Calculation of transport properties of simple dense fluids

Abstract

The transport properties of noble gases and of some other simple fluids including N 2, O 2, F 2, CO, CO 2, CH 4, CF 2Cl 2, C 2H 6, C 3H 8 and SF 6 have been calculated by the modified Enskog theory. The density dependence of the radial distribution function has been evaluated using an analytical equation of state based on the statistical–mechanical perturbation theory. The resultant transport equation of state needs three temperature-dependent parameters, which can be determined by knowing the intermolecular pair potential, plus the zero-density values of the transport coefficients. Using a simple Lennard–Jones (12-6) potential for the calculation of temperature-dependent parameters and the extrapolation of experimental low-density transport coefficient data to the zero-density limit, one can put the transport equation of state in the predictive mode. In this work the thermal conductivity and the viscosity coefficient of the helium-group gases have been calculated over a wide range of temperatures and pressures. A comparison of the calculated and experimental values of the thermal conductivity and the viscosity yields an average absolute deviation of 2.66% for the thermal conductivity and of 3.03% for the viscosity.