Merged DDWFTTW in a “Real” Wind

[jduffy77]

But not to Dr Camp. It is staggering that you, and so many of the cart's supporters, think they know better than those with doctorates. Professional physicists.

The strange thing is Camp sounds convinced they are equivalent; "the treadmill/non-treadmill issue is entirely one of reference frames and physical law is not dependent on reference frame". Do you agree with his statement?

 

[humber]

Did would be the correct word Humber. You need to learn your English tenses.

No. Did, is the simple past. Would is conditional, will is the simple future, meaning that you have already accepted that the BB accelerates by braking itself. It that what you meant?

 

[jduffy77]

No. Did, is the simple past. Would is conditional, will is the simple future, meaning that you have already accepted that the BB accelerates by braking itself. It that what you meant?

Absolutely, as long as the Humberese for braking means using energy from the wheels to spin the prop.

 

[jduffy77]

Read the remainder...a poster second guesses a professor.

I wasn't second guessing anything, I was wondering if you agreed with the quote you keep posting. Do you?

 

[humber]

I wasn't second guessing anything, I was wondering if you agreed with the quote you keep posting. Do you?

I don't care either way. The TM is a toy.
If someone wants to liken it to what has been forced upon them by aggressive persistence, they may use that as an argumentative gambit, yet not take the idea at all seriously. A lot of what was said was conducted over the phone, so the context is missing. But "bag it" is really quite unequivocal.

I don't need his approval, because I know how the TM works. It is as simple as that. And, I sold you the braking cart in real time. Thanks for that.

 

[CORed]

Fantastic. Poster Cored can tell Dr Camp where he went wrong.


Next post;
quote=Spork
"I should point out that I still believe Dr. Camp to be wrong with respect to the treadmill equivilency, but I've not yet convinced him. I suspect I will."

Oh dear.

So, a Ph.D. renders him infallible? I thought that only applied to the Pope.

 

[Jack by the hedge]

No good at all. The wheel sees only force of the generator, and that decelerates the wheel, just as a brake does. Regenerative braking does not drive the car as the car is braked. It stores the energy recovered from the cars KE. I have also recovered the energy and used that to ACCELERATE the cart as the brake is applied and that is what the BB's theory says it will do.

Hmm. Once again it is very far from clear what your point is.

You proposed changing part of a machine (which you insist doesn't work anyway) for an equivalent part, and then play word games with the result. Consequently you still think it doesn't work. Even though it does. The world looks on amazed.

 

[A.T.]

So, a Ph.D. renders him infallible?

Camp was initially full of fail:
http://www.internationalskeptics.com/forums/showthread.php?p=6996758#post6996758

 

[Llyricist]

No. You pulled that out of your backside. "Just enough" would be more accurate.

In fact, theoretically, for a given multiple of wind speed above wind speed, the more force you use to take up power, the more surplus force you can generate with the prop.

"Just enough" comes in, in spades, on the engineering side.

Materials and construction that is both light enough and strong enough, a reasonable sized prop, etc......

 

[spork]

Camp was initially full of fail:
http://www.internationalskeptics.com/forums/showthread.php?p=6996758#post6996758

Yes he was. I claimed that I suspected I could bring him around - not that I was 100% certain I could (you'll be surprised how rarely I make such a claim).

I spoke to him on the phone, and found him to be a completely reasonable and open-minded guy. After a couple of calls and emails, he came to understand exactly how DDWFTTW is possible. He still had trouble accepting the treadmill test as being equivalent to a wind-over-road test, but he didn't care to spend a whole lot more time on it - and I sure as heck didn't see any need to hold his feet to the fire.

Yes he's still wrong about the treadmill. I can point to plenty of PhD's that started off on the wrong side of DDWFTTW and have since come around. I think if Dr. Camp cared to discuss the treadmill with me for another 20 minutes, I could probably bring him around on that too. But I see no reason to trouble the man. It certainly wouldn't change humber's "mind", nor would a care if it did.

 

[jduffy77]

I think if Dr. Camp cared to discuss the treadmill with me for another 20 minutes, I could probably bring him around on that too.

He sure seems to me on the right track already in Humbers quote; "the treadmill/non-treadmill issue is entirely one of reference frames and physical law is not dependent on reference frame".

 

[jduffy77]

I don't care either way. The TM is a toy.
If someone wants to liken it to what has been forced upon them by aggressive persistence, they may use that as an argumentative gambit, yet not take the idea at all seriously. A lot of what was said was conducted over the phone, so the context is missing. But "bag it" is really quite unequivocal.

Right I agree with him, bag it. Just like he said there is no need to to bring it up since the mechanism the ddwfttw cart uses to work is crystal clear without it.

I don't need his approval, because I know how the TM works. It is as simple as that. And, I sold you the braking cart in real time. Thanks for that.

Your welcome.

 

[I Ratant]

Your cart does not appear to have a rigid geared linkage between the prop and the wheels in which case it has nothing in common with the ddw cart. The wheels spin the prop on the ddw cart. You mention you want a "square one set of info", but I just don't see what it has to do with anything we have been talking about.

