Solute Dispersion in Flow through Saturated Porous Media

Dispersion in porous media arises from the chaotic nature of pore level velocity field forced on the flowing fluid by the irregularity of the pore space. In this work, a sandstone pattern etched on glass is considered as porous medium. Visualization of solute dispersion experiments performed on porous model that is initially saturated with the water at varying values of flow rate. The accurate measurements of temporal variation of the solute concentration over various regions of porous models were provided by image analysis of color intensity of continuously provided pictures. The inverse modeling of the convection-diffusion equation is applied and the longitude and transverse dispersion coefficients are determined using a suitable optimization algorithm as a function of flow rate. The results show that at low velocity the order of magnitude of longitude and transverse dispersion coefficients are the same, while at the high velocity they are not. The measured dispersion coefficients values are within the range of experimental data available for different porous media. This study illustrates the successful application of micromodel as a quantitative tool for studying dispersion phenomena in sandstone porous model.

کلیدواژه ها:

Dispersion Coefficients ، Dispersivity ، Sandstone ، Solute ، Micromodel