Transport Properties: Calculation

Abstract

In the previous chapter, a brief description of the kinetic theory was presented. We now consider appropriate applications of the theory to the prediction of transport properties of pure fluids and mixtures in the gaseous and liquid states. The methods chosen are those that have a reasonable connection with the theory and in which a transport property X is written:The critical enhancement AX C will not be considered further here. The dilute-gas term X 0 will be discussed first. Then, the estimation of the excess transport properties AX for compressed gases by the method of Thodos will be examined while, for liquids, the scheme proposed by Dymond and Assael will be presented. Finally, for the estimation of the viscosity and thermal conductivity of non-polar mixtures, the corresponding-states scheme of Ely and Hanley will be outlined.In Section 10.6, numerical examples based on these methods will be given. Dilute Gases and MixturesFor a dilute gas, the viscosity is given from Eq.(9.30) as f is generally taken as unity. This expression, although strictly applicable only to a monatomic gas, is used in practice as a correlating tool for many pure gases including those with polyatomic molecules. The reduced collision integral Q* = Q/(n<P-) has been tabulated as a function of T* = k B T/e for a number of model intermolecular potentials. A few experimental values of the viscosity are then Thermophysical Properties of Fluids Downloaded from www.worldscientific.com by UNIVERSITY OF BIRMINGHAM LIBRARY -INFORMATION SERVICES on 03/22/15. For personal use only.