SimScale CAE Forum

Diffusion in lattice structures using lattice boltzmann or simular

Hello,

I need to simulate the diffusion (permeability) of hydrogen, water and co2 in a gass diffusion layer in a hydrogen fuel cell. The goal is to find the coefficient of diffusion. The plan is to use darcy’s law to calculate the coefficient of diffusion. Therefore I need to know the pressure drop and flow across the gass diffusion layer.

The gass diffusion layer is going to be modelled as a quibic lattice structure and some triply peridoc minimal surfaces structures in varying sizes and compare them together to see which structure that shows the best performance. The unitcells will be in the size range of 50-100 micrometers and are going to be modelled in increasing size: 1 unit cell, 2x2x2 unit cells, 3x3x3 unit cells, 4x4x4 unit cells and so on…untill I find a representative volume element.

I have read that a lattice boltzmann solver is the best approach to model microscopic flow/diffusion. Do you guys agree? Is the LBM solver good for this problem? or is it other possibilities that is better?

Is it possible to change the unit symstem from meter to micrometer?

Thanks!

-Svenn Ove Hoem

Hi Svenn!

I would agree that LBM is quite useful here but the current state of the LBM solver is to my knowledge not able to capture these phenomena.

What you can do is to make use of the standard incompressible module which we offer as well. The approach that you could follow can be found in the Knowledge base here.

Let us know if that’s helpful!

Best,

Jousef