运用模态叠加法研究扩张式消声器的传递损失

摘要

采用声学模态叠加法建立单腔扩张式消声器传递损失计算模型,然后通过Matlab编程实现单腔扩张式消声器传递损失的数值计算.在此基础上,比较声学模态叠加法、有限元法和基于平面波假定的经典公式法在计算单腔扩张式消声器传递损失上的差别,研究单腔扩张式消声器膨胀段尺寸对传递损失的影响.结果表明,对于平面入射波,声学模态叠加法可用于单腔扩张式消声器各频段传递损失的计算;增大膨胀段的半径能有效提高低频段的传递损失,但对高频段的影响较小;随着膨胀段宽度的增大,传递损失的峰值向低频移动,传递损失最大的频段向高频移动.%The acoustic modal superposition method is used to establish the trasmission loss calculation model for the single chamber expansion muffler. Its transmission loss is computed through Matlab programming. On this basis, the difference of the acoustic modal superposition method, the finite element method and the classical formula method in calculating the transmission loss of the single chamber expansion muffler is found. The influence of the size of the single chamber expansion muffler on the transmission loss is studied. The research indicates that, for the incident plane wave, the acoustic mode superposition method can be used to calculate the transmission loss of the single chamber expansion muffler in whole frequency range. Increasing the radius of the expanding section can effectively raise the transmission loss in low frequency range, but has small influence on the transmission loss in high frequency range. With increasing of the width of the expansion section, the peak values of the transmission loss shift to low frequency side and the frequency band of the maximum transmission loss moves to the high frequency side.