Correspondence Principle for Transport Properties of Dense Fluids. Nonpolar Polyatomic Fluids

Abstract

A model for hindered rotation at high densities is based on a simple harmonic oscillator theory. The expression for the Hamiltonian so obtained, substituted into the time correlation function expressions for the transport coefficients, gives rise to a more general principle of corresponding states. The reduced equations contain a rotational coupling coefficient which acts as a third parameter; however, only two independent variables are needed in the correlation. For monatomic fluids, or in the low density limit, these equations reduce correctly to the simple two-parameter correspondence principle. The proposed relationships give good agreement for viscosities, thermal conductivities, and self-diffusion coefficients of the 25 fluids tested over a wide range of temperatures and pressures. The model accounts in a reasonable way for thermodynamic properties of polyatomic fluids.

Viscosity of liquid hydrocarbons and their mixtures

“…For instance, the normal boiling points of n-alkylbenzenes are slightly higher than those of n-alkylcyclohexanes of the same carbon number, whereas the viscosities of the latter are clearly higher. Tham and Gubbins (1970) explained the temperature effect on viscosity by a harmonic oscillator theory. Geometrical data of the molecule are needed together with the acentric factor and an energy parameter.…”

Corresponding states correlation of dissolved‐gas diffusion in normal alkanes

“…The generalized correlation, Eq. 1, is reminiscent of what Tham and Gubbins (1970) developed for self-diffrisivities in saturated liquids involving parameters for intermolecular potential energy and for molecular rotation. When applied to binary diffusion, this procedure entails rational mixing rules for the parameters associated with both components.…”

“…Although the CSP has been successfully utilized to correlate transport properties including viscosity, thermal conductivity (Tham and Gubbins, 1970), and self-diffusivity (Riazi and Daukrt, 1980) in dense fluids, its application to tracer diffusivity will reg resent a significant extension of previous work.…”

Thermodynamic and rheological properties of solid-liquid systems in coal processing. Quarterly technical report: March 1, 1993 to May 31, 1993

“…Many researchers [9,44,56] have proposed correlations for viscosity based on the law of Corresponding States which states that two fluids which have the same values of reduced temperature and reduced pressure are said to be in Corresponding States.…”