离心风机蜗壳振动辐射噪声的数值预测

Prediction of Noise Radiated by the Vibrating Volute Structure of Centrifugal Fan

数值模拟了T9-19No.4A离心风机蜗壳在非定常气动力作用下的蜗壳响应振动及其噪声。首先给出该风机运行时振动及噪声的测量结果,得出基频噪声是主要噪声类型。然后使用CFD软件ANSYS CFX对风机内部流场做了整场瞬态数值模拟。流体压力脉动作用于蜗壳产生一个随时间变化的力,激励其振动,实现流体到结构的单向耦合。接着运用ANSYS multiphysics模块对风机蜗壳进行了谐响应分析,最后应用LMS SYSNOISE模拟了蜗壳振动向外辐射的噪声。

Dynamic response and sound radiation of T9-19No.4A centrifugal fan volute structure,due to the exerting fluctuating aerodynamic force,are calculated at the blade passing frequency(BPF)and the second harmonic frequency.The experiment results about vibration and noise reveal that the BPF noise is predominant over other frequencies,then a transient flow simulation is carried out with commercial CFD code ANSYS CFX.The real and imaginary parts of sinusoidal loads at blade passing and second harmonic frequencies are simulated,the harmonic response analysis is performed for the volute structure with ANSYS.