球坐标系下声场分离的低频辐射声场测量技术  

A Technology of Radiation Fields Measurement in Low Frequency by Sound Field Separation in Spherical Coordinates

作　　者：张鹏[1] 匡正[1] 吴鸣[1] 杨军[1] 

机构地区：[1]中国科学院声学研究所通信声学实验室,北京100190

出　　处：《网络新媒体技术》2014年第4期49-52,共4页Network New Media Technology

基　　金：国家自然科学基金资助;(基于声场控制技术的材料声学特性测量方法研究)项目号11304349

摘　　要：低频扬声器的辐射声场由于消声室低频截止频率的影响,不易使用标准的声场测量方法进行准确的测量。本文利用近场声全息技术以及球面坐标系下的声场分离原理,在球谐函数展开表达式中,导出广义的球谐函数系数求解方程,并采用最小二乘法进行球谐函数展开式中系数的估计,使用推导出的声场分离方法利用非自由空间非球面测量,最终重建出声源在自由空间的辐射声场。为了验证所提方法的有效性,使用偶极子声源以及由数个单极子组成的复杂声源进行了多种情况下的仿真,仿真结果验证了所述方法的有效性。Due to the limitation of the cutoff frequency of the anechoic chamber, it is difficult to measure the low frequency sound field by using the classical method. This paper presents a novel method for measuring the acoustic radiation field of subwoofers. Firstly, ac- cording to the sound field separation principle, a general model of spherical harmonics based on the spherical coordinate system is pro- posed. After that, the coefficients in the spherical harmonic expansion are worked out by the least squares method. And then we use non - free - field aspheric measurements to rebuild the radiated sound fields of the sound source in the free field. Finally, in order to tesity the proposed method, simulations of dipoles and multi - poles cases are carried out.

关 键 词：低频扬声器 球坐标系 球谐波函数 声场分离 近场声全息 

分 类 号：TB52[理学—物理]