CFD Online Discussion Forums

CFD Online Discussion Forums (http://www.cfd-online.com/Forums/)
-   FLUENT (http://www.cfd-online.com/Forums/fluent/)
-   -   mass diffusivity (http://www.cfd-online.com/Forums/fluent/28916-mass-diffusivity.html)

Amanda September 11, 2001 05:22

mass diffusivity
 
Hi! all, When we dealing with multi-species flow, in defining the mixture material, it is required to input the mass diffusivity. What does this mass diffusivity refers to? molecular(Di,m) or turbulent(Dt) diffusivity coefficient? if I'm insterested in mixing of two species of water having the same properties, what value should I use for mass diffusivity?

Thanks in Advance!


Jin-Wook LEE September 11, 2001 20:19

Re: mass diffusivity
 
1. Molecular......

2. If you are interested in the turbulent flow. Turbulent diffusivity is very larger than molecular one, so that some deviation for the mass diffusivity input hardly affects the result. But the effect is fairly large for laminar flow.

SIncerely, Jinwook



All times are GMT -4. The time now is 02:41.