Hi, I am trying to simulate a 3D domain in fluent where I have periodic boundary conditions on all six faces. I have created the mesh in Gridgen, and I did not specify the periodic translate faces in it, but all the faces are of the same area and shape. How may I specify the periodic boundary conditions in Fluent without going back and regenrating the mesh in Gridgen or Gambit. I have specified the faces as walls and tried to changed their status in fluent, but did not see "periodic" in the BC type drop down menue. I will appreciate any help I can get. Thanks alot for the help.

Try changing the phase to 'mixture' in the Boundary conditions panel if that's available.

have you modified them by tui?

grid/modify-zones/make-periodic

hope this help you.

It worked, Thanks alot, I did not know that you have to type the command, I thought that you assign it in the drop down menue. One more question if you can help me please: I have a pressure drop gradient, dp/dx =1, across my domain, how do I assign it in fluent, plus, I need to assign all the domain boundaries to allow fluid flow, not walls. If you can give me hints I will appreciate it. Thanks again elyyan

In the drop down menu of Define you will get periodic conditions, there you can pick specify pressure gradient and give a value of pressure gradient as you want, but I cant tell about the boundary conditions.