微穿孔板吸声结构水下应用研究

马大猷教授提出的微穿孔板吸声结构在空气噪声降低和隔离方面得到了广泛的应用,但未见水下应用的相关研究和报道。本文将空气中微穿孔板理论应用到水中,得到了水下微穿孔板吸声结构的吸声公式。通过理论分析,得出了微穿孔板结构直接应用于水中无法获得宽频吸收的结论。提出了通过匹配液将微穿孔板间接应用到水下的设想。设计了单层板和双层板吸声结构,并对它们的吸声特性进行了理论分析与仿真。结果表明,本文设计的微穿孔板吸声结构在水中能够获得优于空气中的宽频带吸声效果。实验测量了自制的微穿孔板吸声结构,吸声系数的测量值与理论曲线基本吻合,从而验证了理论分析的正确性。

Investigations of micro-perforated sound absorption structures for underwter usage

Micro-perforated sound absorption structures proposed by Professor Maa Dah- You have got abroad application on noise reductions and isolations in air.To our knowledge,however,there are no investigations and reports about their applications underwater.In this paper,the sound absorption formula of the same micro-perforated sound absorption structures underwater is derived from the corresponding theories in air. The conclusion that such structures cannot possess wide absorption is obtained.Then two modified micro-perforated panel sound absorption structures are proposed.Simulation results show that these structures have better sound absorption properties than those in air.The micro-perforated sound absorption structures designed and made by ourselves are tested in a standing-wave tube filled with water,and the experimental values of the sound absorption coefficient are in agreement with the theoretical values,which verify the theoretical analysis.