Hi,
I’d like to create an Axysimmetric 3D mesh for openFOAM. To do this, I need to use the “cyclic” BC, which requires periodic faces to have the same mesh (same cell number).
I tried to use the “copy mesh” utility (I couldn’t use it) and then fill the volume with tetrahedrons. In fact, the volume may contain elements such as vanes that make the sweep difficult to use.
I’ve also tried meshing them separately, but I get different surface meshes.
Can you help me?
Attached is the geometry to be meshed.
Axi.cub5 (93.7 KB)
Thanks,
Rocco
Hi Rocco,
that sounds pretty similar like you would need the same as in this forum post
First you would need to ensure that you got the same topology on each side. I don’t see a problem here but we will just do it to be sure.
For this you will have to copy and rotate the volume to the opposing sides and imprint them.
#!cubit
reset
open "/home/user/Downloads/Axi.cub5"
compress
# first imprinting to create and ensure same topology on sides
Volume 1 copy rotate 60 about z
Volume 1 copy rotate -60 about z
imprint volume all
delete volume 2 3
Then you can set a size and mesh the first side. We will copy the meshed surface to the opposing side and merge it. Then we can mesh the volume.
# set equal mesh size
volume all scheme tetmesh
volume all size auto factor 5
#mesh sides and imprint/merge the mesh on the opposite side
mesh surface 11
surface 11 copy rotate -60 about z
#!python
cubit.cmd(f"merge surface 1 {cubit.get_last_id('surface')}")
#!cubit
delete body all with is_sheetbody
mesh vol all
The two opposing surfaces now got the same number of elements and nodes. Just to be sure we will make 2 copies of the volume again and make a coincidence check. If you check the number of coincidence nodes between 2 volumes you will see that it does match.
#check mesh coincidence
Volume 1 copy rotate 60 about z
Volume 1 copy rotate -60 about z
topology check coincident node volume 1 5 tolerance 1.0e-6 draw brief result group
topology check coincident node volume 1 6 tolerance 1.0e-6 draw brief result group
topology check coincident node volume all tolerance 1.0e-6 draw brief result group
