Hello, I need to determine the mass diffusivity in FLUENT. Can I get the diffusivity value directly in FLUENT or I need to write down UDF in order to get the diffusivity value?

Thanks.

mass diffusivity in fluent is determined in material panel. or you will get the value in display>countors> Lam Diff Coef of species-n (in the Species... category)

hye, thanks to Shoushibo. I cannot find the Lam Diff Coef of species-n in the display window. I need to define something or what? I need to enable any model in define model?

do you activate the species model? if no ,you need. do you want to simulate a species transport in the mixture? in the material panel , there is a item about mass diffusivity. you may check it. good luck.

thanks shoushibo. Actually Im simulate a species transport for mixture in the Eulerian model. Im already found the mass diffusivity item in the material panel. What I want now is the mass diffusivity after certain time step of simulation. How can I get the mass diffusivity value for that?

it should be in the display/countor/species/lam diff of species n

hi Shoushibo, I still cannot find the lam diff of species n as what you said. Im using Fluent 6.3. In the species model, I enable the species transport also the options diffusion energy sorce and full multicomponent diffusion. Is that I missing something in define the species and transport model? Thanks.

you can try to disable the full multicomponent,and see the results. i solve the binary diffusion in the speices model.

[nishith]

hi me too facing the same problem...... i am defining two phases. where i want to include mass diffusivity... but i am not getting how to find out this mass diffusivity panel.... every where it is written ...that it is in the materials panel..... but i could not found ..... please throw some light....

[yc9316]

just as the way given by shoushibo, display/countor/species(not properties)/lam diff of species n is the way to display laminer mass diffusive, my fluent version is Ansys 12. Refer to mass diffusive in materials panel, it is in mixture(material type) only. good luck.

[moulish]

Hai Iam also facing the similar problem but I want to know the fluent computed value after 1000 iterations, not how to specifiy at inlet