Merged DDWFTTW in a “Real” Wind

[humber]

From: http://blog.makezine.com/archive/201...ind-carts.html
Originally Posted by Paul Camp
In fact, we can state this in pretty bare terms — for a car moving downwind at wind speed to go a little faster is physically indistinguishable from a car at rest on the ground in stationary air to suddenly leap into motion.

That still stands.

Needless to say that with this kind of "expertise" Camp initial conclusion about DDWFTTW was :
Originally Posted by Paul Camp
Impossible, would violate conservation of momentum and conservation of energy
This statement, made Camp (a physics teacher at a liberal arts college) the super-authority on aerodynamics, for humber et al. But contrary to what fantasy-boy suggests here, neither spork, nor anybody else (aside from humber) choose Camp as an expert.

That "liberal arts" crack was one that Spork used to belittle the expert he had already spoken to. He did not reveal that.
If I had known that contact had already been made, I would not have written to him to warn him.

Here is his reply on that matter;
"This liberal arts college in particular is higher ranked academically than many research institutions so that really doesn't bother me much"

Unfortunately for humber Camp recanted recently:
http://talkrational.org/showthread.p...15#post1271615
Originally Posted by Paul Camp
I don't see how this system obviously violates conservation of energy. As long as there is energy in the motion of the air, it can in principle be extracted and fed to the car in some way.
So Humber's expert doesn't deny DDWFTTW anymore.

Gradients. Crosswinds.
If you deny his opinion of the TM, then you must deny it on all else. You don't get to cherry pick. He is an expert, or not.

Originally Posted by sol invictus View Post
The treadmill provides by far the best illustration of DDWFTTW.
Prof. Mark Drela (MIT aero dept.) agrees:
http://blog.makezine.com/archive/201...ind-carts.html
Originally Posted by Mark Drela
In my view, the most closely controlled and unambiguous DDWFTTW demo is the cart climbing up the tilted treadmill. The main problem is then convincing some people that this is equivalent to DDWFFTW. But whoever tries to argue against that equivalence is really arguing against Galilean relativity, which is unassailable. So that secondary argument is a complete waste of time

I have two carts that say he may know aerodynamics, but not a lot about the mechanics of things on belts.
Also, his cart proposal bears no resemblance to Sporks ideas, and is flawed and incomplete. The power analysis, which is of course critical to the matter of the C of E, is only 25% complete.

The cause of this fracas, is that Spork seeks external authority to support his case, rather than doing it himself. This re-opened thread, shows that he will not address any matters that are put to him, but only to
snipe at me.

 

[RossFW]

Humber,

Does Camp still think DDWFTTW violates conservation of energy?

 

[Modified]

Big problem for the good ship Sporky.
In his NALSA submission Spork has a wheel driving a generator, which drives a motor at the prop. Unless he (you,of course) can show that the wind can add power to that, then you are proposing that the motor could be connected to another wheel, and run the cart.

Yes, that will indeed work, but you are missing the rather obvious detail that the wind is moving with respect to the ground, so the wheel must also be coupled to something that is moving with respect to the ground. It could be on a moving belt, and the resulting cart could move down belt faster than the belt.

 

[humber]

Yes, that will indeed work, but you are missing the rather obvious detail that the wind is moving with respect to the ground, so the wheel must also be coupled to something that is moving with respect to the ground. It could be on a moving belt, and the resulting cart could move down belt faster than the belt.

Then prove it using the current and voltage in the motor.
There is no need to know the speed of the wind or of the cart.
it can be done without that. Only the AV of the shafts, current and voltage are necessary. The derivative of the current, will say if the vehicle is accelerating or slowing. All you need is Faraday.

 

[humber]

Humber,

Does Camp still think DDWFTTW violates conservation of energy?

I am not bothered if he does or not. Spork proposed asking him. I wrote to Dr Camp, to warm him that involvement may result is Spork publicly defaming him.
I asked no question about the TM or cart. He volunteered that information.

He defamed Dr Wayne Whiteman. I e-mailed him to check if what Spork had said was true. He denied that it was. Spork has called Dan Kammen and idiot, and was quite pleased to know
that Charles Platt had been "fired" over the cart. etc etc.....The acts of a cur.


Anyway, Dr Camp said that he thinks it may not, but that would not mean the cart could exceed the speed of the wind, nor of a machine that may do it.

Just because something is theoretically possible does not mean it is practically possible. But even if it were, that does not mean that Spork has achieved that.

The errors in the trial,and the plausible exploitation of wind change and gradients exist, if the idea is theoretically possible or not.

He has not demonstrated that HIS cart has satisfied the demands of the claim. In fact, Spork denies that the cart breaches the C of E, so it does not matter one way or the other.

 

[RossFW]

I am not bothered if he does or not. Spork proposed asking him. I wrote to Dr Camp, to warm him that involvement may result is Spork publicly defaming him.
I asked no question about the TM or cart. He volunteered that information.

