Surface Tension of Refrigerant Fluids from a Molecular-Based Model

Abstract

This work addresses a revised method of Fowler’s approximation for predicting the surface tension of refrigerant liquids using a Lennard–Jones (LJ) (12–6) model potential. The required LJ parameters were determined from the second virial coefficients. The major finding in this work was that the effective soft-sphere diameters of the studied LJ-like fluids were found to be a function of temperature and the acentric factor (ω). The reliability of the proposed method was determined by comparison with the literature over a temperature range of 85–384 K. From the 296 data points examined for the above-mentioned liquids, the overall average absolute deviation (AAD) was found to be 2.50%. The uncertainty in the surface tension prediction was ±6.85%. Additionally, surface thermodynamic functions, such as the surface entropy (SS) and surface enthalpy (HS), were also computed via our method. The uncertainties were found to be ±8.93% and ±11.64%, respectively. Furthermore, the AADs of the estimated SS and HS values were found to be 7.50% and 4.79%, respectively. Finally, our method was also employed to estimate the critical temperature of some alkanes with an uncertainty equal to ±5.56%.