椭球坐标系中大口径凹面声场特性的计算  

Calculation of the focused sound field characteristics of large circular aperture using oblate spheroidal coordinate system

作　　者：孙敏[1] 李太宝[1] 

机构地区：[1]南京大学声学研究所近代声学国家重点实验室,南京210093

出　　处：《应用声学》2004年第3期7-12,共6页Journal of Applied Acoustics

摘　　要：凹口球形声源发出的聚焦声束可使焦域附近压强成倍增加,在超声加热治疗肿瘤上有很好的应用。本文对流体运动的基本方程组在时域上用有限差分法作数值计算,讨论了几个不同口径的凹口球形声源的声传播情况。为了与实际上的凹口声源的形状和法线振动方向相一致,计算采用了正交椭球坐标系。该方法与已知的其它方法对比,能得到相似的结果,但适用范围更广,计算程序更简单。The focused, high-frequency beams from a circular aperture can multiply the amplitude of sound pressure near the focus. It has a specific application in medical therapy. Numerical calculation is based on the basic wave equations with the method of finite difference time domain in oblate spheroidal coordinate system. Different aperture examples are displayed for the amplitudes of sound pressure along and across the beam axis. The method has an approximate result comparable with the others. It also has a wider applied scope and a simpler program.

关 键 词：凹口球形声源 椭球坐标 时域有限差分 凹面声场 声能量 几何聚焦 

分 类 号：TB52[理学—物理]