Influence of seafloor on acoustic plane wave
Journal
Journal of Engineering Mechanics
Journal Volume
118
Journal Issue
10
Pages
1987-2004
Date Issued
1992
Author(s)
Huang, L.H.
Abstract
The problems of plane acoustic waves acting on an interface between water and poroelastic seafloor of both infinite and finite thicknesses are studied. The analysis includes three frequencies of sound wave, 10 Hz, 103 Hz, 105 Hz, representing low, moderate, and high frequencies respectively, a typical seafloor material, and the incident angles from 0° to 90°. A decoupling procedure of Biot's equations of poroelasticity for oscillatory motion, which divides the perturbation in the poroelastic medium into two longitudinal waves and one transverse wave, is applied. The reflected acoustic intensities for porous seafloors of both infinite and finite thicknesses, and the pressure‐influence layers inside the infinite‐thickness porous seafloor are presented in this study. It is found that when the incident angle is larger than a certain value, it is possible to have exact internal reflection for the first longitudinal wave. It is also found that, in general, the profiles of pressure‐influence layers inside the porous seafloor are quite similar, except when the frequencies of sound are very high and the incident angles are large enough for the internal exact reflection of the first longitudinal wave to occur.
SDGs
Type
journal article