Downwind Faster Than The Wind
Lawrence D'Oliveiro
Me
> Propelled only by the wind. Possible or not?
>
> <http://www.youtube.com/watch?v=xHsXcHoJu-A>
The treadmill experiment is flawed. It requires that the cart is held
in position until the propellor achieves direct-driven speed, when
released it advances, but that advance (driven by inertia in the prop
drive mechanism) is limited by the length of the treadmill. If the
treadmill was long enough, it would fall back to below wind speed.
Lawrence D'Oliveiro
> Lawrence D'Oliveiro wrote:
>
>> Propelled only by the wind. Possible or not?
>>
>> <http://www.youtube.com/watch?v=xHsXcHoJu-A>
>
> The treadmill experiment is flawed. It requires that the cart is held
> in position until the propellor achieves direct-driven speed, when
> released it advances, but that advance (driven by inertia in the prop
> drive mechanism) is limited by the length of the treadmill.
No it's not. You'll notice that several times he pushes it back, only to
have it advance again.
> If the treadmill was long enough, it would fall back to below wind speed.
He left it, and left it, and left it, it never fell back. Remember in a pure
intertial test it only kept going for 7 seconds. On the treadmill with the
wind blowing, it kept going for much, much longer. Therefore, it's not just
intertia. QED.
Matty F
central.gen.new_zealand> wrote:
It's not really clear about a lot of things.
Which way is the wind blowing? It could be either way.
Does the propellor drive the wheels or are the wheels free-running?
Why does he not show the road ahead to prove there isn't a car towing
it?
The quality of the video is so poor it proves nothing.
Me
> In message <hdpu5d$6fg$1...@news.albasani.net>, Me wrote:
>
>> Lawrence D'Oliveiro wrote:
>>
>>> Propelled only by the wind. Possible or not?
>>>
>>> <http://www.youtube.com/watch?v=xHsXcHoJu-A>
>> The treadmill experiment is flawed. It requires that the cart is held
>> in position until the propellor achieves direct-driven speed, when
>> released it advances, but that advance (driven by inertia in the prop
>> drive mechanism) is limited by the length of the treadmill.
>
> No it's not. You'll notice that several times he pushes it back, only to
> have it advance again.
>
>
>> If the treadmill was long enough, it would fall back to below wind speed.
>
> He left it, and left it, and left it, it never fell back. Remember in a pure
> intertial test it only kept going for 7 seconds. On the treadmill with the
> wind blowing, it kept going for much, much longer. Therefore, it's not just
> intertia. QED.
velocity isn't constant.
Inertia to overcome to accelerate the thing forward is low. So the size
of the prop relative to the weight of the vehicle isn't very important,
so the weight of a r/c steering mechanism is irrelevant, so why isn't
there one?
Lawrence D'Oliveiro
b2fd-52b...@g10g2000pri.googlegroups.com>, Matty F wrote:
> Which way is the wind blowing?
Hint: the vehicles are moving DOWNwind.
> Does the propellor drive the wheels ...
That is part of the point.
Lawrence D'Oliveiro
> Lawrence D'Oliveiro wrote:
>
>> In message <hdpu5d$6fg$1...@news.albasani.net>, Me wrote:
>>
>>> If the treadmill was long enough, it would fall back to below wind
>>> speed.
>>
>> He left it, and left it, and left it, it never fell back. Remember in a
>> pure intertial test it only kept going for 7 seconds. On the treadmill
>> with the wind blowing, it kept going for much, much longer. Therefore,
>> it's not just intertia. QED.
>
> I never saw him leaving it &c.
Did you not watch the video <http://www.youtube.com/watch?v=xHsXcHoJu-A>?
> Inertia to overcome to accelerate the thing forward is low.
But constant. It was demonstrated how long the momentum would last from that
speed (4:53 to 4:57). It kept moving up the treadmill for much longer than
that (5:07 to 5:34 and beyond).
Matty F
central.gen.new_zealand> wrote:
> In message <d3c23f14-70cb-4596-
>
> b2fd-52b70e5de...@g10g2000pri.googlegroups.com>, Matty F wrote:
> > Which way is the wind blowing?
>
> Hint: the vehicles are moving DOWNwind.
How do you know that? Just because the guy says so?
I've seen a propellor powered yacht that can go directly upwind, which
is useful.
Me
> In message <hdqob6$9vm$1...@news.albasani.net>, Me wrote:
>
>> Lawrence D'Oliveiro wrote:
>>
>>> In message <hdpu5d$6fg$1...@news.albasani.net>, Me wrote:
>>>
>>>> If the treadmill was long enough, it would fall back to below wind
>>>> speed.
