Apply boundary condition on internal face (faceZones)
 

Hello,


I want to simulate a flow in straight 3D pipe using pressure driven flow. It means that I apply fixedValue p1 at the inlet patch (z=0) and fixedValue p2 at the outlet patch (z=L) while velocity is setting to zero gradient type for both inlet/outlet pathces. Everything is ok and the field is correct. Now I want to create a small region at the inlet of the pipe where the first face is the inlet patch (z=0) and the second is an internal face named intFace placed at z = L/3. I create this geometry from Salome and save the mesh in .unv. When I run ideasUnvToFoam it creates three pathces (inlet, outlet,wall) and one faceZones (intFace). Now I want to apply p1 at the inlet patch, p2 at the intFace and zero gradient at the outlet patch, while for velocity the boundary conditions are the same as before. How can I impose a fixedValue at an internal face ??


This is not working



intFace

{

type fixedValue;
value uniform p2;

}



Thank you

Hi!


You can't impose a boundary condition on an internal face. There is a strong reason why it is called BOUNDARY condition, and not internal condition. In the 0 directory you can't prescribe anything on a faceZone.
But you can create a baffle from that faceZone. See the attached image (Sorry for the poor quality, I'm not an artist. :D ). The left is the initial mesh, where that red face is the faceZone. Then you can split it into two boundary faces as you can see on the right side. Of course the mesh won't distorted, i just draw it like this so you can see that there is 2 face now. And on these faces you can impose cyclic boundary conditions with pressure jump, internal wall, or anything you want. For that check the "createBaffles" utility.

Thank you very much for your reply. I will check it !!!