Entropy Scaling of Viscosity IVApplication to 124 Industrially Important Fluids

In our previous work
[Yang, X. J. Chem. Eng. Data 2021, 66, 1385–1398], a residual
entropy scaling (RES) approach
was developed
to link viscosity to residual entropy using a 4-term power function
for 39 refrigerants. In further research [Yang, X. Int. J. Thermophys. 2022, 43, 183], this RES approach was extended
to 124 pure fluids containing fluids from light gases (hydrogen and
helium) to dense fluids (e.g., heavy hydrocarbons) and fluids with
strong association force (e.g., water). In these previous research
studies, the model was developed by manual optimization of the power
function. The average absolute relative deviation (AARD) of experimental
data from the RES model is approximately 3.36%, which is higher than
the 2.74% obtained with the various models in REFPROP 10.0. In the
present work, the power function was optimized by iteratively fitting
the global (fluid-independent power terms) and local parameters (fluid-specific
and group-specific parameters) and screening the experimental data.
The resulting equation has only three terms instead of four. Most
notably, the AARD of the new RES model is reduced down to 2.76%; this
is very close to the various multiparameter models in REFPROP 10.0,
while the average relative deviation (ARD) amounts to 0.03%, which
is smaller than REFPROP 10.0’s 0.7%. A Python package is provided
for the use of the developped model.