声辐射阻测量系统设计及测量精度影响因素分析*

在噪声控制领域,声辐射阻是一个重要的声学变量,在产品的设计阶段,可以通过改变结构表面形状来改变结构的声辐射阻抗,从而达到降噪的目的。本文基于集中参数模型,设计了测量设备,搭建了实验测量系统,并通过对无限大障板上圆形活塞声源的声辐射阻的测量对影响实验测量结果的因素进行了研究,之后对消音器入口处辐射阻进行了测量。测量结果表明:该实验测量系统具有操作简单,测量方便快捷,测量结果精度高等特点,可用于确定结构表面声辐射阻矩阵。

Design of acoustic radiation resistance measuring system and analysis of factors influencing measuring accuracy

In vibration and noise control, acoustic radiation resistance is a very important acoustic parameter, which changes with the surface shape. Thus, lower noise level radiated from structures can be achieved in the designing stage of the product by changing the surface shape of the structure. Based on lumped parameter model, measuring devices were designed and the measuring system was constructed. Then, the influencing factors have been investigated by measuring of baffled circular piston. After that, the radiation resistance at the entrance of the muffler has been measured. The results show that this measuring system has features of simple operation, convenient use and high text accuracy. Therefore, it can be used to determine the resistance matrix of the structures.