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Linking viscosity to equation of state using residual entropy scaling theory



Xiaoxian Yang, Xiong Xiao, Monika Thol, Markus Richter, Ian Bell


In our previous work, 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. This work extends the RES approach to 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 their 351 mixtures are collected from 1846 references. The investigated pure fluids contain a huge variety of fluids from light gases with quantum effects at low temperatures to dense fluids and fluids with strong association force. More than 68.2% (corresponding to the standard deviation) of the well-selected experimental data agree with the RES model within 3.2% and 8.0% for pure fluids and their mixtures, respectively. If dilute gas viscosity is calculated in the same way, the RES approach yields similar statistical agreement with the experimental data of pure fluids and their mixtures as the best-selected models implemented in the REFPROP 10.0 software (the state-of-the-art for thermophysical property calculation), while the RES approach has much simpler formulation and less parameters.
Aiche Journal


Yang, X. , Xiao, X. , Thol, M. , Richter, M. and Bell, I. (2022), Linking viscosity to equation of state using residual entropy scaling theory, Aiche Journal, [online],, (Accessed July 19, 2024)


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Created October 13, 2022, Updated January 19, 2023