[Gmsh] Error generating simple mesh

[Elisa Schenone]

Dear gmsh developers,

I'm trying to use gmsh to create a cube mesh with a surface separated in
multiple entities: two concentric circles are inscribed into the top
surface (square).
The external circle comes from a 1D mesh that I merge to my geo script.
The internal circle has been created only as a workaround since gmsh could
not create the 2D mesh inside the 1D line (file circleLine1.mesh or
circleLine2.mesh).

Small changes in the script, i.e. characteristic length, line1 or line2,
small circle dimensions, etc., give different errors but none of these
combinations seems to work.

Also, in case the 2D mesh is correctly generated, the surface mesh quality
is very bad in some points and the 3D mesh cannot be generated. I tried
various options for the 2D and 3D mesh algorithms but none of them gives
good results.

What am I doing wrong?

I send you a minimal example of my geo script and the 1D mesh I use to
define the inscribed circle.

Thank you in advance,
bests,
Elisa
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://onelab.info/pipermail/gmsh/attachments/20190919/705b24e7/attachment-0001.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: circleLine2.mesh
Type: application/octet-stream
Size: 11465 bytes
Desc: not available
URL: <http://onelab.info/pipermail/gmsh/attachments/20190919/705b24e7/attachment-0002.mesh>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: testGmsh.geo
Type: application/octet-stream
Size: 3238 bytes
Desc: not available
URL: <http://onelab.info/pipermail/gmsh/attachments/20190919/705b24e7/attachment-0001.geo>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: circleLine1.mesh
Type: application/octet-stream
Size: 13733 bytes
Desc: not available
URL: <http://onelab.info/pipermail/gmsh/attachments/20190919/705b24e7/attachment-0003.mesh>