>>> He left it, and left it, and left it, it never fell back. Remember in a
>>> pure intertial test it only kept going for 7 seconds. On the treadmill
>>> with the wind blowing, it kept going for much, much longer. Therefore,
>>> it's not just intertia. QED.
>> I never saw him leaving it &c.
>
> Did you not watch the video <http://www.youtube.com/watch?v=xHsXcHoJu-A>?
>
http://www.youtube.com/watch?v=1BRvYZd81AQ&feature=related
Lawrence D'Oliveiro
> On Nov 16, 7:45 pm, Lawrence D'Oliveiro <l...@geek-central.gen.new_zealand> wrote:
>
>> In message <d3c23f14-70cb-4596-b2fd-52b70e5de...@g10g2000pri.googlegroups.com>, Matty F wrote:
>>
>>> Which way is the wind blowing?
>>
>> Hint: the vehicles are moving DOWNwind.
>
> How do you know that? Just because the guy says so?
Because the treadmill test is in an enclosed room with no air movement.
JohnO
central.gen.new_zealand> wrote:
> Propelled only by the wind. Possible or not?
>
> <http://www.youtube.com/watch?v=xHsXcHoJu-A>
Impossible, obviously, for as it's speed approaches the wind speed the
propelling wind speed would approach zero.leading to no effective wind
power. Given there has to be rolling and wind resistance, how would it
get near or push through this state?
Further the machine looked like crap, with tiny wheels that looked
like they were pulled from a shopping cart and a primitive propeller.
Good wind turbines only have a mechanical efficiency of only around
20-30%. The wheels would cause significant friction as would the
frame. There's no independent verification in their outdoor or
treadmill test to certify the wind and treadmill speed recordings are
accurate. For all we know the wind speed was double the vehicle speed.
The you-tube video was unwatchably start-stop so I admit I didn't
watch it to the end. But I would believe anything they said as much as
I would believe any other perpetual motion or 'free energy' nutter.
Common sense, intuition, Newton's first law and Occam's razor say
hoax. Some wack-job on youtube with a completely unverifiable video
says otherwise. Who would you believe?
Not to say wind driven craft can't travel faster than the wind,
though. High performance sailing craft regularly do, by sailing at an
angle to the wind. All racing yachts zig-sag downwind rather than
sailing straight downwind.
Lawrence D'Oliveiro
But that’s not the one showing him leaving it, and leaving it, and leaving
it, for a much longer time than the pure inertial test, and it never fell
back. Therefore it’s not just inertia. QED.
Me
Yes, but the other one really looked like it had been shot on a Wal-mart
$9.95 webcam or a cellphone.
Enkidu
> Propelled only by the wind. Possible or not?
>
> <http://www.youtube.com/watch?v=xHsXcHoJu-A>
>
the thing would still move forward.
Cheers,
Cliff
--
The Internet is interesting in that although the nicknames may change,
the same old personalities show through.
Lawrence D'Oliveiro
So what?
Lawrence D'Oliveiro
e86383...@w19g2000pre.googlegroups.com>, JohnO wrote:
> On Nov 16, 10:29 am, Lawrence D'Oliveiro <l...@geek-
> central.gen.new_zealand> wrote:
>
>> Propelled only by the wind. Possible or not?
>>
>> <http://www.youtube.com/watch?v=xHsXcHoJu-A>
>
> Impossible, obviously, for as it's speed approaches the wind speed the
> propelling wind speed would approach zero.leading to no effective wind
> power. Given there has to be rolling and wind resistance, how would it
> get near or push through this state?
Imagine that, instead of the air, you have a horizontal steel rod, fixed in
place, with a screw thread around it. Instead of the propeller, you have a
nut threaded around the rod.
Now, is it mechanically possible to have a linkage between the rotation of
the wheels and that of the nut, so that as the treadmill pushes against the
wheels in one direction, the contraption can propel itself, in the manner of
a worm gear, along the steel rod in the opposite direction?
JohnO
central.gen.new_zealand> wrote:
> In message <5ff384d7-0f17-402c-ba20-
Not sure if I follow you but the mechanical efficiency of a rigid
geared system can be somewhat close to 1 whereas the mechanical
efficiency of a wind turbine can get to a theoretical limit of about
0.6 and a practical limit of around 0.3. So you are well behind
already, before suffering the losses of friction in the wheels and
mechanism, and form drag in the structure.
Rich...@hotmail.com
wrote:
How far 'behind' you are may depend on how much you are paying for the
wind, or where you wanted to go.
Lawrence D'Oliveiro
So is there some threshold below which it becomes impossible to move
forwards off a backwards movement?
JohnO
central.gen.new_zealand> wrote:
Sorry, I have no idea what you are trying to say there. What forwards
and backwards movements, and in what frame of reference?
