Abstract: The invention relates to a wind turbine blade with devices for modifying the aerodynamic surface or shape of the blade. The position and movement of these devices are controlled by a pneumatic actuator powered by pressure from a pressure chamber connected to the actuator via a valve system controlling the powering. The valve system in return is operated by a control unit conveying control signals to the valve system via a signal communication pathway. The communication pathway may comprise a power link or pressure tubes with a liquid or a gas. In one embodiment the gas used is of a lower molecular weight than 28.9 kg/kmol and thereby lower than air, whereby the speed of the pressure signals being sent from the control unit is increased and thereby the operational speed of the aerodynamic devices. The invention further relates to a wind turbine comprising a tower, a nacelle mounted to one end of the tower, and a rotor with at least one wind turbine blade according to the above.

Abstract: A lift device for a wind turbine blade. The lift device includes a first sidewall and an opposing second sidewall. The lift device is configured to be coupled to the wind turbine blade along a leading edge of the wind turbine blade, and to generate lift when airflow is directed across a surface of the lift device.

Abstract: A rotor blade assembly is disclosed. The rotor blade assembly includes a main rotor blade, the main rotor blade including a pressure side and a suction side extending between a leading edge and a trailing edge, and an auxiliary rotor blade associated with the main rotor blade, the auxiliary rotor blade including a pressure side and a suction side extending between a leading edge and a trailing edge. The rotor blade assembly further includes a support member connecting the auxiliary rotor blade to the main rotor blade. The auxiliary rotor blade is configured to modify a lift force associated with the rotor blade assembly.

Abstract: The present disclosure relates to a wind turbine (10) including: a rotor (18) including a rotatable hub (20) and a plurality of rotor blades (22), each of the plurality of rotor blades (22) being attached to the hub (20); and at least one airfoil body (120) including an aerodynamic profile (156) and an airfoil body root portion (122); wherein the aerodynamic profile (156) is configured for increasing aerodynamic lift of at least an inner portion of a rotor blade (22); and the at least one airfoil body (120) is attached to the hub (20) at the airfoil body root portion (122). In addition thereto, the present disclosure relates to an aerodynamic assembly (118) for a wind turbine (10) and a method of assembling a wind turbine (10).

Abstract: Power generation apparatus includes a wing-shaped blade having opposite sides, opposite ends and leading and trailing edges extending between those ends. A lift differential producing device in the blade produces a lift differential at the opposite sides of the blade and that device is switched so that one blade side or the other produces the greater lift. A blade shaft extends along an axis in the blade that is in close parallel relation to the leading edge of the blade and that shaft is fixed to move with the blade. Supports support the blade shaft so that the blade can be positioned in a fluid stream with the leading edge facing upstream and swing about the axis between first and second extreme positions on opposite sides of a neutral position, the blade shaft oscillating with the blade. A coordinating device coordinates the switching of the lift differential producing device with the swinging of the blade so that the switching occurs at the extreme positions of the blade.

Abstract: A lift-type wind turbine having a substantially vertical rotating shaft and a plurality of substantially vertical blades secured to the shaft. Each blade includes a front portion, a rear portion, and a pivot axis pivotally securing the rear and front portions. The rear portion pivots relative the front portion. The blades additionally include bottom and top edges positioned on each of the front portions. Each bottom edge is arranged substantially equidistant from the shaft proximate a first circumference extending substantially horizontally about the shaft, whereas each top edge is arranged substantially equidistant from the shaft proximate a second circumference extending substantially horizontally about the shaft. The blades are angled relative to the rotating shaft. The blades have an open, drag means position as well as a closed, lift means position, and passively switch between the positions based on wind speed for efficient rotation.

Abstract: A helicopter includes an airframe, and a rotor system mounted to the airframe. The rotor system includes a plurality of rotor blades. Each of the plurality of rotor blades includes a root portion that extends to a tip portion through an airfoil portion. The airfoil portion includes first and second surfaces. An effector is mounted within the airfoil portion of at least one of the plurality of rotor blades. The effector includes a first end portion that extends to a second end portion through an intermediate portion, and a flap arranged at the second end portion. The effector is selectively actuated to shift from a first, stowed, position wherein the flap is positioned within the at least one rotor blade to a second, deployed, position, wherein flap projects through at least one of the first and second surfaces of the at least one rotor blade.

