Aerodynamic Noise Distribution in Wind Turbines with Different Microporous Blade Tip Structures

Abstract

A linear microporous blade tip structure is designed in order to reduce the aerodynamic noise of a wind turbine during operations. Various structures of such a kind are considered and the related aerodynamic noise is determined in the framework of large vortex simulation and acoustic array test methods. The findings demonstrate that various blade tip designs can enhance the vortex trajectory in the tip region and lessen the pressure differential between the blade’s upper and lower surfaces. In particular, the wind turbine’s maximum linear velocity at the blade tip can be increased by 10%–23% while also effectively reducing the radial and axial aerodynamic noise during operation. A trailing edge microporous structure displays a better noise reduction effect than a leading edge microporous structure, and the maximum sound pressure level is reduced by an average of 1.92%–3.63%. The main factors influencing the wind turbine’s aerodynamic noise are its size and placement of microporous holes.