Periodic Boundary Conditions for infinite 3D wing

Scott

Hi there,

I have set up a simple 2D test case with a channel to try and get the periodic BC's to work before i move onto something more complex in 3D, but am having no luck. I have a simple channel, with inlet and outlet, and top and bottom walls are the regions that I want the flow to cross. I am trying to implement a x=20m/s and y=10m/s inflow to see the flow transverse across the boundary. I have set the top and bottom walls to "interface", and then tried >Define >Grid Interfaces to link the interfaces, by naming it then by highlighting zone 1 and zone 2 and clicking interface type as coupled and periodic, then pressing create. It creates the interface, but then when i initialize i get the following error. "unnassigned interface zones"

The manual, CFD-Online search and google have not been able to provide me with the required breakdown of steps to actually use these functions! So hopefully someone here can point me in the right direction.

Thanks,

Scott