Molecular simulation of the thermophysical properties of fluids: phase behaviour and transport properties

Abstract

Historically, reliable data for the thermophysical properties of fluids could only be obtained from accurate experimental measurement. The input from theory was, at best, limited to a supporting role by providing correlations. The large number of assumptions and approximations involved in theoretical tools such as equations of state meant that it was unrealistic to expect genuinely reliable predictions. More recently, the advent of powerful molecular simulation techniques has greatly enhanced the usefulness of thermophysical calculations, particularly in chemical engineering. Unlike conventional calculations, molecular simulation determines the properties of a fluid directly by evolving molecular coordinates in accordance with a rigorous calculation of intermolecular energies or forces. In this work, the application of molecular simulation to the prediction of the thermophysical properties of fluids relevant to chemical engineering applications is examined. In particular, the role of three-body interactions on the vapour-liquid coexistence of fluids is illustrated and compared with experimental data. Molecular simulation is also used to compare the viscosities of dendrimer fluids with linear polymers of equivalent molecular weight.

Keywords:

• Molecular simulation
• Dendrimer
• Viscosity
• Phase behaviour