Ultrasonic waves Reflected at Oblique Incidence by Porous Rigid Medium

An ultrasonic reflected wave at oblique incidence by porous medium with rigid frames is considered using equivalent fluid model. The viscous and thermal losses of the medium are described by two susceptibility kernels which depend on the viscous and thermal characteristic lengths. Analytical derivation of reflection coefficient is given in frequency domain. The simulated reflected wave is obtained at time domain by convolution between the reflected operator and the incident field. Experimental results for plastic foam samples of air-saturated porous media are given and compared with theoretical prediction.