Theoretical and computational approaches to predicting the viscosity of liquids

Predictive models for the shear viscosity of liquids and gases along with exact equations of state are of great practical importance for hydrodynamic modeling of processes occurring in nature, industrial plants, and machinery. We consider currently proposed theoretical, including atomistic modeling, and semi-empirical approaches to predicting the viscosity of liquids, gases, and their mixtures in a wide range of thermodynamic conditions. Viscosity models of homogeneous liquids in a thermodynamically stable state are described. The dynamics of supercooled and vitrescent liquids and dispersed systems (colloids, emulsions) remain beyond the scope of this review. We discuss the area of applicability of correlation methods for predicting viscosity and the accuracy of various methods in the pressure range up to 1 GPa. Application examples of various approaches for hydrocarbons—model oil and gas, fuel, and lubrication systems—are given.