关键词: 声学, 传递损失, 消声器, 管道声模态, 高次波

Abstract:

Transmission loss is an important index in evaluating muffler’s acoustic performance. A new method called acoustic mode in pipeline instead of the traditional method was proposed in this paper to estimate transmission loss. It was applied in the muffler with the smaller sectional area on the inlet and outlet whose result is nearly correct and the process is very simple compared with the traditional method, improving the efficiency in computing the transmission loss. For the muffler with the larger sectional area on the inlet and outlet, because of amount of high secondary wave appears in the medium-high frequency, the traditional method has become invalid; but in the low frequency the result is consistent with the traditional method for the plane wave is the main acoustic wave in the pipeline. So the method of acoustic mode in pipeline can estimate the transmission loss at express speed.