Posted by Precise Simulation on
URL: http://forum.featool.com/Importing-gmsh-mesh-file-with-several-subdomains-tp315p323.html

ADSW1243 wrote

...
I saw in the documentation that multiple sub-domains are supported in 3D, I'm just unclear on the process to properly import such a geometry. This is key because the internal subdomain contains all source points and I'm mostly interested in the magnetic fields in the space around the 3D coil.

I'm not quite sure how you created the mesh but with the command:

    gmsh -merge New_Toy_Coil.step -3 -format msh2

or Gmsh ".geo" file:

    Merge "New_Toy_Coil.step";
    Mesh 3;
    Mesh.MshFileVersion = 2;
    Save "New_Toy_Coil.msh";

I get a mesh that imports the two subdomains fine (please make sure you are using the latest version of FEATool, currently 1.12.1). Sometimes the "-save_all / Mesh.SaveAll = 1;" Gmsh option is also required, but it seems to work fine without it here.

That said, for this fairly straightforward geometry it is recommended to use the built-in CAD tools in the FEATool GUI. It should be sufficient to create two blocks, and subtract a third block from the inner one to create the coil.

ADSW1243 wrote

Beyond this, I also wondered whether this toolbox can consider the anisotropic form of the vector magnetostatics equation - i.e the del x (1/mu(r)) curl x A = J which would be significantly more interesting to study.

Although anisotropic coefficients are currently not pre-defined you can define a custom PDE equation to support this, or modify the existing ones as for example has been done in the orthotropic heat transfer example.