区分空气传声和结构传声的研究

降低飞机舱内的噪声首先要弄清引起舱内噪声的主要来源,以便采取合理有效的降噪措施。进入飞机舱内的噪声一般可分成两大类:空气声激励和机械激励下舱壁的声辐射。前者对舱内声场的贡献称为空气传声,后者称为结构传声。本文根据飞机壁板在机械激励和声场激励时,声辐射系数的差异,借助声强方法推导出两种不同激励下壁板辐射声功率的区分公式,并利用这些公式分别对均匀平板和加肋板进行了区分空气传声和结构传声的实验,计算区分结果和实验结果吻合较好。

Study on Separating Airborne and Structureborne Noises

It is important to know the predominant source contributed to the cabin noisein reducing the noise in the aircraft,so that the reasonable and effective noisecontrol treatment can be used.The noise entering the cabin of the aircraft is mainlydivided into two major categories,viz,airborne exciting noise and mechanic excitingnoise.The former is called airborne noise for the contribution to the cabin noiseand the latter structureborne noise.The formulae for separating them are derivedusing two microphone acoustic intensity method in the two types of excitation interms of the difference in the airborne and structureborne noise radiation efficienciesfor the aircraft fuselage.The experiments separating the airborne noise and structureborne noise are performed using these formulae on a uniform plate and a ribbedplate separately.The agreement between the predicted and the experimental resultsis fairly good.