Non-Darcy flow behavior in liquid-saturated porous media

Velocity-gradient data for water-saturated porous media were considered in some detail. Deviations from Darcy's law were found in data originally presented in support of the law. Recent data were analyzed on the basis of a postulated three-parameter equation, in contrast with the one-parameter Darcy proportionality. The equation contains Darcy's law as a special case and in general fits the data quite well for water and electrolyte solutions flowing in sandstones and clays. The fitted parameters behave consistently, and are capable of reasonable interpretation. Possible mechanisms giving rise to non-Darcy behavior are suggested, including that of non-Newtonian liquid effects caused by clay-water interaction.