Boundary Conditions

[Matrixrifle]

Hi,
I am a noob in elmer. I was looking at the case files in the elmer-elmag repo below.

https://github.com/ElmerCSC/elmer-elmag ... D/case.sif

I noticed the following lines defining the BC. I could not understand how elmer links the physical lines to the boundary condition. is the BC number linked with the mesh file numbers somehow. I am confused. In the elmerSolver manual it mentions we have to define Target Boundaries to a value corresponding to the physical line, but this does not seem to have that. How does it work then ?

!--- BOUNDARIES ---
Boundary Condition 1
Name = SB_Rotor
End

Boundary Condition 2
Name = Rotor-Right
Mortar BC = Integer 3
Mortar BC Static = Logical True
Anti Radial Projector = Logical True
Galerkin Projector = Logical True
End

Boundary Condition 3
Name = Rotor-Left
End

[Rich_B]

Hello,

Take a look at the file 'mesh.names', located here:

https://github.com/ElmerCSC/elmer-elmag ... ine2D/mesh

it contains the translation from number to names.

The names may be defined in the meshing program, such as gmsh or Salome, and then converted using elmergrid to mesh.names.

Rich.

[kevinarden]

The use of mesh names for bodies and boundaries is a feature newer than all of the boundaries. So all of the manuals may not be updated to reflect the use mesh name option.
There is actually a flag in the simulation section
Use Mesh Names = True
which may be the default now, but did not use to be.

Referring to bodies or boundaries by number or name is now optional.
the mesh.name file provides the translation from name to number.

Note, that opening a msh file or unv file from ElmerGUI does not create a mesh.name file.
Translating the msh or unv file using ElmerGrid does.

[Matrixrifle]

Thanks understood. Is there an updated manual maybe in the master branch. Then i can read that.

[kevinarden]

There is not an update of the manuals. Perhaps the
https://www.nic.funet.fi/pub/sci/physic ... dElmer.pdf
would be a good start, or just a tutorial on using mesh names.