CFD Online Discussion Forums - Symmetry and Periodic boundary conditions

Hi,

Firstly, I apologize because my English is not very well…rsrsrs…I am a Fluent software new user.

I have studied the effect of the dimples on thermal-hydraulic behavior at a plate-fin by using Fluent software. For this study, I need to divide the domain in inlet, outlet, symmetry and periodic. However, I have never run simulations with periodic and symmetry conditions.
I have prescribed constant wall temperature on tube surface, x-velocity at inlet and outflow as the boundary conditions. I have utilized extended regions at inlet and outlet. Is correct I use the symmetry boundary conditions in inlet and outlet regions?
I have used Tgrid to create the 3-D meshes and the periodic surface (it generates a "shadow surface" from periodic surface with the same characteristics, including number of elements, dimensions, etc.). I verified the mesh quality and no problems were reported by the software. The domain is one-half plate (symmetry condition) connected at a tube and two periodic boundary conditions positioned at one-half (upper and lower at Z-direction) of fin pitch (the periodic is parallel to entrance flow), as indicated on Fig. below (rsrs)

-------------------------------------- Periodic 1

-------------------------------------- Plate

-------------------------------------- Periodic 2

Doubt 2). In my case, the symmetry boundary condition does not report any result and Fluent does not allow that any information can be changed in its setup for this condition. What is happening?

Doubt 3). I have used "Specified mass flow" as periodic boundary condition. For example, if inlet mass flow is 0.2 kg/s, what the value which I have to setup on "Specified mass flow"? Also, what is the flow direction, in x, y and z, that I have to use for this case? I have used Z=1 and X=Y=0.