This is exactly what I was thinking off. Thanks. On Friday, January 3, 2025 at 7:44:48 PM UTC+3 Wolfgang Bangerth wrote:
> > Najwa: > > > I know that merge triangulation in deal.ii will not work properly if > there are > > hanging nodes ( unmatching of the meshes at the interface). > > > > My question is, what if I have to have this hanging node? Is there a way > I can > > work it out, or are there any other suggestions I should try? > > The issue is that if you merge two triangulations, the assumption is that > *all* cells are part of the coarse mesh. If you have a hanging node on one > side, say in a situation like this: > > *--* *---* > | | | | > *--X + | | > | | | | > *--* *---* > > then you end up with a coarse mesh of three cells in which the top and > bottom > vertex of the common interfaces are identified between the two parts, and > the > middle node is not. So you have a "crack" in your domain: an internal > boundary. This cannot be avoided because hanging nodes, *by definition* > are > along interfaces between cells *of different refinement level*. But here, > all > cells are at refinement level zero. > > The ideal approach would of course be to avoid the situation altogether. > If > you can't do that, you have to enforce continuity along the "crack" in a > different way, for example by manually adding constraints for the node > marked > by X above. Alternatively, you can enforce continuity along the crack > weakly, > like in discontinuous Galerkin approaches. It turns out that there is a > tutorial program that actually shows something like this: step-33 (see the > section on "Adaptivity"). > > Best > W. > > -- > ------------------------------------------------------------------------ > Wolfgang Bangerth email: bang...@colostate.edu > www: http://www.math.colostate.edu/~bangerth/ > > > -- The deal.II project is located at http://www.dealii.org/ For mailing list/forum options, see https://groups.google.com/d/forum/dealii?hl=en --- You received this message because you are subscribed to the Google Groups "deal.II User Group" group. To unsubscribe from this group and stop receiving emails from it, send an email to dealii+unsubscr...@googlegroups.com. To view this discussion visit https://groups.google.com/d/msgid/dealii/00ce1771-3200-4271-b7b2-b01e5ae4e410n%40googlegroups.com.
