I don't understand how this car works.

@ebrown p,

Quote:

I was thinking about setting up equations showing that the work done by the Propeller against a tailwind equals the work done on the wheels by the ground-- and then showing how this value can easily be greater then any frictional forces even when the car is going faster then the tail wind.

It harder to set up math equations to prove the impossible then to play words games and yes I would love to see you turn this nonsense into energy and momentum equations as even the hoaxers had not try to do that.

All they had been doing is silly words games.

So good luck.

1 Reply

Lord how about next revisiting the old Dean reacterless space drive?

The math and the models was one hell of a lot more fun then this nonsense and if it had happen to be true most more important also.

Then we could then deal with cold fusion and the Z rays and on and on.............

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@BillRM,

I can't come up with it. It seems like in order to turn the relative velocity of the car vs the pavement into energy, I have to give up that velocity.

1 Reply

@rosborne979,

Quote:

Yet ice-boats routinely travel faster than the winds that propel them because they deflect the wind at an angle. The propeller on this vehicle is doing the same thing except in a rotational phase rather than an angular phase.

And you are confusing a scalar term speed with a vector term velocity.

No ice boat or sail boat can sail faster then the Velocity of the wind and no sail car, ice boat or sail car can sail faster then the wind behind it.

Footnote you are sounding a little like the Dean Drive supporters by the way.
That bit of nonsense I would had love to had been true.

1 Reply

@BillRM,

BillRM wrote:

Quote:
Yet ice-boats routinely travel faster than the winds that propel them because they deflect the wind at an angle. The propeller on this vehicle is doing the same thing except in a rotational phase rather than an angular phase.

And you are confusing a scalar term speed with a vector term velocity.

No ice boat or sail boat can sail faster then the Velocity of the wind and no sail car, ice boat or sail car can sail faster then the wind behind it.

Totally and completely wrong.

Quote:

Modern designs

Modern iceboats designs are generally supported by three skate blades called "runners" supporting a triangular or cross-shaped frame with the steering runner in front. Runners are made of iron or steel and sharpened to a fine edge, most often cut to an angled edge of 90 degrees, which holds onto the ice, preventing slippage sideways from the lateral force of the wind developed by the sails. Once the lateral force has been effectively countered by the runner edge, the remaining force of "sail-lift" vacuums the boat forward with significant power. That power increases as the speed of the boat increases, allowing the boat to go much faster than the wind. The only seeming limitations to iceboat speed are windage, friction, the camber of the sail shape, strength of construction, quality of the ice surface and the level of skill, athleticism and fearlessness of the sailor.[1] Iceboats can sail as close as 7 degrees off the apparent wind.[2]

http://en.wikipedia.org/wiki/Ice_boat

Please, look **** up before you spout off on the board man

Cycloptichorn

2 Replies

@Cycloptichorn,

I know ice boats do that all the time. What are you supposed to do when the facts don't fit the theory?

I know. Change the facts.

1 Reply

@engineer,

Engineer

1) The road does work on the wheels, this energy is used to turn the propeller. The effect is measured relative to the pavement. (Don't you agree?).

2) The propeller does work on the air (i.e. pushes air forcefully backwards). This effect is measured relative to the air speed (No?).

So no, you don't need to give up that velocity.

1 Reply

@ebrown p,

But those two forces should be in equilibrium, minus losses from friction (the tips of the propellers will also form vortices).

If the wind is indeed adding energy, you have to find out where it's coming from.

1 Reply

@Cycloptichorn,

You are pitiful indeed but if you wish to believe in free energy out of nowhere be my guest.

Or if you do not know the different between vectors or a scalars also be my guest.

Speed once more my friend is not vel. and no ice boat ever build or going to be build is able to go downwind faster then the wind. An ice boat speed of ten times the wind speeds is beside the point as it still have winds over it sails thank to the wonderful fact that speed is not a vector.

Did some fool ever passed you in a physics course at any level including high school?

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@roger,

Quote:

I know ice boats do that all the time. What are you supposed to do when the facts don't fit the theory?

I know. Change the facts.

And so what that the ice boat going ten times the ground speed as it is not outracing the wind fool as the winds is at a sharp angle to the path of the boat.

No ice boat is going to go down wind faster then the wind.

Or to put it more correctly no boat is going to have a component of it "speed" in the direction of the wind greater then that wind.

One more speed and Vel. is not the same thing at all.

Lord it is a damn shame that we do not teach real science to most people.

1 Reply

@DrewDad,

DrewDad,

They are not in equilibrium because there is a tailwind (which is a source of energy). This tailwind is blowing in the direction of the car and (this is is key) they propeller is pushing against this tailwind (meaning the action of the propeller is measured against the tailwind).

