离心通风机气动声源识别方法研究与应用

为了满足离心通风机降噪的迫切需要,提出了一种以固体壁面静压变化率为识别参数的主要偶极子声源的简便识别方法。将静压变化率的时均值定义为偶极子声源强度,声源强度大的地方就是主要声源区。该方法只需对非定常流动进行数值模拟,从而省去了繁琐的声场计算,虽不能定量给出通风机气动噪声的大小或具体的降噪效果,但可以为通风机的降噪提供有用的指导。通过将该方法应用于指导T9-19No.4A离心通风机的降噪实践,证实了该方法在工程应用中的有效性。

Study on the Aerodynamic Noise Source Identification for Centrifugal Fan and Its Application

A simple and convenient method is presented for main dipole source identification in a centrifugal fan. By this method, the time derivation of the static pressure fluctuation on solid wall is treated as the identification parameter, and its root mean square value is defined as surface dipole strength. The main dipoles are located at the zones where the dipole strengths are much higher. Since this method is just on the basis of the three-dimensional numerical simulation of the completed unsteady flow field in the fan, the fussy numerical prediction of sound field is avoided. Although the method cannot provide a quantitative prediction on the noise or the noise reduction, the applications of this method could contribute significantly in revealing the sound generation mechanisms inside centrifugal fans and be valuable for noise reduction of centrifugal fans. By applying to guidance the noise reduction of the T9-19No.4A centrifugal fan, the dipole source identification method is verified to be feasible.