Numerical study on noise reduction of wind turbine blade vortex generator

Abstract At present, wind power is widely used, especially in near-residential areas, and blade noise has become an important factor affecting the installation and operation of the unit. Vortex Generator is a new technology that has been used by wind turbine blade manufacturers in recent years. At present, there are few studies on the changes of blade aerodynamic noise after the installation of vortex generators in China. In order to study the influence of vortex generators on aerodynamic noise, the flow field is simulated by numerical calculation method before and after the blade is installed with vortex generators. The visualization results are output and compared, and the parameters such as vorticity and pressure are analyzed. Secondly, based on the detailed parameters of the flow field, FW-H equation is used to calculate the sound source propagation, and the sound pressure level spectrum of the blade before and after the vortex generators added is obtained. The research shows that the vorticity increases in the vicinity of vortex generators and the downstream region, which promotes the mass and energy exchange between the upper fluid and fluid in the boundary layer, so the boundary layer separation is delayed, and the wake vortex subsides. The aerodynamic noise is low frequency noise, and the addition of vortex generators can significantly reduce the aerodynamic noise of the blade.