Abstract: Nowadays the elliptic mufflers are more widely used in the automotive industry. A 3D analysis method, aiming at solving the problem that the traditional 2D analysis method based on cylindrical coordinates cannot make an accurate simulation for the acoustic characteristics of elliptic mufflers, is reached with the importing of elliptical cylindrical coordinates, and then the theoretical derivation is made based on the 3D analysis method. An experiment with example analysis is conducted based on the theory derivation, the computation results of 2D and 3D analysis method are compared with the experimental results, and the deviation of two methods are analyzed. The comparison results show that compared with 2D analysis method, the 3D analysis method builds a more suitable model for the analysis of elliptical muffler, and is more capable of making an accurate calculation for the acoustic field inside the muffler in the whole frequency range, and the multiply combined muffler shows a better acoustic attenuation performance than the single cavity one, thus providing not only the theory basis for the selection and calculation of mufflers, but also a direction of optimization for the development of mufflers.

Key words: 3D analysis method, acoustic attenuation performance, elliptical muffler, multiply combined muffler