Study of miscible fluid flows in a porous medium by an acoustical method

Abstract
We present sound velocity measurements in a pack of glass beads saturated with water-ethanol mixtures of various concentrations. We thus determine the formation factor of the porous medium. Then the velocity measurements provide a means of following the time dependence of concentration during the displacement of a fluid by another miscible fluid. The variation of the longitudinal dispersion coefficient for different flow rates is compared to the theory of dispersion in porous media. From measurements at low flow rates, we derive the same value of the formation factor as the one obtained in the preliminary acoustical experiment