Nowadays, fibrous polyester materials are becoming one of the most important alternatives for controlling reverberation time by absorbing unwanted sound energy in the automobile and construction fields. Thus, it is worthy and meaningful to characterize their acoustic behavior. To do so, non-acoustic parameters, such as tortuosity, viscous and thermal characteristic lengths and thermal permeability, must be determined. Representative panels of polyester fibrous material manufactured by perpendicular laying technology are thus tested via the Bayesian reconstruction procedure. The estimated porosity and airflow resistivity are found in good agreement with those tested via direct measurements. In addition, the homogeneity of polyester fibrous panels was characterized by investigating the mean relative differences of inferred non-acoustic parameters from the direct and reverse orientation measurements. Some parameters, such as tortuosity, porosity and airflow resistivity, exhibit very low relative differences. It is found that most of the panels can be assumed homogeneous along with the panel thickness, the slight inhomogeneity mostly affecting the thermal characteristic length.

Porous media are widely known in the areas concerning noise absorption and interior and exterior acoustics. Among the numerical techniques to simulate a porous layer is finite element method using commercial software exist and actively update the range of models offered. In this work, an investigation is done using a no-flow basic problem. By variating material pore complexity and properties, different models are studied to enhance the understanding of the various treatments.

Porous media are widely known in the areas concerning noise absorption and interior and exterior acoustics. One of the well known numerical techniques to simulate a porous layer is finite element method for which commercial software are available and are up to date according to the most common models to predict the properties of absorber materials. In this work, an investigation is done using a simple no-flow academic problem. By variating material pore complexity and properties, chosen models are studied to enhance the understanding of the various treatments.