Merged DDWFTTW in a “Real” Wind

[Jack by the hedge]

A simple mass has only linear momentum but a wheel has both linear and angular momentum. The two "gears" are on the same shaft, and that means they have the same AV. That means a lot for the matter of acceleration, but as none of you will address the math, there is no means of showing that.

The matters of mass, momentum, inertia and acceleration are not relevant to the simple principle being demonstrated, which is that the underslung chain drives the gearwheel in the same direction as the chain, at a relative velocity equal to the large gear's radius divided by the difference between the two gears' radii.

 

[humber]

Take your silly under version of the reel. Tie the thread to the wall. Now try and move the reel when the thread is tensioned. You need to turn the reel, not pull the thread.
The only way it can travel, is if impulse causes the reel to roll along the thread so that the slack get wound up. doh. It always does that, but its hard to tell.
You can try and make it work up an incline if you like, or can't the cart go up hill?
Do let me know how you get on.

 

[Llyricist]

I have animated the ten seconds of data that NALSA provided. Do you think even that would help? BTW, it's not the vane, but the calculated true wind direction. We won't know of the vane, because Spork refuses to hand over the data.

http://img860.imageshack.us/img860/4558/dqs.mp4

It is the vane and anemometer measurements vector added to the CV direction and speed measurements.

And you animated the derived true wind direction measurement, not the deviation, which would be offset more to the right.

And any sailor would laugh in your face if you told them they could tack in that relative wind.

 

[Jack by the hedge]

The Carteer. Also a unit of density.

Don't give me that psycho-babble. If you could do the math, you would laugh at those who though it possible.

YOU HAVE NOTHING.

Oh, let me think about it:

Cord moves 1m in 1s.
Bobbin moves 2m in 1s.

Let me see now...

V(cord) = 1ms^-1V(Bobbin) = 2ms^-1
"2ms^-1 > 1ms^-1" = "astonishing error"

Is that it?

 

[Jack by the hedge]

Take your silly under version of the reel. Tie the thread to the wall. Now try and move the reel when the thread is tensioned.

Tie it to a wall? Why not tie it to a cat? Or throw it in the ocean? Or fire it into the heart of the sun. Does it work now? Huh? Huh? Does it?

What are you, five?

You can try and make it work up an incline if you like, or can't the cart go up hill?
Do let me know how you get on.

OK. I still have my trusty reel and cord right here. It works uphill and it works downhill too. Are you bored of being wrong yet?

 

[EHocking]

Pure fantasy.

Yep, that's a really convincing argument. Not.

You have mistaken parallax for the angle of the streamer,

No. I've noted perspective. The angles, as was explained in the post, were merely noted to demonstrate that I did not change the perspective of the angle and direction of the arrows, indicating streamer direction and cart direction.

and you can't calculate it without knowing much more than you do.

Strawman (againg). I didn't calculate anything in that post or those screenshots.

I know that, because you have even made the naive error of giving each streamer a different angle. They would be at the same angle to the bar.

To the bar yes, but not from the camera position where the video was taken.

But all this obfuscation of yours does not refute the visual evidence that the streamers in that video and the two in the OP are very good visual aids to show the windspeed relative to the chart.

In the Run2 video they show that the before the start of the run, the wind is a tailwind (relative to the cart) and once running they show that the cart is experiencing a headwind.

How can you keep denying the evidence that everyone is can plainly see?

 

[jduffy77]

Nice Humber. It is nice not to have to wade through your word salad in order to respond to your nonsense. You are really embarrassing yourself again with this post though.

1) The trial says the cart is at least 20 degrees off ddw

Lie. The average was less than 5 degrees. The cart accelerated while almost exactly 0 degrees off the wind.

2) It's not steady-state

Lie. There was no stored energy or energy added from outside the wind/cart/ground system during its run.

3) Average speed 12.5mph

Irrelevant and wrong. The average speed during the record run was actually 67612.5 mph (relative to the sun). Relative to the ground it was only .045 mph (including the lunch break). Relative to what matters it was traveling 2.8x faster than the wind.

4) Without push, 8.5mph

Irrelevant and wrong again. During the drive to El Mirage it reached speeds relative to the ground of 70 mph.

5) Distance traveled 0.41miles

Irrelevant and wrong again. It did not travel anywhere near that far during the measurement period. It traveled hundreds of miles on the truck. Either way you are wrong.

6) No viable theory

Wrong. The theory is not only viable it is trivial. It can be found in any high school physics book. It is hundreds of years old.

7) No peer-reviewed support

Wrong again. A record has been ratified by the worlds leading authority. The same authority you first said would never even test the cart. After it became clear they would you said that you would accept their judgment without question but they would never be fooled. You really must be getting used to being wrong by now.

8) No "tacking props" or "air levers" to be found in any text

Wrong again. Aerodynamics texts are full of information on props and airfoils of all sorts.

9) Wind direction averaged. Totally wrong

Foolishness. If you do not want real wind than use a treadmill. There is no other way to measure real wind.

10) Pilot has no means of keeping a ddw path.

Irrelevant. He did travel ddw.

11) Idiotic nonsense about torque of a Corvette

Higher than a Corvette depending on the WS. You have made yourself into a laughingstock. Lyricist just posted torque calculations which a 6th grader could understand.

12) Data fiddling.

Lie. There was no data fiddling. You just can't understand the data.

 

[phunk]

In a way, but you all still do not see the consequences of the math.
Yes, I am beating you over the head with it, but then again. I have to take lot.

