基于混合计算声学法的高速离心风机气动噪声特性研究

Research on Aerodynamic Noise Characteristics of High speed Centrifugal Fans Based on Hybrid Computational Acoustics Method

本文基于分离涡模拟和声学有限元相结合的混合方法对某船用高速离心风机进行气动噪声理论分析,同时结合试验测试研究,验证了理论分析的合理性。研究表明,叶轮旋转区域声源为气动噪声主要来源,叶频处的气动噪声指向性特征最明显,对离心风机气动噪声贡献量最大。叶轮旋转区域的面声源为离散单音噪声的主要来源,蜗壳和管道静止区域体声源主要贡献了低频段和宽频噪声。气动噪声数值模拟与试验值吻合较好,证明了理论方法的准确性。此项理论方法研究为高速离心风机空气动力学噪声预测提供了有效策略,可为离心风机结构低噪声优化设计提供依据。

This article is based on a hybrid method combining detached eddy simulation and acoustic finite element analysis to conduct theoretical analysis of aerodynamic noise of a certain type of high-speed centrifugal fan for ships application.The rationality of the theoretical analysis is verified experimental research.The research result has shown that the sound source in the rotating area of the impeller is the main source of aerodynamic noise,and the directional characteristics of aerodynamic noise at the blade frequency are the most obvious,contributing the most to the aerodynamic noise of centrifugal fans.The surface sound source in the rotating area of the impeller is the main source of discrete single tone noise,while the body sound source in the stationary area of the volute and pipeline mainly contributes the low-frequency and broadband noise.The numerical simulation of aerodynamic noise matches well with the experimental values,proving the accuracy of the theoretical method.This theoretical method provides an effective strategy for predicting aerodynamic noise of high-speed centrifugal fans,and can provide a basis for optimizing the low-noise design of centrifugal fan structures.