices during a flight of the aircraft, wherein a dynamic stall angle of a pitching airfoil is increased during the flight of the aircraft by forcing plasma over the edge of the pitching airfoil.