How to specify velocity-inlet to interior faces types.
There are cases where user wants to specify velocity-inlet to internal zones. For example, lets say we have a cylinder completely inside the a box. Lets assume that inside of the cylinder is meshed and have cell zone fluid-1, and outside of the cylinder is meshed with cell zone fluid-2. The inlet and outlet of the pipe is an interior type and are named interior-5, and interior-6, respectively. There is node-connectivity between fluid-1 and fluid-2 at all the boundary zones of the pipe.
We know the velocity of the fluid entering. Also, the fluid of the pipe does not mix with the fluid outside at the outlet of the pipe. How to specify velocity inlet to the pipe and make the fluid inside the pipe exit the domain at the outlet?
-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.
How to split wall-5 from wall-5-shadow?
-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.