[McRat]

http://www.foxnews.com/leisure/2012/...ntcmp=features

Huh??? Perpetual Motion at last?

If you can go faster than the air speed, couldn't you drive around with no wind?

[Ziggythewiz]

No, just gearing, like a car in overdrive.

[frodus]

there still has to be wind to get the thing to move.

The propeller blades were replaced with slightly smaller turbine blades that are spun by the oncoming wind and turn the wheels to drive the lightweight car through gears that increase the turbine to wheel speed ratio.

[McRat]

In theory, if you pushed it to 20mph (everything is relative), would it would start to accelerate from there?

[Jan]

Originally Posted by Ziggythewiz

No, just gearing, like a car in overdrive.

At wind speed the relative wind speed is zero. The turbine will not work anymore, how much you'd geared it up or down. And beyond that point the turbine will become an energy loss.

As far I understand the setup: During acceleration below wind speed, a part of the energy is stored, and is used after the point wind speed is reached.

It's only to proof you can go faster than wind speed, not infinitive.

[Ziggythewiz]

Originally Posted by Jan

At wind speed the relative wind speed is zero. The turbine will not work anymore, how much you'd geared it up or down. And beyond that point the turbine will become an energy loss.

As far I understand the setup: During acceleration below wind speed, a part of the energy is stored, and is used after the point wind speed is reached.

It's only to proof you can go faster than wind speed, not infinitive.

No, it is not. The blades are spinning, so the direction of the speed, and really the speed of it is irrelevant to the motion of the vehicle. It's just like a sailboat (which can go far faster than the wind) tacking. You generate a force perpendicular to the direction of the wind.

[McRat]

Originally Posted by Ziggythewiz

No, it is not. The blades are spinning, so the direction of the speed, and really the speed of it is irrelevant to the motion of the vehicle. It's just like a sailboat (which can go far faster than the wind) tacking. You generate a force perpendicular to the direction of the wind.

I had a guy call last year who want me to draw up blueprints for his invention for the patent office. I think I broke his heart when I told him that the patent office requires a working model be submitted for Perpetual Motion machines.

This wind car might have a ground speed in excess of wind speed by steering at a vector to the wind. But wind cars have been around for 100 years, so they are nothing new.

[Jan]

Originally Posted by Ziggythewiz

It's just like a sailboat (which can go far faster than the wind) tacking. You generate a force perpendicular to the direction of the wind.

I couldn't resist this mind teaser. And I finaly admit you're right, it is possible. But not the way you explain it. A sailboat never exceeds the wind speed. It can only exceed the windspeed relative tot the water, only by going transvere of the wind direction. With the wind behind it, it can never exceed the wind speed.

But this thing works differently. Below the windspeed I guess it is just propelled by the wind, like a any object that gives resistance to the wind. Close to the windspeed it reaches an equilibrium. The resistance of the drivetrain is the same force as the wind.

And then I suddenly got it. Even if there is an equilibrium, the spinning wheels harvest the power that is created by those opposite forces. And from that point on, the turbine is powerd by the wheels, and gives an extra force upon the direction of the wind. Making it go faster.

Of course there is a limit, a new equilibrium where the power harvested out of the wind vs. the ground gets even with the increased resisitance of the moving vehicle.

So, the maximum speed is a function of the wind over land speed. And if that speed is zero, the maximum speed is also zero.

It's a brilliant vehicle. A mind teaser. Or a hoax.

[GizmoEV]

Originally Posted by Jan

It's a brilliant vehicle. A mind teaser. Or a hoax.

Not a hoax. Just physics in action. See http://www.youtube.com/watch?v=5CcgmpBGSCI

The wheels and propeller are linked together. Initially the propellers act like a stationary sail. As the car moves forward the wheels turn the propeller in a direction to push the wind back like the propeller on an airplane does. This backward pushing on the air by the propeller compensates for the decreased relative wind speed to the vehicle. As the vehicle moves faster the relative wind speed to the vehicle drops to zero. This occurs in the video around 1:30. By this time the propellers are pushing rather hard on the air further counteracting the decrease in relative wind speed so the vehicle goes faster than the wind until equilibrium is finally established. No magic here. Just great engineering and applying the principles of physics. Just remember, it is NOT the wind directly driving the propeller, it is the wheels. That is key.

You can get more info at http://www.fasterthanthewind.org/

[trueriver]

This is kinda like a sailing dinghy, when the wind is side on you can go faster than the wind. If it is at exactly 90 deg the active component of the wind stays th e same at any speed, and the max speed occurs when the resistance of the headwind equals the push from the sideways component.