Abstract: A wind turbine blade includes a porous window defined in the suction side of the blade. The porous window is permeable to airflow from within an internal cavity of the blade through the suction side. A deployable cover member is configured with the porous window and is variably positionable from a fully closed position wherein airflow through the porous window is blocked, to a fully open position wherein airflow is established through an entirety of the porous window. An actuating mechanism is disposed within the internal cavity of the blade and is configured with the cover member to move the cover member between the fully closed and fully open positions in response to a control signal.

Abstract: A wind turbine blade has a suction side surface and a pressure side surface. A plurality of dynamic vortex elements are formed on at least one of the suction side or the pressure side surfaces. The vortex elements are activatable between a first retracted position that is inwardly recessed relative to a neutral plane of the surface on which they are formed and a second extended position that is outwardly protruding relative to the neutral plane of the surface.

Abstract: A trailing edge aerodynamic airfoil of a load-bearing aerodynamic surface of an aircraft of the crocodile type has two airfoil flaps, with each flap being integral in a forward section with a rotational shaft that determines the axis of rotation of the airfoil flap. In a position called the zero setting, the airfoil flaps are essentially joined and form a rear section of the load-bearing surface, and each airfoil flap is movable in translation independently of the other airfoil flap, relative to the load-bearing surface, with each flap being entrained in rotation relative to the load-bearing surface around its axis of rotation by the motion in translation. The ends of the rotational shaft have extensions guided by runners fastened to these ends and acting conjointly with racks fastened to the load-bearing surface.

Abstract: The invention relates to a wind turbine blade with at least one control surface and an actuator inside the main body of the wind turbine blade for moving the control surface, wherein the actuator comprises a fluidic muscle, a controller and a pump, and wherein the fluidic muscle is adapted to change in length and width when the pressure of the fluid within the fluidic muscle is varied.

Abstract: An active flow control device (10) and a method for affecting a fluid boundary layer of a wind turbine blade (100) are disclosed, as well as a stand-alone module (40) including a plurality of such devices and a wind turbine blade comprising a such devices and/or modules. One or more flow effectors (14) are rotatable back and forth in an oscillating movement (A) in a rotational plane. The flow effectors (14) are also movable in a direction transverse to the rotational plane between a retracted position and an extended position.

Abstract: A wind turbine blade comprises a main blade body and trailing edge section movably connected to the main blade body, and an actuator structure internally within the blade. The actuator interconnects the trailing edge section and the main blade body, and it comprises a stack of a plurality of piezoelectric elements, so that the stack of piezoelectric elements is capable of operating as a linear actuator. The actuator structure is arranged such that it is capable of causing the trailing edge section to move or deform relative to the main blade body in response to aerodynamic loads on the blade. The actuator structure is controllable by a control system applying a voltage to the stack of piezoelectric elements in response to, e.g., detected wind or load characteristics.

Abstract: An electric fan can comprise: an oscillating motor configured to drive an upper shell to rotate; a fan motor connected with blades of the electric fan; a control unit mounted with the oscillating motor configured to modify an oscillating angle of the electric fan by changing an interval of positive and negative rotation of the oscillating motor; a control panel connected with the control unit configured to operate the electric fan; and a transformer unit configured to connect supply power to the control unit, the oscillating motor, the control panel, and the fan motor.

Abstract: The invention relates to an aerodynamic wind propulsion device, particularly for watercraft, comprising an aerodynamic wing being connected to a steering unit located below the aerodynamic wing and coupled to the aerodynamic wing via a plurality of lines, particularly steering lines and/or fixing lines, a tractive cable, wherein a first end of the tractive cable is connected to the steering unit and a second end of the tractive cable is connected to a base platform, the aerodynamic wing having an aerodynamic profile which generates a lifting force in the direction of the traction cable when the air stream direction is about perpendicular to the tractive cable, a plurality of reefing lines located across the aerodynamic wing for increasing and decreasing the lifting force by changing the shape and/or dimension of the aerodynamic wing.

Abstract: A wind turbine includes an electrical stall sensor configured on a pressure surface of at least one turbine blade at a location to detect backflow in a stall condition. The stall sensor includes a flap pivotally configured on the respective pressure surface so as to be moved from a first position towards a second position by backflow over the pressure surface during a stall condition. A sensor circuit responds to movement of the flap between the first and second positions and generates a corresponding electrical signal that indicates the stall condition.

