小尺寸切开式尾缘锯齿对翼型气动噪声的影响

Effect of Small Size Cut Trailing Edge Serration on Aerodynamic Noise of Airfoil

研究小尺寸切开式尾缘锯齿对翼型气动噪声的影响,并分析齿高与尾缘边界层厚度之间的关系对降噪效果的影响.以NACA0012翼型为研究对象,采用混合计算气动声学方法进行仿真.在20 m/s风速下对NACA0012翼型进行噪声实验,验证仿真方法的准确性.通过控制齿高和齿宽研究不同形状尾缘锯齿分别在0°和10°攻角下对翼型气动噪声的影响.研究结果表明,尾缘锯齿的降噪效果与齿高和齿宽均成正比.0°攻角下最大降噪量为3.3 dB,10°攻角下最大降噪量为2.6 dB.切开式尾缘锯齿结构会增加流向噪声的高频分量,尤其在0°攻角下显著.相比嵌入式尾缘锯齿,切开式尾缘锯齿具有更小的极限降噪齿高.

This paper aims to investigate the impact of small-sized cutting serrated trailing edges on airfoil aerodynamic noise and to analyze the influence of the relationship between height and trailing edge boundary layer thickness on noise reduction effectiveness.Taking the NACA0012 airfoil as the research object,a hybrid computational aeroacoustics method was employed for simulation.Noise experiments on the NACA0012 airfoil were conducted at a wind speed of 20 m/s to validate the accuracy of the simulation method.By controlling the height and width of the serrations,the effect of different serrated trailing edge shapes on airfoil aerodynamic noise at angles of attack of 0°and 10°was studied.The results indicate that the noise reduction effect of serrated trailing edges is proportional to both height and width.The maximum noise reduction at a 0°angle of attack is 3.3 dB,while at a 10°angle of attack,it is 2.6 dB.The cutting serrated trailing edge structure increases the high-frequency components of flow noise,especially at a 0°angle of attack.Compared to embedded serrated trailing edges,cutting serrated trailing edges has a smaller limit for maximum noise reduction height.