Wind powered vehicle that goes downwind faster than the wind - Part 60

[Alan Fox]

That's not a problem, Heinz - it's the solution to the apparent paradox. if you constrain the sail/prop blade to a "tiny circular are" then that "tiny circular area" will indeed be travelling directly downwind. The sails aren't - but the "tiny circular areas" is.

And if you happen to be sitting in that "tiny circular area" then you will be taken directly downwind!

Is your objection simply that the sails/blades aren't travelling directly downwind? If so, then of course you are correct. But the neat trick is to package that "tiny circular area" as a cart. Then you have a wind-driven cart that travels directly downwind.

If I can butt in and say it's not a question of objections for me at this point. It feels like a failure to see the emperor's clothes. The specific issue currently is when Windgrins talking about the wheels supplying power to the rotor, which makes no sense to me. Taking power from the wheels is using up "flywheel" power. There is no power input.

[Heinz Hershold]

If I can butt in and say it's not a question of objections for me at this point. It feels like a failure to see the emperor's clothes. The specific issue currently is when Windgrins talking about the wheels supplying power to the rotor, which makes no sense to me. Taking power from the wheels is using up "flywheel" power. There is no power input.

You are exactly right. Wait a bit and you will soon be introduced to Cargo Cult *ground energy*

[Alan Fox]

Alan;

Perhaps if you read all the posts made since 8am today you might get a clue.
Apart from anything by Heinz, unless you want a chuckle or two.

My first impression yesterday, the first time I took notice of this thread and the first time I was aware of someone claiming to be able to get a wind-driven vehicle to head precisely downwind at faster than the speed of the wind, was impossible.

I'm hopeless at math but a fairly practical person with an educational background in biochemistry. I'm also skeptical of video demonstrations in general. So the only way I'm going to get this is to try and work through step by step. It may be a waste of my time and more so for people trying to help. What are we gonna do?

The high volume of invective here doesn't seem conducive to establishing facts and principles. I'm trying to ignore it.

[Heinz Hershold]

@Heinz

Wheels in motion have no Inertial reference frame that can be attached with respect to any fixed point on the rim. That doesn't mean a wheel can't operate in a specified inertial reference frame. No part of the upper surface of the belt of a treadmill is in circular motion. You are a nut.

Very specifically, this sentence you wrote is total nonsense:

"Any point on the belt, that is in contact with the wheel, and spinning the wheel will be in circular motion and will undergo centripetal acceleration."

This would imply that any point on the surface of the earth that a car is operating on with wheels is in circular motion (of the wheel). This really makes you a nutjob.

No one who understands basic physics will agree with you. You don't seem to have a clue about basic physics. No handwaving needed. What you wrote is idiocy.

As usual, the idiot is YOU. You just established you know nothing at all about belts and pulleys. I will have to educate you.

This is a good tutorial you can start with.

You do know there must be a braking force on the wheel at the belt, right?

If we examine an elementary portion of the belt where it contacts the wheel, you can see something like this:



Do you see the way the belt wraps itself around a section of the wheel? It MUST do that in order to spin the wheel. It cannot spin the wheel with a point contact.


Next, we can resolve that braking force into horizontal and vertical (upwards) components:



This establishes three things:

!) the section of belt in contact with the drive wheels is in circular motion, not uniform linear motion.

2) what I said about centripetal acceleration on this section of the belt must be true, and your nonsense about uniform linear motion is false.

3) There is a vertical (upwards) force exerted o the drive wheels by the belt that will push the wheels away, causing intermittent contact.


And your statement This would imply that any point on the surface of the earth that a car is operating on with wheels is in circular motion (of the wheel).
is lunacy. A wheel rolls on the earth, it is not spinning, as the cart wheels are on the treadmill. The difference is profound but even you could understand it if you tried.

[Alan Fox]

@ Pingu,

I saw a couple of comments from you show up in the unread comments indicator but can't seem to find them. Re Gormenghast - they're posting kittie pictures now!

[Heinz Hershold]

My first impression yesterday, the first time I took notice of this thread and the first time I was aware of someone claiming to be able to get a wind-driven vehicle to head precisely downwind at faster than the speed of the wind, was impossible.

I'm hopeless at math but a fairly practical person with an educational background in biochemistry. I'm also skeptical of video demonstrations in general. So the only way I'm going to get this is to try and work through step by step. It may be a waste of my time and more so for people trying to help. What are we gonna do?

The high volume of invective here doesn't seem conducive to establishing facts and principles. I'm trying to ignore it.