He defamed Dr Wayne Whiteman. I e-mailed him to check if what Spork had said was true. He denied that it was. Spork has called Dan Kammen and idiot, and was quite pleased to know
that Charles Platt had been "fired" over the cart. etc etc.....The acts of a cur.


Anyway, Dr Camp said that he thinks it may not, but that would not mean the cart could exceed the speed of the wind, nor of a machine that may do it.

Just because something is theoretically possible does not mean it is practically possible. But even if it were, that does not mean that Spork has achieved that.

The errors in the trial and other the plausible exploitation of wind change and gradients exist, if the idea is theoretically possible or not.

He has not demonstrated that HIS cart has satisfied the demands of the claim. In fact, Spork denies that the cart breaches the C of E, so it does not matter one way or the other.

So that's a "No, he doesn't" then.....

 

[spork]

I guess I need not point out that nearly every statement in humber's recent posts are lies - since nearly every statement in all his posts are either lies - or just pure delusion.

 

[Jack by the hedge]

I know. So there can be no power taken from the wind.
Again. If you claim that the prop can drive the cart without driving the wheel, then it would be capable of doing so without the chain to the wheel

The cart will fail the test proposed, because the current will fall.

The wind pushes on the prop and it pushes on the pylon it's mounted on via its bearings.

The power is not transmitted down the chain.

The chain serves a different purpose and is necessary for that purpose.

You have had all of this explained to you innumerable times, yet you fail to take it in.

 

[humber]

So that's a "No, he doesn't" then.....

If you accept that as the bald, unqualified statement of fact, that you are trying to impose, then his blunt rejection of the TM "bag it", must be seen in the same light.
That means Spork's theory is wrong so, the cart must be wrong, and the result due to poor expermental control.

 

[humber]

I guess I need not point out that nearly every statement in humber's recent posts are lies - since nearly every statement in all his posts are either lies - or just pure delusion.

Let me see. I have lots of evidence, because RP was the go-between, and Yevgheni has emails too.

You said you were to give a talk at NASA Ames. You whined that I do not want to debate you. I took the Ames opportunity to debate you over the internet, or have questions asked by proxy. It transpired that the talk was not official, but at the Staff Yacht Club. That meant no official involvement, and not a technical meeting where things could be arranged. You passed on the questions to your pal, and posted the reply that I have copied here. The mere threat of being questioned by me, caused you to cancel the filming that you had arranged with RP's daughter. You are a mountebank.

 

[humber]

The wind pushes on the prop and it pushes on the pylon it's mounted on via its bearings.

Equally, the cart is not ddw, and that pushes on the pylons as a sail.
It is a sail cart.

The power is not transmitted down the chain.

Then you are saying that the wind pushes on the pylon, so the cart is driven and the wheels turns and drive the prop. Yes, that is how it works. It is not ddw and there are rapidly turning winds etc...

The chain serves a different purpose and is necessary for that purpose.

It is a waste of time.

You have had all of this explained to you innumerable times, yet you fail to take it in.

Then demonstrate that the electrical model may work, I say it is theoretically impossible.

 

[spork]

Still more lies

 

[Jack by the hedge]

...Then demonstrate that the electrical model may work, I say it is theoretically impossible.

You may say so, but you also said this:

The generator may drive the motor, but when the wind drives the prop so as to aid the motor, the back EMF rises, and the current from the generator fall.

Which proves that your interpretation of this electrical model is based on your same consistent failure to comprehend how the cart operates, and is therefore wrong and worthless.

Maybe it would be easier for you to watch the video of the yacht & propeller again and try explaining what flaw you can find in it. Or maybe you can't.

 

[Llyricist]

Well, this one is. There are 4 others, but this on has text, and is more charming.
[qimg]http://www.internationalskeptics.com/forums/attachment.php?attachmentid=21459&stc=1&d=1300592206[/qimg]

And I did say that the connection to the wheel for those bikes that didn't have wheel drive, would not be difficult to solve. Let's assume the bike is pedaled to > WS ,but without a link to the wheel. Please show how then engaging the prop to the wheel, would allow the cart to accelerate, and why one without such a connection, wouldn't.

the same way the BB does, and without such a connection it wouldn't be able to exploit the difference between ground speed and air speed.

The headwind is no different from than experienced by a roadie's van on the way to a gig. That headwind produces an opposing force called "drag". Spork has that same aero-drag as an opposing force, but now you want to tell me that when it hits the prop rather than the chassis, it drives the cart by pushing it forwards?

I'm telling you that the relative headwind never impacts the front surface of the propeller blades in normal operation. Like so:

Nope. The motor at the prop will reduce the current from the generator at the wheel, if any force is applied to aid the prop's rotation.

And no such force is ever applied.

If that is true, and it is, the only way the motor current can rise, is if the generator current rises, but that will only happen if the prop becomes a larger mechanical load for the motor.

And faster the prop spins, the more the relative airstream to the prop blades will oppose the rotation, and increase the load.

