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    基于圆柱-翼型模型的多孔前缘气动特性与干涉噪声

    Study of the Aerodynamic Characteristics and Interaction Noise of Airfoil with Porous Leading Edges Based on the Rod-Airfoil Model

    • 摘要: 为探究多孔材料对翼型前缘湍流干涉噪声的抑制效果,并揭示其降噪的物理机制,采用大涡模拟(LES)结合FW-H声类比方法,对经典的圆柱-翼型(NACA0012)干涉噪声模型进行数值模拟。结合实验数据对比及网格敏感性分析确保结果的可靠性,比较实体前缘与孔隙率分别为40%、50%和60%的多孔前缘的流场与声场特性。研究表明,多孔前缘能有效降低中低频单音噪声,降噪效果随孔隙率增大而增强,降噪量最大可达11.2 dB,但其平均阻力有所增加。对压力脉动、滞止区速度分布和湍流相干性的分析表明,多孔介质抑制了来流垂直速度分量 \nu ' 在撞击前缘时的剧烈放大,从源头上削弱了压力脉动。同时多孔结构也破坏了湍流结构的展向相干性,降低了声辐射效率。

       

      Abstract: To investigate the suppression effect of porous materials on turbulence interference noise at the leading edge of airfoils and reveal the mechanism of noise reduction, numerical simulations of the classic rod-airfoil (NACA0012) interaction noise model were conducted using Large Eddy Simulation (LES) combined with the FW-H acoustic analogy method. The calculation was validated by comparison with experimental data and grid sensitivity analysis. The study compared the flow field and sound field characteristics of a solid leading edge with porous leading edges with porosities of 40%, 50%, and 60%, respectively. The results showed that porous leading edges can effectively reduce the single-tone noise of the low- and mid-frequencies. The noise reduction effects increase with the porosity. A maximum noise reduction up to 11.2 dB was obtained, but the averaged drag also increases accordingly. Analyses of the pressure fluctuations, velocity distribution in the stagnation region, and turbulence coherence were also carried out. The results showed that the porous medium suppressed the vertical velocity component \nu ' of the incoming flow when it impinges on the leading edge, so the pressure fluctuations p' is suppressed meanwhile. Secondly, the porous structure disrupted the spanwise coherence of the turbulence structure, reducing the efficiency of sound radiation.

       

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