A rotorcraft, and, more particularly, to a rotorcraft with a fuselage having a center line, at least one main rotor that generates vortices during operation, and a stabilizer wing, whereby the stabilizer wing has a planform that reduces the unsteady aerodynamic loads caused by the wake of the at least one main rotor. In particular, the stabilizer wing may be provided with a left wing tip, a right wing tip, a quarter chord line with a non-zero curvature, such that an interaction between the vortices generated by the at least one main rotor and the quarter chord line is spread out over time, a leading edge that is arc-shaped, and a trailing edge that is arc-shaped.

A system includes a surface, an actuator, and processing circuitry. The surface includes one or more non-actuating zones and one or more actuatable zones. The actuator is configured to a flow property of a fluid that flows over the one or more actuatable zones of the surface. The processing circuitry is configured to obtain a value of a parameter of the fluid that flows over the surface, and operate the actuator to adjust the flow property of the fluid that flows over the one or more actuatable zones based on the value of the parameter of the fluid.

A wing includes a low pressure side, a high pressure side opposite the low pressure side, and a drag reducing apparatus coupled to the low pressure using an adhesive. The drag reducing apparatus includes a first side coupled to the low pressure side of the wing, and a second side opposite the first side. The second side includes a plurality of vortex generators arranged in an array configuration. The vortex generators generate one or more vane vortices near an end of the low pressure side of the wing, thereby weakening a wingtip vortex generated by the wing.

The present invention is directed to a combination of hydrophilic and hydrophobic features disposed on a surface to control flow over the surface.

An electric reaction control system that can selectively expel a “burst” or “puff” of air to alter the orientation of the aircraft during flight. An aircraft incorporating ducting, an air compressor, an electric motor, and a plurality of nozzles can facilitate in-flight trajectory modifications. When an air burst is needed to provide thrust for the purposes of reaction control, nozzles are selectively opened and closed to provide roll, pitch, and yaw of the aircraft. The ERCS can facilitate an electric aircraft that would be very agile and very light, utilizing electric power, as opposed to jet power.

A boundary layer suction design uses a wingtip vortex core for a lift-generating body with optimized aerodynamic performances. Holes or slots (6), connected to a core or center of a wingtip vortex of the lift generating body via a plenum (9) and pipe (7) with its outlet (8) sticking out from a surface (1) experiencing low pressure, sucked a part of the boundary layer to delay flow transition or separation. Thus, with a more stable boundary layer, the lift is increased while the drag is reduced.

A wing system is provided for an air vehicle, the wing system having a stowed configuration, a pre-deployed configuration, and a deployed configuration. The wing system includes two wings, each wing having aerofoil profiles and being pivotably deployable about a respective pivot axis between the pre-deployed configuration and the deployed configuration. In the stowed configuration the two wings are in first general superposed spatial relationship with respect to one another and are capable of being accommodated within an envelope having an envelope cross-sectional profile and a corresponding envelope cross-sectional area. In the pre-deployed configuration, the two wings are in second general superposed spatial relationship with respect to one another and capable of deploying to the deployed configuration. In the deployed configuration the wings are each capable of generating aerodynamic lift in an airstream. Each aerofoil profile of each wing is a slotted aerofoil having a primary element, a secondary element and a chord, the secondary element being pivotable with respect to the primary element and spaced therefrom by a gap. Each aerofoil profile has a respective maximum thickness, and a respective maximum absolute thickness. In the stowed configuration, the respective second element of eachaerofoil of one wing is set at a different flap angle as compared with the respective second element of each aerofoil of the other wing.

An aircraft has a boom, a propulsion assembly coupled to a first end of the boom, and a first wing coupled to a second end of the boom. The propulsion assembly is coupled to the boom by a rotating joint. A second wing is optionally coupled to the rotating joint. The first wing is coupled to the boom by a rotating joint. The first wing is coupled to the rotating joint by a hinge. A vehicle with roll, pitch, and yaw maneuverability able to mirror the aircraft movements may be coupled to the second end of the boom. The vehicle body may be picked up with a vehicle chassis disconnected from the vehicle body. The boom houses an energy source to power the propulsion assembly. A rudder is coupled to the second end of the boom. A paddle is disposed between the propulsion assembly and the boom.

The present invention discloses a VTOL aircraft with retractable wings and TEMCS (trailing edge mounted control surface) mounted tilt-able engines. The aircraft has two hover modes; a first hover mode with retracted wings which allows takeoff and landing in tight landing spots, and a second hover mode with extended wings, during these hover modes, the aircraft operates as a multi-rotor aircraft with additional means of vectored forces created by tilt-able engines, with engines directed upward, and a cruise mode with the wings extended and the engines directed in forward direction.

Systems and methods are described herein to implement transverse momentum injection at low frequencies to directly modify large-scale eddies in a turbulent boundary layer on a surface of an object. A set of transverse momentum injection actuators may be positioned on the surface of the object to affect large-scale eddies in the turbulent boundary layer. The system may include a controller to selectively actuate the transverse momentum injection actuators with an actuation pattern to affect the large-scale eddies to modify the drag of the fluid flow on the surface. In various embodiments, the transverse momentum injection actuators may be operated at frequencies less than 10,000 Hertz.