calculation of streamFunction on a 2D slice of a 3D case
 

Hi everybody

As you know the streamFunction can be calculated just in 2D cases. I solved a 3D flow in a channel with a square cross-section and now I want to calculate the streamFunction in a plane (to see the secondary flow structures). I can extract the data of that plane using sample or slice (in ParaView). But I don't know how to save it as an initial condition of a 2D OpenFOAM case?

If I could save it as a 2D case, I set "empty" boundary conditions for front and back boundaries.

Do you know how can I do that?

Thanks