Abstract: A wind generator is disclosed in which superconducting ring generators are utilized without the need for a load bearing drive shaft and other mechanical components, decreasing overall weight and enabling the use of variable geometry blades for increased overall efficiency.

Abstract: A rotor blade for a wind turbine comprises a rotor blade body with a root for connecting the rotor blade to a hub of a wind turbine, a tip, a leading edge and a trailing edge. The blade has a movable part, and motion transmitting means for connecting to an actuator being placed preferably outside the blade body, and transmitting motion from the actuator to the movable part. The motion transmitting means is electrically non-conductive, whereby the risk of lightning stroke accidents is reduced.

Abstract: In an exemplary variable area nozzle, a fixed duct section has an inlet and an outlet oriented approximately perpendicular to the inlet. A controllable nozzle member is disposed adjacent the outlet of the fixed duct section. The controllable nozzle member has an area that is adjustable to maintain a substantially constant nozzle pressure ratio. The controllable nozzle member may include first and second flap doors hinged and pivotable in opposite directions between an open position and a closed position and that also may be hinged and pivotable in a same direction so thrust from gas exiting the nozzle is vectorable. When disposed in rotor tips of an aircraft capable of rotary wing flight and fixed wing flight, the variable area nozzle may maintain a substantially constant nozzle pressure ratio near an optimized nozzle pressure ratio as the aircraft transitions from rotary wing flight to fixed wing flight.

Abstract: A wind turbine has a longitudinal airfoil blade that exerts a torque on the generator in response to an impinging air current. A compliant airfoil edge arrangement is disposed along an edge of the airfoil blade for at least a portion of a longitudinal dimension of the airfoil blade. A morphing drive arrangement varies a configuration of the compliant airfoil edge arrangement and consequently the aerodynamic characteristics of the airfoil blade. A drive arrangement applies actuation forces to the upper and lower compliant surfaces via the upper and lower actuation elements. The compliant airfoil edge is arranged as a trailing edge of the airfoil blade.

Abstract: There is provided a turbine having rotating blade surfaces that adjust their geometry based on incident fluid flow. In one aspect, there is provided a turbine having a least one pair of blades rotatably connected such that their geometry is adjusted based on incident fluid flow. In another aspect, there is provided, a turbine having at least one pair of blades connected such that they self-orient themselves to a neutral position under their own weight. In yet another aspect, there is provided, a control surface for a turbine blade which prevents meta-stable stall of the turbine blade in an fluid stream.

Abstract: A wind turbine blade includes a blade body and lift-regulating mechanism adapted for movement in relation to the blade body by at least one actuation mechanism controlled by an actuation controller. The actuation controller controls a setting of the lift-regulating mechanism based on an input from a sensor, and the sensor is a force sensor adapted for sensing a force from a wind flow acting on the lift-regulating mechanism, whereby a wind turbine blade with fast-responding lift-regulating mechanism is provided.

Abstract: A helicopter rotor blade that has a blade body and a control flap secured to the blade body. The rotor blade has a first primary mover capable of generating a first linear motion that is sufficient to generate a high amplitude, low frequency motion of the control flap; and a second primary mover capable of generating a second linear motion that is sufficient to generate a small amplitude, high frequency motion of the control flap. Further, the rotor blade has a coupling transmission for combining the first linear motion with the second linear motion that generates a cumulative linear motion; and a second transmission device that causes the cumulative linear motion to rotate the control flap.

Abstract: A self-lubricated actuator for a rotor blade flap of a helicopter having a housing; a motor having a shaft disposed in a bearing is provided. The actuator further has an output rod and a mechanism operatively associated with the motor and the output rod to transmit movement from the motor to the output rod. The housing includes a lubrication medium capable of substantially immersing the bearing, the motor shaft and the mechanism during operation.

Abstract: A blade (10) for a wind turbine rotor with a hub is described. The blade extends in a longitudinal direction along a longitudinal axis and having a root area (16) closest to the hub and a tip region furthest away from the hub. The blade (10) along at least a portion of the longitudinal direction of the blade has an envelope, which defines an airfoil profile having, in normal operation, a pressure side (20) and a suction side (19), and further having a leading edge (18) and a trailing edge (17), which edges define an airfoil chord line extending between them. The blade (10) comprises adjustable lift-regulating means extending in the longitudinal direction of the blade (10), and activating means by means of which the lift-regulating means can be adjusted and thus alter the aerodynamic properties of the blade (10).

