Problem with Projection 2D/3D mesh

Use of the platform
1

Hi everyone,

I’m working on a stator + rotor model of an electric machine that I’d like to mesh. To reduce simulation time, I plan to simulate only a half-circle and impose periodic boundary conditions. For this, the mesh on the two wedge surfaces needs to align perfectly under a 180° rotation.

Here’s what I’ve tried so far:

  1. I meshed one wedge surface using the Netgen 1D-2D mesher.
  2. Then, I used the Projection 1D/2D algorithm to mesh the second wedge surface.

This approach works fine for simple geometries (e.g., a cylinder wedge). However, when the geometry gets more complex (e.g., with holes), I encounter the error:

can't apply source mesh pattern to the face

Below, you can see the successfully generated mesh on the first surface, with the second (gray) surface shown for reference:

image
image857×748 7.31 KB

The two surfaces are identical under a 180° rotation around the z-axis.

Does anyone know how to create such a mesh for more complex geometries?

Here’s the full file for reference:

SalomeDebug.hdf (1,3 MB)

Thanks in advance for any help!
Raffael

2

Hi,

indeed, projection 1d2d fails here. None of the tries of the algorithm works, maybe because the two faces are not exactly identical (there is a slight difference in the circle length).

What can be done to overcome this is to:

  • generate a 1D2D mesh
  • make a rotation of Face_1 around OZ by 180°
  • create a new mesh with sub-mesh Import 1D2D with this rotated mesh.

Have a look at test_import_1D2D.py, to be launched in your study with File> Load script. Display Mesh_3 and face1_rotated to see that they match.

Morevover, if you need a conformal mesh, you have to call Partition in GEOM before creating a mesh.

Have a look at test_import_1D2D_conformal.py.

As a bonus, in the script, the solid names are retrieved from your step to create the groups on the mesh. Just add a 3D algorithm to generate the volume elements and populate the volume groups.

Best regards,

Christophe