I am the only one who is presenting the math and physics principles and the high volume of invective, you may note, is not coming mainly from me.

I notice you are ignoring my posts. That will ensure that soon you will be a member of the Cargo Cult. Good luck with that.

[Windgrins]

It was my first day. This is why I tried thinking about motor/generators and the flow of electrical power. Regarding the rotor, in sufficient apparent wind, it can generate power to drive the wheels. But if the rotor is driven by the wheels, where is the power to drive the wheels coming from? The braking effect will slow the cart, no?

I'll continue in a second post.

All good, don't worry about your first day. We get cranky with BS like Heinz which has been going on for 7-10 years. I lose count.

Yes. One could build a DDWFTTW cart with a generator on the wheels and a motor on the prop. (not the other way as you surmise).

In this case it becomes more clear. No matter what frame of reference we speak of it becomes clear that energy is being transferred from the wheels to the prop. It is what drives the shaft which drives the propeller. The propeller then turns and creates lift (a force in the direction of the cart travel). And this is where it gets cool. A propeller because it has a Lift/Drag coefficient much >1 generates a force pushing the cart much more than the circumferential drag force that it takes to turn the prop.

Notice that this has the principle of a lever. It multiplies forces, not energy.

Nothing in the cart creates energy. COE has not been violated or even abused!

Now here's the tricky bit. The propeller is generating force but because the wind is actually blowing over the ground, it generates more force than it would if it were traveling at the same speed if the wind (over the ground) was calm (didn't exist). This is the essential trick of the entire cart. The cart benefits from the fact that it has a real tailwind even though it is traveling at windspeed. And the force the prop generates is more than the wheels retard the cart! If it were doing this in calm air, like you pulled it up to speed with a truck and let it go, the force the prop generated would be less than the retarding force at the wheels and it would grind to a stop.

But because there is an actual wind, it generates more force and absorbs energy from that wind. Where does the energy come from for this? It comes from slowing the wind over ground that the cart is operating through.

The energy books balance--the wind loses energy, the cart gains some of it. The rest goes away in heat and turbulence.

The force books balance--the wheels impede the cart, the prop generates more force due to its L/D ratio than the wheels impede. There is a net force in the direction of the cart generated which accelerates the cart. There is an equal and opposite reaction on the air from the prop which adds up to the acceleration force plus the wheel reaction force. This force on the air (that goes through the prop--called the streamtube) causes that air to be slowed (in the direction of the cart motion) more than the surrounding airmass.

The remainder is engineering math and equations depending upon the efficiencies, drag, rolling resistance, prop aerodynamics and a lot of other niggly bits. But when this is done properly, the arithmetic lines up with the qualitative explanations above.

[semper]

That's not a problem, Heinz - it's the solution to the apparent paradox. if you constrain the sail/prop blade to a "tiny circular are" then that "tiny circular area" will indeed be travelling directly downwind. The sails aren't - but the "tiny circular areas" is.

And if you happen to be sitting in that "tiny circular area" then you will be taken directly downwind!

Is your objection simply that the sails/blades aren't travelling directly downwind? If so, then of course you are correct. But the neat trick is to package that "tiny circular area" as a cart. Then you have a wind-driven cart that travels directly downwind.

Yeah, you have to wonder why someone with the genius of a can of beanz can't figure the fact that downwind ice yachts on a tight ddw tack pattern is the same as far as the wind is concerned as a propeller blades with the hub ddw. Gee, I wonder why he can't think about that?

[Heinz Hershold]

Notice that this has the principle of a lever. It multiplies forces, not energy.

Nothing in the cart creates energy. COE has not been violated or even abused!

Fairy tales!

Those Forces must operate over a distance. That is Work and Energy.

Power = Force x Velocity

Generate 1 Watt at the wheels at 5 m/s and the Brake Force = 1/5 N

Use that 1 Watt, with no losses to produce a Thrust at the propeller to drive the cart at 5 m/s over the ground.

Thrust = 1 Watt / 5 m/s = 1/5 N

That is with NO losses! Thrust cannot ever be greater than the braking force at the wheels

[Windgrins]

If I can butt in and say it's not a question of objections for me at this point. It feels like a failure to see the emperor's clothes. The specific issue currently is when Windgrins talking about the wheels supplying power to the rotor, which makes no sense to me. Taking power from the wheels is using up "flywheel" power. There is no power input.

It's a physics trick but a trick nonetheless. See my explanation in this post:

http://talkrational.org/showthread.p...27#post2637527

The wheels apply a retarding force but they do supply power to the cart because the cart body is pushing on the axles (from the propeller thrust) and the wheels are pushing against the ground. This forms a torque couple which produces rotation of the axle. But the power/force gets transmitted to the transmission which powers the prop.

