And, what happen if I use robin boundary conditions? Do I need to put them in the map function? If so, how do I do it?
Like Baerbel already suggested, Robin boundary conditions aren't supported. That said, this is rarely an issue: if you don't say anything in the map about a particular part of the boundary then the Kelly indicator will simply assume that the solution is correct on that part of the boundary and not touch it. Of course, if you have a have a Neumann or Robin boundary, that isn't quite true, there is going to be a difference between the normal derivative of the numerical solution and the Neumann values these normal derivatives should equal. So if we simply ignore those parts of the boundary, we'll underestimate the error. In practice, this rarely appears to be a problem -- you may not refine the cell this time around but you'll probably refine it in the next refinement step and everything is good again. After all, the Kelly indicator is only an indicator, not an estimator, and so the values it computes are not exact error representations anyway.
The problem is a heat pipe. I have a 3d cubic domain with a cylindrical hole. The problem equation in the cube domain is heat diffusion and is subjected to robin and neumann boundary conditions on the external surfaces and a robin boundary condition on the hole surface. This boundary condition depends on the solution of a 1d advection problem. The 1d domain has an internal heat generation depending on the values on the internal hole surface in the 3d domain. I iterate the assembling and solve steps until the difference in both norm solutions is less than .5.
That's not an unreasonable approach. You may want to play with the limit 0.5 a bit. I can't tell whether 0.5 is large or small without knowing what the value is at the beginning but you should make sure this limit is small enough so that changing it a bit does not affect the solution.
Best W. ------------------------------------------------------------------------ Wolfgang Bangerth email: [email protected] www: http://www.math.tamu.edu/~bangerth/ _______________________________________________ dealii mailing list http://poisson.dealii.org/mailman/listinfo/dealii
