Duct noise attenuation using reactive silencer with various internal configurations

The broadband sound attenuation characteristics of expansion chamber silencers can be altered by their internal configuration. Three-dimensional modeling of such systems, especially in the presence of complex internal partitions, remains a challenging task. In order to tackle the system complexity, this paper presents a systematic approach based on the sub-structuring modeling principle, to investigate the effects of several typical silencer configurations and provide guidelines for possible system optimization. Through numerical examples, the effects of various internal arrangements, including the side-branch partitions, multi-chamber partitions, non-symmetric inlet/outlet, and their combined effects are investigated. Numerical predictions show good agreements with both finite element method (FEM) and experiments. Investigations suggest some critical issues and possible solutions for better silencer design.