DWFTTW
Woody Brison
Androcles
"Woody Brison" <woody_...@yahoo.com> wrote in message news:1173736930....@64g2000cwx.googlegroups.com...
> An interesting demo of sailing downwind faster than the wind (DWFTTW)
>
> <http://www.youtube.com/watch?v=aJpdWHFqHm0> ?
1 house per 21 seconds.
That's three houses a minute, 180 houses an hour.
I'd hope the mailman could do better on foot.
Given that the rag-flag drooped, where is the evidence for your
claim that it was faster than the wind?
Woody Brison
wrote:
> "Woody Brison" <woody_bri...@yahoo.com> wrote in messagenews:1173736930....@64g2000cwx.googlegroups.com...
> > An interesting demo of sailing downwind faster than the wind (DWFTTW)
>
> > <http://www.youtube.com/watch?v=aJpdWHFqHm0> ?
>
> 1 house per 21 seconds.
> That's three houses a minute, 180 houses an hour.
> I'd hope the mailman could do better on foot.
> Given that the rag-flag drooped, where is the evidence for your
> claim that it was faster than the wind?
A marathon is 26.22 miles. The current world record is
2 hours 4' 55" = 2.082 hours. That's 12.6 mph. If you
claim your mailman can do better than that *carrying a sack
of mail*, your skepticism over a little machine on wheels
going 13 mph seems odd.
Wood
Androcles
"Woody Brison" <woody_...@yahoo.com> wrote in message news:1173931508.8...@y80g2000hsf.googlegroups.com...
http://upload.wikimedia.org/wikipedia/commons/thumb/a/a4/Hurricane_Katrina_August_28_2005_NASA
Your odd notion of 13 mph being faster than the wind is a lot odd.
Obviously a chase car with a camera aboard was used, what
it didn't show was the tow truck and the nylon fishing line.
We are not all as gullible as you, odd bod.
Woody Brison
wrote:
> "Woody Brison" <woody_bri...@yahoo.com> wrote in messagenews:1173931508.8...@y80g2000hsf.googlegroups.com...
> > On Mar 12, 3:15 pm, "Androcles" <Engin...@hogwarts.physics.co.uk>
> > wrote:
> >> "Woody Brison" <woody_bri...@yahoo.com> wrote in messagenews:1173736930....@64g2000cwx.googlegroups.com...
> >> > An interesting demo of sailing downwind faster than the wind (DWFTTW)
>
> >> > <http://www.youtube.com/watch?v=aJpdWHFqHm0> ?
>
> >> 1 house per 21 seconds.
> >> That's three houses a minute, 180 houses an hour.
> >> I'd hope the mailman could do better on foot.
> >> Given that the rag-flag drooped, where is the evidence for your
> >> claim that it was faster than the wind?
>
> > A marathon is 26.22 miles. The current world record is
> > 2 hours 4' 55" = 2.082 hours. That's 12.6 mph. If you
> > claim your mailman can do better than that *carrying a sack
> > of mail*, your skepticism over a little machine on wheels
> > going 13 mph seems odd.
>
>
> Your odd notion of 13 mph being faster than the wind is a lot odd.
> Obviously a chase car with a camera aboard was used, what
> it didn't show was the tow truck and the nylon fishing line.
>
> We are not all as gullible as you, odd bod.
Link didn't work...
A fishing line was my first impression, too, but after
writing equations of motion, it seems to me that the
leverage to make this work does exist in the system. Jack
Goodman wrote a paper describing the vehicle
<http://www.ayrs.org/DWFTTW_from_Catalyst_N23_Jan_2006.pdf>
Wood
Androcles
"Woody Brison" <woody_...@yahoo.com> wrote in message news:1173965845....@l77g2000hsb.googlegroups.com...
> On Mar 15, 3:37 am, "Androcles" <Engin...@hogwarts.physics.co.uk>
> wrote:
>> "Woody Brison" <woody_bri...@yahoo.com> wrote in messagenews:1173931508.8...@y80g2000hsf.googlegroups.com...
>> > On Mar 12, 3:15 pm, "Androcles" <Engin...@hogwarts.physics.co.uk>
>> > wrote:
>> >> "Woody Brison" <woody_bri...@yahoo.com> wrote in messagenews:1173736930....@64g2000cwx.googlegroups.com...
>> >> > An interesting demo of sailing downwind faster than the wind (DWFTTW)
>>
>> >> > <http://www.youtube.com/watch?v=aJpdWHFqHm0> ?
>>
>> >> 1 house per 21 seconds.