Lawrence D'Oliveiro
e882-4d88-96d...@x25g2000prf.googlegroups.com>, JohnO wrote:
The backwards movement of the treadmill causes forwards movement of the
kart, in the frame of reference in which the air is stationary.
Me
JohnO
central.gen.new_zealand> wrote:
> In message <4be79e4d-
Thanks. I don't believe that there is any such threshold and it won't
work at any speed. It would never move forwards relative to the
stationary air, other than perhaps if the treadmill stopped, having
imparted some kinetic energy in the rotating turbine, some of that
energy could change to forward motion against the still air, until it
ran out, but that is not what they are trying to prove.
Lawrence D'Oliveiro
> Lawrence D'Oliveiro wrote:
>
>> The backwards movement of the treadmill causes forwards movement of the
>> kart, in the frame of reference in which the air is stationary.
>>
> Only if a human hand intervenes.
If you think a backwards movement cannot cause a forwards movement, then how
does a winch work?
Lawrence D'Oliveiro
b2cf-804...@i12g2000prg.googlegroups.com>, JohnO wrote:
> On Nov 17, 1:30 pm, Lawrence D'Oliveiro <l...@geek-
> central.gen.new_zealand> wrote:
>
>> The backwards movement of the treadmill causes forwards movement of the
>> kart, in the frame of reference in which the air is stationary.
>
> Thanks. I don't believe that there is any such threshold and it won't
> work at any speed.
If you think that backwards movement cannot cause forwards movement, then
Lawrence D'Oliveiro
b2cf-804...@i12g2000prg.googlegroups.com>, JohnO wrote:
> I don't believe that there is any such threshold and it won't
> work at any speed.
Many years ago a guy in Russell built a wind-powered boat that, instead of a
sail, had a windmill connected to a propeller. Had no problem moving in any
direction, regardless of the direction of the wind, just so long as there
was a wind.
There was much debate over whether it could sail straight twelve o’clock
into the wind, with many seasoned sailors flatly declaring this was
impossible. Nevertheless, it managed it quite well.
It’s exactly the same mechanical principle as in this case, just flipped
upside-down.
Me
Cite?
I can vaguely recall seeing something about that on TV.
IIRC the windmill wasn't connected to a prop directly, but generated
power and the thing was propelled by an electric motor and batteries.
It's not possible for it to do as described.
In many ways, nothing fundamental has really changed in yacht design in
100 years, just better materials allowing improvements to be achieved.
Lawrence D'Oliveiro
Further analysis of this. Suppose that a rotation of the wheels of the kart
that causes a tangent surface to move backwards a distance S1 also causes a
forward linear movement of the nut (and hence the kart) equal to S2.
So a backwards movement of the treadmill a distance S1 would cause the kart
to move forward a distance S2. Except the total movement of the wheels would
now add up to S1 + S2. Which means the forward movement would be S2 / S1 *
(S1 + S2). Which further increases the forward movement to S2 / S1 * (S1 +
S2 / S1 * (S1 + S2)). Which further increases the forward movement ...
This is an infinite series. Is that bad? In mathematical terms, there’s
nothing wrong with such a thing, provided it converges to a fixed value.
This value S must be such that
S = S2 / S1 * (S1 + S)
From which
S * S1 / S2 = S1 + S
or
S * (S1 / S2 - 1) = S1
In other words,
S = S1 / (S1 / S2 - 1)
= S1 * S2 / (S1 - S2)
This is well-defined provided that
S2 < S1
And there you have it: provided the amount of forward movement of the kart
doesn’t exceed the backward movement tangent to the wheels, it all makes
sense. Furthermore, the mechanical advantage is
S1 / S = (S1 - S2) / S2
So as S2 approaches S1, this becomes very small. Therefore the force needed
to be applied by the treadmill to overcome friction in the mechanism becomes
correspondingly very large. Which makes sense.
Going back to the propeller in air, the original demonstration of the kart
in the wind at the beginning of the video was showing a value of S2 / S1 of
maybe 10-20%. Doesn’t seem too outlandish, does it?
JohnO
central.gen.new_zealand> wrote:
> In message <6a22db60-8191-48fb-
No it is not. The issue with the OP is exceeding the wind speed down
wind. I have already posted that high performance yachts can exceed
the wind speed, but they cannot do it directly down wind.
JohnO
central.gen.new_zealand> wrote:
> In message <6a22db60-8191-48fb-
A winch is different to a wind powered object on a treadmill. The
issue with the OP is exceeding the wind speed downwind.
If the wind is turning the turbine to drive the wheels then as soon as
it exceeded the wind speed the flow through the turbine is reversed
which in conjunction with the form drag would slow the craft down.
