Velocity and attenuation of fast, shear and slow waves in porous media

The porous materials studied are those described as two-component composites where both the fluid phase and the solid phase are continuous and interpenetrating. The bulk acoustic wave propagation in these materials is shown both theoretically and experimentally to include two types of compressional waves. The fast or normal compressional wave corresponds to an in-phase motion of the fluid and the solid, whereas the slow compressional wave corresponds to an in-phase motion. Highlights of the Biot theory are described as well as some recent velocity and attenuation measurements in one particular kind of porous medium