Merged DDWFTTW in a “Real” Wind

[Jack by the hedge]

F = T/r
Force at wheel circumference = Shaft torque/wheel radius
Power = T*w ( w= angular velocity in radians)
Power = torque*angular velocity

Both wheels on the same shaft, so both wheels must see the same torque
Both wheels on the same shaft, so both wheels must see the same AV
Both wheels on the same shaft, so both wheels must see the same power


Conclusion: Force at inner wheel = 2*force_outer_wheel
Well done, if you apply twice the force, it will go twice as fast, just like a single wheel.
Gears need separate shafts.

No point in talking of Lyricist cart. It will be as expected more power = more speed.
Just like he has not bothered to complicate it. PM machines always make the same mistake.
Myriad's idea gives the general problem. Gears never change power. What goes in comes out.

You are deliberately missing the point, aren't you? Nobody could swing and miss with such consistency if they were responding in good faith. It simply defies belief.

The relevance of the diagram, as you really cannot possibly be unaware, is to illustrate that the chain moves relative to the rail, and the gearwheel also moves along the rail, driven by the chain, yet it travels faster than the chain.

The rail, chain and gearwheel are analogous to the ground, wind and cart respectively.

If you have any difficulty grasping any part of that, do please say so and I'm sure someone will be happy to talk you through it in baby steps.

 

[humber]

Oh .... You need to back off just a bit. That was a little too obvious.

-- Roger

It is known that there is always a wind gradient near the surface. The wind velocity changes exponentially with height.
http://en.wikipedia.org/wiki/Wind_gradient

The Windicon, exploits this to travel faster than the wind.

The velocity of of the wind above the prop hub, will always be greater than wind below the hub, no matter how fast the cart is going. The prop "extracts" the difference, and drives the cart. Rolling losses can be arbitrarily low, so there is no theoretical limit to the speed. Efficiency may be increased by replacing the prop with a turbine enclosed in a manifold, that is input to the faster air, and exhausted to the lower. It is expected that this will add thrust to that air, as a result of the wheel driving the enclosed turbine, which from the exhaust frame, appears to be a propeller.

 

[Jack by the hedge]

The prop "extracts" the difference, and drives the cart.

How?

Edit to add: Yes, I appreciate the "Windicon" is extracting something but it ain't power from wind gradients. But just wait till the big race. My Windicon will be a clone of humber's, except I'll nail a sheet of plywood over the lower half of the prop's sweep, and then my cart will accelerate to light speed and win!

 

[EHocking]

The circumference of a wheel is 2pi*r. When it rolls one turn, the axle moves 2pi*r. Work = force*distance This is true. Otherwise the center of the wheel would not move as far as the rest of the wheel. I know....it's a "brainteaser".


Push a simple wheel one turn, with force F.
Work = F*(2pi*r)
The ratio of the magical wheel, is 2:1, so twice as much force is needed at the smaller wheel.
If may move half the distance, but the force is doubled, so the work is the same. Brilliant. Carteers discover fire.

OK. I've struck out all the stuff that wasn't relevant to my post.

So you agree. The outer wheel travels along a surface twice as far as the inner wheel.

The..err...sprocket at the pedals is on a different shaft, so is free to turn at a different AV from the wheel. The gearing is determined by the ratio of the wheel to pedal sprockets, and not the ratio of the gears within the cassette.

By selecting a different gear on the rear cassette, the WHEEL will turn at a different rate for the same rate of travel of the chain driving it.

 

[humber]

OK. I've struck out all the stuff that wasn't relevant to my post.

So you agree. The outer wheel travels along a surface twice as far as the inner wheel.By selecting a different gear on the rear cassette, the WHEEL will turn at a different rate for the same rate of travel of the chain driving it.

No.The distance does not matter, neither does the rack.

Imagine the bicycle wheel on a mounting such that you can turn the gears in the cassette by hand. Turn the wheel once by the largest gear. Then, by the smallest gear. You will need more force, it will be harder to turn.
If you could turn the largest gear with one finger, is would travel a distance of 2Pi*r, so the work done is F*2Pi*r. It's the same for the smaller gear of radius r/2, but it will be twice as hard to turn it, so the work is 2F*2Pi*r/2 = F*2pi*r.

What do you expect? That it takes less work to do the same amount of work?

Power, which is work/time, limits the maximum speed of objects not force or velocity.

 

[humber]

How?

Edit to add: Yes, I appreciate the "Windicon" is extracting something but it ain't power from wind gradients. But just wait till the big race. My Windicon will be a clone of humber's, except I'll nail a sheet of plywood over the lower half of the prop's sweep, and then my cart will accelerate to light speed and win!

Why not? The wind above the hub will be faster, so the rotor will "slow it down" and extract energy. All I have done is introduced new "frames", upper and lower hub. I can take every argument you put for the difference of wind and ground and make it the difference of upper and lower hub, and you can't tell me it won't work, without contradicting your current argument.
Not only that, but I've got the spare frame of the ground to play with.

 

[recursive prophet]

The energy input to the feedback loop comes from the wind being slowed down by the propeller.

