On Muffler Design for Transmitted Noise Reduction

This paper is the results of an undergraduate final term project. The aim of project was to investigate the passive noise reduction methods in mufflers. Also, another aim of this study is to examine and design mufflers with various geometries. This is learning the effect of geometry on noise transmission loss maximization performance of mufflers. Four-pole method is used to determine the noise transmission loss. Two different cross-sectional geometries are considered for the mufflers, i.e. rectangular and circular. These mufflers are produced and tested. A noise transmission test bench is used for the measurement of noise transmission loss of these mufflers. The analytical results from simulation are compared with the experimental results. The effect of geometry of mufflers on the maximization of the transmitted noise loss are investigated and reported. The results of this study can help students to learn the basics of muffler design for noise reduction applications. Furthermore, it shows the effect of geometry on the acoustic performance of mufflers.