冷却用弯掠轴流风机气动噪声预测与试验分析

Aero-Acoustic Prediction and Experiment Analysis of Swept Axial Flow Fan Used for Cooling

采用Navier-Stokes方程和标准k-ε湍流模型,对五种不同结构的弯掠轴流风机A/B/C/D/E进行稳态数值模拟,结合给定的性能要求筛选出B/E风机。以稳态流场为基础,采用大涡模拟(LES)与基于Lighthill声类比的FW-H模型相结合的方法对B/E风机进行非定常计算和气动噪声预测,并将预测结果与试验数据进行了对比验证。分析了以叶轮表面作为噪声源时B/E风机的涡流噪声频谱特性,研究了风机三维非定常内部流场中旋涡分布特性,并探讨了风机旋转区域内部声压级的分布规律。

This paper conducted numerical simulations to five different structures A/B/C/D/E of a swept axial fan by solving three-dimensional Reynolds-averaged Navier-Stokes equations with the standardκ-εturbulent model and selected B/E schemes according to the given performance requirements.Taken the steady flow field as a basis,the large eddy simulation（LES） and the FW-H method based on the Lighthill sound analogy were adopted to simulate the unsteady flow and predict aerodynamic noise of the B/E fans and the numerical results were compared with the experimental data.This paper also analyzed the spectrum distribution characteristics of the eddynoise from the B/E fans when the impeller surface was regarded as the noise source,researched the vortex distribution characteristics in the fans＇ internal three-dimensional unsteady flow field, and discussed the distribution mechanism of the sound pressure level in the impeller＇s rotational region.