That leaves the wheel alone as the source of power. The wind can never add to the power generated at the wheel by any means.

Of course, you don't understand the definition of wind. Which would be the relative motion of air and ground.

The ratchet is not important, but cranks have a way of changing their stories as matters progress. The ratchet simply cuts off one means of evasion, rather than being a problem. It fails ratchet or not.

LMAO now it isn't important, after you brought it up in the first place?

It fell apart on the dyno.

The first picture is of the bent sprocket that happened at Ivanpah, as I described. I didn't check the rest carefully to see that they were of the earlier breakages on the dyno.

The causes are large transient loads produced by the flexing of the tower, the cantilevered prop shaft, and stress concentration within the ratchet housing.

In your imagination.

Good one Ace. The drag would then be 2000-32 = 1968N.

The submission report example gives:
(Fnet = 68N)
Frr = 57N
Fdrag = 1.6N

Fnet ( "Corvette") = 2000- 57- 1.6 = 1941.4N

Do you think a bicycle tyre on dirt would sustain such force? No need to even think about it...no.

With the gearing, which you admittedly don't understand, the torque on the axle would be roughly 1/3 the torque on the prop shaft.

Where you pulled that 2000 from is anyone's guess, but I bet everyone will guess the same place.

a =f/m = `1941N/295kg = 6.5ms-2
Reality: 0.1m/s-2
I put that to the "TAD team" and they didn't want to say anything.

Because it is irrelevant and stupid?

It is part an parcel of the explanation, and the basis of the calculation shredded by Prang over at Rational Skeptic.

Nothing was shredded by prang except any credibility he has on the subject of energy analysis.

Smith's explanation included both extraction by slowing down the air, and the "distance through the air" gambit. I have the email, but much, including the motor current test, was in the email he sent to, and posted by Spork.
It's what goes around comes around time. Spork got my email address from Smith and posted it, but now he has to deny his own expert if he is to defend his position.

No, he doesn't. That you don't understand two different explanations from different FOR's is not spork's problem.

 

[Jack by the hedge]

... the cart is not ddw, and that pushes on the pylons as a sail.

During the period its heading is closest to being exactly downwind, the cart continues to accelerate.

 

[Llyricist]

During the period its heading is closest to being exactly downwind, the cart continues to accelerate.

not only does it continue to accelerate, but the rate of acceleration increases.

 

[RossFW]

the cart is not ddw, and that pushes on the pylons as a sail.

Humber, the pylons are in line with the direction of travel.

Any force produced by the air flowing across them as an angle of attack will be at 90deg to the direction of travel.

How does a force at 90deg cause acceleration in the direction of the axis of the sails?

You might note that to jibe, any sail craft must have it's sail at an angle to it's direction of travel.'

The BB doesn't.

 

[A.T.]

He defamed Dr Wayne Whiteman.

Whiteman defamed himself, by being arrogant while being wrong. But at least he apologized for the arrogance:

http://www.hanggliding.org/viewtopic.php?p=192336#192336

I would like to apologize to Spork and JB for posts that I’ve made to the “DDWFTTW” and “The Myth Buster’s Challenge.”

As for his wrongness, he took the Rhett-Allain-escape-route by declaring himself incompetent and running away.

I would also like to reiterate, as I mentioned on the phone, that I do not consider myself a subject matter expert in aerodynamics, fluids, or technical matters associated with the problem we are discussing.

There goes another of humber's "experts".

IIRC Whiteman's boss (the GA Tech president) congratulated spork & JB, and they featured them on their website:
http://www.gatech.edu/newsroom/release.html?nid=59893

 

[Llyricist]

Humber, the pylons are in line with the direction of travel.

Any force produced by the air flowing across them as an angle of attack will be at 90deg to the direction of travel.

How does a force at 90deg cause acceleration in the direction of the axis of the sails?

You might note that to jibe, any sail craft must have it's sail at an angle to it's direction of travel.'

The BB doesn't.

It was pointed out to me that the lift vector is actually perpendicular to the relative airflow, so it is theoretically possible that a net forward force could happen given a low enough drag component.

Of course, humber is unable to produce the L/D characteristics of a biconvex 50% fat airfoil such as the pylons that would support any such claim in reality.

 

[humber]

During the period its heading is closest to being exactly downwind, the cart continues to accelerate.

Except that the RMS value is 15 degrees not 4 degrees.

The rest of the time from the start, it is more than that. Probably double what is seen.

There is nothing to a claim that relies on the angle or acceleration at some arbitrary time.
If the cart had started 5 seconds later, the wind would have already turned South. Would that have been accepted as a record, or would they try again?

It's a matter of chance if the cart is ddw or not at the time the record is measured. But, the chart shows that it spends most of the time more than 10 degrees away from ddw. The record is statistically unlikely. Only the short periods of the circles are within 5 degrees, (but that is not RMS.)

The result is simply selection and probability. It is not steady state, so says or proves nothing,