Second, Third and Higher Orders of Virial Coefficients for Polar Fluids

Abstract

The paper features the mathematical model of computing the second, third virial coefficient and higher orders of virial coefficients for polar f l u i d s o n t h e b a s i s o f s t a t i s tical mechanics. The model for calculation of equilibrium thermodynamic properties contains all important molecular contributions (translation, rotation, internal rotation, vibration, intermolecular potential energy and the influence of electron and nuclei excitation). The constants necessary for the computation like the characteristic temperatures of rotation, electronic state etc. and the inertia moments are obtained analytically applying the knowledge of the atomic structure of the molecule. The vibration constants are obtained using the modified Urey-Bradley force field. In the present paper we have developed the new model for calculation of second virial coefficient which yields favorable results in practical computations for a large number of components and within a relatively wide range of densities and temperatures. We consider rigid nonlinear molecules with the reference Lennard-Jones interaction potential and dipole moment as the basis of mean field theory. The constants necessary for the computation like the characteristic temperatures of rotation, electronic state etc. and the inertia moments are obtained analytically applying the knowledge of the atomic structure of the molecule. The presented model is the original part of work and and is new in engineering scientific area.