Merged DDWFTTW in a “Real” Wind

[Llyricist]

[Peanut Gallery] So, does anyone have a program of the players in this thread? It looks like there are at least three camps, each of which thinks the others are crazy, but I'd just like to be sure[/Peanut Gallery]

nope just two. On the one hand there is humber and profpangloss (aka a lot of other names), and on the other there are people that have at least a passing acquaintance with Newtonian physics.

 

[Jack by the hedge]

It is truly a monument to the success of technological society, that even those who don't know the meaning of words like "start" and "end", can own a computer. We should all celebrate the mere survival of the Carteer, as general proof of the benevolence of modern industrial society.

A cautious gambit, carefully avoiding an actual answer.

If we may interpret this as saying that you accept it is obvious that the car can still only accelerate to 200mph no matter how fast it was going when released, then why on earth do you still keep bleating on about the Blackbird having been push started to save on track length?

 

[windgrins]

Welcome aboard!

[Peanut Gallery] So, does anyone have a program of the players in this thread? It looks like there are at least three camps, each of which thinks the others are crazy, but I'd just like to be sure[/Peanut Gallery]

Actually, this is a pretty benign forum with players who are actually interested in this DDWFTTW thing. The two camps are the ones who believe this is possible and those who don't. The weird thing is that it has already been achieved with a world record set so its kind of a strange and messy clean up! There are not many shy ones here! The other camp should be on shortly to tell you it most definitely hasn't been accomplished.

Welcome aboard. Declare yourself merely curious or in one camp of your choosing! At any rate, post away!


WindGrins

 

[spork]

So if you can actually state your assertion in some normal meaning of the words, we can have a discussion.

humber VERY rarely makes a clear statement other than to accuse me of lying and fraud. He needs to always give himself room to back out. In the extremely rare case that he does make a clear statement, he ends up backing out with the "you fell for it" gambit.

As long as Humber is actually willing to make concrete statements that have some semblence of reason, I have no problem discussing his points.

He's not.

So Chuck Yeager really didn't break the humberverse sound barrier in '47. The B-29 did most of the pushing and the X-1 only did the last little bit!

And Chuck did none of the pushing.

 

[Subduction Zone]

If we do see that data, almost certainly it will solidly prove that the cart works, even though humber will claim the opposite.

That is one of the reasons that humber rarely links articles these days. Now he will copy and paste and hope that no one finds the article he got the info from, since people would be able to show him how he misquoted it. When he first started out here that would happen to him with almost every link he made. humber takes the concept of hoisting himself with his own petard seriously.

 

[humber]

humber VERY rarely makes a clear statement other than to accuse me of lying and fraud. He needs to always give himself room to back out. In the extremely rare case that he does make a clear statement, he ends up backing out with the "you fell for it" gambit.

I have the data the proves both.

And you know you that same trial data contradicts the supposed theory published in the report, so I wonder what credibility you think you have.

 

[Horatius]

nope just two. On the one hand there is humber and profpangloss (aka a lot of other names), and on the other there are people that have at least a passing acquaintance with Newtonian physics.

See, from reading the last few days, it seemed like humber and profpangloss, while agreeing that it isn't possible, were also taking shots at each other over their understanding (or lack thereof ) of the physics.

Actually, this is a pretty benign forum with players who are actually interested in this DDWFTTW thing. The two camps are the ones who believe this is possible and those who don't. The weird thing is that it has already been achieved with a world record set so its kind of a strange and messy clean up! There are not many shy ones here! The other camp should be on shortly to tell you it most definitely hasn't been accomplished.

Welcome aboard. Declare yourself merely curious or in one camp of your choosing! At any rate, post away!


WindGrins

This is one of those things that I follow sporadically. Back when it was all theory, it seemed an unlikely thing, but the actual results of the trials is pretty persuasive. The big problem is, the explanations of the physics are pretty complex, and I just can't be arsed to actually do the math myself. I'm just wondering why humber and profpangloss seem to reject the results of the actual experiments.

I figure I've got to be missing something that happened, like, a thousand posts back, or something.

 

[humber]

See, from reading the last few days, it seemed like humber and profpangloss, while agreeing that it isn't possible, were also taking shots at each other over their understanding (or lack thereof ) of the physics.

