[Belgio]

I want to model a shock tube in Ansys 12, using the workbench (Design Modeller and Meshing). I am making a geometry - a cylinder with r=10cm and length=60cm as a Thin/Surface with 1cm walls. How can I make a separation of two domains? (I mean low-pressure and high-pressure volumes) and where can I do it? (I mean while drawing geometry or while making mesh?)
Thanks in advance
If somebody has file of shock wave project that would be also fantastic if you could send it to me.

[Belgio]

OK. Another interpretation of the question: Can I do a 0mm wall inside the tube, so it will divide domains and how can I do this?

[PSYMN]

Sure, just model it as two tubes. You could create one tube and split it, but I think I would create one sketch (circle) and extrude it first one direction, then freeze that first part. Then extrude the same sketch in the other direction as a second part.

If you want the mesh to be matched at the interface, then you should join them as a multibody part while in DM. If you would rather have two separate meshes, leave them as separate parts in DM.

Are you meshing the casing also? If not, you don't need a thickness, just extrude the circle to get the fluid volume. If you are, then you can create a third volume for the solid portion.