How to define mass diffusion coefficients in porous media
 

Hi all,

I read a paper recently which is related to channel reacting flow simulation. Catalyst porous wash-coat is coated on the wall. In this paper, the author defined an effective mass diffusion coefficient for every species in porous media.

Attached are equations used in the paper to define effective mass diffusion coefficients in porous media.

I am wondering how can I implement these equations in fluent. Or can anybody tell me how fluent calculate mass diffusion coefficient in porous media by default?

Best.

Weiqiang.