JohnO
> Lawrence D'Oliveiro wrote:
> > In message <6a22db60-8191-48fb-
Bernoulli's Law is all there is to it, really. Unless you are sailing
directly downwind, and as mentioned, that is not the fastest way to
sail to a downwind destination.
Me
> Bernoulli's Law is all there is to it, really. Unless you are sailing
> directly downwind, and as mentioned, that is not the fastest way to
> sail to a downwind destination.
Can be a rather pleasant way to travel though, wung-out with only a hint
of breeze behind, beer in hand, casually enjoying the peace, waiting for
the screaming when the top of someone's head is crushed by the boom in a
chinese jibe, followed by the expensive sound of stuff getting broken...
JohnO
Heh, yeah. Everything rolls around a bit running flat downwind.
Broad reach, a bit of a heel on, all the way to Kawau in a nice
sou'wester. Bliss.
Me
We don't get those here, unfortunately.
George.com
"Lawrence D'Oliveiro" <l...@geek-central.gen.new_zealand> wrote in message
news:hdprsj$og1$1...@lust.ihug.co.nz...
> Propelled only by the wind. Possible or not?
Absolutely possible.
Shane Bond!
point proved.
rob
Pooh
"Matty F" <matty...@yahoo.co.nz> wrote in message
news:10dede57-e6bb-4f4c...@h14g2000pri.googlegroups.com...
> On Nov 16, 7:45 pm, Lawrence D'Oliveiro <l...@geek-
> central.gen.new_zealand> wrote:
>> In message <d3c23f14-70cb-4596-
>>
>> b2fd-52b70e5de...@g10g2000pri.googlegroups.com>, Matty F wrote:
>> > Which way is the wind blowing?
>>
>> Hint: the vehicles are moving DOWNwind.
>
> How do you know that? Just because the guy says so?
> I've seen a propellor powered yacht that can go directly upwind, which
> is useful.
Did you notice the ribbon behind the propellor?
I'm waiting to see MythBusters do an episode on it:)
Pooh
Matty F
> "Matty F" <mattyf9...@yahoo.co.nz> wrote in message
Yes I saw the ribbon. The guy sounded like a crank so I didn't bother
trying to work out everything he was doing. There is so much scope for
fake videos that I don't want to waste time on them.
If he comes up with something useful that works I'm sure will will
hear about it one day. I'm not holding my breath.
Lawrence D'Oliveiro
> On Nov 17, 3:06 pm, Lawrence D'Oliveiro <l...@geek-central.gen.new_zealand> wrote:
>
>> In message <6a22db60-8191-48fb-b2cf-804350f8f...@i12g2000prg.googlegroups.com>, JohnO wrote:
>>
>>> I don't believe that there is any such threshold and it won't
>>> work at any speed.
>>
>> Many years ago a guy in Russell built a wind-powered boat that, instead
>> of a sail, had a windmill connected to a propeller. Had no problem moving
>> in any direction, regardless of the direction of the wind, just so long
>> as there was a wind.
>>
>> There was much debate over whether it could sail straight twelve o’clock
>> into the wind, with many seasoned sailors flatly declaring this was
>> impossible. Nevertheless, it managed it quite well.
>>
>> It’s exactly the same mechanical principle as in this case, just flipped
>> upside-down.
>
> No it is not.
Yes it is. Think about it.
Lawrence D'Oliveiro
> On Nov 17, 3:04 pm, Lawrence D'Oliveiro <l...@geek-central.gen.new_zealand> wrote:
>
>> In message <6a22db60-8191-48fb-b2cf-804350f8f...@i12g2000prg.googlegroups.com>, JohnO wrote:
>>
>>> On Nov 17, 1:30 pm, Lawrence D'Oliveiro <l...@geek-central.gen.new_zealand> wrote:
>>
>>>> The backwards movement of the treadmill causes forwards movement of
>>>> the kart, in the frame of reference in which the air is stationary.
>>
>>> Thanks. I don't believe that there is any such threshold and it won't
>>> work at any speed.
>>
>> If you think that backwards movement cannot cause forwards movement, then
>> how does a winch work?
>
> A winch is different to a wind powered object on a treadmill. The
> issue with the OP is exceeding the wind speed downwind.
>
> If the wind is turning the turbine to drive the wheels then as soon as
> it exceeded the wind speed the flow through the turbine is reversed
> which in conjunction with the form drag would slow the craft down.
The wind is pushing the whole vehicle along, including the part of the wind
which is being held back behind the vehicle by the spinning propeller.
It’s all just a matter of mechanical leverage. Air is matter, so it’s also
mechanical. That’s all there is to it.
Lawrence D'Oliveiro
> Did you notice the ribbon behind the propellor?
