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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。通过数值模拟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 effects of porous materials on turbulence interference noise at the leading edge of airfoils and reveal the noise reduction mechanism, 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 numerical setup was validated via experimental data comparison and grid sensitivity analysis. This study compared the flow field and sound field characteristics of a solid leading edge and porous leading edges with porosities of 40%, 50%, and 60%, respectively. The results showed that porous leading edges could effectively attenuate low- and mid-frequency single-tone noise, and the noise reduction performance improved as porosity increased. A maximum noise reduction of up to 11.2 dB was achieved, yet the average drag also rose correspondingly. Analyses of pressure fluctuations, velocity distribution within the stagnation region, and turbulent coherence were also performed. The results indicated that the porous medium suppressed the vertical velocity component of the incoming flow as the flow impinged on the leading edge; consequently, the pressure fluctuations were also suppressed. Furthermore, the porous structure disrupted the spanwise coherence of turbulent structures and weakened acoustic radiation efficiency.

       

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