Wind Turbine Blade Serrated Edge With Active Anti-Noise Control
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Solution Overview
Problem
Existing wind turbines emit excessive noise during operation, limiting their economic viability and operational flexibility due to the need for curtailed power generation to comply with noise regulations, necessitating improved noise reduction technologies.
Innovation Solution
A combined noise reduction system comprising a serrated trailing edge profile and active noise reduction devices with unsteady pressure sensors, actuators, and a control unit to generate an anti-noise signal based on turbulent flow conditions, enhancing noise reduction by up to 10 dB when used in conjunction with passive serrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If wind turbines operate at full power generation capacity, then productivity is improved, but excessive noise is emitted causing compliance issues with noise regulations
Solution Approach 1:
The patent combines passive noise reduction (serrated trailing edge profile) with active noise reduction (anti-noise signal generation) into a hybrid system. This merging allows the wind turbine to maintain full power generation while achieving superior noise reduction of up to 16 dB, resolving the contradiction between productivity and noise emission compliance
Solution Approach 2:
The active noise reduction device generates anti-noise signals in advance to counteract the turbulent flow noise before it propagates. The serrated edge profile also preliminarily modifies the flow structure to reduce noise generation at the source, allowing full power operation without exceeding noise limits
2Device complexity
If only passive serrated edge profiles are used for noise reduction, then device complexity is reduced, but noise reduction effectiveness is limited
Solution Approach 1:
By merging the simple passive serrated edge profile with a relatively compact active noise reduction device, the system achieves enhanced noise reduction (up to 16 dB) without proportionally increasing complexity. The passive component handles baseline reduction while the active component provides additional 10 dB reduction, creating a scalable solution
3Measurement precision
If the number of sensors is increased to improve noise reduction precision, then measurement precision is improved, but manufacturing costs increase
Solution Approach 1:
The patent places sensors locally at the trailing edge where turbulent flow noise is generated, rather than distributing them throughout the blade. This localized sensing approach achieves sufficient measurement precision for noise reduction control while minimizing the total number of sensors required, thereby controlling manufacturing costs
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 combined system achieves synergistic noise reduction of up to 16 dB, reducing the number of required sensors and lowering fabrication costs while effectively minimizing noise in the surrounding environment.
Implementation Method 1
A method for limiting the noise emitted by a wind turbine blade is the usage of serrations at the trailing edges of wind turbine blades to passively reduce the noise emitted at the trailing edge
Implementation Method 2
The microphones on the blade measure the near-field turbulent pressure fluctuations
Implementation Method 3
loudspeakers located at the blades are actuated to cancel the noise generated by the rotor
Implementation Method 4
an active noise measuring device capable of measuring an original noise signature of the noise emitting wind turbine component is used. Based on the measured noise signature, an inverted noise signature is created and an amplifier is used to amplify the inverted noise signature for emitting it using at least one speaker
Data Source
Figure 1~2
Figure 3~4
AI summary
Noise reduction means for a wind turbine blade, wind turbine blade, wind turbine, and method for noise reduction for a wind turbine blade Noise reduction means for a wind turbine blade (2) comprising an active noise reduction device (8) and a passive noise reduction device (7), wherein the passive noise reduction device (7) comprises at least one serrated edge profile (9) adapted for fixation to a trailing edge (4) of the wind turbine blade (2), wherein the active noise reduction device (8) comprises at least one unsteady pressure sensor (10) adapted to produce an output signal corresponding to a turbulent flow condition during operation of the wind turbine blade (2), at least one actuator (11) and a control unit (12), wherein the sensor (10) is arranged adjacent to a serrated edge (14) of the serrated edge profile (9) and the control unit (12) is adapted to control the actuator (11) in dependence of the output signal of the sensor (10) to emit an anti-noise signal at least partly reducing the noise generated by the wind turbine blade (2).