Noise Radiation from a Continuous Mold-Line Link Flap Configuration
Noise Radiation from a Continuous Mold-Line Link Flap Configuration
复制标题
连续模线连接翼板配置的噪声辐射
DOI：
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发表时间：
2008
期刊：
影响因子：
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通讯作者：
W. Humphreys
中科院分区：
文献类型：
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作者：
F. Hutcheson;T. Brooks;W. Humphreys
本文给出了连续型线连接（CML）襟翼噪声的实验研究结果。在NASA兰利静流实验室中，对带有半翼展CML襟翼的主翼段进行了声学和非定常表面压力测量。声学数据采集与麦克风的中孔径定向阵列（MADA）。应用用于声源映射的反卷积方法（DAMAS）方法来确定测试模型表面上的噪声源的空间分布和强度。一个相干输出功率（COP）的方法，它涉及从非定常表面压力传感器的输出的MADA的输出也被用来获得更详细的特性的噪声源分布在CML的后缘区域。这些结果进行了比较，获得了一个钝皮瓣，以量化的噪音效益的水平，实现与CML皮瓣。结果表明，襟翼CML区的噪声比钝头襟翼侧缘区的噪声低5 ~ 17 dB（取决于襟翼偏转和马赫数）。在所有频率下都能获得较低的噪声水平。从CML和钝襟翼模型的凹区域的噪声的频谱分析也揭示了在高频范围内的频谱峰值，其与主要元件的后缘处的噪声散射有关。CML和钝瓣凹噪声谱中的峰值在水平上接近并且经常超过钝侧边缘噪声。在CML襟翼模型主翼型的后缘上应用一条锯齿形胶带，降低了峰值，但在某种程度上增加了其它噪声。方向性测量表明，CML皮瓣可以比钝皮瓣更定向。
The results of an experimental study of the noise from a Continuous Mold-Line Link (CML) flap are presented. Acoustic and unsteady surface pressure measurements were performed on a main element wing section with a half-span CML flap in NASA Langley's Quiet Flow Facility. The acoustic data were acquired with a medium aperture directional array (MADA) of microphones. The Deconvolution Approach for the Mapping of Acoustic Sources (DAMAS) method is applied to determine the spatial distribution and strength of the noise sources over the surface of the test model. A Coherent Output Power (COP) method which relates the output from unsteady surface pressure sensors to the output of the MADA is also used to obtain more detailed characteristics of the noise source distribution in the trailing edge region of the CML. These results are compared to those obtained for a blunt flap to quantify the level of noise benefit that is achieved with the CML flap. The results indicate that the noise from the CML region of the flap is 5 to 17 dB lower (depending on flap deflection and Mach number) than the noise from the side edge region of the blunt flap. Lower noise levels are obtained for all frequencies. Spectral analysis of the noise from the cove region of the CML and blunt flap models also reveal a spectral peak in the high frequency range that is related to noise scattering at the trailing edge of the main element. The peaks in the CML and blunt flap cove noise spectra are close in level and often exceed blunt side edge noise. Applying a strip of serrated tape to the trailing edge of the CML flap model main airfoil reduced the peak but increased other noise somewhat. Directivity measurements show that the CML flap can be more directional than the blunt flap.