Achieving Axial Fan Sound Reduction with Micro-Perforated Absorbers
* Presenting author
Aeroacoustic noise sources, especially under distorted flow conditions, are one of the main causes of soundemissions on an axial fan geometry layout in a complex ventilation system scenario. To attenuate sound, one caneither modify the aeroacoustic sources by changing the fan blade geometry, or one can use passive absorbingmechanisms which are applied as wall lined structures up- and downstream of the fan.We propose the application of MPAs (micro-perforated absorbers) in the tipflow region of the fan to accountfor tonal components of the emitted sound pressure spectrum. Possible near-field effects on the absorbingstructure will be investigated by simulating MPAs with the Johnson-Champoux-Allard approach in a Finite Element (FE) -framework . This is followed by measurements at an experimental test section where we will investigate theeffect of the MPA structure on pressure drop, performance and the overall emitted sound pressure level of thefan.