On May 15, 2013, at 12:43 AM, Chuck Holbert <cfholb...@yahoo.com> wrote:
> Now that you explain it, this is exactly what I need. I'm not fluent in > programming so not sure how to implement these suggestions within FiPy. Can > you point me to an example that I can use to get started? Any help will be > greatly appreciated!! > > < Do you also want the concentration at the interface to decrease due to > "forward" diffusion? > > Yes, I also want the concentration at the interface to decrease due to > "forward" diffusion. > > < To make a finite reservoir, you should be able to have one or more cells at > the left side that start with some amount of stuff in them and then have a > (default) no-flux boundary condition at the left. > > How do I code this in FiPy? My starting concentration is 250 in the > reservoir cell and 0 everywhere else. reservoir = mesh.x < reservoir_width phi = CellVariable(name="Concentration", mesh=mesh, value=0.) phi.setValue(250., where=reservoir) > < With an explicit, finite reservoir, I would be inclined to model the decay > with an implicit source term that's only active in the reservoir cells. > > Can you provide guidance on how to implement this in FiPy? The decay is > first order where the rate constant k is constant within each period (k = > 0.05 for period 1, k = -1 for period 2, and k = -0.05 for period 3) . k = Variable(0.05) eq = TransientTerm() == DiffusionTerm(coeff=D) - ImplicitSourceTerm(coeff=k * reservoir) : : eq.solve(var=phi, dt=dt) : : k.value = 1. : : eq.solve(var=phi, dt=dt) : : _______________________________________________ fipy mailing list fipy@nist.gov http://www.ctcms.nist.gov/fipy [ NIST internal ONLY: https://email.nist.gov/mailman/listinfo/fipy ]