That was to prove it was moving faster than the wind.
Lawrence D'Oliveiro
> I have already posted that high performance yachts can exceed
> the wind speed, but they cannot do it directly down wind.
Thereby conveniently overlooking the fundamental difference between a
conventional sail yacht and a windmill-boat.
While going upwind and downwind, a sail yacht treats the water as nothing
more than a source of drag to be overcome. But a windmill-boat uses the
water as the fulcrum of a lever: that’s what the propeller is for.
It’s all about mechanical leverage. A sail-yacht can apply that leverage
only going cross-wind (when it can bring its keel into play); because the
windmill-boat can orient its windmill any way it likes, it can apply that
leverage going directly upwind and downwind as well.
Another interesting thing to consider is: under what conditions could you
operate a windmill-powered flying machine? Say start with a lighter-than-air
balloon to avoid the problem of generating lift: could you attach a windmill
and a propeller to it so that the windmill drives the propeller? Could you
drive it straight upwind? Or straight downwind faster than the wind?
Me
> In message
> <5c0be611-4f07-4ac6...@s21g2000prm.googlegroups.com>, JohnO
> wrote:
>
>> I have already posted that high performance yachts can exceed
>> the wind speed, but they cannot do it directly down wind.
>
> Thereby conveniently overlooking the fundamental difference between a
> conventional sail yacht and a windmill-boat.
>
designed and used, energy loss through turbulence is minimised.
>
> While going upwind and downwind, a sail yacht treats the water as nothing
> more than a source of drag to be overcome. But a windmill-boat uses the
> water as the fulcrum of a lever: that’s what the propeller is for.
>
> It’s all about mechanical leverage. A sail-yacht can apply that leverage
> only going cross-wind (when it can bring its keel into play); because the
> windmill-boat can orient its windmill any way it likes, it can apply that
> leverage going directly upwind and downwind as well.
>
to windward. I'm confident you can't, and I'm also confident that gain
to windward by a sail powered boat will exceed that of any windmill
powered boat, even in the unlikely event that a windmill designed boat
could point closer to the wind.
Dave Doe
>
> Lawrence D'Oliveiro wrote:
> > In message
> > <5c0be611-4f07-4ac6...@s21g2000prm.googlegroups.com>, JohnO
> > wrote:
> >
> >> I have already posted that high performance yachts can exceed
> >> the wind speed, but they cannot do it directly down wind.
> >
> > Thereby conveniently overlooking the fundamental difference between a
> > conventional sail yacht and a windmill-boat.
> >
> Yes, a sail is much more effective, probably mainly because if well
> designed and used, energy loss through turbulence is minimised.
> >
> > While going upwind and downwind, a sail yacht treats the water as nothing
> > more than a source of drag to be overcome. But a windmill-boat uses the
> >
> > It?s all about mechanical leverage. A sail-yacht can apply that leverage
> > windmill-boat can orient its windmill any way it likes, it can apply that
> > leverage going directly upwind and downwind as well.
> >
> Show an example of a "windmill powered boat capable of sailing directly
> to windward. I'm confident you can't, and I'm also confident that gain
> to windward by a sail powered boat will exceed that of any windmill
> powered boat, even in the unlikely event that a windmill designed boat
> could point closer to the wind.
This *has* been done - you do yer own googling, you should be able to
find a video of a guy that modified what looks to be a hobie cat or
paper tiger type sized cat. The important thing is that the windmill is
geared *down* to drive a reasonable sized prop.
The boat advances quite slowly directly upwind. Certainly not as
efficient as tacking upwind (in terms of making ground upwind (ie
overall)).
There is another example you should be able to find - looks to be a big
40' - 60' fiberglass thing.
You should also be able to find some video and pics of similar land
based designs. Again, the reason they work is that they are geared
down. A solid surface of course, is different from water - but... not
*that* much - if you have a sufficiently large prop the boat will resist
being pushed backwards - and if you find the examples you'll see they do
indeed travel directly upwind.
As to the craft per the OP, travelling faster than the wind directly
downwind, that's just crap! :) One of the main factors visibly missing
in all the videos is the power source - the wind. I'm sure if it was
smoked up to make the wind visible, it would be apparent the wind is,
effectively, gusting somewhat. Putting these things in a proper wind
tunnel, I think they'd be quickly found out for what they are - a crock
of chit.
--
Duncan.