Abstract: A yaw control system and a method of controlling yaw for an aircraft are provided. The yaw control system includes a first wing set and a second wing set which are rotatable in opposite directions. Each of the wing sets includes at least two wings each including a pivotable flap forming a trailing edge of its respective wing. A flap control assembly controls the pivotable flaps of the first wing set and of the second wing set such that when the pivotable flaps of the first wing set are pivoted in a first direction by a first set angle, the pivotable flaps of the second wing set are simultaneously pivoted by a second set angle in an opposite direction, thereby providing yaw control for the aircraft.

Abstract: The present invention relates to a design concept by which the power, loads and/or stability of a wind turbine may be controlled by typically fast variation of the geometry of the blades using active geometry control (e.g. smart materials or by embedded mechanical actuators), or using passive geometry control (e.g. changes arising from loading and/or deformation of the blade) or by a combination of the two methods. The invention relates in particular to a wind turbine blade, a wind turbine and a method of controlling a wind turbine.

Abstract: An apparatus and system for compensating for various load situations in a turbine includes the use of one or more deployable devices configured to extend an air deflector outwardly from a surface of a rotor blade. The air deflector may subsequently be retracted into the rotor blade once the load falls below a certain threshold. Mechanisms for extending and retracting the air deflector may include pneumatic, hydraulic and/or electromechanical devices. Air deflectors are generally configured to modify the air flow around the rotor blade to increase or decrease power generation, or reduce loads so that the risk of potential damage to components of the wind turbine is minimized. Deflectors may be positioned at various chordwise stations including leading-edge, mid-chord, and trailing-edge locations on the upper and lower surfaces at spanwise positions. Accordingly, a plurality of devices can be actuated to aerodynamically control rotor performance and loads based on wind conditions.

Abstract: A rotor blade including a rotor blade profile including a profile tip region, a profile trailing edge region including a trailing edge and a profile body having a profile core. A covering skin including an upper skin and a lower skin encase the profile core. A reversibly bendable flexural actuator including a first actuator end disposed at the trailing edge region of the rotor blade profile and a second actuator end projecting past the profile body toward the trailing edge. The second actuator end forms part of the trailing edge region and forms a movable rotor blade flap, the movable rotor blade flap being deformable into an arc-shaped rotor blade flap deflection upon a bending of the flexural actuator.

Abstract: A wind deflector for a wind turbine has a vertical wind deflecting surface movable in a circular path about the wind turbine for facing a prevailing wind direction.

Abstract: A rotorcraft rotor blade (1) includes at least one tiltable trailing-edge flap (5), the flap (5) being suitable for pivoting about a virtual hinge axis (Y?) extending substantially along the span of the blade (1) and of the flap (5). The blade (1) is remarkable in that it is provided with at least one main ball joint (30) provided with an inner cage (32) together with a first pin (31) and an outer cage (33), the front portion (33?) of the outer cage (33) of the main ball joint (30) being connected to a linear actuator (10, 10?) arranged in the blade (1) and serving to pivot the flap (5), the first pin (31) of the main ball joint (30) being substantially perpendicular to the virtual hinge axis (Y?) about which the flap (5) pivots.

Abstract: A wind energy to electrical power conversion device provides a protected multiple turbine mechanism axially aligned to convert kinetic energy of air movement, i.e. wind (or other moving fluid such as water), into rotational mechanical power to directly create electrical energy by the reaction of the wind with the turbine. The present wind energy to electrical power conversion device may either be configured as a vertical axis wind turbine (VAWT) or horizontal axis wind turbine (HAWT). An associated wind gathering sail automatically repositions itself to maximize wind intake and to collect and concentrate the wind prior to converting the wind into energy via the axially aligned multi-turbine mechanism into electrical energy. The remaining wind is released via a leeward-facing exhaust. The present axially aligned multi-turbine mechanism avoids interference by birds and other outside objects due to its inherent structural visibility.

