水下微穿孔吸声体结构设计与试验研究

根据马大猷院士的微穿孔板(MPP)理论,提出在可设计的夹芯复合隐身结构的空腔中附加微穿孔板层的水下微穿孔吸声体。基于微穿孔板的精确计算理论及水下声隐身结构的特点,考虑空腔深度、穿孔板厚度、穿孔直径及穿孔率等对微穿孔板吸声性能的影响,对水下微穿孔吸声体进行了结构设计。利用脉冲声管法对水下微穿孔吸声体试样的吸声系数进行了测量,结果表明:水下微穿孔吸声体有效地拓宽了低频吸声频带,其微穿孔板结构参数的影响规律也与理论分析一致;对于多种吸声机理并存的水下微穿孔吸声体的空腔个数、形状及谐振特性等也是影响吸声性能的重要因素,在实际的工程应用中必须结合所关心的频带对水下微穿孔吸声体进行匹配优化设计。

Structure design and experimental research on underwater micro-perforated absorbers

Based on the theory of micro-perforated panel (MPP) by academician MAA Dah-You, an underwater micro-perforated absorber was built by adding a micro-perforated panel in the cavity of sandwich composite structure. Ac-cording to the general theory of micro-perforated panel and the peculiarity of underwater acoustic stealth structures, the structure of underwater micro-perforated panel of under water absorber were designed, by considering the effect of cavity depth, panel thickness, perforated diameter and rate. The absorption coefficient of specimens of underwater micro-perforated absorbers was studied by a pulse tube experimental system. The results showed that the low frequency band was broaden by adding a micro-perforated panel, and the influence of panel parameters suited to the result of theoretical analysis. The experimental results also showed that the cavity number, shape and resonant characters, of the underwater micro-perforated absorbers with several absorption mechanisms, were as well as important factors of ab-sorption properties. So the matching designing in the engineering application must be done according to the concerned frequency band.