当前位置: X-MOL 学术J. Sound Vib. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Experimental investigation of the impact of porous parameters on trailing-edge noise
Journal of Sound and Vibration ( IF 4.7 ) Pub Date : 2020-12-01 , DOI: 10.1016/j.jsv.2020.115694
Minghui Zhang , Tze Pei Chong

Abstract This paper presents a sensitivity and parametric study of the sound generation at the non-tortuous and wall-normal permeable trailing edge of an aerofoil. Design parameters for the porous properties include the porosity, pore-size and porous-coverage. For a combination of large pore-size, small porosity and large porous-coverage, wake vortex shedding is likely to be triggered, and either sharp tone or broadened tone will dominate the radiated field. Using the appropriate hydrodynamic and geometrical length scales, the radiated spectra for the tones are found to follow the Strouhal number relationship, thus allow a reasonably accurate prediction of the primary tone frequency. These extraneous tones can potentially undermine the current porous trailing edge concept. Still, they can also be avoided if the porous parameters are mostly of small pore-size (sub-millimetre), medium to large porosity or small porous-coverage. Under these porous settings, better spatially distributed permeable air will seep through the surface and disrupt the generation mechanism of the turbulent boundary layer, which then translate into a lower level of turbulent broadband noise radiation. The most optimised non-tortuous, wall-normal permeable trailing edge tested in the current study can achieve a maximum of 7 dB reduction for the turbulent broadband noise. Considering that the primary trailing edge noise source is situated very near to the edge, a targeted approach (i.e. small porous-coverage) is already sufficient to achieve significant trailing edge broadband noise reduction.

中文翻译:

多孔参数对后缘噪声影响的实验研究

摘要 本文介绍了翼型非曲折和壁面法向可渗透后缘发声的灵敏度和参数研究。多孔特性的设计参数包括孔隙率、孔径和多孔覆盖率。对于大孔径、小孔隙率和大孔隙覆盖率的组合,可能会触发尾涡脱落,并且尖锐的音调或加宽的音调将主导辐射场。使用适当的流体动力学和几何长度尺度,发现音调的辐射光谱遵循 Strouhal 数关系,因此可以合理准确地预测主音调频率。这些无关的音调可能会破坏当前的多孔后缘概念。仍然,如果多孔参数主要是小孔径(亚毫米)、中到大的孔隙率或小的多孔覆盖率,也可以避免它们。在这些多孔设置下,更好的空间分布的可渗透空气将渗透到表面并破坏湍流边界层的产生机制,然后转化为较低水平的湍流宽带噪声辐射。当前研究中测试的最优化的非曲折壁面法向可渗透后缘最多可将湍流宽带噪声降低 7 dB。考虑到主要后缘噪声源非常靠近边缘,有针对性的方法(即小孔覆盖)已经足以实现显着的后缘宽带降噪。中到大的孔隙率或小的孔隙覆盖率。在这些多孔设置下,更好的空间分布的可渗透空气将渗透到表面并破坏湍流边界层的产生机制,然后转化为较低水平的湍流宽带噪声辐射。当前研究中测试的最优化的非曲折壁面法向可渗透后缘最多可将湍流宽带噪声降低 7 dB。考虑到主要后缘噪声源非常靠近边缘,有针对性的方法(即小孔覆盖)已经足以实现显着的后缘宽带降噪。中到大的孔隙率或小的孔隙覆盖率。在这些多孔设置下,更好的空间分布的可渗透空气将渗透到表面并破坏湍流边界层的产生机制,然后转化为较低水平的湍流宽带噪声辐射。当前研究中测试的最优化的非曲折壁面法向可渗透后缘最多可将湍流宽带噪声降低 7 dB。考虑到主要后缘噪声源非常靠近边缘,有针对性的方法(即小孔覆盖)已经足以实现显着的后缘宽带降噪。更好的空间分布的可渗透空气将渗透到地表并破坏湍流边界层的产生机制,然后转化为较低水平的湍流宽带噪声辐射。当前研究中测试的最优化的非曲折壁面法向可渗透后缘最多可将湍流宽带噪声降低 7 dB。考虑到主要后缘噪声源非常靠近边缘,有针对性的方法(即小孔覆盖)已经足以实现显着的后缘宽带降噪。更好的空间分布的可渗透空气将渗透到地表并破坏湍流边界层的产生机制,然后转化为较低水平的湍流宽带噪声辐射。当前研究中测试的最优化的非曲折壁面法向可渗透后缘最多可将湍流宽带噪声降低 7 dB。考虑到主要后缘噪声源非常靠近边缘,有针对性的方法(即小孔覆盖)已经足以实现显着的后缘宽带降噪。当前研究中测试的壁面法向可渗透后缘最多可将湍流宽带噪声降低 7 dB。考虑到主要后缘噪声源非常靠近边缘,有针对性的方法(即小孔覆盖)已经足以实现显着的后缘宽带降噪。当前研究中测试的壁面法向可渗透后缘最多可将湍流宽带噪声降低 7 dB。考虑到主要后缘噪声源非常靠近边缘,有针对性的方法(即小孔覆盖)已经足以实现显着的后缘宽带降噪。
更新日期:2020-12-01
down
wechat
bug