[Gurkenglas]

If the wind gets slowed by turning the turbine, shouldn't the output side funnel of the turbine be larger than the input side funnel to be able to hold more air? (So the additional wind coming in from behind doesn't have to waste its own kinetic energy pushing the front air out of the system)

[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?