Posted by ADSW1243 on
URL: http://forum.featool.com/Importing-gmsh-mesh-file-with-several-subdomains-tp315.html

Hi there,

I'm interested in making use of the FEA Toolbox. Specifically I'm looking at (initially) solving the vector Poisson equation for the 3D magnetic vector potential across a domain, in the presence of a 3D current source.

Currently from older work I have produced a non-coherent .STEP file defining my geometry. This is then imported to .gmsh. The coherence; command, plus physical groups for each subdomain are used to produce a coherent mesh with a list of domain IDs to identify which elements belong to which subdomain.

The geometry of the entire system can be seen in the figure below, where the internal structure is a current carrying coil with rectangular cross section which is wholly enclosed by a box to form a black-box simulation.
 

Currently importing grid via a .msh (or .msh2 file if you prefer) works, but the internal subdomain is lost - i.e I get an empty box which prevents me from making progress:


Alternatively, importing the .STEP gives two sub-domains but I cannot progress to gridding without somehow merging the geometries:
 

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.

Edit: I have attached an example .STEP and .msh2 file in case recreating this is required to find a solution:
New_Toy_Coil.step
New_Toy_Coil.msh2


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.

Thanks in advance.