[andreachr]

Hello!

I'm relatively new to OpenFoam and I'm having trouble when using the "empty" condition. I'm trying to model some kind of nozzle (pictures included) and due to problem's conditions, I can assume that the flow is axisymmetric. Therefore, I used empty for the front and back of my model, walls for top and bottom and patch for inlet and outlet. I'm using an unstructured mesh with an average non-orthogonality of 19.7421. I used kEpsilon Model for turbulence, bounded Gauss linearUpwind for numerical schemes and 1 nonOrthogonalCorrector. I defined velocity at inlet and pressure at outlet. When I run the simulation, I get a weird pressure distribution:

P_empty.jpg

And also problems with the velocity, as if somehow the cells from the mesh could be seen:

U_empty_2.jpg

When trying to find a solution to this problem, I decided to try symmetryPlane instead of empty, and I noticed that these problems don't seem to appear (all other settings remained the same)

P_symm.jpg

U_symm_1.jpg

Because of this, I'm lead to believe that "empty" has specific requirements regarding the mesh, but until now I haven't found information about unstructured meshes and empty condition. Does anyone have any idea why empty doesn't seem to work with my unstructured mesh?? I would really appreciate any suggestion!!!

Thanks