Design of a Circular-type Pod Silencer for a High-pressure Axial Flow Fan

A circular-type pod silencer has been designed to reduce a high noise level generated from an axial flow fan. The noise consists of two components such as discrete frequency noise component at blade passing frequency due to rotating impellers and broadband noise component due to turbulence produced in the axial fan. Main contribution into the high noise level is due to the discrete frequency noise component. In order to effectively reduce the noise level of the axial flow fan, the circular-type pod silencer has been modelled in this paper. In order to identify critical design parameters, finite element analysis (FEA) with commercial ANSYS acoustic code was implemented. The results of the design parametric study have been used to design the circular-type pod silencer that effectively reduces the high noise level of the axial flow fan in subway ventilation system.