Abstract: This invention relates to a novel twin wind turbine power system. More particularly, this invention pertains to a twin wind turbine power system which has adjustable width blades, adjustable width wind deflectors and a telescoping erection capability. A twin wind turbine electrical power generating system comprising: (a) a first rotatable wind turbine with vertical radially extending blades around its axis; (b) a second rotatable wind turbine deployed parallel to the first turbine with vertical radially extending blades around its axis; (c) a vertical windshield positioned windwardly between the first and second wind turbines; (d) a wind direction member associated with the first and second wind turbines and directing the first and second wind turbines and windshield to face windward; (e) a rotational support upon which items (a), (b), (c) and (d) are mounted; (f) an alternator connected to the first and second wind turbines and generating electricity as the first and second wind turbines rotate.

Abstract: A trim tab assembly includes first and second shape memory alloy (SMA) actuators and a trim tab substrate which provide elastic/plastic locking in response to an induced strain actuation.

Abstract: A multi-section blade for a wind turbine comprising at least one non-pitchable section and at least one pitchable section is provided. The non-pitchable section is configured to be fixed to a hub of the wind turbine. The pitchable section is configured to be rotated about a pitch axis which is substantially parallel to the span of the multi-section blade. A pitch bearing and a pitch motor are located within the blade and near the non-pitchable section and pitchable section interface.

Abstract: An undershot waterwheel is described. The waterwheel has a rotational axis and paddles rotatable about the rotational axis. At least one paddle comprises a blade that is curved when viewed parallel to the rotational axis. Optionally, the waterwheel may be mounted on a watercraft.

Abstract: A method of manufacturing a fan blade includes providing a fan blade blank including opposed major faces, opposed inner and outer extremities, and opposed first and second sides defining opposed first and second edges, respectively. The method further specifies cutting the fan blade blank asunder into first and second parts along a cut line extending from the inner extremity of the fan blade blank to the outer extremity of the fan blade blank inboard of one of the first and second edges forming a first cut edge of one of the first and second parts and a second cut edge of the other of the first and second parts, chamfering one of the first and second cut edges forming a chamfered one of the first and second cut edges, and affixing the chamfered one of the first and second cut edges to the other of the first and second cut edges forming a fan blade consisting of the first part affixed to the second part, the first part being angled relative to the second part.

Abstract: A wind turbine having at least a blade comprising a first component (11) having an aerodynamic profile with a leading edge, a trailing edge and suction and pressure sides between the leading edge and the trailing edge, and a second component (13), attached to the trailing edge and/or to the leading edge of the first component (11) in at least a part of the blade, comprising one or several upwards and/or downwards deflectable flaps (15, 15?) that allow changing the flow over the blade, in which the means for deflecting each of said flaps (15, 15?) comprise an actuating force or torque provided by scaling devices (21) connected to a predetermined location (17) in the outer surface of the blade, through a duct (19), so that the changes in the wind pressure at said location (17) can be scaled to said actuating force or torque.

Abstract: Wind turbines or generators are provided with a larger operating range, and made more efficient through the use of controlling the Bernoulli Effect on air foil blades. The control is effected through the use of rotating bands arranged over at least part of the surface of the blades. The direction of the moving bands is reversible so as to increase or decrease the lift provided by the Bernoulli Effect. In the present invention, greater torque can be developed on the wind generator without increasing the wind speed.

Abstract: A wind turbine having at least a blade comprising a first component (11) having an aerodynamic profile with a leading edge, a trailing edge and suction and pressure sides between the leading edge and the trailing edge, and a second component (13), attached to the trailing edge and/or to the leading edge of the first component (11) in at least a part of the blade, comprising an upwards and/or downwards deflectable flap (15) that allows changing the flow over the blade, in which the means for deflecting the flap (15) are fluid inflatable means (23) placed in a flap inner chamber (25) close to the first component (11) and in which the wind turbine comprises means for controlling said inflatable means (23) depending on the wind situation and/or the blade loads.

Abstract: A wind turbine having at least a blade comprising a first component (11) having an aerodynamic profile with a leading edge (5), a trailing edge (7) and suction and pressure sides between the leading edge (5) and the trailing edge (7) and a second component (13) attached to the trailing edge (7) and/or to the leading edge (5) of the first component (11) in at least a part of the blade, in which the second component (13) comprises an upwards and/or downwards deflectable flap (15) that allows changing the flow over the blade and in which the means for deflecting the flap (15) comprise a stiff plate (31) inserted between the first component (11) and the flap (15) and stiff plate actuating means (33, 43).

