[Gmsh] GMSH for Thermal Codes?

[Joe Koski]

I have some old "legacy" thermal finite element codes that I use
occasionally for consulting work, that would benefit from the use of a mesh
generator. To date, I've been generating simple meshes by hand or with
simple ad hoc Fortran codes. When I first found GMSH, I thought I had found
the answer, but further examination of the manual has brought up some
questions and issues. If any of you experienced GMSH users have some
insights, I'd like to hear them.

First, thermal modelers spend about half of their mesh generation time
attaching convection and thermal radiation boundary conditions to various
surfaces of the model. It appears that GMSH has no facilities for tracking
boundary conditions. Is this correct? Some commercial thermal mesh
generators permit attachment of boundary conditions to the problem geometry,
since entities such as surfaces are much more easily identified than a list
of mesh nodes or element surfaces. Has this been thought about for GMSH? I
realize that this is not usually an issue in structural models.

Second, while I think I could live most of the time with tetrahedrons and
triangles, what is the user experience in "recombining" tets and triangles
into hexahedra and rectangles? Does it take element by element inspection,
or can it be somewhat automated?

By the way, I was amazed at how quickly GMSH became functional on my
Macintosh under OS X.

Joe Koski