Sound Absorption Modeling in Porous Materials: A Critical Review of Empirical, Equivalent-Fluid, Poroelastic, Resonant, and Numerical Methods

This paper provides a comprehensive overview of the main physical and empirical models used to describe sound absorption in porous materials. Each model is described in detail with regard to its theoretical basis, governing equations, and key physical parameters. Special attention is devoted to the assumptions underlying each model, such as whether the frame is rigid or flexible, the applicable frequency range, and the types of porous media they most accurately represent. The advantages and limitations of the different approaches are critically assessed in terms of prediction accuracy, computational complexity, and experimental requirements. In addition, the paper presents illustrative simulations of frequency dependencies of the sound absorption coefficient for various porous materials based on these models, which reproduce experimental data reported in the relevant literature. These comparisons highlight the strengths and weaknesses of different modeling strategies in various acoustic applications and provide guidance for selecting the most suitable model according to material properties and target frequency range.