Zajamsek Branko, Doolan Con J, Moreau Danielle J, Fischer Jeoffrey, Prime Zebb
School of Computer Science, Engineering & Mathematics, Flinders University, Adelaide 5042, Australia.
School of Mechanical and Manufacturing Engineering, University of New South Wales, Sydney 2052, Australia.
J Acoust Soc Am. 2017 May;141(5):3291. doi: 10.1121/1.4983295.
Trailing edge noise from stationary and rotating NACA 0012 airfoils is characterised and compared with a noise prediction based on the semi-empirical Brooks, Pope, and Marcolini (BPM) model. The NACA 0012 is symmetrical airfoil with no camber and 12% thickness to chord length ratio. Acoustic measurements were conducted in an anechoic wind tunnel using a stationary NACA 0012 airfoil at 0° pitch angle. Airfoil self-noise emissions from rotating NACA 0012 airfoils mounted at 0° and 10° pitch angles on a rotor-rig are studied in an anechoic room. The measurements were carried out using microphone arrays for noise localisation and magnitude estimation using beamforming post-processing. Results show good agreement between peak radiating trailing edge noise emissions of stationary and rotating NACA 0012 airfoils in terms of the Strouhal number. Furthermore, it is shown that noise predictions based on the BPM model considering only two dimensional flow effects, are in good agreement with measurements for rotating airfoils, at these particular conditions.
对静止和旋转的NACA 0012翼型的后缘噪声进行了表征，并与基于半经验的布鲁克斯、波普和马尔科利尼（BPM）模型的噪声预测进行了比较。NACA 0012是一种对称翼型，无弯度，厚度与弦长之比为12%。在消声风洞中，使用 pitch 角为0°的静止NACA 0012翼型进行了声学测量。在消声室内，研究了安装在转子试验台上、pitch角为0°和10°的旋转NACA 0012翼型的翼型自噪声发射。测量使用麦克风阵列进行噪声定位，并使用波束形成后处理进行幅度估计。结果表明，在斯特劳哈尔数方面，静止和旋转的NACA 0012翼型的峰值辐射后缘噪声发射之间具有良好的一致性。此外，结果表明，在这些特定条件下，仅考虑二维流动效应的基于BPM模型的噪声预测与旋转翼型的测量结果具有良好的一致性。
