离心风机蜗壳振动声辐射的定量预测  

Quantitative Prediction of Sound Radiation by Casing Vibration of Centrifugal Fan

作　　者：蔡建程[1] 祁大同[1] 唐囡[1] 

机构地区：[1]西安交通大学能源与动力工程学院,西安710049

出　　处：《西安交通大学学报》2009年第9期71-74,共4页Journal of Xi'an Jiaotong University

摘　　要：针对离心风机蜗壳振动产生的声辐射,提出了一种基于边界元分析的声辐射定量预测方法:根据蜗壳声辐射的边界元模型布置振动测点,测量其法向振动的加速度谱;提取加速度谱中峰值较高的基频和旋转频率分量,并将其转换成速度谱后加载于数值模型的对应节点上,作为声辐射问题的速度边界条件;利用边界元法计算声场及声功率,预测蜗壳振动产生的噪声.结果表明:结构振动声比气动声小很多,相对于风机进出口的气动噪声而言,蜗壳因振动辐射的噪声可以忽略不计;当风机进出口安装消声器后,蜗壳振动的辐射噪声可能成为主要噪声源.基于边界元分析的蜗壳振动辐射噪声定量预测方法也可以应用到其他壳体振动辐射噪声的预测中.A method was presented to predict the sound radiation caused by the casing vibration of a centrifugal fan on the basis of the boundary element analysis （BEA）. Measuring points were laid according to the casing BEA acoustic model, and the measurement of the casing normal vibration was conducted. Then the noticeable blade-passing and rotary frequency components in the acceleration spectra were extracted and converted into velocity spectra to serve as the velocity boundary conditions of the sound radiation computation. The sound field and sound power were analyzed using the boundary element method to predict the noise generated by casing vibration. The results show that sound pressure caused by the casing vibration is much smaller than its aeroacoustic counterpart. The fan casing noise radiation may be the major noise contributor near the fan if mufflers are mounted on both the inlet and outlet of the fan. It appears that the present method may be used to predict noise radiation of other kinds of casings.

关 键 词：离心风机 蜗壳 振动 噪声 边界元法 

分 类 号：TH43[机械工程—机械制造及自动化]