蜂窝夹层声衬材料宽频吸声性能优化  

Optimization of broadband sound absorption performance of honeycomb sandwich sound liner

作　　者：罗靓[1,2] 白鹤宇 叶卓然 顾轶卓 LUO Liang;BAI Heyu;YE Zhuoran;GU Yizhuo(School of Materials Science and Engineering,Beihang University,Beijing 100191,China;Beihang Changying UAS Technology CO.,LTD.,Beijing 100191,China;Research Institute for Frontier Science,Beihang University,Beijing 100191,China)

机构地区：[1]北京航空航天大学材料科学与工程学院,北京100191 [2]北京北航天宇长鹰无人机科技有限公司,北京100191 [3]北京航空航天大学前沿科学技术创新研究院,北京100191

出　　处：《复合材料学报》2024年第3期1290-1299,共10页Acta Materiae Compositae Sinica

基　　金：基础加强计划技术领域基金项目(2019-JCJQ-JJ-255)。

摘　　要：针对目前大涵道比涡扇发动机宽频随机的噪声特点,对传统单自由度蜂窝夹层声衬材料进行了结构优化,提升其吸声性能。在保持声衬单自由度蜂窝夹层结构基本形式不变的前提下,为拓宽吸声频谱、达到两个甚至两个以上的特征频率,在单层蜂窝芯内部特定位置复合碳纳米管薄膜,同时为了提高吸声效果,通过快捷的工艺组装,在多孔板和蜂窝芯之间引入金属丝网和柔性多孔材料,并探究了引入材料的放置位置和参数对于声衬材料吸声性能的影响。实验结果显示,孔径37μm的金属丝网置于多孔面板后、15 mm厚的三聚氰胺海绵放置在多孔面板和蜂窝之间、开孔率为2%和4%的碳纳米管薄膜放置在蜂窝夹层结构内近中间位置的吸声性能最好。基于该结果制备的声衬吸声性能优异,在800 Hz到4 500 Hz范围内表现出良好的吸声性能,两个特征频率的峰值吸声系数分别达到0.98和0.99,平均吸声系数达到0.89,相比优化前提升61.8%,同时半峰宽度能够完全覆盖测试的800 Hz到4 500 Hz频率范围,具有良好的宽频降噪特性。In view of the wide frequency noise characteristics of turbofan engine with large bypass ratio at present,traditional single-degree-of-freedom honeycomb sandwich acoustic lining material was optimized to improve its sound absorption performance.Under the premise of keeping the basic form of single-degree-of-freedom honeycomb structure of sound liner unchanged,in order to broaden the sound absorption spectrum and reach two or more characteristic frequencies,carbon nanotube film was compounded at a specific position inside the single-layer honeycomb core.At the same time,in order to improve the sound absorption effect,metal wire mesh and flexible porous materials were introduced between perforated plate and honeycomb core,and they were assembled through a rapid process.The influences of placement position and parameters of the introduced material on the sound absorption performance of the sound absorption composite were also investigated.The experimental results show that the structure with the best sound absorption performance is the introduction of 37 μm hole diameter wire mesh placed behind the porous panel,the placement of 15 mm thick melamine sponge between the porous panel and the honeycomb,and the placement of carbon nanotube film with a porosity of 2% and 4% in the middle of the honeycomb sandwich structure.The sound liner prepared based on this result has excellent sound absorption performance,and shows good sound absorption performance in the range of 800 Hz to 4 500 Hz.The peak sound absorption coefficients of the two characteristic frequencies reach 0.98 and 0.99,respectively,and the average sound absorption coefficient reaches 0.89,which is 61.8% higher than that before optimization.At the same time,the halfpeak width can fully cover the frequency range of 800 Hz to 4 500 Hz tested,which indicates good broadband noise reduction characteristics.

关 键 词：蜂窝夹层结构 吸声材料 声衬 吸声系数 发动机噪声 

分 类 号：TB34[一般工业技术—材料科学与工程] TB333[航空宇航科学与技术—航空宇航推进理论与工程] V231.9