negative drag

due due due due due due please allow me...

http://www.washingtonpost.com/wp-dyn/content/article/2007/12/13/AR2007121300966.html

Quoted message said:

On Thu, 13 Dec 2007 11:13:59 -0800 (PST), peter <[email hidden]>

Quoted message said:

On Dec 12, 2:34 pm, A Muzi <[email hidden]> wrote:

Quoted message said:

Quoted message said:

Every kid who had a Molor Products "Cosmic Whirl" just _knew_ it made
the bike go faster:http://www.deltiology.com/00000images/cosmic.gif
(discontinued product AFAIK)

Quoted message said:

Of course no one here, incl. gaby, ever claimed that the Cosmic Whirl
(CW) would make a bicycle faster. But if it's mounted in front of the
rider in such a way that it doesn't add any frontal area then it won't
make the bike have any more wind resistance either. I.e. there's added
drag on the CW but correspondingly less drag on the rider right behind
it so the sum remains the same. So making the CW spin takes nothing
away from the speed of the bike.

Dear Peter,

You're falling into the same perpetual motion mistake.

Where does the power come from to spin the Cosmic Whirl?

The rider's legs, of course.

Obviously, and again, this is by no means a perpetual motion machine
since no one is claiming that the bicycle will somehow move by itself
- just that in principle a tiny bit of the energy that would normally
go into overcoming wind resistance anyway can instead by harnessed to
give back a bit of useful work. That's not perpetual motion - just a
minor reduction in the efective drag from air resistance.

Quoted message said:

Remember the three laws of thermodynamics, easy enough even for laymen
when described in terms of gambling against the devil in hell.

1) You can't win. (You never get more energy than you start with. You
can't get 101 watts out of a 100 watt system.)

2) You can't break even. (You always lose some energy. You can't even
get 100 watts out of that 100 watt system--frictional losses are
losses.)

3) You can't even quit. (Just sitting there, a closed system tends
toward entropy.)

I've had plenty of thermodynamics courses and the suggested proposal
does nothing to violate the laws of thermo or even the distorted
version you give above.

Quoted message said:

You _can_ improve the aerodynamics to reduce drag, often in a
non-intuitive fashion, but the propeller isn't likely to function that
way--it will likely just create more chaotic turbulence and increase
drag.

Nothing I wrote above indicated that the propellor was reducing the
drag - note that I specifically indicated that the total drag remains
the same. There's no particular reason why a small windmill located
so that it is directly in front of the rider needs to increase the
total drag force.
Non-relevant golf ball example deleted.

Quoted message said:

The ideal aerodynamic effect is a tapered double-ended knitting needle
that pushes as little air as possible gently and slowly outward and
then lets the same air close again just as gently and slowly, leaving
no eddies or turbulence behind--any turbulence means that power has
been wasted accelerating the mass of the air, not the vehicle.

That's why canoes and kayaks are double-ended--the pointy front end
parts the water gently, and the pointy back end lets the water close
gently, leaving scarcely any wake. Put a propeller on the front or
back, and it would just add to the drag, spinning the water into
useless swirls.

A more relevant example would be the streamlined shapes used by the
HPV cycles. And, as I stated before, adding such a fairing would be
both easier and more effective than the windmill suggestion. But
we're not talking about adding the windmill to a properly faired and
streamlined bicycle, but instead to one with a decidedly non-
aerodynamic upright cyclist. That cyclist is already leaving lots of
turbulent air swirls in his wake.

artmichalek said:

peter said:

On Dec 12, 2:34 pm, A Muzi <[email hidden]> wrote:

Quoted message said:

Quoted message said:

Every kid who had a Molor Products "Cosmic Whirl" just _knew_ it made
the bike go faster:http://www.deltiology.com/00000images/cosmic.gif
(discontinued product AFAIK)

Quoted message said:

Of course no one here, incl. gaby, ever claimed that the Cosmic Whirl
(CW) would make a bicycle faster. But if it's mounted in front of the
rider in such a way that it doesn't add any frontal area then it won't
make the bike have any more wind resistance either. I.e. there's added
drag on the CW but correspondingly less drag on the rider right behind
it so the sum remains the same. So making the CW spin takes nothing
away from the speed of the bike.

