[mgraczyk]

I believe the output side should as wide as possible while still preventing turbulent flow, as would exist if there were no output tube.

[Gurkenglas]

Would turbulences be prevented if 3 radial blades (3 so the 45:15=3fold amount of air can pass without problem) divided the wind from the turbine into 3 funnels as large as the input funnel?