Jonathan Guyer <guyer@...> writes: > > > On Jan 23, 2013, at 3:39 PM, Laurence wrote: > > > I'm happy with the mask and how it ascertains to the mesh I've already > > created. > > > > My issue is that I am creating a diffusion field on the mesh, and > > at one place in the mesh, a localised reaction is taking place > > depending on the concentration at that point. This will deplete > > the concentration of the solution at that specific location, > > and so cause further diffusion. I have looked into using the levelset > > functions, but the surfactant equations seem not to specifically describe > > the equations I require. > > > > I thought if I created a subset of the mesh, I could write PDEs that > > only affected those cells. > > > > Is there a way I can write my PDEs such that the area the equations > > effect is limited to certain areas. > > You can just use the mask to limit the coefficients to the area of interest, so you could write a diffusion > equation with a source that applies everywhere and have the source be zero everywhere but where the > reaction is taking place. This just came up a couple of days ago: > > http://thread.gmane.org/gmane.comp.python.fipy/2878/focus=2885 >
In this example, surely you are just setting a constant source to one part of the mesh. I understand how this is set what what implications it has. However, I don't understand how to make this value that you are setting to certain areas of the mesh tie into the differential equations that will govern this particular area. I guess my thoughts are: 1) You set up your CellVariable to record the concentration at any point in the mesh. 2) You need to create another mesh which monitors the number of reaction sites available, at any time, on a sensor surface in a particular area in the mesh 3) The reaction at the sensor will be fuelled by the solution concentration at that sensor interface 4) The reaction at the sensor will in turn deplete the solution concentration and thus cause further diffusion towards the sensor 5) This process will be limited by: a) The bulk concentration of the solution and diffusivity of the solution b) The amount of reaction sites at the sensor at any one time c) The rate at which the reaction can occur at the sensor Thus, you have an equation of reaction which is only going to affect a certain part of the solution mesh. If you use the CellVariable.setValue() function, how do extract the variable from the equation = TransientTerm()==..... to set the CellVariable in specific places Hope this is clear. Thanks Laurence > _______________________________________________ > fipy mailing list > fipy@... > http://www.ctcms.nist.gov/fipy > [ NIST internal ONLY: https://email.nist.gov/mailman/listinfo/fipy ] > > _______________________________________________ fipy mailing list [email protected] http://www.ctcms.nist.gov/fipy [ NIST internal ONLY: https://email.nist.gov/mailman/listinfo/fipy ]
