You could do this without having to "move" the exhaust back up to the top I think.
Just stack them in a line at different elevations so that one's exhaust turns into the fuel for the next one. If speed of the exhaust increases after a cycle you'd be creating stronger "breezes" as you go down each step.
It wouldn't be 'perpetual' but pods of 3-4 like this might be able to increase the yield substantially.
Then again I don't know much about this and I'm just trying to comprehend it all.
This is doable, and it's done in the natural gas turbine world (look up combined cycle turbine, essentially you hook up a lower-power steam turbine to the exhaust of a natural gas turbine).
The main problem is that turbines are expensive and lossy, and when the main turbine is already going off of a relatively small amount of wind energy, the amount of energy you could produce from its' output is probably very small.
if you output one into another, the resistance would back up into the first one and reduce its output, or else the pressure would push the air backward out one of the other tubes of the 2nd device and not spin the rotor.
Well the "pod" could be set up with multiple levels so that every subsequent level receives a mixed flux of natural wind and the ejecta of the previous level, no?
Just stack them in a line at different elevations so that one's exhaust turns into the fuel for the next one. If speed of the exhaust increases after a cycle you'd be creating stronger "breezes" as you go down each step.
It wouldn't be 'perpetual' but pods of 3-4 like this might be able to increase the yield substantially.
Then again I don't know much about this and I'm just trying to comprehend it all.