Determination of the Upper Limit Up To Which the Linear Flow Law (Darcy's Law) Can Be Applied

Abstract

In the practice of hydrodynamic calculations the linear flow law, commonly called Darcy's law, is now widely used. It is well known that it is violated at large pressure gradients. This means that there is a certain limit value of the pressure gradient Δp* above which a deviation from the linear character of the flow law begins. This value of the pressure gradient is the upper limit of applicability. A method is presented for the direct determination of the upper limit of the validity of the linear flow law (Darcy's law) for any porous media. The method is based on the principles of percolation modelling of fluid flows in porous media. The influence of the structure of the pore space on the value of the boundary gradient is analysed. A qualitative comparison with the experimental data is performed.