Quoted message said:

If you now use the energy of its spinning to provide mechanical energy
it would be possible, at least in principle, to make the bike just a
bit faster. In practice I doubt that you could extract enough energy
to make up for the added weight and assorted frictional losses, but
what's proposed is not any kind of perpetual motion or other device
that is prohibited by basic conservation principles. Adding a fairing
to reduce the wind resistance is clearly far easier and more
effective.

That only works if you believe that drag is only a function of frontal
area. Even if we approximate the windmill as a flat plate, it's going
to have a drag coefficient approximately ten times higher than the
cyclist drafting behind it.

My car has a coefficient of drag of 0.35, and it has a much more
streamlined shape than a regular upright cyclist. Where did your
factor of 10 (implying a Cd of 0.1) come from? Figures I've seen for
normal cyclists have been more around 0.6 or 0.7. As long as the
windmill is right in front of the cyclist and smaller than him then I
don't see why it couldn't be designed so that it doesn't increase the
coefficient of drag - it might even be possible to reduce it a bit.

Quoted message said:

A windmill will generate less drag than a
flat plate, but the more drag it creates the more efficient it is. It
doesn't matter if the windmill is connected to the drivetrain. The
power that's turning the windmill is additional power that you've
already put into the system in order to move the bicycle and generate
air flow.

It's not additional - it's power that the cyclist is already providing
to overcome air resistance even if he didn't have the little windmill
in front.

Quoted message said:

Under the ideal, lossless case you'll break even, but
you'll never get anything out of it. What's being proposed is
prohibited by basic conservation principles. You simply cannot get
more energy out of a system than you put into it.

And no one here has proposed any system which would do that. The
bicyclist is still the source of all the power that is propelling the
bike.
But energy is being wasted to air resistance and turned into heat and
turbulence of the air in the rider's wake. There's no conservation
law that says you can't instead use a portion of that energy in a more
useful way.

As I said before, I don't think the proposal is at all practical. But
objections based on thermodynamic and conservation law principles are
not valid against it because it doesn't violate these.

Kid at the library started a conversation on communicating with "alien
civilizations." Whaddya think about it,? he asked after devolving his
idea.
I said, The "aliens" are so far away, the communicating wave form is
lost over the distance. What is needed is what you see: stars. Blank
out a star's emission or particular wavelength band: blink blink blink
zzzzzzzzzzzzzzzzzzzzzzzzzzzzz blink blink blink zzzzzzzzzzzzzzzzzzzz
blink.... And what hath God wrought?
A D cell flashlight isn't enough.
He was speechless.
?

Uncle Al's quote of the day:

Innovation is not the product of logical thought, even though the
final product is tied to a logical structure.

On Dec 13, 6:50 pm, datakoll <[email hidden]> wrote:
http://www.canosoarus.com/08LSRbicycle/LSR%20Bike01.htm
http://images.google.com/images?q=bicycle+speed+records

On Dec 13, 7:32 am, Elmo <[email hidden]> wrote:

On Dec 13, 7:46 pm, "CWatters" <[email hidden]>
wrote:
"One of these can sail dead into wind"
http://i.treehugger.com/images/2007-2-21/Windmill-Sailboat.jpg

On Dec 13, 7:48 pm, "CWatters" <[email hidden]>
wrote:
"This one is bigger"
http://i.treehugger.com/images/2007-2-21/Windmill-Sailboat.jpg

On October 27, 2006 "http://cyclesantamonica.blogspot.com" wrote:
"This is a video clip of the finish of the Nissan One Hour Challenge,
in which Fast Freddie Markham, Olympic cyclist, riding a bicycle of
his own design, achieves world record speed of over 60 miles per
hour."
http://blog.360.yahoo.com/Factuurexpress?p=6842

"Forever Electric car ( by wind force generator)"
http://blog.360.yahoo.com/factuurexpress?p=6802

I put the links here.
http://gabydewilde.googlepages.com/negative-drag-suggested-reading

peter said:

artmichalek said:

Quoted message said:

On Dec 13, 2:13 pm, peter <[email hidden]> wrote:
On Dec 12, 2:34 pm, A Muzi <[email hidden]> wrote:
> Every kid who had a Molor Products "Cosmic Whirl" just _knew_ it made
> the bike go faster:http://www.deltiology.com/00000images/cosmic.gif
> (discontinued product AFAIK)

Quoted message said:

Quoted message said:

Of course no one here, incl. gaby, ever claimed that the Cosmic Whirl
(CW) would make a bicycle faster. But if it's mounted in front of the
rider in such a way that it doesn't add any frontal area then it won't
make the bike have any more wind resistance either. I.e. there's added
drag on the CW but correspondingly less drag on the rider right behind
it so the sum remains the same. So making the CW spin takes nothing
away from the speed of the bike.

