Merged DDWFTTW in a “Real” Wind

[jduffy77]

This is the advantage that those here with two years of RCP history have over the newer participants.

I have no quarrel whatsoever with your position -- just letting you know that he is no more willing to learn than is Humber. His ignorance is willful and his only interest is to enjoy the **** he stirs.

JB

I agree, although I believe he would further his own agenda by taking a lesson from Humber on how to be less obvious.

 

[ThinAirDesigns]

The cart is moving with the wind.

Depending on the speed of the cart, it can be moving backwards relative to the 'wind', exactly the same speed as the 'wind' or forwards through the 'wind'.

You can think of it as a part of the wind.

You can certainly think that if you want, but it won't even be partially correct unless you define the proper speed and even then it will only be partially correct.

What's moving, to the cart, is the ground.

Again, since at all speeds there is airflow over components of the device, the best that statement can ever be is partially correct.

JB

 

[ThinAirDesigns]

Only if you fail to define what you mean by "wind" or even worse: use that word interchangeably for different things:


Here "wind" apparently means "airmass"


Here "wind" apparently means "movement of the airmass"


Here "wind" apparently means "movement of the air relative to the cart"


Here "wind" apparently means "airmass" again


I think that inconsistent terminology add the most confusion in communication.


Experience shows otherwise. The treadmill seems very difficult to understand to laymen, and even to physics professors from liberal art colleges.

A.T., you perfectly nailed the problem that jadebox is having. He switches definition regularly without notification and then believes somehow he's "simplifying".

He may well be "simpliying" for himself and perhaps even moving forward with his own understanding -- all good, but it certainly doesn't translate correctly to others because the switching is done without consistent notification.

JB

 

[Dr. Keith]

This is the advantage that those here with two years of RCP history have over the newer participants.

Entirely. Ignorance is bliss.

I have no quarrel whatsoever with your position --

Thanks.

just letting you know that he is no more willing to learn than is Humber. His ignorance is willful and his only interest is to enjoy the **** he stirs.

I'm getting that, but I'm a slow learner.

Besides that windgrins guy is always looking nicer than me and it pisses me off.

 

[ThinAirDesigns]

Besides that windgrins guy is always looking nicer than me and it pisses me off.

I'm the same way with Spork.

JB

 

[humber]

Clearly, somebody doesn't understand how gears work, but it's not the doctor.

To become a carteer, one must have studied high school physics, and failed.

 

[humber]

I'm having visions of a handheld fan chasing popcorn strewn across the ground.
JB

There is a video of you losing your temper, when your little cart refuses to work in the wind.
You are on record as proposing bubbles as in indicator of the wind.
The geared car is beaten by pop corn let alone bubbles.

The NALSA data quite clearly shows that your cart is a fraud. It's all officially recorded.
Say goodbye, JB.

 

[windgrins]

Entirely. Ignorance is bliss.



Thanks.



I'm getting that, but I'm a slow learner.

Besides that windgrins guy is always looking nicer than me and it pisses me off.

You must be confusing me with Michael C!

Nah, I can't keep it up!:

 

[recursive prophet]

@jb: You'd already done the prop/turbine race. My question was about why the last run with just the prop cart if not to demonstrate ddw..? And as usual with your claims about who said what when; no links. Sure wish I had a nickel for every time you've used 'we've explained this countless times.' It's sort of become your mantra. And not just with me, for sure.

You really are such a ray of rational sunshine in this discussion jb. I'm sure it's clear to everyone that you never initiate any condescending ad homs. It's always those who don't agree with you about something.

I recall Humber suggesting repeatedly you tow the cart on a bicycle to above ws and then let it go. If distance and slow acceleration was the problem, why didn't you try that while you were all set up instead of just running the cart again? And why not-as I mentioned back then-some additional way of measuring ws besides the streamer? Something like IR's foam? It would have refuted Humber's claim an empty plastic coke bottle could have beaten it if nothing else.

Thanks to Dr. Keith, Modified, Michael and for the polite replies. The wind sure moves in mysterious ways. Still seems quite bizarre that the guy in charge of all wind energy research at Berkeley could have missed something so obvious as the TM being an instance of a cart on the road at ws. Looks like we'll be dependent on coal for a long time.

 

[ThinAirDesigns]

There is a video of you losing your temper, when your little cart refuses to work in the wind.

You have to admit - the guy has a fertile imagination.

JB

 

[ThinAirDesigns]

And as usual with your claims about who said what when; no links.

Yeah, LOL -- with all the participants here who know how many times the "holding the cart on the treadmill with the hand" question has been answered over the last couple years you still like to think that no one will notice if you play dumb.

ROFLAO!!

