Advancements in Reducing Drag on Wind Turbine Blades

A vertical-axis wind turbine system that uses a wind director to improve efficiency by reducing drag on the returning blade while increasing force on the advancing blade. The wind director has an inlet that captures wind and an outlet that narrows to increase wind speed. This directed wind is applied to the advancing blade. The wind director also has a secondary duct angled to provide additional forward force on the returning blade.

A wind turbine design that uses a drum-style rotor and multiple generators to increase efficiency and enable flexible mounting options. The main idea is to have a drum-shaped rotor with blades on the outside to eliminate vortices. The rotor connects to a variable number of generators around its circumference. In low wind, only one generator may be connected for optimal efficiency. In high wind, more generators can be connected to capture more energy.

A wind turbine that uses a variable geometry diffuser to control drag forces and maximize power production. The diffuser augmentation increases the wind pressure at the turbine outlet. The variable geometry allows adjusting the diffuser shape based on wind speed to reduce drag at high speeds and increase augmentation at low speeds. The diffuser has a fixed inner section and a rotatable outer section. The rotation angle of the outer section is controlled based on wind velocity to open the diffuser wall between 50% and 100%.

Wind turbine blades designed to make installation, transport, and storage easier and safer. The blades have removable devices on the suction side that disrupt airflow and reduce lift forces. These devices can be removed before installation to prevent blade oscillation during lifting, and for transport and storage to reduce aerodynamic loading. The removable devices disturb the airflow over the blade surface to induce separation and reduce lift forces.

Wind turbine blade design with optimized vortex generator placement on the suction side. The blade has a concave line of vortex generators along the chord. Vortex generators are triangular vanes that trip the airflow to reduce separation and stall. The concave line of VGs improves lift and drag compared to random VG placement. The VGs are positioned with a proximal end near the blade root and a distal end nearer the tip.

Rotor blade for wind turbines that passively reduces loads during operation. The blade has a flow deflection device that changes its configuration based on bending of the blade. When unbent, the device is streamlined to minimize drag. But as the blade bends, the device alters shape to divert airflow away from the blade surface, reducing lift and load. This passive flow control reduces the risk of blade-tower collisions and allows longer, lighter blades than structural fixes.

Wind turbine blade attachments to improve aerodynamics and power generation. The attachments are flow-guiding devices like spoilers or Gurney flaps. The devices are attached to the blade surface with flexible housings filled with adhesive. This allows bonding without grinding or complex prep steps. The attachments are also positioned in triangles to distribute loads, curved to accommodate blade bending, and reinforced with ribs for stiffness.

Propeller blades with an optimized shape to improve efficiency and reduce cavitation compared to conventional blades. The propeller blades have a curved upper end that extends away from the front surface and towards the back surface of the blade. The curve radius at the leading end is smaller than at the trailing end. This shape reduces cavitation and noise by preventing fluid from flowing radially over the blade. The curved upper end forces the fluid to flow rearward in a more axial direction. The blades can be angled relative to the axis of rotation to enhance fluid movement further.

A rotor blade for a wind turbine that reduces lift and load in emergency situations through a fail-safe aerodynamic device. The blade includes an aerodynamic device mounted on the blade surface that protrudes when not pressurized but collapses when pressurized. A control system adjusts the pressure to activate the device. The protruding device configuration reduces lift compared to the collapsed configuration. This fail-safe design prevents loss of control from causing lift increases in emergencies.

Wind turbine blade design to improve aerodynamics and energy production. The design includes attaching flow-modifying devices like spoilers or Gurney flaps to the surface of the blade. The devices are attached with flexible housings filled with adhesive to bond them to the blade surface. This allows the devices to modify airflow and increase lift without compromising blade structural integrity.

A flexible trailing edge extender for wind turbine blades that improves aerodynamic performance without adding weight and cost. The extender is a flexible aeroshell piece that can be attached to the trailing edge of a wind turbine blade section. The extender piece has slits cut into it that allow it to bend and flex. This configuration allows the extender to withstand operational stresses and strains better than a rigid extender.

Wind turbine blade with a trailing edge flap to increase lift without significantly increasing drag. The flap has two sections with an angled orientation. The first section extends from the trailing edge with an obtuse angle between its upstream surface and a plane parallel to the blade chord. The second section extends from the first section and together they form a concave profile.

Multi-segment rotor blade for horizontal-axis wind turbines that allows pitch angle control of each blade segment to optimize performance and reduce loads. The blade is made up of multiple segments that can rotate relative to each other to change the pitch angle. The blade segments are connected by guiding structures and actuating mechanisms that allow variable pitch between segments. This enables independent pitch control of each segment for optimal angle of attack and feathering. The blade design increases efficiency, reduces loads, and allows transportation of larger blades.

A vortex generator device for wind turbine blades that improves mounting strength and aerodynamics compared to existing vortex generators. The device has a base and two asymmetrically sized fins protruding from one side. The fins are arranged so that the distance between their primary ends is greater than the distance between their secondary ends. The fins also have asymmetric heights, with the primary fin end being shorter.

Vortex generators are designed to improve the aerodynamics and efficiency of wind turbine blades by reducing flow separation and increasing lift. The vortex generator has main fins along the blade surface that decrease in size towards the blade tip, plus smaller sub-fins at the end. The sub-fins are placed closer to the main fins than the maximum spacing between the main fins to reduce separation effects.

Arrangement of vortex generators on a wind turbine blade that improves aerodynamic performance over the state of the art. The vortex generators are arranged in pairs with specific ratios.

Damping oscillations in the tower of a wind turbine to increase operational life and reduce wear by individually adjusting the pitch of each rotor blade. This allows generating a lateral damping force to counteract crosswind tower motion. The pitch control signals are calculated based on the tower oscillation phase and rotor blade position.