结构与空气噪声辐射的等效面声源预测

An equivalent surface acoustic source prediction method for structural and air noise

将振动或气动发声系统作为一个整体,建立近场虚拟包络面并划分区域,将实验测试获得的各区域中心近场声压信息作为相应区域的声源,形成整个振动或气动发声系统的等效面声源模型,以此作为声学边界积分方程的边界条件,实现辐射声场的数值计算.以矩形箱振动发声系统为例,应用两种规模的等效面声源预测噪声辐射,与实验相对比获得了较好的准确度,验证了该方法的有效性,同时表明等效面声源规模越大预测结果越准确.将小型离心风机气动声源与理想体积声源置于矩形箱内,应用该方法预测其辐射声场,也得到了理想的结果.

The near-field virtual envelope surface was established and then divided for the vibration or aerodynamic acoustic system as a whole.The regional near-field sound pressure information obtained in the experiment was taken as the sound source of the corresponding region,and then the equivalent surface acoustic model for the vibration or aerodynamic acoustic system was formed.The equivalent surface source was used as the boundary condition of the boundary integral equation for acoustic problems to realize the acoustic radiation field analysis.Firstly,taking the rectangular box vibro-acoustic system as an example,the method effectiveness was verified by the equivalent surface source prediction on two scales.The more the equivalent surface source is,the more accurate the prediction result is.Then,a small centrifugal fan and an ideal volume sound source were placed in the rectangular box,and the radiation field was predicted by this method,with ideal result obtained.