This is a classic feedback loop. But the next question will always be "but where does any energy come into the loop?" The answer is the mechanism as a whole produces a net force by slowing the wind which it pushes against with the prop. When the prop pushes against the wind, it produces a force to push the cart. That force is greater than it would be if no wind were blowing over the ground.

So that's the tricky bit where the energy comes into the system. It usually is a bit easier to think about it from the force perspective than the energy perspective which just says the overall push force on the cart is greater than the retarding force because the wind is blowing. This is completely consistent with the energy description but energy isn't really easy to chase through feedback loops but it can be done.

PS, Heinz keeps changing reference frames in his calculations or leaving out the thrust from the prop which is why his math never adds up. Many years ago, he did a force calculation that showed the cart worked when he actually did it correctly. Since he couldn't believe his own results that said it worked, he has spent years trying to deny that bit of math which was his only correct math.

He will go off on a thousand tangents like trying to prove the flat part of a treadmill is moving in a circular motion (insane) to try to avoid the argument. So basically, his BS is simply looked at like the trash it always is. He has zero physics training (other than people coaching him on this thread which rarely takes) and he always comes up with a fatal flaw from "physics like he wants it to be, not like it is" which like his recent derivation of "circular motion of a flat surface" is just nuts. I'll let you judge.

[Alan Fox]

I am the only one who is presenting the math and physics principles and the high volume of invective, you may note, is not coming mainly from me.

I notice you are ignoring my posts. That will ensure that soon you will be a member of the Cargo Cult. Good luck with that.

Heinz,

I don't know you and I've only yesterday noticed this thread. I'm not ignoring your comments though I may not have responded directly. I'm sceptical of the phenomenon but always open to better (in the sense of more intelligible to me) explanations.

I can see there is a long history to the subject. I'm not interested so much in the history as in whether the ability of a wind-powered vehicle travelling directly downwind at faster than windspeed is genuine and repeatable. I think an inquisitorial rather than an adversarial approach might be better suited to establishing the facts.

[Alan Fox]

Windgrins writes:

It's a physics trick but a trick nonetheless. See my explanation in this post:

http://talkrational.org/showthread.p...27#post2637527

The wheels apply a retarding force but they do supply power to the cart because the cart body is pushing on the axles (from the propeller thrust) and the wheels are pushing against the ground. This forms a torque couple which produces rotation of the axle. But the power/force gets transmitted to the transmission which powers the prop.

This is a classic feedback loop. But the next question will always be "but where does any energy come into the loop?" The answer is the mechanism as a whole produces a net force by slowing the wind which it pushes against with the prop. When the prop pushes against the wind, it produces a force to push the cart. That force is greater than it would be if no wind were blowing over the ground.

So that's the tricky bit where the energy comes into the system. It usually is a bit easier to think about it from the force perspective than the energy perspective which just says the overall push force on the cart is greater than the retarding force because the wind is blowing. This is completely consistent with the energy description but energy isn't really easy to chase through feedback loops but it can be done.

When you say: "So that's the tricky bit where the energy comes into the system" that is exactly my problem. I'll have a look at your link.

[Heinz Hershold]

Heinz,

I don't know you and I've only yesterday noticed this thread. I'm not ignoring your comments though I may not have responded directly. I'm sceptical of the phenomenon but always open to better (in the sense of more intelligible to me) explanations.

I can see there is a long history to the subject. I'm not interested so much in the history as in whether the ability of a wind-powered vehicle travelling directly downwind at faster than windspeed is genuine and repeatable. I think an inquisitorial rather than an adversarial approach might be better suited to establishing the facts.

Fine by me but please don't lay the blame for the adversarial approach all on my doorstep. You can see the attacks aimed at me in the thread, can you not?

Frankly, I don't give a rat's ass about all that and I respond in kind, but if you read my posts you will find content there that the others do not provide.

I have just shown that COE will ensure the thrust cannot be greater than wheel brake, contrary to windgrins unfounded assertions.

I have also shown the part of the belt in contact with the drive wheels is not in uniform linear motion.

Those are important facts in debunking this claim.

[Heinz Hershold]

PS, Heinz keeps changing reference frames in his calculations or leaving out the thrust from the prop which is why his math never adds up. Many years ago, he did a force calculation that showed the cart worked when he actually did it correctly. Since he couldn't believe his own results that said it worked, he has spent years trying to deny that bit of math which was his only correct math.

