中文摘要：

本文采用LES/FW-H的匹配方法,研究了开式轴流风扇内部旋涡流动特征及其与叶片表面干涉引起的气动噪声之间的联系,同时进行了远场噪声预测,探讨了叶轮不同表面辐射噪声时的频谱分布特征。研究结果表明,开式轴流风扇吸力面附近形成的叶尖涡和前缘分离涡在吸力面叶片表面相应位置形成大压力波动,形成主要噪声源;叶片吸力面的辐射噪声可以通过改善吸力面附近的旋涡流动来降低;低速轴流叶轮由叶轮壁面辐射的噪声以宽频成分为主。

英文摘要：

The vortices flow characters inside the open axial flow fan and the associated aerodynamic noise were studied using large-eddy simulation and the FW-H equations. The far field aerodynamic noise was predicted and the spectra of the noise radiated from various rotor surfaces were discussed. Calculation results indicate that both the tip vortex and the leading edge separation vortex formed near the suction surface induce large pressure fluctuation at the corresponding position on suction surface, which forms the main noise source. The noise level radiated from the suction surface can be reduced by weakening the vortices flow nearby. The dominant source for low-speed axial flow fan＇s noise is the broadband noise.