A novel serration with sloping root was designed based on the traditional serrated trailing edge with blunt root on NACA0018 airfoil. The influence of sloping angle on trailing edge noise was studied by an experiment. It was found that the novel serrations can reduce the noise by 3.2-17.1dB at high angle of attack (12°-18°)

and had a certain inhibitory effect on the hump shaped noise peak which appeared in the middle sound pressure spectrum at low angle of attack. When the sloping angle was 30°

the hump shaped noise peak was eliminated and the overall sound pressure level had a reduction of 0.2-1.5dB.