He will go off on a thousand tangents like trying to prove the flat part of a treadmill is moving in a circular motion (insane) to try to avoid the argument. So basically, his BS is simply looked at like the trash it always is. He has zero physics training (other than people coaching him on this thread which rarely takes) and he always comes up with a fatal flaw from "physics like he wants it to be, not like it is" which like his recent derivation of "circular motion of a flat surface" is just nuts. I'll let you judge.

First of all, I have never changed reference frames, that is what YOU do all the time.



Where is the reference frame being changed here?

Power = Force x Velocity

Generate 1 Watt at the wheels at 5 m/s (with respect to the ground) and the Brake Force = 1/5 N

Use that 1 Watt, with no losses to produce a Thrust at the propeller to drive the cart at 5 m/s over the ground.

Thrust = 1 Watt / 5 m/s = 1/5 N

That is with NO losses! Thrust cannot ever be greater than the braking force at the wheels

And, if you had any sense at all, you would see the belt cannot be moving in uniform linear motion at the point where it contacts the wheels and wraps around a small section to spin them.

I have just posted a source that confirms that.

[Alan Fox]

please don't lay the blame for the adversarial approach all on my doorstep

I haven't.

[Windgrins]

Heinz,

I don't know you and I've only yesterday noticed this thread. I'm not ignoring your comments though I may not have responded directly. I'm sceptical of the phenomenon but always open to better (in the sense of more intelligible to me) explanations.

I can see there is a long history to the subject. I'm not interested so much in the history as in whether the ability of a wind-powered vehicle travelling directly downwind at faster than windspeed is genuine and repeatable. I think an inquisitorial rather than an adversarial approach might be better suited to establishing the facts.

If you understand the explanations and state "Oh, I see how it works, now!" Heinz becomes your sworn enemy for life. He's spent years agreeing with another complete idiot named Humber (who was at least amusing at times) who came up with every possible bad physics you can imagine and about 5000 bad physics explanations that I will assure you that you could never imagine even if you try hard.

Many of the people here actually came to the thread independently (like me). I was at first skeptical and unable to see the trick but after a couple of days of patient explanations, it dawned on me what I was missing. Since then, we've come up with countless devices to help visualize the mechanics like the sailboats rolled up into "cylinder world" which morphs into a propeller and the "carts on paper" which are shown earlier. I went on to create a whole slew of boring videos that basically disproved exactly what these two clowns stated definitively would prove it wouldn't work but every experiment came out exactly opposite of what they predicted but consistent with what we predicted. (Surprise!)

If you use the "carts on paper" example, you will see the carts won't work with no paper motion. But if you add paper relative motion (and it doesn't matter which paper is moved (which is why the TM works) then you can see that the paper provides the energy/force to make it work.

To make the almost exact analogy to the wind cart, you grease the set of wheels on the moving paper and start pulling. The carts will slip at first and if you add sand to the grease, it will pass the speed of the moved paper (windspeed) and eventually go faster than the moved paper (down paper). This you can pretty easily visualize because you can easily imagine all of the parts including the greasy wheels and sandy grit!

[Alan Fox]

Now here's the tricky bit. The propeller is generating force but because the wind is actually blowing over the ground, it generates more force than it would if it were traveling at the same speed if the wind (over the ground) was calm (didn't exist). This is the essential trick of the entire cart. The cart benefits from the fact that it has a real tailwind even though it is traveling at windspeed. And the force the prop generates is more than the wheels retard the cart! If it were doing this in calm air, like you pulled it up to speed with a truck and let it go, the force the prop generated would be less than the retarding force at the wheels and it would grind to a stop.

But because there is an actual wind, it generates more force and absorbs energy from that wind. Where does the energy come from for this? It comes from slowing the wind over ground that the cart is operating through.

So can I focus on where my scepticism points. You say "the propellor is generating force" and I say no, if a net force is being transferred down to the wheels by the propellor it must be being transferred to the propellor by moving air losing some momentum. But if the propellor is in apparent zero wind, there is no momentum to transfer to the propellor. What am I missing?

[Windgrins]

That is with NO losses! Thrust cannot ever be greater than the braking force at the wheels

But amusingly it is and here's the real world proof for all the non-idiots:

DDWFTTW WG Merciful End! - YouTube

DDWFTTW WG Merciful End! - YouTube

But, of course, the obvious will not be obvious to you and you will come up with some total happy horseshit about circular motion or some other insane idea!

