Extract boundary faces from vtk file
I have the attached vtk mesh made up of hexahedra, which I converted to vtk manually from https://github.com/OpenFOAM/OpenFOAM-9/blob/master/tutorials/basic/laplacianFoam/flange/flange.ans .
I would like to import that mesh in gmsh and then extract the boundary faces, in order to enforce boundary conditions on them by grouping them in physical groups.
I proceeded like in t13.geo:
SetFactory("OpenCASCADE");
Merge "flange.vtk";
ClassifySurfaces{40 * Pi / 180, 1, 1, Pi};
CreateGeometry;
But I got the message “no triangles to reclassify in surface mesh”. Does ClassifySurfaces
only work with tetrahedra?
If that’s the case, how could I convert the mesh to tetrahedra? I tried to export it as stl and got an empty solid.
Thanks so much