The Variance of the Measurement of Sound Absorption of Material in an Underwater Reverberation Chamber
Random-incidence sound absorption coefficient of underwater acoustics materials can be measured by the method of reverberation chamber. Method of reverberation chamber used in underwater acoustics area is analog to national standard (GBJ 47-83) about Measurement of sound absorption in a reverberation room in air acoustics area. The ensemble variance has a great impact to the accuracy of sound absorption coefficient of underwater acoustics material. The accuracy of sound absorption coefficient can be guaranteed by reducing the ensemble variance in the measurement of reverberation time. Ensemble variance is influenced by the uniformity of the sound field, the excitation mode of source and the variation of volume, temperature and air bubble of water. The maximum value of ensemble variance approaches 10％. The value of ensemble variance can reduce to 3％ by effective method. Result of this research is helpful to reduce the errors in the measurement of sound absorption coefficient of under water acoustic material.
sound absorption coefficient reverberation chamberi reverberation timet ensemble variance
Yang Daheng Li Qi
College of Underwater Acoustic Engineering Harbin Engineering University, 150001 Harbin,China Colleg College of Underwater Acoustic Engineering Harbin Engineering University, 150001 Harbin,China
国际会议
重庆
英文
327-330
2011-01-21（万方平台首次上网日期，不代表论文的发表时间）