Merged DDWFTTW in a “Real” Wind

[windgrins]

Spork,I hate it when you are so right!

I'll take that bet.



D'OH! I win

You just have to walk away.

Dam'n Spork, you're good!

Now explain to JB about a NB balloon not having PE!

I think you are correct. Don't walk away, just run away!

WindGrins

 

[windgrins]

Oops JB!

Believe me -- I was being sarcastic and producing and example of a humber like answer.

You gave him a 'box' to work in with a clear set of spec. humber doesn't accept clear specifications as any sort of limit on a thought problem.

JB

Oops! I missed the joke and already sent Spork after you!

WindGrins

 

[humber]

Believe me -- I was being sarcastic and producing and example of a humber like answer.

You gave him a 'box' to work in with a clear set of spec. humber doesn't accept clear specifications as any sort of limit on a thought problem.

JB

http://img571.imageshack.us/img571/8532/48f.mp4

 

[humber]

You were supplied this:

From Wikipedia:

"This parameter is often specified as hFE or the DC current-gain (βDC) in datasheets."

You were supplied β=100.

You are faking it again, and again, poorly!

Also, notice how I credit my sources, instead of pretending I'm the fount of all knowledge.

What's in blue was never anything I promised. I've already supplied my force analysis and you couldn't find any issue with it-you just stated it was naive-without justification.

Keep producing your non-answer answers. It serves the other posters well as a gauge of your abilities.

Regards,

WindGrins

It's a trope, which you ripped off.
Now about your claim to your personal rather than stolen skill, show where my math is wrong.

 

[humber]

It's a pure voltage source at the output terminals as illustrated. One doesn't need an impedance to analyze the problem. You are faking it buddy-and poorly I might add!

Doh.

You just have to walk away

Back away. More mustached rearguard action.

 

[windgrins]

Humber, You are amusing!

It's a trope, which you ripped off.
Now about your claim to your personal rather than stolen skill, show where my math is wrong.

Nope. It's a trivial circuit that I copied that you can't analyze. The source is completely inconsequential. And, apparently so is the quality of your bluster.

You are only annoyed that you can't find the answer in Wikipedia!

If you had a clue, you would have been jumping all over it after your big claim of expertise.

I'm convinced that you are now incompetent in multiple disciplines!

I'm done! Have fun with your remaining nonsense!

WindGrins

 

[A.T.]

The Greenbird contender: http://lehighlandyacht.com/

Interesting stuff about how they want to optimze the tires for lateral loads:
http://lehighlandyacht.com/?page_id=75

Here more info on it:

http://lukeyoder.com/?page_id=143

http://www3.lehigh.edu/images/userImages/jem406/Page_8893/WEB_Stilson_Yoder.pdf

Their key point is that the L/D ratio of the tires (lateral force/drag force) is equally important as the aerodynamic L/D ratio of the vehicle.

And since you cannot improve much on the aerodynamic side compared to the Greenbird, they concentrate on the tires, which seems like a good idea.

The professor involved was behind another record braking vehicle:
http://www3.lehigh.edu/engineering/resolve7/land-speed-record.html

And last but least: A certain Luke Yoder is involved, who probably combines the jedi-powers of Luke and Yoda.

 

[humber]

Nope. It's a trivial circuit that I copied that you can't analyze. The source is completely inconsequential. And, apparently so is the quality of your bluster.

You are only annoyed that you can't find the answer in Wikipedia!

If you had a clue, you would have been jumping all over it after your big claim of expertise.

I'm convinced that you are now incompetent in multiple disciplines!

A simple example, that you did not have the courage to create yourself, without the security of a canned solution. Shot both feet this time.
A symbolic simulator will yield the answer in seconds, so you even failed to pose a suitable question.

However, you have ignored the simple applications of kinematics that break the cart's back. One wonders why you can't respond to that.

I'm done! Have fun with your remaining nonsense!

A forced choice after re-iterating the same mistake about PE.
...and beta is DC current gain, hFE, hfe, are large and signal small signal h parameters for common emitter amplifiers. On your bike...

 

[humber]

Here more info on it:

http://lukeyoder.com/?page_id=143

http://www3.lehigh.edu/images/userImages/jem406/Page_8893/WEB_Stilson_Yoder.pdf

Their key point is that the L/D ratio of the tires (lateral force/drag force) is equally important as the aerodynamic L/D ratio of the vehicle.

[qimg]http://lukeyoder.com/wp-content/uploads/2010/11/LD_Equation-450x206.jpg[/qimg]

And since you cannot improve much on the aerodynamic side compared to the Greenbird, they concentrate on the tires, which seems like a good idea.

The professor involved was behind another record braking vehicle:
http://www3.lehigh.edu/engineering/resolve7/land-speed-record.html

And last but least: A certain Luke Yoder is involved, who probably combines the jedi-powers of Luke and Yoda.

What do you know? No prop. It seems they are not at the cutting edge of Planet Oil Barrel hyperphysics.

 

[A.T.]

