31 patents in this list

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Wind turbine blades operating at typical tip speeds of 75-80 m/s generate both aerodynamic and mechanical noise, with sound pressure levels commonly reaching 95-105 dB(A) at the source. The interaction between blade surfaces and air flow creates distinctive acoustic signatures that propagate through both the blade structure and surrounding air, affecting communities within a 500-meter radius.

The fundamental challenge lies in developing material solutions that can absorb or redirect acoustic energy while maintaining the structural integrity and aerodynamic performance of the blade.

This page brings together solutions from recent research—including hybrid coating systems with sound-absorbing layers, acoustic metamaterial flaps at trailing edges, and polymer-based damping materials for tower surfaces. These and other approaches focus on practical noise reduction while addressing the durability requirements of utility-scale wind turbines.

1. Hybrid Layered Coating System with Sound-Absorbing and Anti-Corrosion Layers for Wind Turbine Blades

GITAM DEEMED TO BE UNIVERSITY, 2023

An eco-friendly hybrid coating system for wind turbine blades that reduces noise and prevents corrosion. The coating has two layers: a sound-absorbing layer to reduce noise and an anti-corrosion layer to protect against environmental damage. The layers are strategically arranged and thickened to enhance absorption and corrosion resistance. The coating materials are chosen and the layer thicknesses optimized through experiments or modeling to balance noise reduction and corrosion prevention.

2. Screed Application System for Smoothing Transitions on Wind Turbine Blade Pressure Surfaces

WOBBEN PROPERTIES GMBH, 2023

Reducing noise emissions from wind turbine blades by smoothing transitions between the pressure side and auxiliary parts like trailing edge combs. The method involves applying a screed, like a leveling material, over the transition area to eliminate steps or transitions that can create noise. Adhesive strips are used to hold the screed in place. This smoothes the pressure side surface and reduces noise compared to a sharp transition.

3. Acoustic Damping Structure for Wind Turbine Tower

THIELSCHER WINDKRAFT GBR, THIELSCHER WINDKRAFT GBR VERTRETUNGSBERECHTIGTER GES PROF DR MED DR RER POL CHRISTIAN THIELSCHER 537, 2022

Reducing noise and vibrations generated by wind turbines to mitigate their impact on nearby residents and wildlife. This involves improving the soundproofing of the tower to reduce harmful low frequency sounds and vibrations like infrasound. By reducing the propagation of these frequencies through the tower, it can help minimize the disturbance to people and animals in the surrounding area.

DE202022002234U1-patent-drawing

4. Wind Turbine Blade with Adjustable Acoustic Metamaterial Trailing Edge Flap

GUANGDONG PROVINCIAL LABORATORY OF SOUTHERN MARINE SCIENCE AND ENG GUANGZHOU, GUANGDONG PROVINCIAL LABORATORY OF SOUTHERN MARINE SCIENCE AND ENGINEERING, SOUTHERN UNIVERSITY OF SCIENCE AND TECHNOLOGY, 2022

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.

5. Wind Turbine Blade with Adjustable Trailing Edge Flaps Incorporating Acoustic Metamaterials and Drive Mechanism

GUANGDONG PROVINCIAL LABORATORY OF SOUTHERN MARINE SCIENCE AND ENG GUANGZHOU, GUANGDONG PROVINCIAL LABORATORY OF SOUTHERN MARINE SCIENCE AND ENGINEERING, SOUTHERN UNIVERSITY OF SCIENCE AND TECHNOLOGY, 2022

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.

6. Acoustic and Vibration Insulation System for Wind Turbine Towers

THIELSCHER WINDKRAFT GBR, THIELSCHER WINDKRAFT GBR VERTRETUNGSBERECHTIGTER GES PROF DR MED DR RER POL CHRISTIAN THIELSCHER 537, 2022

Reducing noise and vibrations of wind turbines to minimize disturbance to nearby marine life like whales. The solution is to insulate the wind turbine tower to prevent harmful sounds and vibrations from being transmitted through the tower as the rotor blade passes by. This addresses the issue of offshore wind turbines disrupting marine life like whales due to the blade's noise and vibrations as it passes the tower.

