A new mathematical model for the viscosity of vegetable oils based on freely sliding molecules

Abstract

Viscosity is one of the most important parameters for vegetable oil. A new mathematical viscosity model was developed based on freely sliding molecules with Lennard-Jones’ potential and linear density-temperature relation. According to the functions derived from the new model, viscosity gradually decreases with temperature at atmospheric pressure. Viscosity increases with density, however, due to the molecular momentum transfer and statistical effect of average molecular potential. After the temperature dependent function is fitted to the 417 experimental data points collected from references and distributed among the ranges: 278.15–453.15 K and 2.6-192.6 mPa.s, it was found that the calculated data agreed well with experimental data with R2 ≥ 0.961 for 13 oil samples. The density dependent function was also satisfactorily fitted to the 143 viscosity data points versus density from 5 oil samples with R2 ≥ 0.917.

Keywords

• density
• model
• temperature
• vegetable oil
• viscosity