Don't all types of PM employ some kind of feedback loop? The wind provides energy for the cart via the wheels, which turn the prop to provide the force for creating more apparent wind to add to the natural tailwind by slowing it down. What could be simpler? Over to you, humber!

 

[Llyricist]

Don't all types of PM employ some kind of feedback loop? The wind provides energy for the cart via the wheels, which turn the prop to provide the force for creating more apparent wind to add to the natural tailwind by slowing it down. What could be simpler? Over to you, humber!

Feedback loops are perfectly acceptable with an energy input to sustain them. Just ask Hyevprang. According to him, that's how the cart works on the treadmill, only his feedback loop remains entirely unexplained, except that it somehow has to do with a resonance to the vibrations of the treadmill motor.

At least the mechanism, and the math, of the actual feedback loop in play has been fully explained.

 

[Llyricist]

Why not? The wind above the hub will be faster, so the rotor will "slow it down" and extract energy. All I have done is introduced new "frames", upper and lower hub. I can take every argument you put for the difference of wind and ground and make it the difference of upper and lower hub, and you can't tell me it won't work, without contradicting your current argument.
Not only that, but I've got the spare frame of the ground to play with.

You and Harold are the ones that constantly switch frames. He has conclusively proven the cart works repeatedly by using the cart frame analysis, then he always introduces the ground frame to raise an objection, double count wheel drag, miscalculate changes in energy, whatever it takes to bungle the math.

In the instantaneous analysis in the FOR of the cart, all the energy comes from the ground (so the H's heads explode). The ground's KE powers the wheels, the forces retarding the wheels are calculated, the aerodynamic drag is calculated, then the thrust available at that power after losses is calculated, and it always adds up to a net positive in favor of thrust. That is definitive. The calculation is done. The cart accelerates.

 

[Modified]

Feedback loops are perfectly acceptable with an energy input to sustain them. Just ask Hyevprang. According to him, that's how the cart works on the treadmill, only his feedback loop remains entirely unexplained, except that it somehow has to do with a resonance to the vibrations of the treadmill motor.

That is possible, but highly unlikely for anything moving as smoothly as the treadmill and cart.

 

[Andrew Wiggin]

One is PM, the other isn't.

I would see your point if and only if the claim was that the cart would accelerate in still air. That happens to not be the claim. If the wind dies down, the cart coasts to a stop.

The cart extracts energy from the wind in a way that I can see, and in fact many of the folks here can see, but you can not. I don't know if that's a cognitive deficit, a trick of thought or visualization you're missing, or just general bloodymindedness, but the fact remains that you're arguing about something that the rest of us can see and you can't. That doesn't make it perpetual motion, any more than a car is perpetual motion to a kid who gets driven to soccer practice, but never gets to see mommy or daddy put the gas in the tank.


Here's a bit of trivia; anyone here besides me ever use a yankee screwdriver? It uses a downward push to turn a screw. It can also be adjusted to UNSCREW a screw. Usually whatever is being screwed is stationary, and the screwdriver is pushed, but there's no reason it wouldn't work if the screwdriver was stationary and the work was pushed against it. Imagine I screwed a woodscrew into a block of wood. I brace a yankee screwdriver against the wall, insert its bit into the screw, and push the block of wood forward. The forward motion of the block will push the screw against the screwdriver, which will unscrew the screw. The screw head will be moving towards the wall faster than the block of wood is. There you have it. Screwing directly downwood faster than the wood.

 

[GlennB]

Here's a bit of trivia; anyone here besides me ever use a yankee screwdriver? It uses a downward push to turn a screw. It can also be adjusted to UNSCREW a screw. Usually whatever is being screwed is stationary, and the screwdriver is pushed, but there's no reason it wouldn't work if the screwdriver was stationary and the work was pushed against it. Imagine I screwed a woodscrew into a block of wood. I brace a yankee screwdriver against the wall, insert its bit into the screw, and push the block of wood forward. The forward motion of the block will push the screw against the screwdriver, which will unscrew the screw. The screw head will be moving towards the wall faster than the block of wood is. There you have it. Screwing directly downwood faster than the wood.

Actually I still have one, rusting in an old tool box. Battery power took over.

 

[Andrew Wiggin]

Actually I still have one, rusting in an old tool box. Battery power took over.

I still dig mine out now and then. Not a big fan of battery powered screwdrivers. They never seem to be charged and ready when needed. The big problem has been finding modern bits; the original came with a good selection of straight blades, but no phillips, square, torx, or any of the other modern types. Turns out you can grind down the end of an extended 1/4 inch hex bit to fit the old 1/2 circle 1/4 inch drive.

 

[EHocking]

The problem with all Carteers is that they don't understand simple machines, so fall prey to all sorts of imaginings, while equating cows and hats along the way.

The circumference of a wheel is 2pi*r. When it rolls one turn, the axle moves 2pi*r. Work = force*distance. This is true. Otherwise the center of the wheel would not move as far as the rest of the wheel. I know....it's a "brainteaser"

Push a simple wheel one turn, with force F.
Work = F*(2pi*r)

The cows and hats reference above is ironic, considering that we were discussing this scenario

Yep. Or this version, that could get the car of an old-fashioned chain-driven roller coaster up the hill faster than the chain is going:
http://www.internationalskeptics.com/forums/imagehosting/130124925c11c452d4.jpg

.. and you keep on introducing force discussions and ignore relative speed.

