define mass diffusivity for each zone
 

Dear Fluent-User!

I am modelling mass transfer in two zones.

One zone is a normal duct and another zone is a porous media.

I want to use kinetic theory for mass diffusivity in the duct.

For the porous media, as I know, I must write DEFINE_DIFFUSIVITY.

But, if I define DEFINE_DIFFUSIVITY in the materials panel, I can not use kinetic theory, can I?

What can I do for this case?

Thank you in advance

Hi Kim

I have a similar problem, did you find any answer? it would help me a lot. I want to use the kinetic option theory for both and then use C_DIFF_L macro to manipulate the diffusivity. What do you suggest? I had a problem with my UDF.h code it is online now.

Cheers,