Aerodynamic Blades for Silent Wind Turbines

Bionic wind turbine blade design that reduces noise without sacrificing aerodynamic performance. The blade has a non-smooth leading edge and a curved sawtooth trailing edge, especially at the middle to end sections of the blade. This bionic shape inspired by owl wings and feathers aims to significantly reduce aerodynamic noise generated by wind turbine blades while maintaining aerodynamic efficiency. The non-smooth leading edge and curved serrated trailing edge are applied to the noise source areas near the blade mid-span.

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Blade design for wind turbine blades that reduces noise compared to conventional blade shapes. The blade has a profile inspired by the wings of long-eared cuckoos. The blade has a lower convex curve and an upper concave curve. This shape guides airflow into the concave section which throws it out, reducing unstable circulation and noise. The cuckoo wing-inspired blade design was found to significantly reduce noise compared to conventional blade shapes through numerical simulation and experimental testing.

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Wind turbine blade design with sawtooth panels at the trailing edge to improve power generation and reduce noise. The blade has a main body and multiple sawtooth panels attached to the trailing edge. The sawtooth panels increase lift by creating vortices and delaying airflow separation compared to a smooth trailing edge. This provides higher torque and annual power generation. The sawtooth panels are bonded to the blade body rather than fastened to avoid impacting structural stability and noise.

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Optimizing wind turbine blades for low air density sites to improve power generation without changing blade geometry. The technique involves adding sound protection features near the blade tip that increase induction factor at low air densities. The features are serrations with spikes along the blade edge. By upsizing the spikes, installing them at an angle, and adjusting their shape, the blade's effective trailing edge is altered to boost blade performance in low density conditions. This compensates for reduced lift and power from the lower air density without modifying the blade shape.

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Wind turbine blade noise reduction device that significantly reduces wind turbine blade noise compared to conventional noise reduction methods. The device has a wind turbine blade noise reduction body with a first noise reduction component on one side and a second noise reduction component on the other side. The first component has an inner blade, an air knife, an upper flow hole, and a lower flow hole. The air knife is fixed to the inner blade. The upper flow hole is at the top of the air knife and the lower flow hole is at the bottom. This disperses the airflow around the inner blade to reduce noise. The second component has a damping component attached to the end to further reduce vibrations and noise.

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Reducing noise from wind turbines by adding a dorsal fin-like structure at the blade tips. The fin extends vertically from the blade tip and has a curved shape that follows the blade profile. The fin reduces noise by breaking up the vortex shedding that occurs at the blade tips. This vortex shedding is a major source of noise from wind turbines. The fin disrupts the vortex shedding pattern, which reduces the noise emitted by the turbine. The curved shape of the fin matches the blade profile to maintain aerodynamic efficiency while still reducing noise.

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Bionic wind turbine blade design to reduce noise and improve durability. The blades have a unique shape with curved sections joined at tapered ends. The curved sections form an arc transition between larger and smaller planes. Multiple curved sections are stacked perpendicularly to form the blade. Wings are attached to the blade surface. This bionic blade shape reduces noise by reducing pressure pulsations on the blade surface. The tapered ends and curved sections also improve durability by reducing stress concentrations. The wings further reduce noise by altering the flow over the blade.

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Bionic blade design for wind turbines that reduces aerodynamic noise compared to conventional blades. The blade has a non-smooth leading edge shape with features like sawtooths, bumps, and concave points. This bionic leading edge structure helps rectify the airflow velocity distribution on the blade surface, reducing pressure pulsations and separations that cause noise. The irregular edge induces vortex generation to control separation and stability. It aims to uniformize airflow over the blade and mitigate wake turbulence at the trailing edge.

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Low-noise wind turbine blade design that improves aerodynamic efficiency while reducing noise. The blade has an adjustable flap at the trailing edge made of acoustic metamaterial. The flap angle can be changed to increase lift at low wind speeds. The flap is also made of materials that absorb noise. By optimizing blade shape and adding noise-reducing flaps, the blade efficiency is increased while noise is reduced compared to traditional blades.