But it's the key to understanding why, in general, the idea has no merit whatsoever. Looking at it, and doing small experiments to demonstrate the obvious, does not tell you why that is.

You seem to think there is some value in "seeing" problems by way of "intuition", well math is at least another way. Not all engineers are good at math, but in the end, that rules over perceptions and seat-of-the- pants instinct. It's not that the latter does not "work", but that it often doesn't.
Answer the "puzzle" about the bicycle, and you will see why.

When the math tells you the opposite of easily demonstrated reality, you probably have a mistake in the math. There's certainly no mistake in reality.

You can do the experiment with the spool outrunning the string slowly and uphill to prove that it's not the inertia of the spool making it wind up the string. Maybe I'll make a video when I get home tonight.

 

[Jack by the hedge]

2.8x faster than the wind.

[pedant] 2.8x as fast as the wind.[/pedant]

(Actually, I suppose my "[/pendant]" bit is probably not accurate.)

 

[jduffy77]

When the math tells you the opposite of easily demonstrated reality, you probably have a mistake in the math. There's certainly no mistake in reality.

I agree. Fortunately in this case the easily demonstrated reality and the trivial math agree.

 

[jduffy77]

[pedant] 2.8x as fast as the wind.[/pedant]

(Actually, I suppose my "[/pendant]" bit is probably not accurate.)

Thanks.

 

[phunk]

Will you accuse me of using special effects when I show it doing what you claim is impossible?

 

[humber]

Yep, that's a really convincing argument. Not.No. I've noted perspective. The angles, as was explained in the post, were merely noted to demonstrate that I did not change the perspective of the angle and direction of the arrows, indicating streamer direction and cart direction.Strawman (againg). I didn't calculate anything in that post or those screenshots.To the bar yes, but not from the camera position where the video was taken.

But all this obfuscation of yours does not refute the visual evidence that the streamers in that video and the two in the OP are very good visual aids to show the windspeed relative to the chart.

In the Run2 video they show that the before the start of the run, the wind is a tailwind (relative to the cart) and once running they show that the cart is experiencing a headwind.

How can you keep denying the evidence that everyone is can plainly see?

No you made several errors and the sum does not add up to the amount the cart has been rotated.
But you see, the cart is not in motion, so the streamers are indicating the true wind. When in motion, there will be the apparent wind that will suppress the indication of the true wind. as is always the case. If the streamers are not a clear and accurate indicator when stationary, then they will be worse when in motion. You have no way of sustaining a claim to 20 degrees accuracy, let alone 4.
Cranky salesmen are not to be taken seriously.

 

[GlennB]

No little ones, it won't work on an incline. It's a show-stopper in neon, that will be hard to deny. I doubt that you will get many to share your vision on that one.

Well, I just hauled my spool of line up quite a nice slope. Try it yourself.

What is you enjoy here, humber, the thrill of the attention or the actual fact of being relentlessly wrong in public?

 

[humber]

Will you accuse me of using special effects when I show it doing what you claim is impossible?

You will need CGI to make that reel move up the incline.
How embarrassing for you! A simple trick, performed by a powdered monkey, had you believing in magic reels.

 

[phunk]

You will need CGI to make that reel move up the incline.
How embarrassing for you! A simple trick, performed by a powdered monkey, had you believing in magic reels.

No, you don't understand. No tricks, I wasn't fooled by anyone else. I've done this already, it works.

 

[humber]

No, you don't understand. No tricks, I wasn't fooled by anyone else. I've done this already, it works.

Oh yeah. On a smooth surface, with the thread underneath. Up an incline. BS

 

[phunk]

Yes. On my kitchen table, with the string underneath, with one end of the table propped up on a chair.

 

[humber]

Cotton reels don't roll down hill in Carteerland. The next project is a rocket made from Christmas-tree lights and tinsel. You just need to "get it"

 

[EHocking]

No you made several errors and the sum does not add up

Strawman. No wonder you are having trouble with this - you are seeing things that are not there. Nowhere in any of my posts or in the screen shots have I done and "sums".

to the amount the cart has been rotated.

It is clear from the video that the back axle ends up at a right angle to its initial position after being moved. All the arrows do is serve as the initial reference to position one. The angles indicated are so you can check that I had not adjusted them from one photo to another.

But you see, the cart is not in motion, so the streamers are indicating the true wind.

How obtuse can you get?
The POINT of this little sideshow in the thread is that you claim that the streamers are NOT good indicators of wind direction. Now you're saying the ARE?
I agree (and indeed it was the point I was making), they are good indicators of wind direction relative to the cart.
When it is stationary they indicate the "true" wind direction.[/quote] When in motion, there will be the apparent wind that will suppress the indication of the true wind. as is always the case.[/quote]So you agree. They are a good indicator of wind direction relative to the cart.

If the streamers are not a clear and accurate indicator when stationary, then they will be worse when in motion.

But since you've already stated above that,

But you see, the cart is not in motion, so the streamers are indicating the true wind.
​

You contradict and confuse yourself in the same post.

You have no way of sustaining a claim to 20 degrees accuracy, let alone 4.

Strawman.
I have not (ever) made such a claim. It seems the only way you can win an argument is to misrepresent (or, indeed, invent) your opponent's statement.

If the above was a dig at the NASLA Record run data - it wasn't measured by streamer observation. Again, you are constructing arguments from whole cloth as it seems to be the only method which you have to be able to disprove them.