Scattering by an array of perforated cylinders with a porous core
Journal article, 2014

In this work multiple scattering by an array of perforated cylindrical shells with a porous core has been investigated. A semi-analytical model to predict scattering from such cylindrical units is presented in the context of the multiple scattering theory (MST), and validated against laboratory experiments. The suggested semi-analytical multiple scattering model uses an impedance expression to include the perforated shell in the scattering coefficients, which is a compact way to describe a composite scatterer in MST. Calculation results of a small array are shown to be in excellent agreement with measured data. Predictions and data show that perforated cylinders with empty cavities exhibit a strong and narrow insertion loss peak at resonance, though simulta- neously suffer from amplification below resonance. By adding porous material in the core of the scatterer adverse effects below the resonance peak were suppressed. In addition, it was found that the reduction peak broadens, though at a cost of a reduced peak amplitude. Finally, it has been shown that adding porous material in a perforated shell will introduce partial absorption of the incoming field, which can be optimized by adjusting the perforation ratio of the shell.

Sonic crystals

Multiple scattering

Noise barrier

Multiple scattering theory

Porous material

Author

Bart van der Aa

Chalmers, Civil and Environmental Engineering, Applied Acoustics

Jens Forssén

Chalmers, Civil and Environmental Engineering, Applied Acoustics

Journal of the Acoustical Society of America

0001-4966 (ISSN) 1520-8524 (eISSN)

Vol. 136 5 2370-2380

Areas of Advance

Transport

Building Futures (2010-2018)

Materials Science

Subject Categories

Civil Engineering

Physical Sciences

DOI

10.1121/1.4896566

More information

Latest update

11/21/2018