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Wind turbine blade design to reduce noise at the trailing edge. The blade has a noise reducing portion near the trailing edge with multiple acoustic resonators. Each resonator has an opening in the blade surface and a cavity with a length between the opening and bottom. The resonators absorb sound waves and mitigate trailing edge noise. The cavity length can be optimized for different frequencies. The resonators can have partition walls to divide the cavity into multiple parts. Some resonators can be covered with permeable layers. The resonators can be curved or slanted. The blade can have serrations with resonators.

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Low-noise wind turbine blade with adjustable flaps at the trailing edge that can be moved to change the blade shape and improve lift and efficiency at low wind speeds. The flaps have sound-absorbing acoustic metamaterials to reduce noise radiation compared to fixed blades. The flaps can be moved using a drive mechanism to adjust the blade angle of attack. This allows optimizing blade shape for low wind starts and reducing noise pollution.

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Wind turbine blade with trailing edge serrations that reduce noise and improve aerodynamics. The blade has serrations along the trailing edge with flow alignment vanes positioned apart from the notional line connecting the serration base to apex. The vanes align flow towards the notional line to reduce trailing edge vortices and noise. The serrations protrude into the wake, continuing the flow alignment effect after the air leaves the serrated surface. The vanes are preferably plastic to match the blade material. The blade can have a profiled contour with a bead between the trailing edge and leading edge. The serrated panel can attach to the blade edge.

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High speed wind turbine blade design to reduce noise levels when the turbine rotates at high speed. The blade shape is optimized with swept and unhedral curves on the leading and trailing edges to create a low noise airflow around the blade tips. This reduces noise compared to conventional blade shapes by naturally guiding the airflow along the curved surfaces instead of causing turbulence and noise impacts. The swept and unhedral curves aim to minimize low frequency noise absorption and maximize high frequency noise dissipation.

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Wind turbine blade design with a noise reducer to mitigate trailing edge noise. The noise reducer comprises aligned spine members on the blade trailing edge. Each spine has a stiff first section and a flexible second section. Adjacent spines are connected at the stiff sections but not at the flexible sections. This creates a rigid structure followed by flexible sections. The stiff sections provide stability while the flexible sections allow deformation to reduce noise.

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Wind turbine blade design with internal damping elements to reduce noise and vibration during operation. The blades have cushioning elements extending from the interior surface to absorb impacts and vibrations. This prevents debris falling inside the blade from striking the interior surface and generating noise. The cushioning elements also reduce structural damage from internal debris impacts. The blades can further have acoustic dampening elements to absorb noise propagation through the blade interior.

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A low-speed, low-noise wind turbine blade design for urban areas with low rotor speeds to mitigate noise and vibration issues. The blade has a maximum tip speed of 100 km/h or less, regardless of wind speed. The blade shape has a covered metal suction panel on one side, rather than fully occupying the side. This reduces drag and noise compared to fully enclosed blades. The covered metal structure allows fossil fragments inside to reduce noise further. The reduced tip speed and unique blade shape enable low-noise, low-speed urban wind power generation.

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Retrofit system for a wind turbine blade that reduces noise generated by wind turbine blades. The system includes a trailing edge, a mounting structure, and at least one serrated portion extending at least partially along the mounting structure.

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Wind turbine blade design with a non-truncated, flow-permeable add-on attached to the sharp trailing edge to mitigate noise, prevent clogging, improve lift, and promote flow reattachment. The add-on is flow-permeable and attaches to the pressure and/or suction side of the trailing edge. This improves noise reduction by mitigating broadband and tonal noise components, prevents clogging by allowing debris passage, improves lift generation at high incidence flow, and promotes flow reattachment.

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Noise reduction structure for wind turbine blades that reduces blade noise without sacrificing strength. The structure has a series of teeth along the blade trailing edge. The teeth are connected by a reinforcement portion. The teeth length increases from root to tip. This shape changes the blade trailing edge profile to avoid shedding vortices that cause noise. The reinforcement divides the teeth into sections. The triangular tooth edge enhances noise reduction. The teeth structure reduces broadband scattered noise compared to sharp edges.

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Wind turbine blade tip design with double winglets to improve aerodynamic performance and reduce noise. The blade tip has a Y-shaped winglet with a curved-swept leading edge and concave trailing edge. The winglet has an air termination device connected to the lightning arrester. This design reduces tip loss, improves blade efficiency, and changes airflow distribution to reduce noise compared to conventional blade tips.

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