Surrounding meshes with "vacuum domain" mesh

Mesh generators, CAD programs, and other tools
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NickR7
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Surrounding meshes with "vacuum domain" mesh

Post by NickR7 » 23 Aug 2013, 01:14

Anyone using the WhitneyAV solver to compute magnetic and electric fields in 3D is likely needing to make "meshes" representing bodies that are set to be electrically conductive in the solver, or set to carry a fixed "source current" in the solver.

Then the user needs to make a meshed volume that encloses them, representing the non-conductive "air" or "vacuum" region that fills the space between conductors and sources.

For simple shapes, this is easily done with a GMSH script (manually making .geo files).

For complex shapes, I am having difficulty. I have downloaded the 30 day trial of AutoCAD - I can make shapes OK, I can export to IGES. IGES files know nothing about volumes/solids so I then have to import into netgen, use the STEP/IGES topology doctor, generate solids, then export to a STEP file.

Problem is, the topology doctor in netgen (which uses opencascade) doesen't like solids with holes. So I can't surround my objects with a big computational domain box or sphere having holes where my conductors and sources are.

How can I surround my conductor/source geometries, which are in a .STEP file, with a computational domain?

millim
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Re: Surrounding meshes with "vacuum domain" mesh

Post by millim » 23 Aug 2013, 09:51

Hi,

I suggest using Salome platform with Netgen 1D-2D-3D mesh, export to UNV and using Elmergrid to convert to Elmer mesh format. Salome has an excellent python interface for building geometries.

BR

NickR7
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Joined: 29 Jul 2013, 18:03
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Re: Surrounding meshes with "vacuum domain" mesh

Post by NickR7 » 30 Aug 2013, 06:48

Thanks. The solution to my problem was to use a 30-day trial version of CREO parametric 2.0 to remove all of the little screw-holes and junk out of an existing, complicated CAD file, and then use Salome to do the meshing, following this tutorial:

http://www.elmerfem.org/elmerwiki/index ... e_to_Elmer

There is a nice post about a workflow using SketchUp but unfortunantly SketchUp just wasn't up to editing that geometry or making a simpler version of it.

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