>> >> That's three houses a minute, 180 houses an hour.
>> >> I'd hope the mailman could do better on foot.
>> >> Given that the rag-flag drooped, where is the evidence for your
>> >> claim that it was faster than the wind?
>>
>> > A marathon is 26.22 miles. The current world record is
>> > 2 hours 4' 55" = 2.082 hours. That's 12.6 mph. If you
>> > claim your mailman can do better than that *carrying a sack
>> > of mail*, your skepticism over a little machine on wheels
>> > going 13 mph seems odd.
>>
>> http://upload.wikimedia.org/wikipedia/commons/thumb/a/a4/Hurricane_Ka...
>>
>> Your odd notion of 13 mph being faster than the wind is a lot odd.
>> Obviously a chase car with a camera aboard was used, what
>> it didn't show was the tow truck and the nylon fishing line.
>>
>> We are not all as gullible as you, odd bod.
>
> Link didn't work...
Not my problem.
>
> A fishing line was my first impression, too, but after
> writing equations of motion, it seems to me that the
> leverage to make this work does exist in the system. Jack
> Goodman wrote a paper describing the vehicle
>
> <http://www.ayrs.org/DWFTTW_from_Catalyst_N23_Jan_2006.pdf>
>
> Wood
The propeller will act as an energy storage device, pushing the vehicle
when the wind drops and absorbing energy when wind speed is greater
than vehicle speed (gusts), both speeds being measured relative to the
ground. However, the vehicle will not exceed *mean* velocity of the
wind relative to the *wind*.
If you'd ever done any sailing you'd know that you don't feel
wind in your hair because you are moving with the air mass.
The propeller is simply a sail, if Goodman really wants to prove
the vehicle exceeds wind speed he'll need to mount an anemometer on it.
(Or run it in a wind tunnel.)
http://www.pfmt.org/standman/images/anameter1.gif
If Goodman's vehicle exceeds wind speed the anemometer will run
backwards. If the vehicle runs at exactly wind speed the anemometer
will stop. Any forward motion and the vehicle is travelling at less
than wind speed. The rag-flag is a crude anemometer but is
clearly perturbed by the turbulence from the propeller. Doubtless
Goodman chose a windy day for his run, and we all know
wind gusts, particularly around buildings. Chicago is called the
"Windy City" because wind is channelled into the artificial canyons
formed by the tall buildings.
Turbulence:
http://www.af.mil/shared/media/photodb/photos/060516-F-9712C-956.JPG
All motion is relative.
http://www.androcles01.pwp.blueyonder.co.uk/PoR/PoR.htm
Incidentally, this vehicle goes against the wind simply by gearing
the vertical shaft to the wheels:
http://home.comcast.net/~awatkins42/zephyr.html
Add a differential and it will turn without dragging.
http://www.androcles01.pwp.blueyonder.co.uk/Differential.gif
However, they are neither efficient or stable, you couldn't
run one on a public road.
Nature also has propellers in the form of the sycamore seed.
http://www.newscientist.com/blog/technology/uploaded_images/sycamore_seed-789909.jpg
These spin as they descend from trees and are carried on the wind
for miles.
Woody Brison
wrote:
> The propeller will act as an energy storage device, pushing the vehicle
> when the wind drops and absorbing energy when wind speed is greater
> than vehicle speed (gusts), both speeds being measured relative to the
> ground. However, the vehicle will not exceed *mean* velocity of the
> wind relative to the *wind*.
A prop like this could store energy, but that's not how
this works. I think it really does exceed the mean v
of the wind.
> If you'd ever done any sailing you'd know that you don't feel
> wind in your hair because you are moving with the air mass.
Yes, if you are sailing downwind.
> The propeller is simply a sail, if Goodman really wants to prove
> the vehicle exceeds wind speed he'll need to mount an anemometer on it.
> (Or run it in a wind tunnel.)
> http://www.pfmt.org/standman/images/anameter1.gif
>
> If Goodman's vehicle exceeds wind speed the anemometer will run
> backwards. ...
Howzzat?
>... If the vehicle runs at exactly wind speed the anemometer
> will stop. Any forward motion and the vehicle is travelling at less
> than wind speed. The rag-flag is a crude anemometer but is
> clearly perturbed by the turbulence from the propeller.
Right. The cloth streams away with the wind, faster
wind => less vertical. Some people don't realize that
the cloth is out on the left side of the vehicle, out
of the prop stream. But this can be ascertained in some
of the footage where the vehicle gets ahead of the chase
car.