DE202022001295U1-patent-drawing

7. Cladding Structure with Irregular Surface and Sound-Absorbing Material for Wind Turbine Noise Attenuation

SHANGHAI ELECTRICITY AND WIND POWER GROUP SHARE LIMITED CO, SHANGHAI ELECTRICITY AND WIND POWER GROUP SHARE LTD CO, YUNYI JING ENERGY NEW ENERGY CO LTD, 2022

A noise reduction device for wind turbines that can significantly reduce the noise generated by wind turbines and mitigate the adverse effects on nearby residents. The device consists of a cladding piece with a sound-absorbing material attached to the outside of the wind turbine tower. The cladding piece has irregular shapes like holes, bumps, pits, or particles on its surface. This allows some noise to be reflected, some to penetrate the cladding, and some to be absorbed and converted to heat by the sound-absorbing material. This reduces the overall noise transmitted by the turbine to nearby areas.

8. Serrated Trailing Edge Retrofit System for Wind Turbine Blades

GE INFRASTRUCTURE TECHNOLOGY LLC, 2022

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.

9. Multilayer Trailing Edge Enclosure for Wind Turbine Blades

INSTITUTE OF NUCLEAR ENERGY RESEARCH ATOMIC ENERGY COUNCIL EXECUTIVE YUAN ROC, 2020

Blade protection member for wind turbine blades that reduces blade surface stress fatigue, suppresses vortexes, and reduces noise. The protection member encloses the trailing edge of a wind turbine blade. It has three layers: an adhesive layer on the blade, an opaque flexible layer covering that, and an outer porous layer exposed to the environment. The porous layer absorbs airflow and friction reduces noise. The opaque layer protects the blade, and the adhesive bonds it. This prevents cracks, absorbs vortexes, and reduces noise compared to solid protection devices.

US2020370533A1-patent-drawing

10. Damping Material Application on Wind Turbine Towers for Vibration and Noise Transmission Reduction

CHEN GUOLIN, 2020

Noise reduction method for wind turbines that aims to mitigate blade noise and infrasonic waves generated by wind turbines. The method involves applying a damping material like polymer tiles to the surface of the wind turbine tower. This increases the damping properties of the tower walls and reduces the transmission of vibrations and noise through the tower. The damping material can also help absorb low frequency infrasonic waves. The technique aims to reduce noise levels and vibrations transmitted from the wind turbine blades to the tower and surrounding environment.

11. Boundary Layer Airflow Modifying Structures for Acoustic Emission Reduction on Blade Surfaces

SIEMENS GAMESA RENEWABLE ENERGY AS, 2019

Noise reducer that is applied along a portion of the blade upstream of the trailing edge without adversely increasing aerodynamic drag. The reducer includes a layer for attachment to a portion of a blade partially upstream from a trailing edge of the blade, airflow modifying structures configured to extend at least partially into a boundary layer of airflow over the blade upstream of the trailing edge, and a noise reducer disposed on a portion of the blade extending partially upstream from the trailing edge for modifying airflow over the blade effective to reduce acoustic emissions.

US10451033B2-patent-drawing

12. Multi-Layered Honeycomb and Acoustic Reflection Structure on Wind Turbine Blade Leading Edge

Nanjing University of Aeronautics and Astronautics, NANJING UNIVERSITY OF AERONAUTICS AND ASTRONAUTICS, 2019

A wind turbine blade design to reduce noise levels by incorporating a noise reduction structure on the leading edge. The structure has multiple layers: a small-hole honeycomb layer, a larger-pore honeycomb layer, and an acoustic wave reflection layer. The honeycomb layers absorb and scatter noise, while the reflection layer sends remaining noise back through the honeycombs for further absorption. This multi-layer setup converts, scatters, and absorbs noise to reduce overall blade noise levels.

13. Wind Turbine Blade with Graded Impedance Trailing Edge Structure

China Aerodynamics Research and Development Center Low-Speed Aerodynamics Research Institute, 2018

A wind turbine blade design with a graded impedance trailing edge to reduce noise. The blade has a gradual structure at the trailing edge instead of the conventional smooth or sawtooth trailing edges. A sound absorbing material with thickness grading is applied to the trailing edge. This graded impedance structure suppresses vibration of particles near the blade edge when high velocity incoming gas hits. This reduces diffraction of sound and noise. The gradual trailing edge design mitigates noise without affecting blade aerodynamics as much as brush, porous, or sawtooth trailing edges.

