Sub-chamber optimization for silencer design

Abstract

This study proposes sub-chamber optimization for the design of a silencer. A theoretical basis is presented for a description of the overall transmission loss (TL) of the silencer, using the TLs of each of the cascade-connected multiple sub-chambers and the interactions between them. Three typical sub-chamber configurations are considered, representing the effects of varying geometrical parameters, adding internal partitions, and introducing perforated liners. The characteristics of the sub-chambers, influences of the parameters, and the limits of design are investigated to provide guidelines for optimization. It is demonstrated that, by connecting sub-chambers with optimized TLs to tackle different frequency regions, a desired broadband attenuation performance can be achieved. The proposed design scheme with sub-chamber optimization greatly reduces the design variables and calculation costs compared with global optimization, thus offering wider scope in silencer design.