Experiment on noise control of trailing edge brushes

Some experimental investigations are done on suppressing the airfoil noise by trailing edge brushes. All the experiments are carried out in the low-speed open jet wind tunnel which is in the anechoic chamber. The study is focused on the influence of the angle of attack of the airfoil on the far field noise and the airfoil surface pressure. In addition, the effect of the proposed method and that of the serrated trailing edge method on noise reduction are compared under different operating conditions. The result shows that the trailing edge brush is a feasible way to reduce the airfoil noise, especially for the low frequency component. It is revealed that the noise reduction is related to the length and interval of brush. And the trailing edge brushes are superior to a serrated trailing edge in noise reduction. Meanwhile, trailing edge brushes have little effect on the surface pressure of the airfoil.