Their key point is that the L/D ratio of the tires (lateral force/drag force) is equally important as the aerodynamic L/D ratio of the vehicle.

What do you know? No prop.

LOL, that reminds me: Humber doesn't believe that wheels can counter lateral loads. Here is a fun exchange:
http://talkrational.org/showthread.php?p=1290133&post1290133

The rest of F is cancelled by the lateral resistance of the wheels.

B***s*** ... We can assume that your knowledge of how the wheels may act, matches your observational and analytical skills.

Few posts later even invokes the ratchet hubs to justify his nonsense objections.

For comparision: http://lehighlandyacht.com/?page_id=21

Traveling 90 degrees to the wind will produce a very large force sideways and a smaller force that propels us forward. Without something to counteract that large sideways force, we are not able to travel forward. On a sailboat, the solution to this problem is placing a large flat surface attached to the boat under the water. This is referred to as a keel.

Instead of using a keel, our land yacht will use tires to counteract that large sideways force.

 

[humber]

1) A molecule moving vertically towards the plate with velocity -u in the ground frame has a velocity -u-v in the reference frame of the plate and hence bounces back from the front side with the velocity u+v ( the plate (prop) is more massive than the air molecules). so in the ground frame the velocity of the molecule is now u+2v.

2) At the backside of the plate, a molecule with velocity u in the ground frame has a velocity u-v in the reference frame of the plate and thus after reflection, a velocity -u+v
In the ground frame the velocity is now -u+2v. T

3) This means in the ground frame, the kinetic energy of the molecules being reflected from the front has increased from m/2*u² to m/2*(u+2v)² =m/2*u² +2*m*u*v + 2*m*v², i.e. an increase of +2*m*u*v + 2*m*v².

4) Molecules reflected from the back side, have changed their energy from m/2*u² to m/2*(-u+2v)² = m/2*u² -2*m*u*v + 2*m*v²
i.e. a change of -2*m*u*v + 2*m*v².

Adding and averaging (3) and (4) gives the average increase of the kinetic energy of the molecules with mass m hitting the plate with velocity v as
ΔK = 2*m*v².

A plate traveling at v wrt the air, will lose KE. So will the cart.
To suggest otherwise is to claim the cart can be pushed in still air and spontaneously accelerate.


http://blog.makezine.com/archive/2010/11/what-ive-learned-about-wind-carts.html

I wondered what a physics professor would make of all this, so I emailed Dr. Paul J. Camp, a professor in the physics department at Spelman College in Atlanta, Ga. Camp had helped me with other physics brain-teasers in the past and I appreciated his clear explanations. I asked him to take a look at Goodman’s video, as well as Charles Platt’s article, and the treadmill cart videos. “What do you say?” I asked.

“Impossible,” replied Camp. “Would violate conservation of momentum and conservation of energy … 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. What can be done in one inertial frame can be done in any other inertial frame with the same physical circumstances

A is a stationary cart in still air
B is the cart above WS
C is the above conclusion, based on Spork's claim.

 

[windgrins]

Spork, You certainly told me so!

I'll take that bet.

D'OH! I win

You just have to walk away.

Wisdom learned the hard way-By falling in the hole myself.

It is now blindingly, abundantly, absurdly clear and I certainly deserve a big "I told you so!"

I now sit at the next level of wisdom. I wonder how long it will last?

Windgrins

 

[humber]

Wisdom learned the hard way-By falling in the hole myself.

It is now blindingly, abundantly, absurdly clear and I certainly deserve a big "I told you so!"

I now sit at the next level of wisdom. I wonder how long it will last?

Windgrins

You can keep that as a consolation prize.

 

[A.T.]

http://blog.makezine.com/archive/2010/11/what-ive-learned-about-wind-carts.html

I wondered what a physics professor would make of all this, so I emailed Dr. Paul J. Camp, a professor in the physics department at Spelman College in Atlanta, Ga. Camp had helped me with other physics brain-teasers in the past and I appreciated his clear explanations. I asked him to take a look at Goodman’s video, as well as Charles Platt’s article, and the treadmill cart videos. “What do you say?” I asked.

“Impossible,” replied Camp. “Would violate conservation of momentum and conservation of energy … 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. What can be done in one inertial frame can be done in any other inertial frame with the same physical circumstances

The poor Dr. Camp who forgot the ground velocity in his coordinate transformation.

Of course he already retracted those statements, but the cranks will keep quoting them to make sure that Camp's name will forever be connected with the failure to perform a Galilean transform on three objects by a physics professor.

From the same article:

I was even more convinced that DDWFTTW was real when I learned that Mark Drela, a world-renowned aerodynamicist at MIT, says it’s possible. Drela is the designer and maker of a variety of amazing human-powered, propeller-driven vehicles. In 1998, Drela designed a human-powered airplane called the Daedalus, which set a world record when it island-hopped more than 72 miles from Crete to Santorini.

