变工况下前弯离心风机宽带噪声的数值模拟及分析

Numerical Simulation and Analysis of Broadband Noise on a Forward Curved Centrifugal Fan in Variable Conditions

为了解前弯离心风机不同工况下宽带噪声的变化规律及特性,本文以一款前弯高压离心风机为研究对象,针对带宽频特征的涡流噪声,运用基于Lighthill理论的FW-H方程和Proudman方程对前弯离心风机近场、远场噪声进行积分计算,通过三维非定常与定常数值模拟研究了其在设计流量,大流量与小流量三个运行工况下的噪声频谱特性,以及风机叶轮、蜗壳的宽带噪声分布特性,并将模拟结果与试验进行了对比验证。结果表明,该风机噪声宽频特性随流量增大变得明显。叶轮处宽带噪声声功率最高出现在离蜗舌最近的两个叶片上,蜗壳处宽带噪声最大声功率级主要出现在蜗舌处。

To comprehend the variations and characteristics of the broadband noise on a forward centrifugal fan under different conditions,this paper takes a forward centrifugal fan for study.Aiming at the broadband noise problem of fan,the equations of FW-H and Proudman based on the theory of Lighthill were taken as tools to conduct three-dimensional numerical simulation of unsteady and steady on the fan.The simulation results had been conducted to study.The noise spectrum in three operation conditions of larger flow,small flow and design flow and the broadband noise on impeller and volute were study.And the results of simulation are verified by the experimental data.The results showed that the broadband noise characteristics become apparent with the increase of the flow rate.The highest broadband noise sound power of the impeller appeared on the two blades near the volute tongue,while to the volute,it appeared on the tongue.