APPLICATION OF ENSKOG THEORY ON THE VISCOSITY OF ARGON.

The viscosity of argon at temperatures above the critical temperature can be described by the classical Enskog theory for hard spheres over a moderate density range intermediate between zero and the melting density. In the high density Enskog part of the theory the temperature dependent impact diameter has been substituted corresponding to the density of the fluid at the melting point. On the other hand, in the low density Chapman-Enskog part the low velocity diameter sigma //c corresponding to phi ( sigma //c) equals 0 has been applied, as suggested by this theory. Furthermore, it is shown how these diameters fit into the intermolecular potential phi (r).