Drela is also the developer of a computational aerodynamic analysis system called XFOIL, which allows aircraft designs to be tested before they’re built. An article in MIT’s Aero-Astro magazine reports that Drela has “engineered aircraft for Boeing, the wing for the Predator UAV, the keel of America’s Cup yachts, and experimental aircraft used by NASA. In addition to XFOIL, he has written design programs for rotorcraft, machinery blading, and axisymmetric bodies such as zeppelins.”

In other words, Drela knows his stuff. And so what does his analysis conclude?

“Although DDWFTTW seems like it violates physics, it really does not,” Drela explained to me via email. “The various analyses show this, and the cart experiments on YouTube are definitive proof. 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.”

So Goodman, Andrews, and Cavallaro have been vindicated. DDWFTTW is possible.

 

[windgrins]

Great Quote

The poor Dr. Camp who forgot the ground velocity in his coordinate transformation.

Of course he already retracted those statements, but the cranks will keep quoting them to make sure that Camp's name will forever be connected with the failure to perform a Galilean transform on three objects by a physics professor.

From the same article:

Wow! That's a fantastic quote A.T. I had not seen this. Has this been posted earlier?

Congratulations to Camp for changing his mind once it was explained!

In light of the previous two posts:

But the world is full of zanies and fools
Who don't believe in sensible rules
And won't believe what sensible people say.
And because these daft and dewey-eyed dopes keep building up impossible hopes,
Impossible things are happening every day.

Rodgers and Hammerstein had it right!


WindGrins

 

[humber]

The poor Dr. Camp who forgot the ground velocity in his coordinate transformation.

Of course. Dr camp is wrong, but a carteer who likens the air to stick, is right.

Of course he already retracted those statements, but the cranks will keep quoting them to make sure that Camp's name will forever be connected with the failure to perform a Galilean transform on three objects by a physics professor.

Like

Dr. Paul J. Camp Physics Department Spelman College: "I'm happy to be quoted by name on this issue by anyone who wishes to do so. The treadmill/non-treadmill issue is entirely one of reference frames and physical law is not dependent on reference frame choice. . . I believe it is not just a different reference frame but in fact a different experiment but that doesn't matter. Personally, I would just bag it."

Dr Camp is quite adamant that the TM is false, and does not accept the belt can represent the road. It is common amonsgt zealots to claim a change of mind. Creationists have imputed that to Darwin, the church to David Hume, and Homeopaths to Pasteur.


And I have news for Drela. Carts without props can do the same, and the quote that includes Spork's name is not by Drela. Drela snubbed Spork when posting on the boating forum.

Drela's idea is to scavenge small amounts of energy from static aerodynamic effects at WS. To do that, his wheels have a drag that is "arbitrarily low", meaning sliding.
He has a problem with power and his analysis was never completed.

 

[humber]

Wow! That's a fantastic quote A.T. I had not seen this. Has this been posted earlier?

Congratulations to Camp for changing his mind once it was explained!

In light of the previous two posts:

But the world is full of zanies and fools
Who don't believe in sensible rules
And won't believe what sensible people say.
And because these daft and dewey-eyed dopes keep building up impossible hopes,
Impossible things are happening every day.

Rodgers and Hammerstein had it right!


WindGrins

But not you. Fill a balloon with gas to make an NB balloon. Carry the balloon and the gas to the tenth floor and make another one, and then convince Dr Camp they have the same PE.

BTW. I can ignore Xc at 1KHz, because that is about 16ohms. There is no emitter resistor, and the bias resistor is 200K, which tells me what the expected base current is ( if I know the beta or not) and I think that results in an Re of ~ 10ohms. Gain will be between 50 and 100. Typical example says 100.

 

[A.T.]

Of course. Dr camp is wrong,

C'mon, just because he made a silly error, doesn't mean you have start his name with a lower-case letter. It is bad enough that you are making sure, any Google search of his name will list a lot of references to that embarrassing error.

Drela's idea is to ...

No

 

[A.T.]

Wow! That's a fantastic quote A.T. I had not seen this. Has this been posted earlier?

Congratulations to Camp for changing his mind once it was explained!

Yes a link to Camps e-mail was posted several times. He now says that DDWFTTW doesn't necessarily violate any conservation laws. Humber not only omits that key part when he quotes Camp email, he deliberately quotes Camp's earlier embarrassingly wrong statements that claim the opposite.

I wonder why humber hates Camp so much.

 

[spork]

Wisdom learned the hard way-By falling in the hole myself.

It is now blindingly, abundantly, absurdly clear and I certainly deserve a big "I told you so!"

No need for that. I just happen to know how hard it is not to respond to such powerfully incorrect statements. It took me a long time to realize that I never need to point out that humber is wrong or lying, since everyone that reads more than a page or two knows that he's always wrong or lying.

Congratulations to Camp for changing his mind once it was explained!

Indeed. I've spoken with him several times. He was always polite and open-minded. He did accept that DDWFTTW is real, but never accepted the treadmill as a valid transform. I still have little doubt that he would if we spent some more time on the topic, but he's a busy guy like most of us, and I bothered him enough.