风机在不同流量下的气动噪声测试及分析

Aerodynamic Noise Testing and Analysis of Fans at Different Flow Rates

摘要: 本研究针对轨道交通牵引风机在动态流量工况下的气动噪声特性展开实验研究，基于GB/T 1236-2017与GB/T 2888-2008标准搭建半消声实验室测试平台，系统分析了离心风机在五种流量工况(0.938~1.875 m³/s)下的进出口声压级、频谱分布及1/3倍频带特性。实验结果表明：进口噪声在额定流量(1.25 m³/s)下达到最低值92.3 dB(A)，偏离额定工况时噪声显著升高，其中小流量(0.938 m³/s)进口噪声较出口高4.9 dB(A)，而大流量(1.875 m³/s)下进出口噪声差值趋近于零。频谱分析揭示了第一、二阶旋转频率(785 Hz、1570 Hz)对主频带的主导作用，非额定工况下低频宽频噪声与高频能量扩散特征显著。研究结果为牵引风机的低噪声设计与运行优化提供了数据支撑。

Abstract: This study conducts experimental research on the aerodynamic noise characteristics of rail transit traction fans under dynamic flow conditions, and builds a semi-anechoic laboratory test platform based on the standards of GB/T 1236-2017 and GB/T 2888-2008. The inlet and outlet sound pressure levels, spectral distribution and 1/3 octave band characteristics of the centrifugal fan under five flow conditions (0.938~1.875 m³/s) were systematically analyzed. The experimental results show that: The inlet noise reaches the minimum value of 92.3 dB(A) at the rated flow rate (1.25 m³/s). When deviating from the rated working condition, the noise increases significantly. Among them, the inlet noise at A small flow rate (0.938 m³/s) is 4.9 dB(A) higher than the outlet noise, while at a large flow rate (1.875 m³/s), the noise difference between the inlet and outlet approaches zero. Spectral analysis reveals the dominant role of the first and second rotational frequencies (785 Hz, 1570 Hz) on the main frequency band. Under non-rated conditions, the characteristics of low-frequency wideband noise and high-frequency energy diffusion are significant. The research results provide data support for the low-noise design and operation optimization of the traction fan.