Abstract: Provided are an apparatus and method for controlling a vertical axis wind power generation system that controls the rotation of guide vanes according to wind direction and speed, appropriately controls a direction of wind passing over an impeller, thereby maintaining a rotational speed generating the maximum power, maintains output power of a generator as rated power according to wind direction and speed, and stops the generator when a low or high wind speed outside a setting value range, an error in a structure, a fault in a braking unit, and/or a fault in guide vanes is detected.

Abstract: To control vortices originating at the tips of a rotor's blades rotating through the air at a revolution frequency f, separation control device(s) are actuated to periodically introduce perturbations into the airflow moving over the blades. The periodic introduction of perturbations is controlled in accordance with a periodic modulating frequency of introduction f0 while the frequency of the perturbations so-introduced is designated as fe. Vortex control is achieved when the periodic modulating frequency of introduction f0 satisfies the relationship nf?f0?fe where n is the number of blades.

Abstract: A control system for a rotorcraft is disclosed. The control system includes a stepped mixing linkage, such that a selected amount of right-left lateral cyclic output is generated for certain amounts of forward-aft cyclic input. The stepped mixing linkage includes two supporting links and a floating link pivotally coupled between the two supporting links. The ratio of the lengths of the two supporting links to the length of the floating link is small, thereby generating a selected lateral sinusoidal output, a selected rotation of the sinusoidal output, and a selected ramped output in response to each forward-aft pilot input command.

Abstract: A wind turbine includes a rotor assembly having at least one blade with a blade body defining a leading edge and a trailing edge and adapted for movement in response to a wind flow over the body to produce electricity. A rigid acoustic flap extends outward from the trailing edge, and a distal end of the acoustic flap is substantially smooth and continuous. The flap reduces acoustic noise generated by the blade in use.

Abstract: A ceiling mounted fan comprising: a first housing portion; a second housing portion; and a motive unit operably coupled to the second housing portion, wherein the motive unit is configured to adjust a position of the second housing portion from a position proximate to the first housing portion to a position distal to the first housing portion.

Abstract: An aerodynamic profile includes a main profile body defining a profile depth direction and being shear-flexible in the profile depth direction, a tension-stiff and compression-stiff upper covering skin, a tension-stiff and compression-stiff lower covering skin, wherein the upper and lower covering skins envelope the main profile body, a bearingless and hingeless rear profile deformation region disposed at a rear edge region, and at least one actuator disposed in the main profile body. The at least one actuator is configured to initiate a flexural motion of the main profile body resulting in a curvature of the upper and lower covering skins and to deform the rear profile deformation region and so as to yield a flap deflection directed opposite to a direction of the flexural motion.

Abstract: The invention relates to a method and a device for regulating the airflow around a blade of a windmill. The device comprise a spoiler, which is provided with a cavity. The spoiler is mounted to a surface of the blade in connection with an another flow regulating unit, and the spoiler can change the airflow around the blade by assuming different forms. When the spoiler is in a deactivated form no particular changes of the airflow takes place, as the spoiler runs continually and follows the contour of the blade. When the spoiler is in an activated form the airflow, however, is changed in that the spoiler no longer follows the contours of the blade and creates a discontinuity or at least changes the profile of the blade in such way that the airflow conditions are changed. In particular the airflow conditions can be changed so the effect of the second flow regulating unit completely or partly is eliminated.

Abstract: A wind-energy power machine and it's energy-storage generation system and wind-energy power generation system relate to a field of wind-energy power, generating technology and generating device. The wind-energy power machine is composed of a central rotor, a plurality sets of frames and at least a set of wind-pressure pushing mechanism provided within each set of frame. The central rotor vertically rotatablely mounted within a mounting frame in a special high-story frame structure with wind collecting wall is formed to a large scale power and generating system by means of combining with vertical or horizontal integrated system, or both systems in series and in parallel.

Abstract: An airborne mobile platform generally includes a plurality of rotating rotor blades operating in an airflow that forms a boundary layer on each of the rotor blades. At least one of the rotor blades includes a section that encounters the airflow that includes an unsteady subsonic airflow having at least a varying angle of attack. At least one of the rotor blades also includes one or more vortex generators on the at least one of the rotor blades that generate a vortex that interacts with the boundary layer to at least delay an onset of separation of the boundary layer, to increase a value of an unsteady maximum lift coefficient and to reduce a value of an unsteady pitching moment coefficient for the section.