How Wind Turbine Blades Reduce Noise with Small Fins

This patent describes how small, flat fins attached to the tips of wind turbine blades can reduce noise and improve efficiency by managing swirling air, called vortices.

What it covers

This patent describes a wind turbine blade designed to reduce noise and improve efficiency by managing swirling air at its tip. It uses several "substantially flat flaps" (Claim 1) that stick out "substantially perpendicular" from the blade's "suction surface" (Claim 1) near its end. These flaps are placed along "different chord lines" (Claim 1) and are specifically shaped so their "trailing edge" is taller than their "leading edge" (Claim 1). Their job is to "capture and direct tip vortices toward a trailing edge of the blade" (Claim 1), which means they grab the swirling air and guide it away, making the blade quieter and more effective. For example, a wind turbine blade might have three such fins, each about a quarter of the length of the blade's width at that point, helping to smooth out the airflow.

What it doesn't cover

• —Does not cover flaps that are not "substantially flat" (Claim 1), such as curved or complex shapes.
• —Does not cover flaps that are not positioned "substantially perpendicular" (Claim 1) to the blade's suction surface.
• —Does not cover flaps where the "trailing edge" is not taller than the "leading edge" (Claim 1).
• —Does not cover flaps with a length outside the range of 0.2 to 0.6 times the chord line length (Claim 1).
• —Does not cover systems that manage vortices using methods other than these specific flaps (Claim 1).

The clever bit

The clever part is using simple, "substantially flat flaps" (Claim 1) with a specific height difference from front to back to actively manage the powerful swirling air (tip vortices) at the blade's edge. Instead of just letting the vortices form and create noise, these flaps capture and redirect them, turning a problem into a controlled flow.

Why it matters

Wind turbines are a key part of renewable energy, but the noise they make can be a significant issue for nearby communities. This patent addresses that problem by offering a way to reduce the distinct "whooshing" sound caused by air swirling off the blade tips. By making turbines quieter, it helps them be more widely accepted and allows for more flexible placement, contributing to the growth of clean energy infrastructure.

Real-world examples

• 1.Modern utility-scale wind turbines
• 2.Wind turbine blade designs focused on noise reduction
• 3.Aerodynamic add-ons for existing wind turbine blades