I am looking for binary diffusion coefficients of water vapour in air at normal pressure for various water/air temperatures. I found the following relation
Diff (T) = 22.5*10-6 (T/273.15K)1.8 [m2/s]
However, no reference is given, where it comes from. Do you have an equation or coefficients in tabular format or a reference for the formula shown above?
I think the book Transport Phenomena see https://en.wikipedia.org/wiki/Transport_Phenomena_(book) or http://eu.wiley.com/WileyCDA/WileyTitle/productCd-EHEP003580.html is a good reference for this. If I remember correctly it includes a section about how to calculate binary diffusion coefficients.
Probably a bit late but I came across a very similar expression in the book of H. Pruppacher & James Klett "Microphysics of clouds and precipitation'.
Is an interesting issue. Thank you for the information you provided
You are right, Mohiuddin Ahmad. But this is a problem of the Researchgate web-site. The '-' disappears and reappears depending on the format in which you view the initial question. Better this way?
Diff (T) = 22.5E-06 * (T/273.15K)^(1.8) [m*m/s]
The book "Handbook of tables of applied engineering and science" by Boltz contains a table relating temperature with diffusion coefficient. The fit of the data yields that equation.
https://books.google.com/books?id=Xn8KbsgeFrwC&q=diffusion+constant+of+water+vapor+in+air#v=snippet&q=diffusion%20constant%20of%20water%20vapor%20in%20air&f=false
Hello,
There is a correlation that could be found in MELCOR Material properties Package Reference Manual.
D_sa = 4.7931e-5 (T^1.9)/P .T in Kelvin and P in Pascal.
Reference report: Norman, T. L., Revankar, S. T., Ishii, M. "Steam-air mixture condensation in a subcooled water pool"
Hi, I just found this paper , probably it's the source of your formula
Gaseous Diffusion Coefficients- T. R. Marrero and E. A. Mason , 1972
Journal of Physical and Chemical Reference Data 1, 3 (1972); https://doi.org/10.1063/1.3253094
figure 78 (water-air)
- Badges
- Science topic