JohnO
central.gen.new_zealand> wrote:
> In message <b265b0a9-b0bb-472f-9bec-e854d4ae4...@b25g2000prb.googlegroups.com>, JohnO wrote:
>
>
>
>
>
> > On Nov 17, 3:04 pm, Lawrence D'Oliveiro <l...@geek-central.gen.new_zealand> wrote:
>
> >> In message <6a22db60-8191-48fb-b2cf-804350f8f...@i12g2000prg.googlegroups.com>, JohnO wrote:
>
> >>> On Nov 17, 1:30 pm, Lawrence D'Oliveiro <l...@geek-central.gen.new_zealand> wrote:
>
> >>>> The backwards movement of the treadmill causes forwards movement of
> >>>> the kart, in the frame of reference in which the air is stationary.
>
> >>> Thanks. I don't believe that there is any such threshold and it won't
> >>> work at any speed.
>
> >> If you think that backwards movement cannot cause forwards movement, then
> >> how does a winch work?
>
> > A winch is different to a wind powered object on a treadmill. The
> > issue with the OP is exceeding the wind speed downwind.
>
> > If the wind is turning the turbine to drive the wheels then as soon as
> > it exceeded the wind speed the flow through the turbine is reversed
> > which in conjunction with the form drag would slow the craft down.
>
> The wind is pushing the whole vehicle along, including the part of the wind
> which is being held back behind the vehicle by the spinning propeller.
If the vehicle is at or exceeding the wind speed the wind cannot push
it along.
Similarly, once exceeding the wind speed, the turbine will want to
rotate in opposition to the wheels.
JohnO
central.gen.new_zealand> wrote:
> In message
> <5c0be611-4f07-4ac6-9874-8e337aec7...@s21g2000prm.googlegroups.com>, JohnO
> wrote:
>
> > I have already posted that high performance yachts can exceed
> > the wind speed, but they cannot do it directly down wind.
>
> Thereby conveniently overlooking the fundamental difference between a
> conventional sail yacht and a windmill-boat.
>
> While going upwind and downwind, a sail yacht treats the water as nothing
> more than a source of drag to be overcome.
Absolutely incorrect. The keel's resistance to sideways motion ensures
that the forward component of the lift vector drives the boat in the
correct direction. The drag of the keel in the water is a fundamental
requirement to sail in any direction other than straight downwind.
Me
defies known principles of physics isn't likely to be possible, and is
likely to be a hoax.
You do the googling, and come up with some evidence to prove me wrong.
You say it has been done, I say that you've been hoaxed.
<snip>
Lawrence D'Oliveiro
> On Nov 18, 12:22 pm, Lawrence D'Oliveiro <l...@geek-central.gen.new_zealand> wrote:
>
>> While going upwind and downwind, a sail yacht treats the water as nothing
>> more than a source of drag to be overcome.
>
> Absolutely incorrect. The keel's resistance to sideways motion ensures
> that the forward component of the lift vector drives the boat in the
> correct direction. The drag of the keel in the water is a fundamental
> requirement to sail in any direction other than straight downwind.
That’s why those first five words are in the paragraph.
Lawrence D'Oliveiro
bfdc-322...@e4g2000prn.googlegroups.com>, JohnO wrote:
> If the vehicle is at or exceeding the wind speed the wind cannot push
> it along.
Why not? I have explained how it can; now it’s up to you to explain why it
can’t.
JohnO
central.gen.new_zealand> wrote:
> In message <5cc1f3b6-3a66-4bf9-
>
> bfdc-322435d78...@e4g2000prn.googlegroups.com>, JohnO wrote:
> > If the vehicle is at or exceeding the wind speed the wind cannot push
> > it along.
>
> Why not? I have explained how it can; now it’s up to you to explain why it
> can’t.
"pushing the whole vehicle along..." - nonsensical. If it is exceeding
the wind speed, the wind is pushing the whole vehicle back.
If the propeller is geared to drive the wheels when pushed blown from
behind, it would slow the vehicle when exceeding the wind speed. If
the propeller is geared to be driven by the wheels then when initially
stationary it would want to go backwards.
JohnO
central.gen.new_zealand> wrote:
But it is still a nonsensical five words. Yachts cannot sail directly
upwind. In practice they do not sail directly downwind either. At
least not if they want to get there quickly.
Dave Doe
In what way does it defy the laws of physics?
--
Duncan.
Lawrence D'Oliveiro
e03985...@b25g2000prb.googlegroups.com>, JohnO wrote:
> On Nov 18, 1:39 pm, Lawrence D'Oliveiro <l...@geek-
> central.gen.new_zealand> wrote:
>> In message <5cc1f3b6-3a66-4bf9-
>>
>> bfdc-322435d78...@e4g2000prn.googlegroups.com>, JohnO wrote:
>> > If the vehicle is at or exceeding the wind speed the wind cannot push
>> > it along.
>>
>> Why not? I have explained how it can; now it’s up to you to explain why
>> it can’t.
