Hello all, A possibility is to define the diffusion as a variable (similar to mesh1D with position dependent diffusion). In this case I can use something like
phi = CellVariable(name="Concentration (M)",mesh=mesh,value=0.0) and then: facesphi=phi.arithmeticFaceValue to obtain the concentration at the faces. Can I then use statements in the form: D.setValue(facesphi*slope+intercept,where="concentration rage") My concern is that facesphi will not update as the solution is being obtained. Thanks for any guidance. Salomon On Fri, Jan 4, 2013 at 2:51 PM, Salomon Turgman Cohen <[email protected]>wrote: > Hello developers and users, > I am interesting in solving a simple 1D diffusion equation using fipy. > My requirement is that the diffusion coefficient is concentration > dependent. Following the mesh1D example I know how to do this if I have a > simple functional form to describe the diffusion's dependence on > concentration. However, what I have is just 5 data points of diffusion > versus concentration. What I want to do is a linear interpolation of the > diffusion in between the data points. I constructed the following function > as an example: > > def diffusion(phi): > if (phi>=0.0) & (phi<0.902449): > return phi*(-7.63256E-8) + 1.05240E-7 > elif (phi >= 0.902449) & (phi < 1.807062): > return phi*(-1.37296E-08) + 4.87503E-08 > elif (phi >= 1.807061587) & (phi < 2.713202143): > return phi*(-2.23797E-08) + 6.43815E-08 > elif (phi >= 2.713202143) & (phi < 3.570465711): > return phi*-1.48121E-09 + 7.67966E-09 > elif (phi >= 3.570465711) & (phi < 4.425457264): > return phi*-4.04495E-10 + 3.83529E-09 > elif (phi >= 4.425457264): > return phi*-4.62147E-10 + 4.0904E-09 > > But it cannot handle the arrays obtained from CellVariables command. What > would be the right way to do this? > > Thanks! > > -- > Salomon Turgman Cohen > Postdoctoral Associate > Cornell University > (919) 341-9650 > -- Salomon Turgman Cohen Postdoctoral Associate Cornell University (919) 341-9650
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