COMSOL可视化仿真在声学理论课程中的应用与实践

辛锋先 刘学伟 伍晓红 吴莹

摘  要：多孔介质中的声波传播是连续介质力学的重要研究方向之一，在力学研究生课程《声学理论与工程应用》中引入COMSOL多物理场有限元软件，进行可视化的数值仿真课程教学，提高了学生学习兴趣，增强了学生对声波在多孔介质中传播与耗散机理的理解，取得了良好的教学效果。在课程教学中，应用COMSOL软件中构建了多孔吸声材料的声传播有限元模型;结合数值计算设置过程，讲解了声压、粒子振速、声强和能量耗散等声学概念;开展数值计算，根据计算结果讲解了如何在软件中求解表面声阻抗、声压反射系数和吸声系数等声学参量，并进一步分析讨论了声波在多孔材料中的传播规律与能量耗散机理。通过以上教学，促进了学生的理论知识学习和软件仿真学习，开拓了学生创新性思维，增强其自主学习能力。

关键词：多孔介质;声传播;COMSOL软件;有限元建模;课程教学

中图分类号：G642      文献标识码：A 文章编号：2096-000X（2018）24-0001-04

Abstract： Acoustic wave propagation in porous media is one of the most important researches of continuous medium mechanics. In the course of Acoustic Theory and Engineering Application， the COMSOL multi-physics finite element software is introduced into the course teaching. The visualization simulations based on COMSOL are carried out to improve the students' learning interest and to help further understand the acoustic wave propagation and dissipation in porous materials. Specifically， a finite element model for acoustic wave propagation in porous material is developed in COMSOL software. Meanwhile， the concepts of acoustic pressure， particle velocity， sound intensity and energy dissipation are explained in the process of numerical calculation. Numerical calculations are conducted to explain how to solve the surface acoustic impedance， reflection coefficient and absorption coefficient in the software. Moreover， the propagation and energy dissipation mechanism of acoustic waves in porous materials are discussed. The above teaching method promotes the students' theoretical learning and software simulation， and remarkably enhances the students' innovative thinking and autonomous learning ability.

Keywords： porous media; acoustic wave propagation; COMSOL software; finite element modeling; course teaching

引言

聲学理论是连续介质力学的一个重要分支学科，主要研究声波在连续介质（包括固体介质、流体介质、固液或固气两相介质）中的传播与衰减规律。声学理论课程主要讲解声波的波动方程、声波在管中的传播、声波的辐射、声波的散射和声波的吸收等方面的知识[1，2]。为了使理论联系实际，作者在声学理论课程教学过程中穿插讲解工程应用方面的知识，从而形成面向力学研究生的《声学理论与工程应用》课程。……