Quoted message said:

Quoted message said:

If you now use the energy of its spinning to provide mechanical energy
it would be possible, at least in principle, to make the bike just a
bit faster. In practice I doubt that you could extract enough energy
to make up for the added weight and assorted frictional losses, but
what's proposed is not any kind of perpetual motion or other device
that is prohibited by basic conservation principles. Adding a fairing
to reduce the wind resistance is clearly far easier and more
effective.

Quoted message said:

That only works if you believe that drag is only a function of frontal
area. Even if we approximate the windmill as a flat plate, it's going
to have a drag coefficient approximately ten times higher than the
cyclist drafting behind it.

My car has a coefficient of drag of 0.35, and it has a much more
streamlined shape than a regular upright cyclist. Where did your
factor of 10 (implying a Cd of 0.1) come from? Figures I've seen for
normal cyclists have been more around 0.6 or 0.7. As long as the
windmill is right in front of the cyclist and smaller than him then I
don't see why it couldn't be designed so that it doesn't increase the
coefficient of drag - it might even be possible to reduce it a bit.

Quoted message said:

A windmill will generate less drag than a
flat plate, but the more drag it creates the more efficient it is. It
doesn't matter if the windmill is connected to the drivetrain. The
power that's turning the windmill is additional power that you've
already put into the system in order to move the bicycle and generate
air flow.

It's not additional - it's power that the cyclist is already providing
to overcome air resistance even if he didn't have the little windmill
in front.

Quoted message said:

Under the ideal, lossless case you'll break even, but
you'll never get anything out of it. What's being proposed is
prohibited by basic conservation principles. You simply cannot get
more energy out of a system than you put into it.

And no one here has proposed any system which would do that. The
bicyclist is still the source of all the power that is propelling the
bike.
But energy is being wasted to air resistance and turned into heat and
turbulence of the air in the rider's wake. There's no conservation
law that says you can't instead use a portion of that energy in a more
useful way.

As I said before, I don't think the proposal is at all practical. But
objections based on thermodynamic and conservation law principles are
not valid against it because it doesn't violate these.

The practical designs will need to evolve but that can only happen if
we know there is useful energy there for the taking.

http://sketchup.google.com/3dwarehouse/search?q=wind+powered+bicycle&btnG=Search&styp=m

A Muzi said:

That's not even among the more humorous and entertaining 'perpetual
motion' follies. Get rid of the silly red-line animations and draw in a
few complex mechanical distractions maybe?

This good enough for a start?

http://sketchup.google.com/3dwarehouse/search?q=wind+powered+bicycle&btnG=Search&styp=m

"CWatters" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

"Elmo" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Of course what would really happen is that the wind would initially

blow

Quoted message said:

Quoted message said:

you backwards slightly, the backwards motion causing the fan to rotate
backwards which would cause you to go backwards faster, causing the fan
to rotate faster and so on. The effect would snowball until you were
going backwards at the speed of sound.

elmo

One of these can sail dead into wind....

http://i.treehugger.com/images/2007-2-21/Windmill-Sailboat.jpg

It can? How is that possible?
Vince

datakoll said:

Uncle Al's quote of the day:

Innovation is not the product of logical thought, even though the
final product is tied to a logical structure.

more, excuse multiple posts asa the product of a cluttered mind.
the internet bloomed in time when I began looking to integrate "my
science" into the general scientific body of knowledge. And what did I
find?

NOTHING

almost nothing. not a van roof mounted toliet seat anywhere.

I did find several, a handful of self publicizing fellow travelers who
were following traditonal paths selling you know CD's, herbal and non
herbal remedies, various self help or self destruction manuals-the
usual.

Irene Pepperberg and Alex were a remarkable exception
BUT no applicable science.

another indication of finding something useful and original.

then Google tuned in. Imagining several clots of Googlers in Mt View
software sifting thru cyberspace to the leading edge is not difficult,
right? So when im would get THERE in cyberspace, Google would
sometimes be waiting for me like Selden himself to say hi and welcome
to this platform.

