Meshing U-shaped cylindical pipe
 

Hello

I'm learning sHM and I'm having a problem with generating internal mesh for an U-shaped cylindrical pipe presented on the image ushape.jpg.

I generated successfully a mesh for straight cylinder so I moved to U shaped geometry but it is not easy.

I'm having a problem with strange tetWedges which I can't get rid of. Could anyone please help me with some advices which might help me to generate fine mesh.

This problem was raised in thread: http://www.cfd-online.com/Forums/ope...of2-0-1-a.html

Case dir can be found here (blockMesh is in system dir). There is as well a VTK folder where i've separated those bad tetWedges.
One of my aproaches was to define refinement box around the my shape but that does not helped. I tried the same stl as a refinement surface but it doesn't helped either.
I was looking on the SwiftSnap tutorial and I saw that it is possible to generate a nice mesh from bend pipe. I did tried blender plugin but I failed.

Second problem little bit less important is to generate boundary layers. (currently switched off in attached case dir). I did not managed to generate them as well.

I'm using OF 2.1.1:
Build : 2.1.1-221db2718bbb
Exec : snappyHexMesh

Thank you in advance for your help.
Best regards,
Jakub.