I came back to this thread because I finally believe that the model may work. This seems like a fun project for an engineering competition or something of the like.
I wonder if it would work better with a better shaped windmill blade? Maybe try and improve upon the 2.8x value. Sounds like a good supermileage car to me
.
Once you get above a threshold ground speed, I guess you could travel in any wind direction, right?
Going into the wind would cause the car to go forwards automatically.
Going down wind was proven the guy I think.... Once you got above the air velocity, the energy from the wheels would have to go into pushing the air to go into the blades... that doesn't work. But once you are going into the wind, it is just like if you are going into a head wind.
A cross wind has no power and you can't get something for nothing, so you would have to have a swivel mount on the blades.
The video on the treadmill (stop4stuff) was convincing in the fact that the energy has to come from somewhere (the treadmill). The same can work in reverse with the wind.