But my idea, which is kinda like your idea, requires a normal energy
source: THE SUN

That's what Newton said from his cold stone farm house: IT'S THE SUN
STUPID.

So my functional explaination of reality, taken to it's logical
conclusion rattle rattle rattle is to degrade the Universe expansion a
bit and place that degrade into a battery.

I assume this leads to eternal life.

read Ann Rand.

On Thu, 13 Dec 2007 14:09:44 -0800 (PST), peter <[email hidden]>
wrote:

[snip]

Quoted message said:

Obviously, and again, this is by no means a perpetual motion machine
since no one is claiming that the bicycle will somehow move by itself
- just that in principle a tiny bit of the energy that would normally
go into overcoming wind resistance anyway can instead by harnessed to
give back a bit of useful work.

[snip]

Dear Peter,

Think about that some more.

Basically, you end up arguing that adding more and more tiny
propellers to the front of a bicycle will somehow make it go faster
and faster because they're "harnessing" something.

More power is required to move the bicycle _and_ spin the propeller
than can be recovered from propeller.

It's about the same as arguing that the store loses a dime on every
widget that they sell, but they make it up through increased volume.

Cheers,

Carl Fogel

Quoted message said:

Basically, you end up arguing that adding more and more tiny
propellers to the front of a bicycle will somehow make it go faster
and faster because they're "harnessing" something.

Yes, I think you almost understand it now.

Quoted message said:

More power is required to move the bicycle _and_ spin the propeller
than can be recovered from propeller.

Yes, exactly right. But you are forgetting something here.

If we can replace say 10% of the drag by say a 50% regenerative
system.

Then the rider suffers 5% less drag.

The remaining 95% of the drag is suffered by the rider and it
decelerates the vehicle.

On Dec 14, 1:10 am, "Vince Morgan" <vinharAtHereoptusnet.com.au>

Quoted message said:

"CWatters" <[email hidden]> wrote in message

Quoted message said:

One of these can sail dead into wind....

Quoted message said:

http://i.treehugger.com/images/2007-2-21/Windmill-Sailboat.jpg

It can? How is that possible?
Vince

yes

I sat down and designed a propeller that would increase the speed of a
bicycle with NO INCREASE IN POWER INPUT. I wound up with a propeller that
had no moving parts, and whose blades were shaped like a fairing.

On Thu, 13 Dec 2007 17:56:16 -0800 (PST), peter <[email hidden]>
wrote:

[snip]

Quoted message said:

Now does this make any practical sense? No.

[snip]

Dear Peter,

You're getting closer.

You can extract useful energy by sticking a propeller into an
airstream to use onboard, just as you can extract useful energy
through a generator's roller to run a light.

You cannot, however, extract energy that is useful for propelling the
vehicle forward _faster_ because you lose more than you gain.

Cheers,

Carl Fogel

On Dec 14, 2:49 am, "Leo Lichtman" <[email hidden]>

Quoted message said:

I sat down and designed a propeller that would increase the speed of a
bicycle with NO INCREASE IN POWER INPUT. I wound up with a propeller that
had no moving parts, and whose blades were shaped like a fairing.

Me to.

A slight spiral shape should generate centrifugal force depending on
the speed and drag. Then have a recumbent slide down the vacuum in the
center of a vortex. It's that what Victor Schauberger calls light air.

But to smoothly pedal the air up to speed the bike would become much
to long.

That's why one would use a propeller I think. Or a rotating cone. :-)

I doubt efficiently gearing windmills to the wheels a bit.

It would be better to use the wind to further enhance the air flow.

http://gabydewilde.googlepages.com/negative-drag
gabydewilde - negative drag

Peter Rathman said:

...
Now does this make any practical sense? No. The fairing without fins
is undoubtedly a better way to go and far less complex. And for
overall utility it's probably best to stick with the original unfaired
bike for less weight and greater convenience....

In the case of a long-wheelbase recumbent, the performance increase of a
front fairing is well worth the weight and expense (not to mention the
side benefit of greater comfort in cold and wet conditions).

