Wind Turbine Blade Trailing Edge Wedge Noise Reduction
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Solution Overview
Problem
Wind turbine blades with blunt trailing edges generate significant operational noise due to vortex shedding, and existing solutions like splitter plates are prone to damage and complicate maintenance.
Innovation Solution
Increasing the trailing edge solid angle by adding a wedge element with a specific solid angle on the pressure side of the blade redirects airflow, reducing vortex shedding and noise, while maintaining structural integrity and aerodynamic performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If a splitter plate is used at the blunt trailing edge, then vortex shedding is reduced, but the device is easily damaged and requires complex handling and maintenance
Solution Approach 1:
The invention changes the geometric parameter of the trailing edge by increasing the solid angle through a wedge-shaped modification. This parameter change redirects the airflow and reduces vortex shedding without introducing fragile protruding elements, thereby reducing noise while maintaining reliability.
Solution Approach 2:
Instead of adding a protruding splitter plate that extends into the airflow (conventional approach), the invention modifies the trailing edge geometry by adding a wedge that increases the solid angle. This inverted approach achieves vortex reduction through geometric redirection rather than flow blocking, eliminating the reliability issues of protruding elements.
2Ease of manufacture
If a thick or blunt trailing edge profile is used, then manufacturing is easier and structural strength is improved, but trailing edge noise increases due to vortex shedding
Solution Approach 1:
The invention applies a localized wedge-shaped modification specifically at the trailing edge region while maintaining the overall blunt trailing edge profile. This local quality change redirects the airflow at the critical trailing edge zone, reducing vortex shedding and noise without compromising the global structural advantages of the blunt profile.
Solution Approach 2:
The invention modifies the local geometric parameter (solid angle) at the trailing edge by adding a wedge element. This parameter change alters the airflow redirection angle, reducing vortex shedding intensity while preserving the ease of manufacture and structural strength associated with blunt trailing edges.
3Object-generated harmful factors
If the trailing edge solid angle is increased, then vortex shedding strength is reduced and noise is decreased, but the blade geometry becomes more complex
Solution Approach 1:
The trailing edge modification is segmented into a distinct wedge element that can be designed and manufactured separately. This segmentation allows the complex geometric function to be isolated to a specific component, simplifying the overall manufacturing process while achieving the noise reduction benefit.
Solution Approach 2:
The invention achieves noise reduction through a controlled change in a single geometric parameter (solid angle) via the wedge element. By focusing the complexity on adjusting this one parameter rather than redesigning the entire trailing edge geometry, the solution maintains relative simplicity in manufacturing and design.
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 approach effectively reduces trailing edge noise by approximately 2-3 dBA, enhancing the reliability and performance of wind turbine blades with blunt trailing edges without significant impact on aerodynamics.
Implementation Method 1
one of the disadvantages of such a thick or blunt trailing edge profile is the relatively large levels of operational noise created by the trailing edge, primarily due to vortex shedding behind the trailing edge
Implementation Method 2
increasing the solid angle will enhance the mixing of the flow behind the trailing edge, which will avoid any kind of sustainable vortex shedding formations
Data Source
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AI summary
A system and method for reducing the operational noise of a blunt trailing edge of a wind turbine blade is described. The system involves increasing the trailing edge solid angle at the blade trailing edge by providing a wedge element or projection adjacent the trailing edge of the blade, the wedge element acting to provide improved mixing of the suction side and pressure side flows at the blunt trailing edge, thereby reducing the strength of vortex shedding at the trailing edge and the associated operational noise.