目前，水溶液、海水的声吸收测量一般通过充水共振器内的混响时间测量来实现。对一充水圆柱形共振器内的混响特性进行理论分析发现，在共振器内不同空间位置处声压级衰减曲线的不同，使得由声压级衰减曲线斜率计算的混响时间存在差别。因此，如果采用的测量混响时间方法不准确，必定导致待测水介质的声吸收系数的结果中存在较大的测量误差。构建并研制1套圆柱形充水共振器，搭建相应的电子测量系统，对标准水溶液的声吸收系数进行实验研究，分析不同混响时间测量方法所导致的测量误差。结果表明：如果对纯水介质和待测水介质的混响时间测量方法不同，确实会导致待测水介质的声吸收系数存在较大的误差。同时，针对该充水圆柱形共振器，给出了可使声吸收系数测量误差较小的混响时间测量方法。研究结果对水下封闭空间内的混响时间测量、悬浮泥沙颗粒水介质的声吸收系数测量等具有一定参考价值。
Nowadays, the coefficient of sound absorption in the water solutions, seawater has been measured by the measurement of reverberation time in a resonator. The property of the reverberation in a cylindrical resonator was theoretically analyzed. The decay curves of sound pressure level at different spatial points in the resonator are found to be different. The reverberation time at different points, which is calculated by the slope of decay curves, is also different. If the measurement method of reverberation time is improper, bigger measurement error can exist in the results of the coefficient of sound absorption in water medium. A cylindrical resonator and the corresponding electronic system were built up. The coefficient of sound absorption in standard solution was measured in the experiments. The error of different measurement methods of reverberation time was analyzed. It shows that the measurement methods of reverberation time do induce bigger measurement error in the coefficient of sound absorption in the liquids. After that, the method of smallest measurement error in the coefficient of sound absorption in the liquids has been given. The results have provided some reference for measuring the reverberation time of underwater enclosed space and coefficient of sound absorption in the liquids of suspended sediment particles.
2016,(s1): 177-183 收稿日期：2016-08-05
DOI：10.3404/j.issn.1672-7619.2016.S1.033
分类号：TB566
基金项目：水声技术重点实验室重点基金资助项目（9140C200104140C20003）；中央高校基本科研业务费专项资金资助项目（HEUCF160502）；声隐身技术重点实验室基金资助项目（9140C280104150C28002）；国家重点研发计划资助项目（2016YFF0200900）
作者简介：刘永伟(1981-),男,博士,讲师,从事水声技术研究。
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