ONE-DIMENSIONAL PLANE MONOCHROMATIC FILTRATION WAVES

Equations and relations to describe one-dimensional plane monochromatic fi ltration waves in a homogeneous isotropic porous medium have been obtained. To this end, use was made of the equation of motion of a liquid phase with account of frictional forces, which in the case of steady-state fi ltration with parallel streamlines agrees with Darcy′s filtration law for an anisotropic medium. The equations of motion and continuity reduced to an equation of telegraphy enabled us to construct relations for the wave number, the absorption and attenuation coeffi cients, and the velocity of fi ltration waves. The expression for the phase velocity, the absorption coeffi cient, and the wave number of fi ltration waves has made it possible to investigate the correlation between this velocity and the velocity of elastic acoustic waves and the dependence on frequency. The extended theory of fi ltration-wave pressure fi elds refi nes the ideas of propagation of monochromatic fi ltration wave disturbances in a porous medium and confi rms the substantial decrease in the velocity in the low-frequency region compared to the velocity of propagation of elastic waves.
   
Author:  A. I. Filippov and O. V. Akhmetova
Keywords:  porous medium, filtration waves, attenuation coeffi cient, piezoconductivity coefficient
Page:  287