Problem with boundary/interface
 

hi guys
I'm new in OF and i have a problem so I'll try to explain it and get back a solution.
I have 3 different closed geometry (Duct-Filter-Airbox). I tried to mesh them with snappyHexMesh and, for the first time, the mesher didn't create the boundary for the interface but only 2 faceZone (duct_to_filter , filter_to_airbox). I hoped that, as inolther cases, it would have created the boundaries.


After that I would know why it didn't create the interface and if I want to create them manually, how should i do them? Because I saw the createBafflesDict but i don't know how it works.

thanks for helping me