BC in Electrochemistry solver

Numerical methods and mathematical models of Elmer
jfaraudo
Posts: 17
Joined: 11 May 2018, 11:50
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Re: BC in Electrochemistry solver

Post by jfaraudo »

Don't worry.. thank you anyway for reading the posts and trying to help!
Jordi :)
mzenker wrote:
jfaraudo wrote:Matthias, please, read my comment more carefully.
You are right. Before answering, I should have taken more time to analyze your problem - or, since I am not an electrochemistry expert, I should not have answered at all.

Matthias
jfaraudo
Posts: 17
Joined: 11 May 2018, 11:50
Antispam: Yes

Re: BC in Electrochemistry solver

Post by jfaraudo »

Thank you for your help!

Yes, you are right. I am interested in situations in which all three contributions to the electrochemical flux N are important: diffusion, advection/convection by the fluid and Nernst-Planck electrochemical flow.

I think that implementing this is something that can be done, it is just a question of enough resources in terms of "hours-person".

jordi
annier wrote:Matthias,
I think you have answered very correctly in the second post .

In fact, flux BC is available for any PDE having diffusion and advection/convection term.
https://github.com/ElmerCSC/elmerfem/bl ... delPDE.F90

D grad_c = g ---(for a general PDE).
dC/dt = D nabla^2 c - v_{conv}.c


D_{em} grad_c = h ---(for electrochemical solver with the fluid motion nearly equal to zero).
1/M_{i} dC/dt = D_{em} nabla^2 c - grad_phi.c,
where , D_{em} = D/M_{i}
M_{i} = Dze/(kT),
So, we need to put 1/M_{i} in the coefficient of time-derivative term and D/M_{i} in the coefficient of diffusion term. Then, the flux BC applies for Nernst Planck term.
Now, the difficult part, what Jordi is trying to say is the inclusion of flow solver, which has an additional convection vector (fluid velocity) different than grad_phi.

Yours Sincerely,
Anil Kunwar
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