--
Tom Sherman - Holstein-Friesland Bovinia
"Localized intense suction such as tornadoes is created when temperature
differences are high enough between meeting air masses, and can impart
excessive energy onto a cyclist." - Randy Schlitter

Quoted message said:

On Thu, 13 Dec 2007 17:56:16 -0800 (PST), peter <[email hidden]>
wrote:

[snip]

Quoted message said:

Now does this make any practical sense? No.

[snip]

Dear Peter,

You're getting closer.

You can extract useful energy by sticking a propeller into an
airstream to use onboard, just as you can extract useful energy
through a generator's roller to run a light.

You cannot, however, extract energy that is useful for propelling the
vehicle forward _faster_ because you lose more than you gain.

Cheers,

Carl Fogel

proposing an expanding universe converts energy to dark matter?

the dark matter linking worm holes to seperate but connected
universes?

is that what you're trying to pull on us Fogel?

well, you'll not get away with it.

Peter Rathman said:

...
My car has a coefficient of drag of 0.35, and it has a much more
streamlined shape than a regular upright cyclist. Where did your
factor of 10 (implying a Cd of 0.1) come from? Figures I've seen for
normal cyclists have been more around 0.6 or 0.7....

Here is what a bicycle with a coefficient of drag of slightly less than
0.1 looks like:
<http://www.ent.ohiou.edu/~et181/hpv/Andrea_64.7mph.jpg>. (Yes, she is
pedaling the bicycle in excess of 64 mph without wind or gravitational
assistance.)

--
Tom Sherman - Holstein-Friesland Bovinia
"Localized intense suction such as tornadoes is created when temperature
differences are high enough between meeting air masses, and can impart
excessive energy onto a cyclist." - Randy Schlitter

Andrew Muzi said:

I'll put some cash on a bet that anything you add to your bicycle's
frontal area reduces speed for any given constant effort. Magic fans,
ducts, rotors, ouija boards, windscreens and sails included. Name it.
How's $100 sound to you??...

Not a good bet. For example, the Varna Diablo II [1] has more frontal
area with the fairing on than off. Yet, Sam Whittingham's reported top
speed on an unfaired lowracer similar to the Diablo chassis is in the
low 40 mph range, while he has gone a verified 81 mph on the faired
Diablo without the benefit of wind or gravity assist.

I know from experience this bicycle [2] is much faster with the front
fairing and sock, which I have to believe increases frontal area.

[1] <http://www.varnahandcycles.com/gallery/varna_diablo_01.jpg>.
[2] <http://www.ransbikes.com/Gallery/Archive/images/Sherman1.jpg>.

--
Tom Sherman - Holstein-Friesland Bovinia
"Localized intense suction such as tornadoes is created when temperature
differences are high enough between meeting air masses, and can impart
excessive energy onto a cyclist." - Randy Schlitter

On Dec 14, 5:18 am, Tom Sherman <[email hidden]>

Quoted message said:

Peter Rathman said:

...
My car has a coefficient of drag of 0.35, and it has a much more
streamlined shape than a regular upright cyclist. Where did your
factor of 10 (implying a Cd of 0.1) come from? Figures I've seen for
normal cyclists have been more around 0.6 or 0.7....

Here is what a bicycle with a coefficient of drag of slightly less than
0.1 looks like:
<http://www.ent.ohiou.edu/~et181/hpv/Andrea_64.7mph.jpg>. (Yes, she is
pedaling the bicycle in excess of 64 mph without wind or gravitational
assistance.)

The faster it goes the sharper the wind angle so a fixed sail has a
speed with each angle at which it works best, in a fixed position it
could work as a tail fin, stick a horizontal blade at the top (in a T
shape) and it would make the ride some what more stable I think.

http://www.evworld.com/evworld_audio/michael_lewis.mp3
http://www.evworld.com/article.cfm?storyid=922

Quoted message said:

On Thu, 13 Dec 2007 17:56:16 -0800 (PST), peter <[email hidden]>
wrote:

[snip]

Quoted message said:

Now does this make any practical sense? No.

[snip]

Dear Peter,

You're getting closer.

You can extract useful energy by sticking a propeller into an
airstream to use onboard, just as you can extract useful energy
through a generator's roller to run a light.

You cannot, however, extract energy that is useful for propelling the
vehicle forward _faster_ because you lose more than you gain.

Cheers,

Carl Fogel