[Weiqiang Liu]

Hi all,

I want to define different mass diffusive coefficient in different zones with UDF. For example, I need to assign effective diffusion coefficient to porous zone. To calculate effective diffusion coefficient, I need to know molecular diffusion coefficient of species which is mixture averaged or multi-component depending on models I use.

I checked UDF manual and found that C_DIFF_L(c,t,i,j) is used to obtain binary diffusion coefficient and C_DIFF_EFF(c,t,i) is used to obtain effective coefficient.
none of these two macros can be used to obtain molecular diffusion coefficient.

my question is do I have to calculate molecular diffusion coefficient based on binary diffusion coefficient I derive and then assign this molecular diffusion coefficient with DEFINE_DIFFUSIVITY (name, c, t, i)?

Or maybe some macros can be used to obtain molecular diffusion coefficient directly?

Best.

Weiqiang