Generalized equation of state for Lennard-Jones fluids—I. Pure fluids and simple mixtures

Abstract

An extensive computer simulation (molecular dynamics) has been done for the calculation of PVT data of Lennard-Jones fluids and their binary equimolar mixture in a wide range of pressures and temperatures. The two pure fluids used form a somewhat artificial model which has either a weaker or stronger attractive interaction compared with argon, but is the same size as argon. Their Lorentz-Berthelot mixture is the now well-used LB-2-1 model. The obtained PVT data, together with existing data for argon, are used to establish optimized coefficients in a modified BWR-type equation of state used by Nicolas et al. This new generalized equation has been proved to reproduce PVT relations of both model and real fluids if optimized potential parameters are used for the latter. A preliminary account is given for the validity of van der Waals one-fluid approximation in the description of rather simple model mixtures such as LB-2-1.