Coupling of 2d axially symmetric geometry with 3D-T-junction

Dear all,

I am modeling a flow simulation where I would like to couple axially symmetric tubes to a 3D T junction (pipe flow would not be an option for me as my fluid flow is a little special - I need control over its radial districution).

So I have to do the coupling from the end of a 2D-tube (radial 'line' bounday) to 3D T-junction (sphere boundary, same diameter). I just found information on extrusion coupling which is not working for my case (I guess).

Does anybody have an idea how to map this?

Best regards,

Nils