Ivar KJELBERG
COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)
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Posted:
1 decade ago
12 nov. 2011, 05:27 UTC−5
Hi
By default al reference frame overlap, it's only when you deform (i.e. solid, or cfd or ...) or flow (cdf ...), or change the meshing or geoemtry via deformation (i.e. ALE or DG) that you get splitting of the references frames.
But, what it look as like for yuor case is that you add material by adding a mesh layer (? tbc) but then it looks for me like a change in topology and that is not obvious to handle as you say you get id renumbering.
But another thing that strikes me is that you talk always about the mesh. In COMSOL meshing is not the reference, this makes me believe you have quite some experience with older, traditional FEM programmes, or books, where everything (physics, BC ... were linked to nodes and mesh elements. COMSOL has another volumetric approach, that is far more correct physically. Thereforeone should not think "mesh" but volumes, or more precisely "Elements" (Domains Boundaries, and Edges + Points if dimension > 1D), which are unique distinct and identified (numbered).
Then you can apply your physics to these, and if you add a layer you can either make the material characteristics, change with distance from the boundary, or set physics ON the boundry
--
Good luck
Ivar
Hi
By default al reference frame overlap, it's only when you deform (i.e. solid, or cfd or ...) or flow (cdf ...), or change the meshing or geoemtry via deformation (i.e. ALE or DG) that you get splitting of the references frames.
But, what it look as like for yuor case is that you add material by adding a mesh layer (? tbc) but then it looks for me like a change in topology and that is not obvious to handle as you say you get id renumbering.
But another thing that strikes me is that you talk always about the mesh. In COMSOL meshing is not the reference, this makes me believe you have quite some experience with older, traditional FEM programmes, or books, where everything (physics, BC ... were linked to nodes and mesh elements. COMSOL has another volumetric approach, that is far more correct physically. Thereforeone should not think "mesh" but volumes, or more precisely "Elements" (Domains Boundaries, and Edges + Points if dimension > 1D), which are unique distinct and identified (numbered).
Then you can apply your physics to these, and if you add a layer you can either make the material characteristics, change with distance from the boundary, or set physics ON the boundry
--
Good luck
Ivar