[legendyxg]

My model is about the diffusion of multicomponents in porous media. I want to modify the mass diffusion coefficients including the effects of porosity and tuotorsity so I need to define the mass diffusion coefficients of each species separately, so how can I make it?

[gemini]

Originally Posted by legendyxg

My model is about the diffusion of multicomponents in porous media. I want to modify the mass diffusion coefficients including the effects of porosity and tuotorsity so I need to define the mass diffusion coefficients of each species separately, so how can I make it?

Hi, I think you are modeling fuel cells. You can use define_diffusivity macro, in this way you can define only Dim (i.e, dffusivity of species i in mixture). Another issue in fuel cell electrodes, you cannot specify different porosity tortuosity correction for different directions.

I am also working on modeling of fuel cells but I could not find a proper way to incorporate "full" multicomponent diffusion in porous electrodes in a fuel cell. Also, I could not solve direction dependent porosity corrections issue, yet.

good luck to you