PS, Alan, I created this set of videos and show exactly how the measurement setup is constructed so that anybody with one of the little carts, a kitchen gram scale, and a treadmill can easily replicate every one of my experiments for themselves (unlike Pons and Fleischmann) and obtain the results shown from any of the videos.

Also, this video should very viscerally answer your question of "can a cart produce positive thrust in relative still air". Not only does it, but it's clearly measured exactly to how much and the V_minhover speed is shown where the "windspeed" is too slow to operate (where the cart backs down the TM) and how a stronger wind produces more force as described earlier. This should be the visual proof of performance that it works and you are welcome to reproduce it if you like.

This video makes Heinz .

And then he has to come up with insane stuff like TMs aren't equivalent, they are in circular motion, the vibration is what make it work, and a ton of other obvious bullshit refutations which are all shown to be nonsense.

[Heinz Hershold]

If you understand the explanations and state "Oh, I see how it works, now!" Heinz becomes your sworn enemy for life. He's spent years agreeing with another complete idiot named Humber (who was at least amusing at times) who came up with every possible bad physics you can imagine and about 5000 bad physics explanations that I will assure you that you could never imagine even if you try hard.

Many of the people here actually came to the thread independently (like me). I was at first skeptical and unable to see the trick but after a couple of days of patient explanations, it dawned on me what I was missing. Since then, we've come up with countless devices to help visualize the mechanics like the sailboats rolled up into "cylinder world" which morphs into a propeller and the "carts on paper" which are shown earlier. I went on to create a whole slew of boring videos that basically disproved exactly what these two clowns stated definitively would prove it wouldn't work but every experiment came out exactly opposite of what they predicted but consistent with what we predicted. (Surprise!)

If you use the "carts on paper" example, you will see the carts won't work with no paper motion. But if you add paper relative motion (and it doesn't matter which paper is moved (which is why the TM works) then you can see that the paper provides the energy/force to make it work.

To make the almost exact analogy to the wind cart, you grease the set of wheels on the moving paper and start pulling. The carts will slip at first and if you add sand to the grease, it will pass the speed of the moved paper (windspeed) and eventually go faster than the moved paper (down paper). This you can pretty easily visualize because you can easily imagine all of the parts including the greasy wheels and sandy grit!

nothing but more ad homs and more *tricks* and no physics or math. pathetic

[buttershug]

If I can butt in and say it's not a question of objections for me at this point. It feels like a failure to see the emperor's clothes. The specific issue currently is when Windgrins talking about the wheels supplying power to the rotor, which makes no sense to me. Taking power from the wheels is using up "flywheel" power. There is no power input.

You know those cars that you pull back and let go?
When you pull back you are providing energy to a spring.

Also if you have a hand crank and turn it, you are providing energy are you not?

[Alan Fox]

If you use the "carts on paper" example, you will see the carts won't work with no paper motion. But if you add paper relative motion (and it doesn't matter which paper is moved (which is why the TM works) then you can see that the paper provides the energy/force to make it work.

I get that. This is not an issue. Incidentally the force to move the carts is muscular via gearing. It's not mysterious to me. I've done the cotton reel thing.

[buttershug]

My first impression yesterday, the first time I took notice of this thread and the first time I was aware of someone claiming to be able to get a wind-driven vehicle to head precisely downwind at faster than the speed of the wind, was impossible.

I'm hopeless at math but a fairly practical person with an educational background in biochemistry. I'm also skeptical of video demonstrations in general. So the only way I'm going to get this is to try and work through step by step. It may be a waste of my time and more so for people trying to help. What are we gonna do?

The high volume of invective here doesn't seem conducive to establishing facts and principles. I'm trying to ignore it.

Imagine a corkscrew turning being turned and going into a cork.
It is moving forward.

Now imagine that cork moving in the same direction.
The corkscrew is going faster than the cork.

[Heinz Hershold]

But amusingly it is and here's the real world proof for all the non-idiots:

DDWFTTW WG Merciful End! - YouTube

there is no indication there that thrust is greater than wheel drag, steady state.

In fact, there is plenty of evidence of instability caused by the wheels making intermittent contact as they spin and slide.

The cart is oscillating on the belt.

[Alan Fox]

You know those cars that you pull back and let go?
When you pull back you are providing energy to a spring.

Also if you have a hand crank and turn it, you are providing energy are you not?

Et alors?

[Heinz Hershold]

Imagine a corkscrew turning being turned and going into a cork.
It is moving forward.

Now imagine that cork moving in the same direction.
The corkscrew is going faster than the cork.

yes, I do believe even the Babylonians had successfully conquered such great leaps of physics.