Finite Element Modeling of Acoustic Cloaking and Wave Redirection in Poroelastic Metamaterials

International Journal of Physics | Vol. 6, No. 9, September 2015 | pp. 65–72

DOI: 10.46882/2015/IJP/000065

Research Article

Title: Finite Element Modeling of Acoustic Cloaking and Wave Redirection in Poroelastic Metamaterials

Names of Authors: P. J. O’Connor¹, H. J. Mueller²

Authors’ Affiliations: ¹Department of Civil and Environmental Engineering, University College Cork, Cork, Ireland; ²Institute of Physics, Karlsruher Institut für Technologie, Karlsruhe, Germany

Abstract: Controlling acoustic paths in underwater and structural environments is essential for stealth technologies and specialized noise insulation. This study implements a finite element modeling approach to simulate acoustic cloaking and wave redirection within poroelastic acoustic metamaterials. The design leverages a coordinate-transformation method applied to Biot's dynamic poroelastic equations to determine the required anisotropic distribution of density and elastic moduli tensors. We performed numerical scattering simulations across an ultrasonic frequency band from 20.0 kHz to 100.0 kHz. The computational models show that a cylindrical cloak constructed with 24 concentric sub-wavelength layers successfully routes an incident acoustic wave around a rigid obstacle. This configuration reduces the total scattering cross-section by 84.0% at a design frequency of 50.0 kHz. We analyzed the impact of fluid viscosity on cloaking performance, finding that viscous dissipation in the porous channels dampens higher-order harmonic fields. This damping restricts forward transmission to a minor 4.2% energy loss. Experimental validation was carried out using 3D-printed perforated polyurethane matrices immersed in water. The measured pressure fields matched the simulated profiles within a ±5.0% margin. These results provide practical strategies for building underwater acoustic shields and high-performance sound absorbers.

Keywords: Acoustic metamaterials; finite element modeling; acoustic cloaking; Biot's theory; wave redirection; porous media

Manuscript Timeline: Received: May 12, 2015; Revised: July 03, 2015; Accepted: July 25, 2015; Published: September 11, 2015

Citation: O’Connor, P. J., & Mueller, H. J. (2015). Finite Element Modeling of Acoustic Cloaking and Wave Redirection in Poroelastic Metamaterials. International Journal of Physics, 6(9), 65–72.

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