Dynamic Viscosity of Some Lubricants in Terms of Local Nano-Void Fraction

Abstract

In the current study, the dynamic viscosity has been established by the preceding viscosity correlation equation in terms of thermo-occupancy function, Y h = Y h ( h, T ) , for three types of chemically differ-ent pure substances between 283.15–398.15 K and up to 100 MPa. The thermo-occupancy function, Y h = Y h ( h, T ) , comprises temperature T and hole (nano-void) fraction h = h ( P, T ) estimated by the Simha–Somcynsky equation of state through the published density data. The density fitting results were found by this report to be from 0.026 to 0.051%. The predictive dynamic viscosity of dialkyl carbonates, ethylene glycol dimethyl ethers, and di(2-ethylhexyl) sebacate was obtained with an overall uncertainty of 0.29%, 0.40%, and 0.38%, respectively. The effects of the optimized volumetric and rheological parameters on the compounds’ molecular structure and architecture were investigated. The increase in fraction h with an increasing temperature suggests a decrease in the rate of change in dynamic viscosity (viscoholibility) of the samples over a computed hole fraction range.