A molecular simulation study of shear and bulk viscosity and thermal conductivity of simple real fluids

TL;DR

This study uses equilibrium molecular dynamics with the Green-Kubo method to predict shear viscosity, bulk viscosity, and thermal conductivity of simple fluids and their mixtures, comparing results with experimental data.

Contribution

It demonstrates the effectiveness of Lennard-Jones models and Green-Kubo method in predicting transport properties of simple fluids and highlights issues with experimental bulk viscosity data.

Findings

Good agreement for shear viscosity and thermal conductivity with experiments.

Poor agreement for bulk viscosity suggests experimental data may be inaccurate.

Lennard-Jones models effectively predict certain transport properties.

Abstract

Shear and bulk viscosity and thermal conductivity for argon, krypton, xenon, and methane and the binary mixtures argon+krypton and argon+methane were determined by equilibrium molecular dynamics with the Green-Kubo method. The fluids were modeled by spherical Lennard-Jones pair-potentials with parameters adjusted to experimental vapor liquid-equilibria data alone. Good agreement between the predictions from simulation and experimental data is found for shear viscosity and thermal conductivity of the pure fluids and binary mixtures. The simulation results for the bulk viscosity show only poor agreement with experimental data for most fluids, despite good agreement with other simulations data from the literature. This indicates that presently available experimental data for the bulk viscosity, a property which is difficult to measure, are inaccurate.