仿鱼体柔性变形运动流噪声特性研究

发布时间：2018-07-24 17:28

【摘要】：鱼类游动具有低噪声、高效率等特点,鱼体摆动可抽象并表征为壁面的柔性变形运动。柔性变形将诱导产生复杂的涡系流场结构,其流噪声的形成机理及特性在很大程度上有别于常规问题。以美国国家航空咨询委员会开发的NACA0012翼型为研究对象,考虑流噪声计算的需求,建立可模拟柔性变形的数值模型。基于声类比理论获得其流噪声特性,揭示柔性变形对流噪声的影响机制,获得流噪声辐射场指向性。结果表明:柔性变形运动诱发的复杂涡系流场演变是流噪声的主要来源;不同方位下流噪声总声压级随距离的增加均呈衰减趋势;在柔性变形壁面正上方和正下方,辐射噪声达到极值,噪声指向与偶极子声源的辐射场特性最为相似。
[Abstract]:Fish swimming is characterized by low noise and high efficiency. The swinging of fish body can be abstracted and characterized as a flexible deformation motion on the wall. Flexible deformation will induce complex vortex flow field structure, and the formation mechanism and characteristics of flow noise are different from conventional problems to a great extent. Taking the NACA0012 airfoil developed by the National Aviation Advisory Commission of the United States as the research object, a numerical model for simulating flexible deformation is established considering the demand of flow noise calculation. Based on the theory of acoustic analogy, the characteristics of the flow noise are obtained, the influence mechanism of the flexible deformation convection noise is revealed, and the directivity of the flow noise radiation field is obtained. The results show that the flow field evolution of complex vortex system induced by flexible deformation motion is the main source of flow noise, and the total sound pressure level of flow noise decreases with the increase of distance under different azimuths. The radiation noise reaches the maximum value and the noise direction is the most similar to the radiation field of the dipole sound source.
【作者单位】：北京机电工程研究所;
【分类号】：TB53

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