Which is the subject of the post.

The ratio of the magical wheel, is 2:1, so twice as much force is needed at the smaller wheel.
If may move half the distance, but the force is doubled, so the work is the same. Brilliant. Carteers discover fire.

You're nearly there.

The point of the post was that the outer wheel tracks along a surface at twice the distance than the inner wheel.

Force is not being discussed here, merely the resultant action imparted by the large wheel on a surface when drive is applied to the inner wheel.

The..err...sprocket at the pedals is on a different shaft, so is free to turn at a different AV from the wheel. The gearing is determined by the ratio of the wheel to pedal sprockets, and not the ratio of the gears within the cassette.

All we're looking in the example is the length of chain that moves across a sprocket and the resultant distance travelled by the outer rim.

 

[A.T.]

Don't all types of PM employ some kind of feedback loop?

Yes, but that doesn't imply that every feedback loop is a PMM.

That's the idea of this brainteaser: Make it look like a PMM for halfwits who apply flawed logic instead of analysis. They fail to see that PMMs are isolated feedback loops, while this one isn't.

 

[Jack by the hedge]

Why not? The wind above the hub will be faster, so the rotor will "slow it down" and extract energy. All I have done is introduced new "frames", upper and lower hub. I can take every argument you put for the difference of wind and ground and make it the difference of upper and lower hub, and you can't tell me it won't work, without contradicting your current argument.
Not only that, but I've got the spare frame of the ground to play with.

Is your propeller being turned by the wind, or is it being driven by something else which turns it faster than the headwind would freewheel it?

Either way, if there is a greater force acting on the upper blade than on the lower, then that will produce a torque perpendicular to the driveshaft. How exactly does your design extract useful work from this force?

 

[A.T.]

I can take every argument you put for the difference of wind and ground and make it the difference of upper and lower hub, and you can't tell me it won't work, without contradicting your current argument.

And I can take every argument you put for the difference of upper and lower hub and make it the difference of air and ground, and you can't tell me it won't work, without contradicting your current argument.

 

[sol invictus]

It is known that there is always a wind gradient near the surface. The wind velocity changes exponentially with height.
http://en.wikipedia.org/wiki/Wind_gradient

The Windicon, exploits this to travel faster than the wind.

[qimg]http://www.internationalskeptics.com/forums/attachment.php?attachmentid=21484&stc=1&d=1300750266[/qimg]

The velocity of of the wind above the prop hub, will always be greater than wind below the hub, no matter how fast the cart is going. The prop "extracts" the difference, and drives the cart.

That is perfectly possible (well, probably not for a prop and certainly not for this cart, but in general). It's possible for exactly the same reason DDWFTTW is - you can extract energy at any interface where there's a velocity difference between two masses, be it air and ground (the cart) or air and air (this thing you're proposing) or ground and ground (down ruler faster than the ruler) or table and finger, regardless of your speed.

Rolling losses can be arbitrarily low, so there is no theoretical limit to the speed.

You've just admitted that not only can one extract energy from such an interface, theoretically one can use it to go at any speed... including faster than either mass. You've just acknowledged that DDWFTTW is possible.

Is the thread over now?

 

[Jack by the hedge]

Is the thread over now?

The thread has been over for ages. It's just fond reminiscence of humber's previous failed arguments now.

 

[jduffy77]

I would see your point if and only if the claim was that the cart would accelerate in still air. That happens to not be the claim. If the wind dies down, the cart coasts to a stop.

The cart extracts energy from the wind in a way that I can see, and in fact many of the folks here can see, but you can not. I don't know if that's a cognitive deficit, a trick of thought or visualization you're missing, or just general bloodymindedness, but the fact remains that you're arguing about something that the rest of us can see and you can't. That doesn't make it perpetual motion, any more than a car is perpetual motion to a kid who gets driven to soccer practice, but never gets to see mommy or daddy put the gas in the tank.

This response pretty much encapsulates everything that needs to be said to, or about Humber. Of course what is remarkable is that it can all be summed up so succinctly.

I have done some statistical analysis of his posts on ddwfttw and I believe he has written about 7 and 3/4 million words to date. The bible has about 600 thousand.

Here's a bit of trivia; anyone here besides me ever use a yankee screwdriver? It uses a downward push to turn a screw. It can also be adjusted to UNSCREW a screw. Usually whatever is being screwed is stationary, and the screwdriver is pushed, but there's no reason it wouldn't work if the screwdriver was stationary and the work was pushed against it. Imagine I screwed a woodscrew into a block of wood. I brace a yankee screwdriver against the wall, insert its bit into the screw, and push the block of wood forward. The forward motion of the block will push the screw against the screwdriver, which will unscrew the screw. The screw head will be moving towards the wall faster than the block of wood is. There you have it. Screwing directly downwood faster than the wood.

I believe many analogies and thought experiments enrage Humber and Hprang not because they don't understand them; instead it is because they do.