The Enskog theory for transport coefficients of simple fluids with continuous potentials

Miyazaki, Kunimasa ; Srinivas, Goundla ; Bagchi, Biman (2001) The Enskog theory for transport coefficients of simple fluids with continuous potentials Journal of Chemical Physics, 114 (14). pp. 6276-6285. ISSN 0021-9606

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Official URL: http://jcp.aip.org/jcpsa6/v114/i14/p6276_s1

Related URL: http://dx.doi.org/10.1063/1.1355978

Abstract

The Enskog theory for the self-diffusion coefficient for fluids with continuous potentials, such as the Lennard-Jones, is developed. Starting from the Green-Kubo formula (rather than the conventional kinetic equation) and introducing the similar assumptions upon which the Boltzmann equation is based, we derived a general expression for the memory kernel and the self-diffusion coefficient. The numerical analysis is implemented for the Lennard-Jones fluid. The time-dependent memory kernel is calculated and compared with the latest molecular dynamics simulations. Excellent agreement is obtained at the low density. The self-diffusion coefficient is evaluated for various temperatures and densities. The ratio of the Enskog self-diffusion coefficient to the simulation value is plotted against density. Significant difference of this density dependence from that for the hard-sphere fluid is observed. In particular, the well-known maximum observed (in the diffusion versus density plot) for the hard sphere fluid is found to be completely absent in the Lennard-Jones fluid. Our results reduce to the conventional Chapman-Enskog expression in the low density limit and can be applicable to the systems with singular potentials such as the hard sphere.

Item Type:Article
Source:Copyright of this article belongs to American Institute of Physics.
ID Code:4186
Deposited On:18 Oct 2010 09:15
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