Chapman-Enskog theory

Extension to Polar Molecules

By Jim Ross and Michael Weeks

Chbe 401 Final project


H2O A Polar Molecule

The electrons are more strongly attracted

to the oxygen atom, which causes an uneven

distribution of charge and, subsequently, an

electric interaction between molecules.

*Source -




Scientific Background

       Boltzman Equation


Comparison of Non-Polar and Polar Models

       Lennard-Jones and

Extension to Polar Molecules

Viscosity from Chapman-Enskog Theory







R. B. Bird, et al., Transport Phenomena, 2nd Ed., John Wiley & Sons, Inc.: 2002.


S. G. Brush, Kinetic Theory, Vol. 2 & 3, Pergamon Press: 1972.


S. Chapman and T. G. Cowling, Mathematical Theory of Non-Uniform Gases, 3rd Ed., Cambridge Press: 1970.


L. Monchick and E.A. Mason, J.Chem. Phys. 9, 398 (1941).