Non-Equilibrium Molecular Dynamics Calculation of the Shear Viscosity of Carbon Dioxide/Ethane Mixtures

Abstract

Non-equilibrium molecular dynamics simulations of the shear viscosity of mixtures of carbon dioxide and ethane at a fixed total density (20 mole-dm³) and at five compositions ranging from pure carbon dioxide to pure ethane are reported. In this study, two-site Lennard-Jones potential models are used for all the inter-molecular interactions. The cross parameters of ethane/carbon dioxide potential have been fitted to the azeotrope of the mixture. Results from the simulations are in good agreement with experimental data. In particular, a plateau region in the experimental data as a function of composition is reproduced by the simulations but is not predicted by extended corresponding states correlations.

Key Words:

• Mixture
• shear viscosity
• intermolecular potentials
• molecular dynamics
• carbon dioxide
• ethane