For a continuous random walk in 2-D
steps to travel a distance d, where l is the mean free path. The time required is then
where is the sound speed. Defining a diffusion coefficient
yields
Diffusion Coefficient, Diffusion Equation, Eddy Diffusion, Effusion, Graham's Law of Effusion, Mean Free Path
References
Crank, J. The Mathematics of Diffusion, 2nd ed. Oxford, England: Oxford University Press, 1975.
Ghez, R. A Primer of Diffusion Problems. Wiley, 1988.
Weisstein, E. W. "Books about Diffusion." http://www.ericweisstein.com/encyclopedias/books/Diffusion.html.
