Ultrasonic waves Reflected at Oblique Incidence by Porous Rigid Medium.

Compared with the usual uniform layout, giv- ing a lamella network structure to a material provides additional sound absorption below the quarter wave- length resonance frequency

A sensitivity analysis is performed on the additional parameters, showing that only the viscous surface Σ has an influence on transmitted waves in the high frequency regime,

The purpose of this paper is to present a method for the ultrasonic characterization of air- saturated porous media, by solving the inverse problem using only the reflected waves

At oblique incidence with theta=30 0 , the optimized wedge for case (a) has a mean reflection coefficient of approximately -22 dB but for case (b) the mean value is -30 dB so

Propagation of Acoustic Waves in Porous Media and their Reflection and Transmission at a Pure Fluid/Porous Medium Permeable Interface... Propagation of Acoustic Waves in Porous

Simul- taneous determination of porosity, tortuosity, viscous and thermal characteristic lengths of rigid porous materials... ous and thermal harateristi lengths of

and the simulated reeted signals (solid line) using the reonstruted value of k 0 , for the sample. M1 in the frequeny

This method is based on a temporal model of direct and inverse scattering problems for the propagation of transient ultrasonic waves in a homogeneous isotropic slab