[Gmsh] Additional surface after boolean operation on volume boundary

[Zenker, Dr. Matthias]

Hi,

I try to create a block with the top surface containing a disk:

//+
SetFactory("OpenCASCADE");
//+
Box(1) = {-25, -25, -50, 50, 50, 50};
//+
Disk(7) = {0, 0, 0, 0.5, 0.5};
//+
BooleanDifference{ Surface{6}; Delete; }{ Surface{7}; }
//+
Characteristic Length {9} = 0.05;
//+
Delete {
  Volume{1};
}
//+
Surface Loop(2) = {1, 3, 5, 4, 2, 6, 7};
//+
Volume(1) = {2};
//+
Physical Volume("bulk") = {1};
//+
Physical Surface("disk") = {7};
//+
Physical Surface("top") = {6};
//+
Physical Surface("bottom") = {5};
//+
Physical Surface("side") = {1, 4, 2, 3};

The problem is that the surface 6 is not attached to the volume, but there is a new surface 8 instead which is identical to surface 6, and which is used for the volume.
Consequently, when I create a mesh, the boundary corresponding to surface 6 is not attached to the volume, i.e. the nodes of surface 6 do not figure in tetrahedra of the volume, and surface 6 is not recognized by Elmer on import.
What do I do wrong?

Thank you for a hint,
Matthias


________________________________

Erbe Elektromedizin GmbH Firmensitz: 72072 Tuebingen Geschaeftsfuehrer: Christian O. Erbe, Reiner Thede Registergericht: Stuttgart HRB 380137

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://onelab.info/pipermail/gmsh/attachments/20190510/dfebd327/attachment.html>