Low Frequency Noise Attenuation inside Ducts using locally resonant periodic flush mounted Steel Patches
Regular paper
ASU Sound and Vibration Lab, Faculty of Engineering
Wednesday 3 june, 2015, 11:40 - 12:00
0.3 Copenhagen (49)
Abstract:
Traditional passive noise control techniques using Helmholtz resonators have
size limitations at low frequency due to the long wavelengths. Promising noise
reductions, with flush mounted Stainless Steel patches with no such
constraints can be obtained building on local resonance phenomenon implemented
in acoustic metamaterials techniques. The objective of the current paper is to
introduce locally resonant thin Steel patches flush mounted to an acoustic
duct walls aiming at creating frequency stop bands at the low frequency zone
(below 1 KHz). Green’s Function is used under the framework of interface
response theory to predict the degree of attenuation of the local resonant
patches. The experimental results were compared with Two-port theory and
Finite elements and a close agreement was found.