A sequential-analytic method for determining the radial distribution function and predicting the thermodynamic properties of real fluids

A new concept of differential phase has been proposed. The flux of molecule s between two phases, rather than the fugacity, is used to formulate the ph ase equilibrium. A double-resistance physical model is presented for modell ing the flow of molecules through the interface of two phases. By equating the equilibrium between differential phase and bulk phase, a generalized se quential-analytic method for determining the radial distribution function ( RDF) is developed. The proposed method is capable of giving RDF values clos e to those obtained by molecular simulation. It has been shown that when co upled with the Lennard-Jones potential model, the pressure-volume-temperatu re (PVT) relation of pure fluids with molecular size up to n-hexane can be predicted satisfactorily in wide ranges of temperature and pressure. (C) 19 99 American Institute of Physics. [S0021-9606(99)52802-X].