Re: Deposition within a porous electrode

Hi Pieter:
A dilute neutral species in the electrolyte is reduced at the cathode, and combines with the cations to form the insoluble deposit.
When I model this without reduction of porosity, the results are sensible: the thickness of the deposit grows smoothly with time, the concentrations of cation and neutral species are depleted in the cathode, the concentrations of cation and anion grow in the free region close to the anode such that the total amounts (integrated concentration) remain constant.
I can use the (local) thickness of deposit to slow the reaction rate (actually increase the over-potential at constant current) by reducing the active area in proportion to Ldep, and/or by decreasing the exchange current.
So I believe that I have the physics correct up to the point of inducing flow due to the lost volume in the porous region. And as I said last time, the flow velocity and pressure appear to make sense. The ternary current node and Darcy's Law node both apply in the free and porous regions. Does that not make the concentrations and (Darcy) velocity continuous at the interface?

Thanks, Campbell