>
> "pushing the whole vehicle along..." - nonsensical. If it is exceeding
> the wind speed, the wind is pushing the whole vehicle back.
That’s how a third-class lever works.
> If the propeller is geared to drive the wheels when pushed blown from
> behind, it would slow the vehicle when exceeding the wind speed.
It’s a lever, with the fulcrum being at the contact with the ground.
Lawrence D'Oliveiro
> On Nov 18, 1:38 pm, Lawrence D'Oliveiro <l...@geek-central.gen.new_zealand> wrote:
>
>> In message
>> <5ef9b91b-5e0c-47e7-9168-34f75bef0...@m7g2000prd.googlegroups.com>, JohnO
>> wrote:
>>
>> > On Nov 18, 12:22 pm, Lawrence D'Oliveiro
>> > <l...@geek-central.gen.new_zealand> wrote:
>>
>> >> While going upwind and downwind, a sail yacht treats the water as
>> >> nothing more than a source of drag to be overcome.
>>
>> > Absolutely incorrect. The keel's resistance to sideways motion ensures
>> > that the forward component of the lift vector drives the boat in the
>> > correct direction. The drag of the keel in the water is a fundamental
>> > requirement to sail in any direction other than straight downwind.
>>
>> That’s why those first five words are in the paragraph.
>
> But it is still a nonsensical five words. Yachts cannot sail directly
> upwind.
Not at all?
Dave Doe
From...
http://en.wikipedia.org/wiki/Sailing
Some non-traditional rigs purportedly capture energy from the wind in a
different fashion and are capable of feats that traditional rigs are
not, such as sailing directly into the wind. One such example is the
wind turbine boat, also called the windmill boat[3], which uses a large
windmill to extract energy from the wind, and a propeller to convert
this energy to forward motion of the hull. A similar design, called the
autogyro boat, uses a wind turbine without the propellor, and functions
in a manner similar to a normal sail [4].
http://www.treehugger.com/files/2007/02/windmill_sailbo.php
http://www.boatdesign.net/forums/projects-proposals/windmill-wind-
turbine-powered-boats-how-many-out-there-they-viable-14182.html
http://forum.darwinawards.com/lofiversion/index.php/t7858.html
http://www.multihullcentre.co.uk/mhcnews.htm
http://www.main.org/polycosmos/silicbar/sailscrw.htm
You may contend that the evidence is not direct nor conclusive - however
it is, in reality, no different from tacking into the wind - there is
still a VMG component, though small, just like tacking into the wind,
but (seemingly) not as efficient.
http://www.youtube.com/watch?v=PIUKNYLATl8
http://www.youtube.com/watch?v=NNbNNSDljGI
http://www.youtube.com/watch?v=9AV0H1EpTYI
--
Duncan.
Lawrence D'Oliveiro
e03985...@b25g2000prb.googlegroups.com>, JohnO wrote:
> If the propeller is geared to be driven by the wheels then when initially
> stationary it would want to go backwards.
Why? The kart goes forwards, the wheels spin the propeller to add to the
thrust in the forward direction, this adds even more speed, all the energy
coming from the wind.
Me
from the windmill.
OTOH, it would be dead easy to make a land based windmill powered cart
that can move directly into the wind.
Dave Doe
No you don't - indeed, you cotton onto the land based cart - there's
your hint - imagine a very large prop for example - it's not that
different from rubber on a road (it won't go backwards (much) against
the water).
--
Duncan.
Lawrence D'Oliveiro
>> In what way does it defy the laws of physics?
>>
> Because you'd need to expel more energy at the prop than you can gain
> from the windmill.
Who says you’d have to? Do you know what “leverage” means?
Me
fulcrum, as well as dealing with frictional losses and screw
inefficiency, you're fucked.
Me
Lawrence D'Oliveiro
> Lawrence D'Oliveiro wrote:
>
>> In message <hdvqfn$mg$1...@news.albasani.net>, Me wrote:
>>
>>>> In what way does it defy the laws of physics?
>>>>
>>> Because you'd need to expel more energy at the prop than you can gain
>>> from the windmill.
>>
>> Who says you’d have to? Do you know what “leverage” means?
>
> Yes - it needs a fulcrum ...
Go watch the video again, and this time spot the fulcrum.
JohnO
central.gen.new_zealand> wrote:
Not directly to windward, of course not.
JohnO
central.gen.new_zealand> wrote:
> In message <fa56c69b-1502-4a9f-b503-
You continue to miss the point, and I tire of your obtuseness. I'll
let you continue on making yourself look dim by yourself.
Me
> In message <hdvv66$6qc$1...@news.albasani.net>, Me wrote:
>
>> Lawrence D'Oliveiro wrote:
>>
>>> In message <hdvqfn$mg$1...@news.albasani.net>, Me wrote:
>>>
>>>>> In what way does it defy the laws of physics?
