A Viscosity Model of Liquid Based on Absolute Rate Theory at High Pressures

In this work, a viscosity model for liquid at high pressure modified from Macías-Salinas's model was presented, in which the pressure influence on vacancy formation energy was considered and a reference state was introduced. Compared with other model, the enthalpy of vaporization and the compressibility factor at saturated condition are eliminated in the new model, which improves the accuracy and leads to a simpler form. The model was tested by using the experimental viscosity data of 15 liquids at temperatures from 90 K to 440 K and pressures up to 251.3 MPa. The overall average absolute relative deviation of the present model was estimated to be lower than 2%, and the absolute maximum deviation was lower than 9.4%, which verified the precision of the present model.