锯齿型翼型尾缘噪声控制实验研究

翼型湍流边界层与尾缘相互作用产生的尾缘噪声是翼型自噪声的最主要分量,多年来研究者们已经在理论、数值和实验方面开展了多方面研究,但有关翼型尾缘噪声的产生机理和抑制方法仍有待深化与发展.本文利用具有全消声环境的低速开口风洞研究了采用锯齿型翼型尾缘来控制翼型噪声的方法,重点研究了不同攻角情况下不同锯齿形对翼型远声场气动噪声的影响以及翼型表面压力的影响.实验结果表明,翼型尾缘附加锯齿是一种可行的降噪方案,尤其对中低频段的远场气动噪声有比较明显的降低效果；而且,降噪效果与锯齿的齿数和齿间倒角有关.附加锯齿对翼型壁面动态载荷的影响较小,基本不影响翼型的气动性能.

An experiment study of the serrated trailing edge noise

Trailing edge noise,which is generated by the interaction of turbulence boundary layer and trailing edge,is the dominant component of airfoil self-noise.In last decade,many contributions have been made to the development of the theory,numerical simulation and experiment of the trailing edge noise.However,much effort is still required to advance understanding of the noise generation mechanism and for the suppression strategies.In this paper,some experimental research has been done on suppressing the airfoil noise by serrated trailing edge.The experiments are all 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.The far-field measurement shows that the serrated trailing edge is an alternative way to reduce the airfoil noise,especially for the low frequency component.Moreover,it is revealed that the noise reduction is related to the number and the shape of sawtooth.Meanwhile,the surface measurement shows a little change of the surface pressure in the cases with the different serrated trailing edge in present.