The investigation of the flow of polymer solutions in porous media is systematically studied. Polysaccharide and polyacrylamide polymers are used in this study. The shear-rate dependent viscosity of polymer solutions is measured by capillary viscometers and fitted by the Meter model. The flow experiments are conducted with a porous media viscometer. The porous media under investigation include sintered bronze and filter cloth. Results indicate that the experimental pressure drop deviates from the pressure drop predicted by the capillary model. This deviation in the pressure drop depends on the rheological property of polymer solutions and the geometry of porous media. When sintered bronze is used, the trend and the magnitude of the pressure drop deviation for polysaccharide solutions is different from that for polyacrylamide solutions. This difference is attributed to the viscoelastic effect of polyacrylamide. A structural model which consists of periodic constricted tubes is proposed to simulate the porous medium. Effects of both rheological parameters and geometric parameters on the pressure drop are demonstrated from the theoretical analysis of the structural model. It indicates that the capillary model of the porous medium can either underpredict or overpredict the experimental pressure drop, depending on the geometry of the porous medium. This structural model is proved to be more successful for correlating and interpreting the experimental data. Overall, the present study is believed to contribute a better description of the flow of non-Newtonian fluids in porous media. It provides the quantitative evidence that a model with the convergent-divergent geometry is required to model the porous medium.
