Diffusivity of Simple Fluid Mixtures in Porous Media: Molecular Dynamic Simulations and Correlation Models

It iswell knowthatmolecular dynamics simulations can provide an insight into the microscopic characters and relate them to the microscopic properties, and MD simulations are widely used to study the microscopic flows in porou media. The diffusivity ofLennard-Jones liquid argon, krypton and their binarymixtures in the macrovolumen systems ha been calculated by equilibriummolecular dynamic(EMD) simulations in order to prove this program′s validity. In addition, the diffusivity of liquid mixtures of argon and krypton in slit porous media has been obtained by EMD simulations a differentreduced temperatures, densities and pore widths. The result shows that the diffusivity of fluids will increas sharply in narrow pores. Based on the Chapman-Enskog theory and Heyes equations, two correlation models, which can describe the diffusivity of simple fluid mixtures in porous media, are proposed as functions of the reduced temperature, density and porewidth. The results calculated fromthe models are in good agreementwith the data fromMD simulations.