Starting from the tutorial exemple Working with meshes for creating a volume mesh from two surface meshes (a cube and a sphere), I would like to mark a specific sub-surface of one of the surfaces, let’s say one face of the cube, in order to have a Boundary Marker to be used in a FEM equation.
How should the tutorial exemple be modified to do so?
Thanks for your help
Always keeping in mind the tutorial exemple Working with meshes, but beeing a bit more specific, let’s say I want to assign a custom boundary condition name to one of the square faces of the first mesh. What I would do is :
geo1 = CSGeometry()
geo1.Add (OrthoBrick( Pnt(0,0,0), Pnt(1,1,1) ))
m1 = geo1.GenerateMesh (maxh=0.1)
m1.SetBCName(0, 'face1')
So that, its FaceDescriptors will look like:
[surfnr = 0, domin = 1, domout = 0, tlosurf = 0, bcprop = 1, bcname = face1, domin_sing = 0, domout_sing = 0, colour = (0, 1, 0, 1),
surfnr = 4, domin = 1, domout = 0, tlosurf = 0, bcprop = 2, bcname = default, domin_sing = 0, domout_sing = 0, colour = (0, 1, 0, 1),
surfnr = 3, domin = 1, domout = 0, tlosurf = 0, bcprop = 3, bcname = default, domin_sing = 0, domout_sing = 0, colour = (0, 1, 0, 1),
surfnr = 5, domin = 1, domout = 0, tlosurf = 0, bcprop = 4, bcname = default, domin_sing = 0, domout_sing = 0, colour = (0, 1, 0, 1),
surfnr = 1, domin = 1, domout = 0, tlosurf = 0, bcprop = 5, bcname = default, domin_sing = 0, domout_sing = 0, colour = (0, 1, 0, 1),
surfnr = 2, domin = 1, domout = 0, tlosurf = 0, bcprop = 6, bcname = default, domin_sing = 0, domout_sing = 0, colour = (0, 1, 0, 1)]
Now I want to merge the mesh of this object with the mesh m2 of a sphere to a new mesh, and keep the reference to this surface “face1” to the bounday condition names of the new mesh.
So I would create, in addiction to the FaceDescriptors associated with the two domanies, a FaceDescriptor for this surface like so:
fd_outside = mesh.Add (FaceDescriptor(bc=1,domin=1,surfnr=1))
fd_inside = mesh.Add (FaceDescriptor(bc=2,domin=2,domout=1,surfnr=2))
fd_face1 = mesh.Add (FaceDescriptor(bc=2,domin=2,domout=1,surfnr=3))
My question is: when coping all boundary points from first mesh to new mesh, how can I set the FaceDescriptor fd_face1 to only the surface elements which have the bcname==‘face1’ in the old mesh?
Thanks for your help.