水下圆柱壳空气管隔声性能分析及试验研究

Analysis and experiment on sound isolation of air-tube layer on underwater cylindrical shell

利用水下阻抗失配原理,提出了水下空气隔声层的概念,利用模态法及隔声层等效参数法求解了隔声层水下单层圆柱壳的降噪效果。利用橡胶气管实现了空气隔声层,并在新安江水库进行小圆柱壳模型的外场声辐射试验,验证了空气管隔声层的隔声效果,计算及试验结果表明:采用等效参数能够较好地描述橡胶气管隔声层;采用阻抗失配原理构建的气管隔声层具有较好的水下隔声性能,在100 Hz以上频率范围内达到2-15 d B隔声降噪效果;隔声层厚度越厚,降噪效果越好,双层气管隔声层隔声效果较单层气管隔声层好3 d B左右。

Within the concept of impedance unmatching, a new type of underwater sound-isolation layer constituted with hollow rubber tube is presented, and the mode-decomposition method is adopted to analyze the sound reduction of a simply single cylindrical shell covered by this kind of sound-isolation layer. Then an experiment is carried out to testify the sound reduction effect of the layer. Both the calculation and test results show that： the equivalent parameter could well describe the characteristic of the layer; and the effect of the layer demonstrated fine sound-isolation behavior, up to 2-15 d B above the frequency of 100 Hz; the thicker the layer is, the better the sound-isolation behavior of the layer shows, which is testified by the experiment that the double-layer presents 3 d B sound-isolation more than single-layer.