Influence of Cross-Sectional Geometry on the Acoustic Performance of Mufflers: A Finite Element Study

In this study, the acoustic performance of two muffler prototypes with elliptical and cylindrical cross-sections is numerically investigated and compared. The primary objective is to quantify the influence of cross-sectional geometry on sound transmission loss (STL) characteristics and to identify the resulting changes in wave propagation behavior. Finite element simulations were conducted in COMSOL Multiphysics®, and STL spectra were obtained over a broad frequency range. The results show that both mufflers exhibit comparable transmission loss at low frequencies; however, distinct differences emerge as frequency increases. The elliptical muffler demonstrates enhanced attenuation across certain mid- and high-frequency bands, attributed to the asymmetric distribution of the acoustic pressure field and the altered propagation paths of incident waves. In contrast, the cylindrical muffler, owing to its geometric symmetry, aligns more closely with analytical predictions and idealized acoustic models at lower frequencies. Detailed analysis of pressure contours and resonance patterns further confirms that the elliptical configuration introduces frequency shifts in pressure peaks and distinct mode shapes. These findings underscore the significant role of geometric design in determining muffler performance and provide valuable guidelines for optimizing cross-sectional profiles to achieve superior noise reduction in automotive and industrial applications.

کلیدواژه ها:

Transmission loss ، Acoustics ، Muffler ، Resonance