...R. Anaghraj; K. Mahesh; R. S. Mini Low-frequency broadband sound absorption with minimal dimensions and material cost is an ongoing research challenge in engineering acoustics. Common acoustic structures, such as microperforated panels (MPPs) and porous structures, are ineffective in alleviating...

...Andrea Santoni; Paolo Bonfiglio; Patrizio Fausti; Francesco Pompoli The transfer matrix method (TMM) has become an established and widely used approach to compute the sound absorption coefficient of a multilayer structure. Due to the assumption made by this method of laterally infinite media...

...) on the sound absorption performance of an underwater rubber layer containing periodically distributed axial holes. A theoretical model is developed based on the method of transfer matrix as well as the concept of equivalent layering of holes with variable cross section. Numerical simulations with the method...

...           ∑ i = 1 n Ω i / n ≈ Ω where Ω is the expected averaged porosity since both the mass and volume of the sample are fixed. Fig. 8 Predicted sound absorption coefficient plotted as a function of frequency for semi-open cellular metal: comparison amongst...