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Diffusion with Langmuir Adsorption

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Hello All,
I have been using Comsol4.0a to model diffusion with adsorption through a porous medium. I have used a sink term in the normal diffusion equation to represent the adsorption to the surfaces of the medium, and rearranged to incorporate this into the diffusion coefficient like so:

dc/dt = D/(1+KG/(1-Kc)^2) Del^2(c)

where G is the number of absorbing sites and K is the adsorption coefficient. In a 3D model I am concerned that the diffusion will be slowed too much by this term, as the value for D in Comsol is accounted for seperately in each direction (which I found when looking in equation view). Any information on how Comsol uses these parameters would be useful as If this is the case I will need to reconsider how I account for adsorption.

0 Replies Last Post Oct 25, 2010, 5:01 a.m. EDT
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Hello Christopher White

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