The accuracy of some models to predict the acoustical properties of granular media

There is a general lack of understanding on the accuracy theoretical and empirical models which can be used to predict acoustical properties unsaturated granular media. It also unclear how well these are suited for parameter inversion in application In this work three popular prediction available commercial software packages, e.g. COMSOL Multiphysics, invert key non-acoustical parameters two types glass beads fractions silica sand data obtained with standard acoustic impedance tube setup. These results compared against predictions made four established analytical relate characteristics effective particle size other pore characteristics. A discrepancy between model classes (acoustical models) measured quantified. This quantifies characterisation methods estimate media relatively inexpensive laboratory setup rapid method based optimisation.