Thanks Daniel! On Mon, Oct 19, 2009 at 12:02 PM, Daniel Wheeler <[email protected]> wrote: > > On Mon, Oct 19, 2009 at 12:46 AM, weasky <[email protected]> wrote: >> >> Hi, >> >> I noticed there are a couple of examples in the folder about >> cylindrical cords, and my question is about the the BCs: >> mesh.getFacesLeft(0) is the boundary for r=r_{inner} >> Right would be r_{outer} >> top would be z_{highest} >> bottom would be z_{lower} >> >> Is my understanding correct? > > Yes, perhaps we should add in stub methods that are named something > more appropriate (inner, outer, upper,lower???). > >> Basically, I want to solve a 2D diffusion >> eqn in a geometry of (r,z) and use the antisymmetry of the center >> line. > > Antisymmetry? I'm not sure exactly what you mean. Is that just a typo?
Sorry, I mean axial symmetry. Do I need to add a no flux BC for that? I think if I do nothing ,Fipy will automatically give me that BC then. >> so for the BC part I will do >> >>> boundaryConditions = ( >> ... FixedFlux(faces=mesh.getFacesLeft(), value=0), #center-line, flux >> is 0 >> FixedValue(faces=mesh.getFacesRight(),value=valueRight), >> FixedValue(faces=mesh.getFacesTop(),value=z1), >> >> FixedValue(faces=mesh.getFacesBottom(),value=z0), >> ... ) >> >> is my understanding correct? > > I think that is all good, but I don't think you need a BC for the left > faces. Their surface area vanishes. > > I have had issues with the corner cells for flow problems, I shift the > mesh away from 0 by some very small amount. You may or may not need to > this. I think it is only for flow problems that I found this to be > necessary. Thanks! I may try this and see the differences. BTW: is there a way to visualize the mesh? or export the mesh to other format (such as tecplot)? or better to visualize the mesh in 3D cylinder? Thanks a lot for this great app! Tim > > Cheers > > -- > Daniel Wheeler > >
