Elastic Trailing-Edge Serrations for Quieter Wind Turbine Blades
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Solution Overview
Problem
Wind turbines operating near residential areas face challenges in reducing noise emissions from rotor blades without compromising power output, as large serration base radii in trailing-edge serrations impair sound reduction properties while ensuring structural integrity.
Innovation Solution
Incorporating an elastic element made of a material with lower stiffness than the serrations, which reduces the serration base radius between serrations, maintaining structural stability and improving noise reduction properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the serration base radius is reduced to improve sound reduction properties, then noise emissions are reduced, but structural integrity deteriorates
Solution Approach 1:
The solution divides the serration structure into two functional parts: the serration elements themselves (made of stiff material) and the base radius region (filled with elastic material). This segmentation allows each part to be optimized independently - the serrations for noise reduction and the base for structural integrity.
Solution Approach 2:
The patent applies different material properties to different regions: the serrations use stiff material (GRP, CFRP) for aerodynamic function, while the base radius region uses elastic material (rubber, silicone) for structural support. This local differentiation resolves the contradiction by giving each region the quality it needs.
Solution Approach 3:
The invention creates a composite structure combining stiff serration material with elastic base material. This composite approach allows the structure to simultaneously achieve the rigidity needed for noise reduction and the flexibility needed for structural integrity.
2Stability of the object's composition
If the serration base radius is kept large to maintain structural integrity, then structural stability is improved, but sound reduction properties deteriorate
Solution Approach 1:
The elastic material acts as an intermediary element between the stiff serration structures and the rotor blade surface. It mediates between the conflicting requirements by providing structural support where needed while allowing the serrations to maintain their noise-reducing geometry.
Solution Approach 2:
The patent changes the material parameter (stiffness) in the base radius region from stiff to elastic. This parameter change allows the base radius to be structurally adequate without compromising the aerodynamic function of the serrations for noise reduction.
3Object-affected harmful factors
If elastic material is used to reduce serration base radius, then noise reduction is improved, but material stiffness decreases
Solution Approach 1:
The patent applies different material properties to different regions: the serrations use stiff material (GRP, CFRP) for aerodynamic function, while the base radius region uses elastic material (rubber, silicone) for structural support. This local differentiation resolves the contradiction by giving each region the quality it needs.
Solution Approach 2:
The invention creates a composite structure combining stiff serration material with elastic base material. This composite approach allows the structure to simultaneously achieve the rigidity needed for noise reduction and the flexibility needed for structural integrity.
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
The elastic element enhances sound reduction by minimizing notch stresses and cracks, while preserving structural integrity and power generation efficiency.
Implementation Method 1
at least one elastic element made of a second material, which is designed to reduce the first serration base radius between at least two of the several serrations to a second serration base radius, and where the stiffness of the second material is less than the stiffness of the first material
Data Source
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AI summary
The invention relates to a rotor blade, a method for using an elastic element to reduce the tooth root radius between at least two serrations of a rotor blade, and a wind turbine. A rotor blade for a wind turbine is provided, wherein the rotor blade has a rotor blade length from a rotor blade root to a rotor blade tip in the longitudinal direction, a rotor blade depth from a rotor blade leading edge to a rotor blade trailing edge in the direction of the rotor blade profile depth, a suction side extending between the rotor blade leading edge and the rotor blade trailing edge, a pressure side extending between the rotor blade leading edge and the rotor blade trailing edge, a rotor blade thickness extending between the suction side and the pressure side in the direction of the rotor blade thickness, and several serrations arranged on the rotor blade trailing edge.wherein the rotor blade trailing edge has a first serration base radius between each pair of the multiple serrations, wherein the rotor blade further comprises: at least one elastic element, wherein the multiple serrations consist of a first material, in particular GFRP, and at least one elastic element consists of a second material, which is configured to reduce the first serration base radius between at least two of the multiple serrations to a second serration base radius, and the stiffness of the second material is less than the stiffness of the first material.