I was inspired by Bernoulli’s observation that the higher speed of the air on the top side of an airfoil creates a low pressure zone. The vehicle is then lifted by the higher air pressure beneath the airfoil. My twelve year old brain knew that to make a vehicle fly, I needed to lower the air pressure above the wing surface — essentially, to displace air away from the top — thereby creating a partial vacuum above the vehicle. But there was no rule saying that the displaced air had to end up directly underneath the vehicle.
My crazy scheme was to design a flying machine that would create a partial vacuum on its top surface (which is also what a helicopter does), by displacing the air sideways, rather than downward. The vehicle would be drawn up into the region of lower pressure just above it, and voila, flight.
The diagrams below show roughly what I had in mind. The result looked something like a flying saucer — which is not surprising, considering that its inventor was a twelve year old boy. 😉
The top view (1) shows rotors atop the disk spinning, which creates centripetal force that pushes air (the blue arrows) radially outward. The perspective view (2) is a schematic representation of the rotating blades. In practice a lot of work would need to be done to figure out the right size and shape for these spinning airfoils. The side view (2) shows how air comes in at the top and is then pushed out to the side. The partial vacuum above the vehicle results in lift (the red arrow):
In principle, you could stand right underneath one of these flying saucers and not feel any downward wind force. Of course, as they say, theory and practice are the same in theory, but different in practice. I suspect that by now somebody has long since had a similar idea, has probably tried to build one of these things, and has realized why it wouldn’t really work.
But when I was twelve, thinking about stuff like this kept me off the streets and out of trouble. 🙂