Fluid Phase Equilibria, Vol.175, No.1-2, 311-323, 2000
A new method for predicting saturated liquid viscosity at temperatures above the normal boiling point
A new temperature viscosity relationship similar to the Rackett equation for saturated liquid volumes is proposed for predicting saturated liquid viscosity at temperatures above the normal boiling point. The first order group contribution Values proposed earlier by the authors for predicting the viscosity at the normal boiling point are revised. Combining these two, the viscosities of organic liquids can be predicted at any temperature above the normal boiling point using the normal boiling point, critical temperature and chemical structure only as inputs. The accuracy of the correlation compares favourably with those used for the low temperature region. It is observed that the three properties, volume, thermal conductivity and viscosity, of saturated liquids can be predicted by using the same generalised empirical approach starting from a form of the Rackett equation.
Keywords:viscosity;method of calculation;organic liquids;normal boiling point;critical temperature;chemical structure