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本文设计了一种尾缘(TE)上游多孔渗透结构,通过在全消声低速射流风洞,利用远场麦克风测量研究了不同工况和材料物性下尾缘辐射噪声的影响。结果表明:所设计的多孔渗透结构产生了额外的方腔噪声特征,相对密度4.7%的泡沫金属所产生的附加噪声最小,颗粒状多孔材料比泡沫金属产生的附加噪声小。对称流动条件下多孔平板尾缘噪声中出现的方腔单音噪声特征,在人工非对称流动条件干涉下消失,表明压差推动渗流穿过表面是这种设计的关键。缩小人工非对称流动与非对称曲面翼型产生的压力条件之间的差异以及避免过大面积多孔设计是改进的方向。
In this paper, we design a porous structure of porous structure upstream of the trailing edge (TE). By using the far-field microphone measurements, we study the influence of radiation noise on the tail edge under different conditions and material properties by using a full anechoic low-velocity jet wind tunnel. The results show that the designed porous structure produces extra square cavity noise, and the foam metal with the relative density of 4.7% has the least additional noise. The granular porous material has less additional noise than the foam metal. The noise characteristic of the square tone appearing in the trailing edge noise of porous plate under symmetrical flow disappears under the interference of artificial asymmetric flow conditions, which shows that the pressure difference is the key to promote seepage through the surface. Narrowing the difference between the pressure conditions created by asymmetrical artificial airfoils and asymmetric curved airfoils, and avoiding oversized porous designs is an improvement direction.