Effect of dual vortex shedding on airfoil tonal noise generation
Effect of dual vortex shedding on airfoil tonal noise generation
复制标题
双涡脱落对翼型音调噪声产生的影响
DOI：
10.1063/5.0050002
复制
发表时间：
2021-07
影响因子：
4.6
通讯作者：
Li Ye
中科院分区：
文献类型：
--
作者：
Yang Yannian;Probsting Stafan;Liu Yu;Zhang Haoyu;Li Chenzhao;Li Ye
为了加深对后缘双涡脱落对翼型音调噪声产生的影响的理解，对NACA（National Advisory Committee for Aeronautics）0012翼型在攻角接近零和雷诺数为220 000时进行了同步速度和噪声测量。粒子图像测速仪获得的瞬时流场显示了分离剪切层的发展，涡卷起，涡破裂翼型后缘附近。时均流场两侧出现分离泡，流向速度脉动均方根值呈三峰结构。速度谱与噪声谱在宽带峰和离散音调方面吻合得很好。通过本征正交分解（POD）分析，识别出最具能量的模态，这些模态代表了流场的全局结构。后缘噪声是后缘附近速度脉动的综合效应，POD分析为理解噪声产生机理提供了一种新的视角。第一和第二模态主要由沿翼型表面沿着和近尾流中的异相涡脱落所支配，该异相涡脱落主导高振幅噪声发射过程。第三和第四模式代表同相旋涡脱落，其主导低振幅噪声发射过程。噪声源区域由速度和声压之间的相关性确定，其显示与第一和第二POD模式近似相同的周期图案。
To improve understanding of dual vortex shedding over a trailing edge with regard to airfoil tonal noise generation, synchronized velocity and noise measurements are conducted on a NACA (National Advisory Committee for Aeronautics) 0012 airfoil at angle of attack near zero and a Reynolds number of 220 000. Instantaneous flow fields obtained by particle image velocimetry show the development of separated shear layer, vortex roll-up, and vortex breakup near the airfoil trailing edge. The time-averaged flow fields feature separation bubbles on both sides, and the root mean square values of streamwise velocity fluctuations show triple peak structures. The velocity spectra agree well with the noise spectra in terms of broadband humps and discrete tones. Through proper orthogonal decomposition (POD) analysis, the most energetic modes are identified, which represent global structures in the flow field. The trailing edge noise being an integral effect of the velocity fluctuation near the trailing edge, the POD analysis provides an alternative view for understanding the noise generation mechanism. The first and second modes are dominated by out-of-phase vortex shedding along the airfoil surface and in the near wake, which dominates the high amplitude noise emission process. The third and fourth modes represent in-phase vortex shedding, which dominates the low amplitude noise emission process. The noise source region is determined by the correlation between the velocity and sound pressure, which shows approximately the same periodic pattern as the first and second POD modes.
登录
查看更多内容
影响因子：
2.4
作者：
A. Henning;Kristian Kaepernick;K. Ehrenfried;L. Koop;A. Dillmann
通讯作者：
A. Henning;Kristian Kaepernick;K. Ehrenfried;L. Koop;A. Dillmann
影响因子：
2.4
作者：
Schrijer, F. F. J.;Scarano, F.
通讯作者：
Scarano, F.
影响因子：
2.4
作者：
C. Tam
通讯作者：
C. Tam
影响因子：
0.8
作者：
SIROVICH, L
通讯作者：
SIROVICH, L
影响因子：
5.6
作者：
Yannian Yang;T. Zhou;A. Sciacchitano;L. Veldhuis;G. Eitelberg
通讯作者：
Yannian Yang;T. Zhou;A. Sciacchitano;L. Veldhuis;G. Eitelberg