Adding 1d physical groups to gmsh model causes errors when convert it to dolfinx mesh

mesh
2

This is because line_x_axis is not part of the surface, as seen by calling:

    boundary = gmsh.model.getBoundary([(2, surface)])
    print(f"{boundary=}, {line_x_axis=}")

Thus, if you instead add:

    for boundary_dim, boundary_tag in boundary:
        gmsh.model.addPhysicalGroup(boundary_dim, [boundary_tag], tag=boundary_tag)

you will get all your outer boundaries tagged.

2 Likes