Hey Daniel, Apologies since this is probably basic stuff, but what do you mean with explicit, implicit, and coupled? I see in the documentation the implicitsourceterm and I understand how to use that one. By explicit you mean just write the equation mathematically? Without using ImplicitSourceTerm? What do you mean by coupled?
Salo On Tue, Jan 22, 2013 at 6:36 PM, Salomon Turgman Cohen <[email protected]>wrote: > 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 > -- Salomon Turgman Cohen Postdoctoral Associate Cornell University (919) 341-9650
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