Entropy scaling framework for transport properties using molecular-based equations of state

Abstract

Modeling transport properties is important for many applications. In this work, an entropy scaling framework for modeling transport properties using molecular-based equations of state (EOS) is presented. It can be applied for modeling the viscosity, thermal conductivity, and self-diffusion coefficients. The framework is formulated in a general way such that it can be coupled with various EOS. It is demonstrated that the model, when coupled to molecular-based EOS, provides not only good descriptions of existing data but also reasonable predictions in a wide range of states covering liquid, gaseous, supercritical, and meta-stable regions. Moreover, the model can be used for reliably predicting transport properties of mixtures. The universal parameters of the model were fitted to computer experiment data of the Lennard-Jones fluid. This procedure provides inherently a robust form of the basic scaling function. Thereby, only few data points are required for the determination of the component-specific model parameters. The applicability of the developed framework is demonstrated for model fluids as well as for a wide variety of real substances including non-polar, polar, and associating pure fluids and mixtures.