Boundary layer characterization and acoustic measurements of flow-aligned trailing edge serrations
Boundary layer characterization and acoustic measurements of flow-aligned trailing edge serrations
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DOI：
10.1007/s00348-016-2272-z
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发表时间：
2016-11
影响因子：
2.4
通讯作者：
C. Arce León;R. Merino-Martínez;D. Ragni;F. Avallone;M. Snellen
中科院分区：
文献类型：
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作者：
C. Arce León;R. Merino-Martínez;D. Ragni;F. Avallone;M. Snellen
尾缘锯齿设计，以减少翼型自噪声改装的NACA 0018翼型。利用时间分辨立体PIV对边界层流动统计特性进行了研究。对锯齿边缘的三个流向位置进行了比较。对结果的分析表明，虽然没有上游效应，但当气流在锯齿上向边缘对流时发生了显著的变化。其中最重要的是，剪切应力的降低和湍流谱的改变表明非定常表面压力的有益变化将导致尾缘噪声的降低。麦克风阵列测量另外进行，以确认降噪确实观察到的应用所选择的锯齿形设计在未修改的翼型。
Trailing edge serrations designed to reduce airfoil self-noise are retrofitted on a NACA 0018 airfoil. An investigation of the boundary layer flow statistical properties is performed using time-resolved stereoscopic PIV. Three streamwise locations over the edge of the serrations are compared. An analysis of the results indicates that, while there is no upstream effect, the flow experiences significant changes as it convects over the serrations and toward its edges. Among the most important, a reduced shear stress and modifications of the turbulence spectra suggest beneficial changes in the unsteady surface pressure that would result in a reduction of trailing edge noise. Microphone array measurements are additionally performed to confirm that noise reduction is indeed observed by the application of the chosen serration design over the unmodified airfoil.