Meshing a large geometry

Hello, I have a geometry with a large cylinder and thousands of fins that take up about 500 MB of space. I’m trying to mesh about 100 long fins at a time but it’s taking forever. It seems that the netgen 3d-2d-1d algorithm works best on smaller geometries but I’m having a tough time finding the right combination for the bigger geometry. The length for the section of 100 fins can be up to five meters long, 1 cm in width, 2 cm in height and 1 cm between fins. Any ideas for meshing it the fastest would be much appreciated. Thanks.

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I got a recommendation here to change the meshing algorithm with a large computational domain.

Thanks @Francisco and @MRousseau for the recommendation. I tried the gmsh hxt algo and am getting the following error:

Error during Generation of Gmsh Mesh
Gmsh should be compiled with Hxt to enable this option
error occurred while meshing entity:
tag=1
dimension=3
native pointer=000001BF2587A338
level=Error msg=HXT 3D mesh failed
Error during Generation of Gmsh Mesh
HXT 3D mesh failed
error occurred while meshing entity:
tag=1
dimension=3
native pointer=000001BF2587A338
level=Error msg=No elements in volume 1
Error during Generation of Gmsh Mesh
No elements in volume 1
error occurred while meshing entity:
tag=1
dimension=3
native pointer=000001BF2587A338
level=Progress msg=Meshing 3D…
level=Info msg=Done meshing 3D (Wall 0.0003035s, CPU 0s)
level=Info msg=12667 nodes 39862 elements
th. 0000002E001FFA80 - Trace e:\s\salome-9.8.0\sources\smesh\src\smesh\smesh_submesh.cxx [2051] : GMSH failed on sub-shape #70289 with error COMPERR_NO_MESH_ON_SHAPE
th. 0000002E001FFA80 - Trace e:\s\salome-9.8.0\sources\smesh\src\smesh\smesh_submesh.cxx [2051] : GMSH failed on sub-shape #70289 with error COMPERR_OCC_EXCEPTION “OSD_Exception_ACCESS_VIOLATION: ACCESS VIOLATION at address 0x0000000000000008 during ‘READ’ operation”

I have windows 11 and have been researching what this means with no luck. Any thoughts would be great, thx.

“Gmsh should be compiled with Hxt to enable this option”

I guess you got this error because Gmsh was not compiled with HXT algorithm on Windows. Maybe a developper should help here. You could run your meshing on a Linux machine to confirm my guess.

Moise

I would first try to simplify the geometry before meshing, removing all small features as radius, chamfers and small holes. Then maybe the fins can be reduced to a shell mesh and the cylinder meshed with hexa elements also. Feel free to share your geometry to a better help.

+1 to share the geometry (or at least a image of it), but if I imagine it correctly from the description couldn’t be possible to mesh only a small cross section of it (Mesh_1) and then translate it while coping the mesh? so you construct your mesh sept by step?
also, can confirm HxT does not work (at least out of the box) in windows
F.

I downloaded salome to use in ubuntu and gmsh now works and produces results much much faster. Everything also runs a bit smoother using ubuntu instead of windows. Thanks for everyone’s input.

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