[PeterDaniel]

Hello,
My name is Jun, I am a PhD student and I need some help to generate a Mesh for my computation.
I am trying to mesh a simple geometry (3 cylinders with the same diameter)to get familiar before working on my final geometry.
The mesh I want to obtain will be compose of an Hexa domain followed by an tetra one and finally an other Hexa domain. I will add later prismatic layers at the boundaries.

I tried to mesh each part separately and then merge everything.
Everything goes right for the Hexa mesh. I save the end of this part as a mesh and imported to the next part which will be in tetra. The problem is that when I use this surface mesh for the next part, ICEM does not generate any pyramids to make the transition. It simply split every surface quads into tri. Does anyone has an idea about what i did wrong? Or is it possible to merge two cylinders which have the same diameter?

Thank you in advance,
Jun