Thanks again for your help Daniel. Always appreciate it. I will report back with the results.
Salo On Tue, Jan 22, 2013 at 6:06 PM, Daniel Wheeler <[email protected]>wrote: > 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 > > _______________________________________________ > fipy mailing list > [email protected] > http://www.ctcms.nist.gov/fipy > [ NIST internal ONLY: https://email.nist.gov/mailman/listinfo/fipy ] > > -- Salomon Turgman Cohen Postdoctoral Associate Cornell University (919) 341-9650
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