14. Serrated Trailing Edges with Acoustically Absorbent Materials for Wind Turbine Blades

GE INFRASTRUCTURE TECHNOLOGY LLC, 2017

Reducing noise generated by wind turbine blades to improve efficiency and avoid restrictions by adding serrated trailing edges with acoustically absorbent materials. The serrations reduce coherent scattering of noise sources, while the absorbent material reduces noise reflection. This mitigates the noise emanating from wind turbine blades in motion.

US2017145990A1-patent-drawing

15. Porous Layer with Boundary Layer Airflow Modification Structure for Wind Turbine Blades

SIEMENS GAMESA RENEWABLE ENERGY AS, 2017

Reducing noise generated by wind turbine blades by modifying the airflow upstream of the trailing edge. The modification involves attaching a porous layer with an airflow modification structure that extends into the boundary layer upstream of the trailing edge. This effectively reduces acoustic emissions without adding drag by disrupting the flow before it reaches the trailing edge.

CN106460788A-patent-drawing

16. Rotor Blade with Porous Cover for Boundary Layer Flow Alteration

SIEMENS GAMESA RENEWABLE ENERGY AS, 2017

A rotor blade for wind turbines with a noise reduction device to mitigate blade-generated noise. The device has a porous cover spaced a distance from the blade surface. The cover connects to the blade with a means. The cover has an open area fraction between 30-95%, like a grid or flexible material. The cover alters the boundary layer flow over the blade to reduce turbulence and surface pressure. This reduces noise compared to a solid blade surface.

17. Noise Scattering Element for Destructive Interference on Wind Turbine Blades

SIEMENS AG, SIEMENS AKTIENGESELLSCHAFT, 2015

Reducing noise from wind turbine blades by adding a noise scattering element that generates anti-noise when wind flows over it. This scattering noise interferes destructively with the trailing edge noise to reduce overall blade noise. The scattering element is placed at the blade tip or suction side to counteract trailing edge noise. The idea is to generate anti-noise that cancels out the trailing edge noise.

EP2851556A1-patent-drawing

18. Modular Rotor Blade Assembly with Mounting Plate and Integrated Lightning Protection

GENERAL ELECTRIC CO, 2013

Rotor blade assembly for wind turbines that allows easy on-site replacement and reduces vulnerability to lightning strikes compared to directly glued noise reducers. The assembly has a mounting plate attached to the blade surface, and the noise reducer attaches to the plate. This allows replacing just the noise reducer instead of the whole blade, as the mounting plate protects the blade surface. The plate also provides a lightning protection feature inside the blade to reduce strike damage.

US2013272892A1-patent-drawing

19. Trailing Edge Structure with Fiber Elements for Vortex Suppression in Windmill Blades

LM GLASFIBER AS, 2012

Reducing noise of windmill blades by modifying the trailing edge to prevent vortex formation that generates noise. The trailing edge is made with tightly packed fibers like aramid or carbon that curl slightly. This helps dissipate the pressure difference between the top and bottom airflows as they meet at the trailing edge, reducing vortex formation and noise. The fibers can be cleaved from a woven tape or applied as a separate strip to the blade.

20. Hydrophobic Textured Wind Turbine Surfaces with Protruding Particles for Enhanced Ice, Dirt, and Noise Reduction

VESTAS WIND SYSTEMS AS, 2012

Wind turbine components with hydrophobic surfaces that prevent ice buildup, reduce dirt and noise. The components have surfaces made of hydrophobic material with a texture providing a contact angle of at least 150 degrees. This prevents water and dirt adhesion. To prevent ice, the hydrophobic coating is applied with protruding particles. This reduces ice formation compared to smooth surfaces. The hydrophobic coating prevents ice by preventing water from spreading and freezing. The texture prevents water beading and promotes sheeting, which reduces ice accumulation. The hydrophobic coating also reduces dirt and noise by preventing adhesion and reducing surface roughness compared to non-hydrophobic surfaces.

21. Wind Turbine Blade Noise Reduction Device with Soft Foam Layer and Low-Shear Adhesive

22. Wind Turbine Blade with Integrated Cellular Material Structure for Noise Reduction

23. Silicone Polyurethane Polymer Coating for Interior Surfaces of Shrouded Wind Turbines

24. Rotor Blade Surface Coating with Micro-Scale Protrusions for Noise Reduction

25. Rotor Blade with Cellular Material Integration for Noise Reduction

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