>... Doubtless
> Goodman chose a windy day for his run, and we all know
> wind gusts, particularly around buildings. Chicago is called the
> "Windy City" because wind is channelled into the artificial canyons
> formed by the tall buildings.
>
> Turbulence:
> http://www.af.mil/shared/media/photodb/photos/060516-F-9712C-956.JPG
What in sam hill is that?
>
> All motion is relative.
> http://www.androcles01.pwp.blueyonder.co.uk/PoR/PoR.htm
>
> Incidentally, this vehicle goes against the wind simply by gearing
> the vertical shaft to the wheels:
> http://home.comcast.net/~awatkins42/zephyr.html
Goodman sez his vehicle will do that too, with a linkage
adjustment.
I've put some notes together on this:
<http://users.sisna.com/wwbrison/cbgir.htm>
Wood
Androcles
"Woody Brison" <woody_...@yahoo.com> wrote in message news:1173977537....@y80g2000hsf.googlegroups.com...
> On Mar 15, 7:45 am, "Androcles" <Engin...@hogwarts.physics.co.uk>
> wrote:
>
>> The propeller will act as an energy storage device, pushing the vehicle
>> when the wind drops and absorbing energy when wind speed is greater
>> than vehicle speed (gusts), both speeds being measured relative to the
>> ground. However, the vehicle will not exceed *mean* velocity of the
>> wind relative to the *wind*.
>
> A prop like this could store energy, but that's not how
> this works. I think it really does exceed the mean v
> of the wind.
And I *know* it doesn't, whatever you hallucinate.
>> If you'd ever done any sailing you'd know that you don't feel
>> wind in your hair because you are moving with the air mass.
>
> Yes, if you are sailing downwind.
Turn that little buggy around and sail it upwind, then. I'm sure
it's really important to have one wheel at the front and two wheels
at the back.
http://www1.istockphoto.com/file_thumbview_approve/500640/2/istockphoto_500640_hot_rodding.jpg
Why isn't it going against the wind?
>
>> The propeller is simply a sail, if Goodman really wants to prove
>> the vehicle exceeds wind speed he'll need to mount an anemometer on it.
>> (Or run it in a wind tunnel.)
>> http://www.pfmt.org/standman/images/anameter1.gif
>>
>> If Goodman's vehicle exceeds wind speed the anemometer will run
>> backwards. ...
>
> Howzzat?
Magic, of course. Violation of Newton's second law.
>>... If the vehicle runs at exactly wind speed the anemometer
>> will stop. Any forward motion and the vehicle is travelling at less
>> than wind speed. The rag-flag is a crude anemometer but is
>> clearly perturbed by the turbulence from the propeller.
>
> Right. The cloth streams away with the wind, faster
> wind => less vertical. Some people don't realize that
> the cloth is out on the left side of the vehicle, out
> of the prop stream. But this can be ascertained in some
> of the footage where the vehicle gets ahead of the chase
> car.
>
<yawn>
http://www.af.mil/shared/media/photodb/photos/060516-F-9712C-956.JPG
>>... Doubtless
>> Goodman chose a windy day for his run, and we all know
>> wind gusts, particularly around buildings. Chicago is called the
>> "Windy City" because wind is channelled into the artificial canyons
>> formed by the tall buildings.
>>
>> Turbulence:
>> http://www.af.mil/shared/media/photodb/photos/060516-F-9712C-956.JPG
>
> What in sam hill is that?
A plane dropping flares. The smoke shows the vortex created by the wings
and is bigger than the plane.
In Goodman's vehicle the flag-rag is in the prop vortex, you can read anything
you like from it.
>
>>
>> All motion is relative.
>> http://www.androcles01.pwp.blueyonder.co.uk/PoR/PoR.htm
>>
>> Incidentally, this vehicle goes against the wind simply by gearing
>> the vertical shaft to the wheels:
>> http://home.comcast.net/~awatkins42/zephyr.html
>
> Goodman sez his vehicle will do that too, with a linkage
> adjustment.
I don't care what the moron sez, he's an idiot or a con-artist if
he claims his vehicle runs faster than mean wind velocity.
>
> I've put some notes together on this:
>
> <http://users.sisna.com/wwbrison/cbgir.htm>
>
> Wood
Whoopee for you, it's just an engine and a gearbox.
What you failed to realize is the lever principle.
m_________________M
^
The mass m will go up much faster than M will go down, but M
applies a greater force than m.
Your conveyor belt will have to supply a greater force to increase
the speed of the buggy by your pulley ratio.
In the case of wind the force depends on the area of the sail
as well as the speed of the wind (which is why yachts have
large sails, of course).