-Define -> Boundary Condition
-Select interior-5 under Zone
-Select wall on the right column under Type
-Click on Yes to change the type.
-two internal walls will be created, wall-5 and wall-5-shadow. ID of wall-5 will be the same as the ID of interior-5. These two new walls with be Coupled by default and the available types for them are fan, interior, porous-jump, radiator, and wall. We don't have velocity-inlet type for internal wall. In order to have types that can be applied on external zones, they need to be split.
-In text user interface (TUI), type: /grid/modify-zones/slit-face-zone wall-5. Two additional walls will be created: wall-5, and wall-###. It will print on the cortex window of Fluent to find out which zone is wall-###. These are two external zones, one is adjacent to fluid-1 and the other is facing fluid-2. To have the fluid entering the pipe, the one which is adjacent to fluid-1 needs to be changed to velocity-inlet type. To find which one is adjacent to fluid-1, you need to visit the boundary condition panel for that zone and look under 'Adjacent Cell Zone'.
-Repeat the above procedure to apply pressure-oulet to interior-6.