Elmer Discussion Forum

I created a simple pipe for a diffusion test. The pipe is in two sections. It was created with FreeCAD and exported via a .brep file to gmsh. , The result, as shown, has a large notch in the mesh. Multiple attempts have failed to improve things. How can I fix this? The .brep file is attached.

Thanks in advance
Gary R.

I imported the brep into gmsh and had the same notch occur
I opened the brep in ElmerGUI and it meshed OK
I imported the brep into salome and it meshed OK
I imported the brep into FREECAD and then exported it as a step file
I imported the step file into gmsh and gmsh meshed it without the notch.

Thanks Kevin
If anyone can shed light on why the notch happened it would be both appreciated and instructive.
I now have a problem with ElmerGUI (I don't think related) but will post that on the ElmerGUI forum.

Thanks again
Gary R.

If I start in gmsh with the original brep file and immediately mesh the notch happens. However, if I set the mesh to something finer. Tools, options, mesh, general size factor. Set it to 0.3 instead of 1.0, it meshes ok. It appears gmsh can't follow the surface definition with a coarse mesh size.

I found the problem. When I ran validation on the Freecad sketch I found 3 missing coincidences. When I fixed these, the problem went away. The moral to this story is run validation on your sketches before proceeding.
Gary R.