.
What it is is the first step in determining if there is any improvement when adding the drive mechanism.
First, find the response of the no-prop configuration to the input... the wind.
The wind speed and wheel rpm need to measured.
2. Find the response of the fixed prop, no connection to the drive to the input..the wind.
Again measuring the wind speed and wheel rpm.
3. Then let the prop freewheel, still with no connection to the drive, in response to the input...the wind.
Measure the wind speed, the wheel speed, and the prop rpm.
4..Then... hook up the drive.
And measure the wind speed, the wheel speed, and the prop rpm.
Any difference between 3 and 4 is the result of connecting the drive.
The hypothesis is that the velocity will improve.
.
It's called building up the test syllabus, to measure all the variables.
One does this by identifying the variables, and testing each separately if possible, to detect what contribution, positive or negative each has on the performance.
Were there any economic potential for this stuff, any savvy investor would ask for this data, not just the end result, which has nothing useful to find what affects the performance, and in what manner.
Just casting the thing loose doesn't test the hypothesis.

 

[I Ratant]

But... but... humber told us, that you can tack downwind at 2.8 windspseed, just by using the "lift" of a symmetrical chassis.

.
Something way beyond the scope of the simple Square One test, dependent as that one was on the very limited supply of high velocity wind at the location used.
Someone else can do all that engineering stuff... measuring the wind speed... I won't. Measuring the wheel speed...I won't.. Measuring the prop rpm... I won't.
All of this data would be required for a real test of this thing.
I just found that the prop alone will push the cart.
How to do that better.... I can't be bothered.
The $6.25 I spent on the foam board exhausted my budget.
Let's some other real-life demonstrations.. not CGI or animations.

 

[jduffy77]

.
What it is is the first step in determining if there is any improvement when adding the drive mechanism.
First, find the response of the no-prop configuration to the input... the wind.
The wind speed and wheel rpm need to measured.
2. Find the response of the fixed prop, no connection to the drive to the input..the wind.
Again measuring the wind speed and wheel rpm.
3. Then let the prop freewheel, still with no connection to the drive, in response to the input...the wind.
Measure the wind speed, the wheel speed, and the prop rpm.
4..Then... hook up the drive.
And measure the wind speed, the wheel speed, and the prop rpm.
Any difference between 3 and 4 is the result of connecting the drive.
The hypothesis is that the velocity will improve.
.
It's called building up the test syllabus, to measure all the variables.
One does this by identifying the variables, and testing each separately if possible, to detect what contribution, positive or negative each has on the performance.
Were there any economic potential for this stuff, any savvy investor would ask for this data, not just the end result, which has nothing useful to find what affects the performance, and in what manner.
Just casting the thing loose doesn't test the hypothesis.

Sounds good, just a slight difference of opinion on the right place to draw the line. I notice you didn't start with square wheels so I guess we could have been even further apart.

Keep us posted.

 

[I Ratant]

So it's a sail. What happens if the prop is replaced with the same area of card (foam?)
...

.
The flat plate area of that prop is about 8 sq. in.
No reason to expect a flat plate to not move the cart.
The prop disk area is 10 times that much.
I kinda think the cart would also move.
.
Any definitive test could determine the amount of improvement (or not) of each stage in building up to the full drive-prop condition.
And would be expected to be included and analyzed in a proper engineering report.
But I won't bother getting the equipment to measure the wind speed and direction, the wheel rpm and the prop rpm.
The wind pushes the cart better with the prop rotating.
Golly, write that down.

 

[spork]

.
What it is is the first step in determining if there is any improvement when adding the drive mechanism.

Given that a free-wheeling prop can't possibly drive the thing faster than the wind, and that we've demonstrated 2.8X wind speed with the prop driven by the wheels, it's hard to see that you've added anything but noise.

It's called building up the test syllabus, to measure all the variables.

It's called adding nothing but noise to a conversation you said wasn't worth having in the first place.

One does this by identifying the variables, and testing each separately if possible, to detect what contribution, positive or negative each has on the performance.
Were there any economic potential for this stuff, any savvy investor would ask for this data, not just the end result, which has nothing useful to find what affects the performance, and in what manner

So, you're doing this for the hypothetical investor, that you've already told us doesn't exist, because the whole thing is pointless. And you think you know what data that investor would need!?

Just casting the thing loose doesn't test the hypothesis.

Unbelievable! Finally, someone is here to do some real "science".

Just curious - do you have any clue why I find you so annoying?

 

[I Ratant]

Sounds good, just a slight difference of opinion on the right place to draw the line. I notice you didn't start with square wheels so I guess we could have been even further apart.

Keep us posted.

.
Many years back I read a story about a group of US Army fliers trapped in the Philippines behind the Japanese lines.
They had a P-40, which needed tires, and they had no tires.
They constructed a bamboo cradle like a sleigh to hold the plane in the takeoff attitude.. which dropped off after the plane got airborne.
It was flown to China, intending to land at the AVG base at Kunming, but was intercepted by the AVG.
And were shot down.
Seems they hadn't been informed of the deletion of the red center to the US insignia in early 1942, and the AVG guys interpreted that as the Japanese meat ball.
.
Anyway, square wheels and skids would hardly be something worth testing unless there was some overwhelming need to do that.
A few thousand years ago the superiority of wheels over skids was demonstrated, with skids being mostly superior in snow.

 

[jduffy77]

Anyway, square wheels and skids would hardly be something worth testing unless there was some overwhelming need to do that.

Right I agree. Same as a model cart with a free wheeling prop.

 

[I Ratant]

Right I agree. Same as a model cart with a free wheeling prop.

.
How much improvement over a downwind cart with a freewheeling prop versus powering the prop is there?
Finding that out for this project would give it some cachet of professional credibility.
Would the cart get to 50% windspeed? 75%?
What would be the actual gain?
The only way to tell is to try it.