【摘要】 针对弯掠轴流风机气动噪声问题,采用大涡模拟(LES)和基于Lighthill声类比的FW-H模型相结合的方法进行非定常计算,通过快速Fourier转换(FFT),得到风机远场气动噪声声压级分布。对比研究了三种转速下旋转区内声压级分布规律、时域及频域特性,结果表明:旋转区域内声压级随转速增加而增大,前缘分离涡在某一转速时影响区域和强度最大;在一个旋转周期内,声压脉动呈现出6个波峰与波谷,验证了叶片转动频率是风机内部气动噪声的主要激励频率.更多还原

【Abstract】 Aiming at the aero-acoustics problem of swept axial fan,taken the large eddy simulation(LES) and the FW-H method based on the Lighthill sound analogy to simulate the unsteady flow of the fan.Through the fast Fourier transform(FFT) process,the far field pneumatic noise pressure level distribution of the fan was acquired.Compared and researched pneumatic noise pressure level distribution pattern and properties of time-domain and frequency-domain in the rotate domain with three different rotate speed.The results show that the noise pressure level in the rotate domain increases with the increasing of rotate speed.The separate vortex of affect region and intensity in the leading edge were in peak at a rotate speed.In a spin cycle,pressure pulsation present six peaks and troughs value,which verified that the blade rotation frequency was the main driving frequency of aerodynamic noise in the fan.更多还原