Flow-induced noise and vibration in axial fan: a case study

Abstract Reducing axial fan noise is crucial in residential, commercial, and industrial applications. This study explores how attaching different add-on designs to axial fans reduces aerodynamic noise. Eight design cases were examined, including extending the outlet and inlet ducts, using Chevron nozzles, placing internal spherical balls in staggered and straight patterns, applying a wavy inner wall treatment, and combining some of these nozzle designs. CFD and acoustic analyses were performed using Ansys Fluent 2022 R1. Noise reduction was measured at the nozzle outlet in each design case. All nozzle modifications reduced noise levels, with noise reductions ranging from 3 to 10% at the blade tip and 26–55% at the outlet. As an add-on to existing fan cases, the design cases investigated in this study can potentially improve the acoustic environment in various settings. The findings of this study can contribute to the development of quieter axial fans.