On Tue, Jan 22, 2013 at 3:22 PM, Salomon Turgman Cohen
<[email protected]>wrote:
> What I was thinking is this:
>
> A = Gas, B=Liquid
>
> Equation 1 for A:
> dCA/dt=d/dz(D*dCA/dz) - ka*CA*CB + kb*CA*CB
>
> Equation 2 for B:
> dCB/dt=d/dz(D*dCB/dz) - kb*CA*CB + ka*CA*CB
>
Something like this might work.
from fipy import TransientTerm, etc
...
eqnCA = TransientTerm(var=CA) == DiffusionTerm(D, var=CA) -
ImplicitSourceTerm(ka * CB, var=CA) + ImplicitSourceTerm(kb * CA, var=CB)
eqnCB = TransientTerm(var=CB) == DiffusionTerm(D, var=CB) -
ImplicitSourceTerm(ka * CA, var=CB) + ImplicitSourceTerm(ka * CB, var=CA)
eqn = eqnA & eqnB
...
for sweep in range(sweeps):
res = eqn.solve()
print res
It's just a question of adjusting the ImplicitSourceTerms to give the
optimal convergence. Try explicit to start and then see if implicit helps
any and then try coupled. Having both implicit and coupled should improve
convergence.
>
> I am not sure yet of the order of the reaction rates or if I will need to
> add a third component (since the reaction is in fact A + B <-> C). Can you
> guide me in setting up such a system?
>
Try explicit sources, implicit and then coupled and see how the convergence
changes for a very simple system. Try 1D to start with.
Set something up and then I can help you debug it. Cheers.
--
Daniel Wheeler
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