JB

 

[ThinAirDesigns]

Still seems quite bizarre that the guy in charge of all wind energy research at Berkeley could have missed something so obvious as the TM being an instance of a cart on the road at ws.

Yeah, that makes sense -- since so much research is done regarding wind power generation at exactly wind speed.

It ain't his wind energy research that makes his lack of understanding of basic Galilean relativity an embarrasment, that's for sure.

JB

 

[jadebox]

Only if you fail to define what you mean by "wind" or even worse: use that word interchangeably for different things:

Here "wind" apparently means "airmass"

Here "wind" apparently means "movement of the airmass"

Here "wind" apparently means "movement of the air relative to the cart"

Here "wind" apparently means "airmass" again

I think that inconsistent terminology add the most confusion in communication.

Yep ... like I said, talking about the wind can make it confusing.

Experience shows otherwise. The treadmill seems very difficult to understand to laymen, and even to physics professors from liberal art colleges.

I think each piece of the puzzle may need to be explained separately.

The treadmill clearly illustrates the mechanics of the vehicle - how the wheels move the propeller and the propeller accelerates the vehicle. And, if you can convince them that the cart on the treadmill is equivalent to the cart travelling directly down wind¹, then that, at least, it would help them understand that the propeller can accelerate the cart to faster than wind speed - that the propeller isn't like a sail preventing the cart from going faster than the wind.

-- Roger
¹ Wind being defined as .... oh, never mind .....

 

[ThinAirDesigns]

And why not-as I mentioned back then-some additional way of measuring ws besides the streamer? Something like IR's foam?

Because anyone with half a brain will tell you that "IR's foam" bouncing across the ground is a poor way to check relative airspeed as compared to a streamer on the vehicle.

JB

 

[ThinAirDesigns]

Yep ... like I said, talking about the wind can make it confusing.

If one does not use the term consistently, it sure can.

JB

 

[ThinAirDesigns]

The treadmill clearly illustrates the mechanics of the vehicle - how the wheels move the propeller and the propeller accelerates the vehicle.

I believe you when you say that it was a "clear illustration to you", but it's just not the case for many. Over and over people see the treadmill videos and rather than understanding the mechanics of the vehicle, accuse us of cheating via fan or other.

And, if you can convince them that the cart on the treadmill is equivalent to the cart travelling directly down wind¹, then that, at least, it would help them understand that the propeller can accelerate the cart to faster than wind speed - that the propeller isn't like a sail preventing the cart from going faster than the wind.

All quite true if one assumes the GIANT "if" at the beginning of that paragraph. We have found that most folks, due to the flaws of intution, immediately reject the treadmill as equal.

JB

 

[Dr. Keith]

I recall Humber suggesting repeatedly you tow the cart on a bicycle to above ws and then let it go. If distance and slow acceleration was the problem, why didn't you try that while you were all set up instead of just running the cart again? And why not-as I mentioned back then-some additional way of measuring ws besides the streamer? Something like IR's foam? It would have refuted Humber's claim an empty plastic coke bottle could have beaten it if nothing else.

I wasn't here, but why would they care what humber asked them to do? They will never convince humber and anyone else would be satisfied by the evidence and the physics, once they laid it out in painstaking detail. It isn't that hard to understand and humber's willful ignorance won't be dented no matter how many hoops they jump through.

Thanks to Dr. Keith, Modified, Michael and for the polite replies. The wind sure moves in mysterious ways.

No, it doesn't. The wind is actually very predictable. Sails, propellers, wings, gears, wheels, friction, this is all pretty basic stuff. It is just set in odd arrangement for the sake of this brain teaser.

My first exposure to this was the Wired article and by the time I finished the article it made sense. The whole thing. I came here just to revel in the minutia. It really shocks me that so many people don't get it.

Still seems quite bizarre that the guy in charge of all wind energy research at Berkeley could have missed something so obvious as the TM being an instance of a cart on the road at ws. Looks like we'll be dependent on coal for a long time.

Not really, the cart has no practical purpose I can think of. (Corrections welcome.) I would hope that this guy, even if he is at Berkley, is thinking of practical applications of wind power, not mind teasers.

If he really set his mind to it I think he would get it, but from his position he has to be careful not to appear to be endorsing some kind of perpetual motion thing, so I can understand being cautious. Better to not endorse anything than to make one bad endorsement.

 

[jadebox]

If one does not use the term consistently, it sure can.

Gee, I'm trying to understand how the cart works and how to explain it to others. You're just trying to be an ass.

-- Roger

 

[ynot]

Gee, I'm trying to understand how the cart works and how to explain it to others. You're just trying to be an ass.

-- Roger

Welcome to the true nature of Spork & Co.

 

[ynot]

If we didn't scare him away ....

-- Roger

Not - (be careful you don't get fleas)