基于微穿孔板的模型直升机舱内降噪研究

Reduction of Model Helicopter Cabin Noise Based on Micro‑perforated Panel

为验证微穿孔板吸声结构对直升机舱内噪声抑制的可行性和有效性,基于某轻型直升机模型机舱,开展了仿真与试验研究。首先,给出了适用于直升机舱内壁板的典型微穿孔板吸声结构方案;其次,建立了主减速器/机体声振耦合有限元模型,得到了微穿孔板吸声结构的设计频率范围,并通过仿真验证了吸声效果;最后,搭建了安装有微穿孔板吸声结构的模型直升机机舱试验平台,开展了舱内噪声试验研究。结果表明,在机舱内安装微穿孔板吸声结构后,相比于未安装微穿孔板机舱,在800~1 000 Hz和1 200~2 000 Hz的频率范围内,均具有优良的舱内降噪效果,最大噪声衰减量超过20 dB。

In order to verify the feasibility and effectiveness of the micro-perforated panel absorber structure for noise suppression in helicopter cabin,simulation and experimental research are carried out based on a light helicopter model cabin.Firstly,a typical structure of a micro-perforated panel absorber suitable for the inner wall of a helicopter cabin is given.A finite element model of the main gearbox/airframe acoustic-vibration coupling is further established.The design frequency range of the micro-perforated panel absorber structure is obtained,and the sound absorption effect is verified by simulation.Finally,a model helicopter cabin test platform installed with the micro-perforated panel absorber structure is built,and noise test in the cabin is carried out.The test results show that after installing the micro-perforated panel absorber structure in the cabin,compared with the cabin without the micro-perforated panel,cabin with such structure has an excellent effect on reduction of cabin noise in the frequency range of both 800~1000 Hz and 1200~2000 Hz,in which the maximum attenuation are more than 20 dB.