小型混响舱测量材料吸声系数

Measurement of Sound Absorption Coefficient of Materials of Small Reverberation Chambers

针对现有的基于混响室测量材料吸声系数方法所需场地空间较大和试件尺寸较大,而驻波管法只能测量对应于材料轴向入射的吸声系数,无法应用于不规则试件测量的问题,结合参考文献,设计制作小型混响舱用于应对该类问题。介绍通过小混响舱测量材料吸声系数的背景及应用场景,比较基于传统混响室和小混响舱测量材料吸声性能的方法,通过多次实验验证小混响舱整体结构实验环境的稳定性及分析测点位置不同对测量结果的影响,重点介绍小混响舱的结构及相关测量设备、测量方法及其在测量小试件无规入射吸声系数方面的优势。

Present method of sound absorption coefficient of materials is based on reverberant room method and impedance tube method, of which the former method needs a large space and large samples, while the latter method only reflects the axial incident sound absorption coefficient of materials. They are unlikely to be applied to the measurement of irregular samples. In this paper, a small reverberation chamber is designed to deal with this kind of problems. The background and application scene of the small reverberation chamber to measure the sound absorption coefficient of materials are introduced.The structure, measuring equipment and measuring methods of the small reverberation chamber are introduced. The advantage of the small reverberation chamber in measuring the random incidence absorption coefficients of small samples is discussed. Comparison is made between the traditional reverberant room method and the small reverberation chamber method.The stability of the whole structure of the small reverberation chamber and the influence of different measuring points on the measurement results have been verified through several experiments.