Wind turbine blade damage detection using aerodynamic noise

Wind energy is one of the most important renewable energy sources, effectively addressing climate change issues and promoting sustainable development on a global scale. Blade failures may cause long shut-down times and may present a safety hazard. Continuous and real-time monitoring of the blade conditions is helpful for finding blade damage at an early stage and for predicting its development. Non-contact damage detection methods have the advantage of easy and flexible installation and deployment, especially for current in-service wind turbines. This thesis aims to investigate and develop a new non-contact method for wind turbine blade damage detection based on measurements of aerodynamic noise. The principle of the proposed method relies on the fact that damage to the blade may modify the boundary layer over the blade surface and the flow field around the blade, and, as a consequence, alter the noise generated aerodynamically. This noise propagates to the far-field and be measured by microphones, which could provide a remote way to detect blade damage. In this thesis, the detection of two types of damage, trailing edge crack and leading edge erosion, is experimentally investigated in the wind tunnel. The results show that the proposed aeroacoustics-based approach can effectively detect the damage mentioned above under some circumstances, which might be a promising solution complementing traditional damage detection methods in wind farms in the future.