Linking viscosity to equations of state using residual entropy scaling theory

Abstract

Abstract In our previous work (J. Chem. Eng. Data 2021, 66, 3, 1385–1398), a residual entropy scaling (RES) approach was developed to link viscosity to residual entropy (a thermodynamic property calculated with an equation of state, EoS) using a simple polynomial equation for refrigerants. Here, we present an extension of this approach to a much wider range of fluids: all pure fluids and their mixtures whose reference EoS and experimental viscosity data are available. A total of 84877 experimental points for 124 pure fluids and 351 mixtures are collected from 1846 references. The investigated pure fluids contain a wide variety of fluids from light gases with quantum effects at low temperatures to dense fluids and fluids with strong intermolecular association. More than 68.2% (corresponding to the standard deviation) of the evaluated experimental data agree with the RES model within 3.2% and 8.0% for pure fluids and mixtures, respectively. Compared to the recommended models implemented in the REFPROP 10.0 software (the state-of-the-art for thermophysical property calculation), if the dilute gas viscosity is calculated in the same way, our RES approach yields similar statistical agreement with the experimental data while having a much simpler formulation and fewer parameters. To use our RES model, a software package written in Python is provided in the supporting information.