Contribution to the modeling of the shear viscosity of sulfur hexafluoride (SF6): Comparative study of some representative models

[Display omitted] •Shear viscosity of SF6 has been modeled (from 225.18 to 473.15K up to 51.21MPa).•Physically based viscosity models using from 1 to 6 parameters yield good results.•Effective repulsive steepness of the SF6 potential is higher than expected. Three recent physically based models (Lennard-Jones, free volume, thermodynamic scaling) for representing the viscosity of sulfur hexafluoride (SF6) are discussed together with two models (friction theory and Enskog 2σ) that have been recently applied to this fluid. The experimental database employed for adjustment (1562 data points) considers a large temperature (225.18 to 473.15K) and pressure intervals (0.0264 to 51.21MPa). The absolute average deviation is 3.8% for the Lennard-Jones model (one parameter), 1.7% for the free volume model (three parameters) and 1.5% for the thermodynamic scaling model (six parameters). Thus, it is shown that when physically based approaches are employed, a limited number of parameters is sufficient to represent accurately the shear viscosity of SF6. Furthermore it has been confirmed, using the thermodynamic scaling approach, that the repulsive steepness of the SF6 interaction potential is higher than usually found for fluids composed by non polar spherical molecule.