风扇三维设计阶段宽频噪声快速评估方法及运用

Broadband noise fast evaluation method and its application in three dimensional design stage of fan

针对风扇三维设计阶段,本文开发了一种快速宽频噪声预测方法,用于预测风扇的转/静干涉宽频噪声水平。该方法目的在于可以在风扇三维设计阶段中,对风扇的气动性能进行计算后,快速地得到风扇的宽频噪声频谱与特性。本文的风扇三维阶段宽频噪声模型是基于定常雷诺平均方程(RANS)的半解析模型,该模型通过定常计算流体力学(CFD)方法提取声源上游叶片尾迹湍流信息,进而与解析模型耦合,从而实现快速预测出风扇宽频噪声水平。首先,对文中的快速宽频噪声预测模型进行了介绍;然后,通过1台环形叶栅声学试验平台的试验数据对该模型的解析部分进行了考核;最后,利用快速宽频噪声预测模型分别对1台单级轴流风扇和1台双级轴流风扇开展了气动性能与声学性能的预测评估工作。结果显示,声源来流的湍流分布形式与上游叶片二次流有直接关系。另外,当风扇的实际工作状态点远离设计点时,宽频噪声水平会明显增加。

In this study,a fast broadband noise prediction method was developed for the three-dimensional design stage of fans to predict the fan rotor-stator interaction broadband noise.The main purpose is to quickly obtain the broadband noise spectrum and characteristics after obtaining the aerodynamic characteristics in the fan threedimensional design stage.The three-dimensional stage broadband noise model of the fan in this paper is a semianalytical model based on the steady Reynolds Average Navier-Stokes equation(RANS),which extracts the up⁃stream blade wake turbulence information of the sound source through the steady Computational Fluid Dynamics(CFD)calculation results,and then couples the turbulence information with the analytical model to quickly predict the fan broadband noise level.In this paper,the established fast broadband noise prediction model is firstly introduced,followed by verification of the analytical method part of the broadband noise model by the experimental data of an an⁃nular cascade acoustic experimental platform,and finally,the prediction and evaluation of aerodynamic performance and acoustic performance of a single-stage axial fan and a two-stage axial fan are conducted using the established fast broadband noise prediction model.The results show that the distribution of upstream turbulence of the sound source is directly related to the secondary flow of the upstream blades.In addition,the level of broadband noise increases sig⁃nificantly when the actual operating state of the fan deviates from the design operating state.