A theory is developed for the propagation of stress waves in a porous elastic solid containing a compressible viscous fluid.
The emphasis of the present treatment is on materials where fluid and solid are of comparable densities as for instance in the case of water-saturated rock.
The paper denoted here as Part I is restricted to the lower frequency range where the assumption of Poiseuille flow is valid.
It is found that the material may be described by four nondimen-sional parameters and a characteristic frequency. There are two dilatation waves and one rotational wave.
The physical interpretation of the result is clarified by treating first the case where the fluid is frictionless. The case of a material containing a viscous fluid is then developed and discussed numerically.
Phase velocity dispersion curves and attenuation coefficients for the three types of waves are plotted as a function of the frequency for various combinations of the characteristic parameters.THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA, Vol. 28, No. 2, 168-178, March, 1956.