A control surface of an aircraft comprises a fixed skin panel, a first flexurally elastic skin panel and a second flexurally elastic skin panel, which is connected to the first flexurally elastic skin panel and is configured to at least partially overlap the fixed skin panel. Furthermore, the control surface comprises an actuator system, which is configured to move the second flexurally elastic skin panel parallel to the fixed skin panel, wherein the actuator system has a fixed structural element arranged in a root region of the control surface, and a structural element that is movable relative to the fixed structural element.

A morphing panel mechanism may include a central panel and a side panel, where a first edge of the side panel may be pivotally coupled to a first edge of the central panel. A morphing panel mechanism may further include a guide panel that may be coupled with a first corner of the central panel via a ball joint, where the guide panel may include a first slit. A morphing panel mechanism may further include a flexible panel, where a first edge of the flexible panel may be pivotally coupled with a second edge of the side panel, and a second edge of the flexible panel may be slidably disposed within the slit of the guide panel.

An airfoil structure for an aircraft includes a spanwise-extending load-carrying member, a leading-edge structure, a trailing-edge structure, an upper cover, and a lower cover. The load-carrying member is configured to react more than half of all flight loads experienced by the airfoil structure during flight and is configured to have selected stiffness properties selected such that the airfoil structure bends and twists in a predefined manner in response to applied flight loads. The leading-edge structure is configured to form a leading-edge part of an aerodynamic surface of the airfoil structure. The trailing-edge structure is configured to form a trailing edge part of the aerodynamic surface. The upper cover is configured to form an upper part of the aerodynamic surface. The lower cover is configured to form a lower part of the aerodynamic surface.

The present disclosure defines a morphing airfoil having a dynamic flexible anisotropic skin system that is capable of carrying high level aerodynamic (or fluid) pressure loads over a structural surface. The structural surface can morph and bend in response to control inputs to change a lift force without separate movable control surfaces. The anisotropic skin is attached to underlying active and compliant structures. A control system causes the underlying support structure to move to a desired location which in turn causes the skin to bend and/or flex without exceeding a stress threshold and thus vary the lift profile along a span of the airfoil.

A drag reduction device includes a first part and a second part. The first part is attached to the second part, and the second part is detachably attached to a body. The first part is made of a flexible material and configured to be able to change its shape under the action of a flow field. According to this application, through providing the drag reduction device on the body in need of drag reduction by detachably attaching the drag reduction device to the body, the need to modify the shape of the body itself is dispensed with. According to this application, the drag reduction device is very simple in structure and easy to assemble and disassemble, almost does not add weight to the body and has very low cost. According to this application, the drag reduction device is able to change its shape without consuming energy at all. Moreover, under different flow field conditions, it can assume different shapes that adapt it to the flow field conditions.

A bridging structure for a deforming foil, such as a morphing wing, that provides a fluid-dynamic surface throughout foil deformation that forms a curved fluid-dynamic surface with a relatively low drag. A high extent of foil deformation can be provided, with lower actuation force, providing a fluid-dynamic surface with a simple or complex curve in one direction, by providing a set of rail-mounted members that are joined at one end to a deforming sheet. By coupling the members with high elongation, resilient bodies, adjacent members can support each other, while permitting extension, and accommodating curvature.

A blade or wing element includes a plurality of ribs (20) rotatable and/or slidable with respect to one another whereby to vary the aerodynamic configuration of the blade or wing element by causing a twist thereof. A blade or wing or blade or wing assembly, including such a blade or wing element is disclosed, as well as an aerodynamic apparatus such as an aircraft, or a wind turbine. A method of assembling a blade or wing element is also disclosed.

An airfoil surface skin, comprising a network of a solid material, embedded in a base of deformable solid material. Fluid pressure applied to the interface between the network and the surrounding embedding material, opens an internal network of channels by viscous peeling of the surrounding solid from the network. The network is offset from the centerline the surround material, such that pressure driven viscous flow through the narrow channels generates two types of deformation of the skin—an in-plane elongation and a curvature of the skin plane itself. The shape of the internal solid core element and its material, and the material of the encompassing solid are chosen to achieve a desired integral structural rigidity. The injected fluid pressure determines the extent of extension and bending. Use of this skin enables shape amending airfoils having reduced drag compared with similar airfoils having conventional flap mechanisms

A morphing airfoil includes a dynamic flexible skin system that is capable of carrying high level aerodynamic (or fluid) pressure loads over a structural surface. The structural surface can morph and bend in response to control inputs to change a lift force without separate movable control surfaces. A plurality of standoff mounts is attached to an inner surface of anisotropic skin. The standoff mounts include through apertures for receiving a flexible stringer. The anisotropic skin is attached to underlying structure through the flexible stringers. The flexible stringers interface with actuated position control ribs and passive compliant support ribs. A control system causes the underlying support structure to move to a desired location which in turn causes the skin to bend and/or flex without exceeding a stress threshold and thus vary the lift and drag distributions along a span of the airfoil without separate control surfaces.

An airfoil surface skin, comprising a network of a solid material, embedded in a base of deformable solid material. Fluid pressure applied to the interface between the network and the surrounding embedding material, opens an internal network of channels by viscous peeling of the surrounding solid from the network. The network is offset from the centerline the surround material, such that pressure driven viscous flow through the narrow channels generates two types of deformation of the skin—an in-plane elongation and a curvature of the skin plane itself. The shape of the internal solid core element and its material, and the material of the encompassing solid are chosen to achieve a desired integral structural rigidity. The injected fluid pressure determines the extent of extension and bending. Use of this skin enables shape amending airfoils having reduced drag compared with similar airfoils having conventional flap mechanisms.