复合材料环状声衬降噪特性试验研究

根据民用飞机结构轻质化、高性能化的发展需求,利用发动机声模态模拟试验平台开展复合材料环状声衬的降噪特性试验研究,探索复合材料声衬在发动机短舱的可行性。针对发动机短舱声衬的某特定工况,以高分子树脂基复合材料,利用无缝拼接和环装整体成型等先进工艺研制出无拼缝的、两种不同长度的环状声衬试验件；通过基于旋转轴向传声器阵列方法的管内声模态测试和指向性测试开展声衬降噪效果试验。试验结果表明,声衬的降噪效果具有强烈的模态选择性,切向来流速度对声衬的降噪效果具有显著影响。

Noise Reduction Characteristics Test on Composite Material Annular Acoustic Liner

The composite material annular liners were developed according to the need of lightweight and high performance civil aircraft structure. The experimental study on the noise reduction characteristics of composite material annular liner was carried out by applying in the engine acoustic spinning mode synthesizer test rig, to explore the feasibility of composite material liner in engine nacelle. For the particular condition of engine nacelle liner, two kinds of different length of liner test pieces were signed and prepared by using seamless splicing, overall molding and other advanced processes. The noise reduction characteristics of acoustic liners were achieved by means of far-field directivity test and in-tube acoustic mode based on the method of rotary axial microphone array. The experimental results show that the noise reduction effect of liner has a strong mode selectivity, and the shear flow velocity has a significant effect on the noise reduction effect of sound liner.