关键词: 声学, 扩张室式消声器, 传递损失, 有限元法, 声学特性

Abstract: The finite element method is used to analyze the acoustic characteristics of an expansionchamber muffler with its inlet and outlet pipes being coaxial. Its transmission loss (TL) is calculated. The result is compared with that of the onedimensional solutions based on planar wave theory. The limitation of onedimensional planar wave theory is discussed. The acoustic characteristics of eccentric outlet muffler, doubleoutlet muffler and doublecavity muffler are analyzed. The result indicates that the position and the number of outlet can affect the acoustic characteristic of a muffler for higher and medium frequencies; while the doublecavity muffler has high noiseelimination efficiency for lower and medium frequencies.

Key words: acoustics, expansionchamber muffler, transmission loss (TL), finite element method, acoustic characteristic