Wind Turbine Rotor Blade Trailing Edge Serrations
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Solution Overview
Problem
Wind turbine rotor blades experience noise emission and power output drops due to turbulence at the trailing edge, and existing serration designs are inefficient and require disproportionate effort for optimal geometry.
Innovation Solution
The rotor blade features a trailing edge with serrations whose geometry is adapted to the contour of the trailing edge, with serration edges non-parallel to the flow direction and varying angles to optimize flow behavior, reducing turbulence and noise emission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If serrations are added to the trailing edge to reduce noise and turbulence, then noise emission is reduced, but the design complexity and manufacturing effort increase disproportionately
Solution Approach 1:
The patent applies local quality by making the serration geometry adaptive to the local trailing edge contour. Each serration's orientation and dimensions are specifically tailored to its position along the trailing edge, where the trailing edge angle varies. This localized adaptation allows effective turbulence reduction at each position without requiring a universally complex design, thereby reducing noise while managing design complexity through position-specific optimization rather than uniform complexity throughout.
Solution Approach 2:
The patent implements dynamics by making the serration geometry variable along the trailing edge span. The serration angle relative to the trailing edge contour changes continuously from the root to the tip of the blade, adapting to the changing trailing edge angle. This dynamic variation allows the serrations to maintain optimal effectiveness across different sections of the blade without requiring overly complex fixed geometry, thus reducing noise while controlling design complexity through systematic variation.
2Productivity
If serration geometry is optimized for specific flow conditions, then flow behavior is improved, but adaptability to different wind conditions decreases
Solution Approach 1:
The patent applies dynamics by designing serrations that automatically adapt to different flow conditions through their geometric variation along the trailing edge. The continuous change in serration angle and dimensions along the span allows the structure to respond effectively to varying wind speeds and angles of attack without requiring active control or adjustment mechanisms. This dynamic geometric adaptation maintains power output across different wind conditions while preserving versatility.
Solution Approach 2:
The patent implements parameter changes by systematically varying the serration geometric parameters (angle, height, spacing) along the trailing edge span. These parameter variations are correlated with the local trailing edge angle and position, creating a gradient that optimizes performance across different operating conditions. This continuous parameter variation allows the serrations to maintain effectiveness for power generation across a range of wind conditions without sacrificing adaptability.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This design effectively reduces noise emission and increases power output by optimizing serration geometry based on the trailing edge contour, accommodating different wind conditions and flow angles, and can be applied to various wind turbine profiles.
Implementation Method 1
The difference in pressure between the suction side and the pressure side can cause turbulences to be produced, which may result in an emission of noise and a drop in power output at the trailing edge of the rotor blade
Data Source
AI summary
A wind turbine rotor blade that has a rotor blade tip, a rotor blade root, a suction side, a pressure side, a rotor blade length, a profile depth and a pitch axis of rotation. The profile depth decreases along the rotor blade length from the rotor blade root to the rotor blade tip. The trailing edge has a trailing edge delimiting line, which replicates the contour of the trailing edge. The trailing edge has a plurality of serrations to improve flow behavior at the trailing edge. The serrations respectively have a serration tip, two serration edges and an angle bisector. The serration edges are provided non-parallel to a direction of incident flow that is perpendicular to the pitch axis of rotation. The serration edges are non-perpendicular to a tangent to the trailing edge delimiting line. The trailing edge delimiting line has a plurality of portions, at least one of the portions extending non-parallel to the pitch axis of rotation.