So it's possible to build a sail car that can move faster than the wind pushing it... · 10:07am Apr 25th, 2014
And it's really fucking cool how it works!
First, to understand this, you need to see the design of the sail car:
The rotor, the sail, is mechanically linked to the rear wheels by transmission, but it doesn't work like you're thinking it works. The rotor isn't used to turn the wind's energy into mechanical energy. If that happened with this car's design the vehicle would actually move against the wind, but that doesn't happen because the vehicle is more aerodynamically efficient going forwards than backwards. Instead what happens is the wind pushes the car forward by the frame of the car and the sails on the rotor, which causes the rotor to turn against the wind, not with it.
To understand why that's important we need to look at aircraft for a minute. When an airplane flies into the wind the propellers lose efficiency because the wind is going in the same direction they're pushing the air, the propellers can't push against the wind as hard. However, when an airplanes flies away from the wind the propellers gain efficiency because the wind is going in the opposite direction they're pushing the air, the propellers can push harder against the wind. That concept applies here.
A normal sail car can only go as fast as the wind because after it's moving as fast as the wind there's no wind relative to it. This case is different because the sail has a mechanical link to the ground, which allows the sail, the rotor, to push against the wind's speed relative to the ground, not relative to its own speed. The rotor pushes against the wind the same way an airplane does when it flies away from the wind.
This design allows the vehicle to capture the wind's energy and store it as momentum faster than it can spend the energy, at least until the trickle of energy provided by the wind can't overcome air resistance and friction.
That's fucking brilliant, isn't it?
I want one.
2045076
It only moves in one direction!
2045080
No.
No One Direction.
Bad Queue.
Soooo, how fast have they gotten it to go?
2045086
Somewhere slightly above twice the speed of wind is their record, or roughly 30 mph in 15 mph wind.
2045085
You Don't Know You're Beautiful!
2045089
YOUR BRAINWASHING TACTICS WON'T WORK ON ME!!!
[Struggling Intensifies]
2045093
And that's the only One Direction song I know, so I won't be able to give you a Heart Attack.
2045100
I have been swooned!
2045105
unf
2045080
So? I didn't say I want one for my primary means of transportation. I just said that I want one.
2045162
It'd be like sledding on a flat plane, fun as hell, but you'd need to bring it pull it back around to the starting line.
2045167
True. Either that or hope for shifting winds.
Imagine how fast that thing would be in a storm...
2045232
Hm.
During a tornado.
"Fuuuck yooouuu 'naaadooo! Yooouuu caaan't caaatch meee!"
2045239
You'd be the first person to achieve supersonic speed unintentionally. You'd likely also be the first person to ever strike a brick wall so hard that you left a you-shaped hole in it.
2045242
Damn, these things are cool. I want one!
Reminds me of those scram jets the Nazis developed where the jet engine had no moving parts, and only required fuel, ignition, and a forward breeze through the combustion funnel and the faster the jet flew the faster the engine was fed further increasing the speed.