Hardly

And you think this can possibly be a ddw cart? This is raw NALSA data.

 

[Subduction Zone]

Both humber and profpangloss have been debating this long before the Blackbird was built. humber was possibly arguing it before spork did his treadmill tests. I am not sure of the timing. And for exactly how far profpangloss goes you would have to ask spork or JB. He keeps changing his name but his attitude and consistency of error is very telling. Neither one seem to be able to admit that they were wrong in the first place. humber has gone to extremes to develop a physics where the cart does not work, it has been dubbed the humberverse. profpangloss always starts out as if he was sincerely interested in the cart and wants to learn about it but soon we find out he is Harold/Christoph/schroeder/profpangloss and at least two others that I have forgotten. He will always either double count negative effects or change the sign of a positive effect so that his math says the cart won't work. There are simple questions that show the cart works or that the treadmill is the same as a test at wind speed that he will not answer since they go against his beliefs.

Both are almost besides themselves with all of the positive feedback that spork and JB have received for all of their hard work.

 

[Subduction Zone]

humber, what is the source of this graph of yours? Surely you have a link that backs you up. If you don't why should we believe you? You have been shown to lie about this topic many times in the past, why would we believe you now?

 

[recursive prophet]

humber, what is the source of this graph of yours? Surely you have a link that backs you up. If you don't why should we believe you? You have been shown to lie about this topic many times in the past, why would we believe you now?

The source of the graph-or at least the raw data-was Bob Dill of NALSA, SZ. I know because Bob sent it to me, and I forwarded it to Humber. You can write Bob and ask him if you have any doubts.

 

[ThinAirDesigns]

It's worse than that graph actually -- we even collected data when the cart was going totally upwind.

Oh the shame.

JB

 

[humber]

It's worse than that graph actually -- we even collected data when the cart was going totally upwind.

Oh the shame.

JB

Doh. It tacks up wind. Of course you knew that, before you mentioned the "challenge" to do it.

And there is crystal clear evidence that the cart is worse when ddw.
And the trial results contradict the theory.

 

[ThinAirDesigns]

Doh. It tacks up wind.

No, but it goes upwind nicely while sitting on a trailer.

JB

 

[Llyricist]

humber, what is the source of this graph of yours? Surely you have a link that backs you up. If you don't why should we believe you? You have been shown to lie about this topic many times in the past, why would we believe you now?

That graph is the same data I posted as 2 graphs a few pages ago. He just prefers to show the cart direction and wind direction separately, while I prefer to show the more relevant deviation between the 2.

 

[humber]

No, but it goes upwind nicely while sitting on a trailer.

JB

And the Jenkins video shows it operating into a true headwind, and there is data to support the general claim that it does.
No matter what you say, the chart shows you were willing to test for ddw under those obviously changing winds.
Of all the trials, you, not NALSA, chose the run on which the record was based.
It is no surprise, that you selected the pick of the bunch, and that one, is no very convincing. It too has changes of 40 degrees.

 

[Llyricist]

He still thinks the deviation gauge was a streamer.
He thinks that everybody didn't already know that winds don't stay steady in one direction.
He thinks that the record setter shouldn't be allowed to choose the best run. LMAO
He thinks what happened after the record was set is relevant at all.

 

[ThinAirDesigns]

And the Jenkins video shows it operating into a true headwind, ...

LOL. I fool might think that, yes.

JB

 

[Subduction Zone]

LOL. I fool might think that, yes.

JB

Talk about missing the point of the video Does humber think that Jenkins was fooled by you two? Somehow you took the cart on a 180 degree course and managed to fool an expert at sailing under these conditions if humber's claim is true.

 

[69dodge]

The spreadsheet uses the generic propeller formulas on the page I linked to a couple of times already, but here. [...]

And regarding the relative acceleration of the air you asked about above, that is also derived from those formulas.

Thanks. I understand it now.

I used equation (1) on that page, plugged in 160 N for the thrust, 4.8768 m (16 feet) for the propeller diameter, 2 m/s for the air speed, and 1.225 kg/m³ for the air density, then solved the resulting quadratic equation for delta-v. I got 2.24 m/s, which matches well with profpangloss's 2.2 m/s.