Noise Prediction Of Wind Turbines

For study the effects of Chinese wind turbine noise on the environment surrounded, noise of wind turbines of different types was measured. Based on the blade shape and the radiated noise frequency spectrum of wind turbines in China, the noise prediction model for wind turbines with blunt trailing edges was modified. Then, noise from wind turbines of five types was predicted and compared with the measured noise. The comparison results showed that the modified model could well reflect the noise attenuation of wind turbines. When the horizontal distance between wind turbine tower and receiver was greater than 2 times the rotor blade diameter, the difference between the measurement values and the predicted values of the modified model was general within±3 dB(A). Based on the modified model, noise prediction software for wind farm was developed using the MatLAB language.Fit the measured noise from wind turbines of different types and the distance between rotor center and receiver using model of point source. The results showed that, the noise attenuation agreed satisfactorily with directionally radiating point source in the half free field (R2≥0.95). According to this, the noise prediction model for wind turbines were simplified. Using the modified model, sound power level and directivity index of different kinds of wind turbines can be calculated. Substitute them into the point source model, the noise from wind turbine can be predicted more simplified when the distance between wind turbine tower and receiver was greater than 2 times the rotor blade diameter.