Computational analysis of acoustic transmission through periodically perforated interfaces

• Main Authors: Rohan E., Lukeš V.
• Format: Article
• Language: English
• Published: University of West Bohemia 2009-06-01
• Series: Applied and Computational Mechanics
• Subjects: Acoustic transmission; Homogenization; Perforated layer; Numerical modelling
• Online Access: http://www.kme.zcu.cz/acm/old_acm/full_papers/acm_vol3no1_p10.pdf

The objective of the paper is to demonstrate the homogenization approach applied to modelling the acoustic transmission on perforated interfaces embedded in the acoustic fluid. We assume a layer, with periodically perforated obstacles, separating two half-spaces filled with the fluid. The homogenization method provides limit transmission conditions which can be prescribed at the homogenized surface representing the "limit" interface. The conditions describe relationship between jump of the acoustic pressures and the transversal acoustic velocity, on introducing the "in-layer pressure" which describes wave propagation in the tangent directions with respect to the interface.This approach may serve as a relevant tool for optimal design of devices aimed at attenuation of the acoustic waves, such as the engine exhaust mufflers or other structures fitted with sieves and grillages. We present numerical examples of wave propagation in a muffler-like structure illustrating viability of the approach when complex 3D geometries of the interface perforation are considered.