Acoustic Attenuation of Hybrid Sonic Crystal Made with Periodic Cylindrical Scatterers and Porous Panels

Abstract

Acoustic attenuation of a hybrid sonic crystal made with periodic cylindrical scatterers and cascaded porous panels in a broad frequency range is endeavoured in this paper. It is observed via simulations that, the insertion loss (IL) of hybrid configuration is larger than the summation of IL of individual contributors such as periodic scatterers and parallel porous panels in post first Bragg resonance frequency band. The key finding of the research is that the passband in post first Bragg resonance is turning to stopband on introducing the cascaded porous panels within scatterers. Other configurations such as periodic array of cylindrical scatterers in series with porous panels in upstream, downstream and bounded with porous panels are examined and compared. The potential of said claim is shown by investigating a multi-resonant array of scatterers with cascaded porous panels. Finally, the experimental results are presented to authenticate the observed findings of simulations.