The tailwind is the source of energy. It is the propeller that allows the car to use this energy even when the car is going faster then the wind. Remember that the faster the car goes along the ground, the faster the propeller spins and the more forcefully it pushes air backwards against the tailwind.

Think of it this way... there is a big difference between a propeller and a sail (in that a propeller can push the car faster then the the wind speed even when the car is going in the same direction as the wind.)

2 Replies

@ebrown p,

I read that the car also works in a headwind. Does that work with your explanation?

1 Reply

So, what keeps the car from accelerating forever? What forces acting against the car limit it's speed?

I'd really like to see some math on this.

3 Replies

@BillRM,

BillRM wrote:

Or to put it more correctly no boat is going to have a component of it "speed" in the direction of the wind greater then that wind.

That is correct if it's going "in the direction of the wind", however, ice boats move at an angle to the wind. And it's the angle of the sail which generates a vector component of the wind which is moving at a higher velocity than the wind itself.

The propeller on this vehicle acts as a sail impacting the wind at an angle which makes use of the increased velocity of the deflected wind (it's a bit more complicated than that because it's rotating and pushing on a tailwind, but that's essentially what is happening).

1 Reply

@maporsche,

maporsche wrote:

So, what keeps the car from accelerating forever? What forces acting against the car limit it's speed?

There is a point at which the frictional forces exceed the forward component, in addition the pitch of the propeller will affect the efficiency of airflow (just like in a normal plane). So the vehicle reaches an equilibrium at some speed in excess of the tailwind. This is the same reason an ice boat traveling at an angle to the wind won't simply accelerate forever.

0 Replies

@ebrown p,

ebrown p wrote:

They are not in equilibrium because there is a tailwind (which is a source of energy). This tailwind is blowing in the direction of the car and (this is is key) they propeller is pushing against this tailwind (meaning the action of the propeller is measured against the tailwind).

The tailwind is the source of energy. It is the propeller that allows the car to use this energy even when the car is going faster then the wind. Remember that the faster the car goes along the ground, the faster the propeller spins and the more forcefully it pushes air backwards against the tailwind.

Think of it this way... there is a big difference between a propeller and a sail (in that a propeller can push the car faster then the the wind speed even when the car is going in the same direction as the wind.)

But take the case where the car is moving at the same speed as the wind. From the car's perspective, the air is still and the ground is moving.

How is this tailwind still providing energy to accelerate the car?

1 Reply

@DrewDad,

Quote:

But take the case where the car is moving at the same speed as the wind. From the car's perspective, the air is still and the ground is moving.

In this case you are forgetting the key part.... the propeller which (being driven by the wheels) is pushing the car forward (by pushing air backwards). This certainly provides an acceleration. The key to understanding this is that the thrust of the propeller adds to the tailwind (or to put it another way, it is measured relative to the tailwind).

If there was no tailwind (in your example) instead of the car moving at the "same speed as the wind"... the wind would be going against the motion of the car (from the cars perspective). The point being, the tailwind certainly "helps" the car in any of these circumstances (i.e. the energy being added to the car is always greater with a tailwind then without).

1 Reply

@rosborne979,

Bill is saying that there's a difference between "speed" and "velocity". Speed is how fast you move in any direction. Velocity is how fast you move in a particular direction.

An iceboat's speed can be faster than the wind, but only when moving across the wind. But point the iceboat downwind, the speed drops off, and it can never average a speed downwind faster than the wind itself.

These folks are claiming that the car can go downwind indefinitely at 2.85x the speed of the wind. I'm not seeing where the energy to do so is coming from.

That being said, I'm not seeing how that little car manages to climb up the incline of the treadmill. I suppose there could be a fan blowing on it, that's out of frame.

2 Replies

@maporsche,

Quote:

So, what keeps the car from accelerating forever? What forces acting against the car limit it's speed?

I'd really like to see some math on this.

The counter-intuitive part to this car is that it can get energy from the wind even when it is going faster then the wind. Once you get over this hurdle, you can just think of it as a wind powered car.

You can ask the same question of a solar powered car; What keeps a solar-powered car from accelerating forever?

0 Replies

@maporsche,

Quote:

So, what keeps the car from accelerating forever? What forces acting against the car limit it's speed?

I'd really like to see some math on this.

I think the headwind case is easier to understand.

Going with the wind, the wheels drive the propeller. The propeller "pushes" the car forward in a way that works together with the tailwind (which adds energy to the car).

Going into the wind-- you simply have the propeller drive the wheels. The wind turns the propeller which causes the wheels to push against the ground which pushes the car forward.

0 Replies

I don't understand how this car works.

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