Acoustic Black Hole With Functionally Graded Perforated Rings: Modeling and Experimental Performance

Abstract This article presents a comprehensive theoretical and experimental investigation of a novel class of acoustic black hole (ABH) waveguides that harnesses the functionality of an array of optimally designed functionally graded perforated rings (FGPR). Through this approach, the developed ABH exhibits inherent energy dissipation characteristics derived from the flow through the perforations, which enhances its acoustic absorption behavior, resulting in rapid attenuation of the propagating waves as it traverses the length of the waveguide. Accordingly, this article presents a comsol-based finite element modeling (FEM) approach to predict the behavior of this class of ABH. The model aims to demonstrate the merits of the proposed ABH as an effective means for absorbing sound propagation. Numerical simulations are conducted to showcase the advantages and behavior of the proposed ABH configurations in comparison with the predictions of our previously developed transfer matrix model (TMM). The theoretical predictions of both the FEM and TMM models are validated against experimental results which are collected using manufactured prototypes of the ABH/FGPR that are tested using the ACUPRO impedance tube. Comparisons between the predicted and measured results show close agreements.