>>>>>
>>>> Because you'd need to expel more energy at the prop than you can gain
>>>> from the windmill.
>>> Who says you’d have to? Do you know what “leverage” means?
>> Yes - it needs a fulcrum ...
>
> Go watch the video again, and this time spot the fulcrum.
what video?
Lawrence D'Oliveiro
> On Nov 18, 3:12 pm, Lawrence D'Oliveiro <l...@geek-central.gen.new_zealand> wrote:
>
>> In message <fa56c69b-1502-4a9f-b503-
>>
>> e039857e7...@b25g2000prb.googlegroups.com>, JohnO wrote:
>> > On Nov 18, 1:39 pm, Lawrence D'Oliveiro <l...@geek-
>> > central.gen.new_zealand> wrote:
>> >> In message <5cc1f3b6-3a66-4bf9-
>>
>> >> bfdc-322435d78...@e4g2000prn.googlegroups.com>, JohnO wrote:
>> >> > If the vehicle is at or exceeding the wind speed the wind cannot
>> >> > push it along.
>>
>> >> Why not? I have explained how it can; now it’s up to you to explain
>> >> why it can’t.
>>
>> > "pushing the whole vehicle along..." - nonsensical. If it is exceeding
>> > the wind speed, the wind is pushing the whole vehicle back.
>>
>> That’s how a third-class lever works.
>>
>> > If the propeller is geared to drive the wheels when pushed blown from
>> > behind, it would slow the vehicle when exceeding the wind speed.
>>
>> It’s a lever, with the fulcrum being at the contact with the ground.
>
> You continue to miss the point ...
Which is? All you’ve done is continue to insist it cannot be done, without
explaining why.
> ... and I tire of your obtuseness. I'll let you continue on making
> yourself look dim by yourself.
So many people have built these things; they’re not even that hard to build.
Lawrence D'Oliveiro
> Lawrence D'Oliveiro wrote:
>> In message <hdvv66$6qc$1...@news.albasani.net>, Me wrote:
>>
>>> Lawrence D'Oliveiro wrote:
>>>
>>>> In message <hdvqfn$mg$1...@news.albasani.net>, Me wrote:
>>>>
>>>>>> In what way does it defy the laws of physics?
>>>>>>
>>>>> Because you'd need to expel more energy at the prop than you can gain
>>>>> from the windmill.
>>>> Who says you’d have to? Do you know what “leverage” means?
>>> Yes - it needs a fulcrum ...
>>
>> Go watch the video again, and this time spot the fulcrum.
>
> what video?
Propelled only by the wind. Possible or not?
Lawrence D'Oliveiro
Not much of a sailor, are you?
How do you tack, then? Do you have to turn the long way round?
Me
You're back to the "downwind faster than the wind" video, which I don't
believe.
Me
like a herd of cows, except more predictable in action.
Lawrence D'Oliveiro
> You're back to the "downwind faster than the wind" video, which I don't
> believe.
Why not? I have explained how it works; you have yet to explain why it
cannot possibly work.
Lots of people have built these sorts of machines, and got them to work; do
you really believe they’re all part of a gigantic conspiracy against you?
Me
> In message <he06rs$hbc$1...@news.albasani.net>, Me wrote:
>
>> You're back to the "downwind faster than the wind" video, which I don't
>> believe.
>
> Why not? I have explained how it works; you have yet to explain why it
> cannot possibly work.
>
You've shown links to some dodgy video "evidence".
Lawrence D'Oliveiro
> Lawrence D'Oliveiro wrote:
>
>> In message <he06rs$hbc$1...@news.albasani.net>, Me wrote:
>>
>>> You're back to the "downwind faster than the wind" video, which I don't
>>> believe.
>>
>> Why not? I have explained how it works; you have yet to explain why it
>> cannot possibly work.
>>
> No you haven't!
Read my posting
<http://groups.google.co.nz/groups?selm=hdt416$km0$1...@lust.ihug.co.nz>.
> You've shown links to some dodgy video "evidence".
Nothing dodgy about it. Both the outdoor footage of the kart on the road,
and the indoor footage on the treadmill, was as clear as can be.
Particularly the indoor footage--notice how he kept pushing the kart back,
but it kept regaining speed and coming forward, purely under its own
propulsion. How do you explain that?
>> Lots of people have built these sorts of machines, and got them to work;
>> do you really believe they’re all part of a gigantic conspiracy against
>> you?
Well?
Lawrence D'Oliveiro
> In message <hdtvaa$1epu$1...@adenine.netfront.net>, Pooh wrote:
>
>> Did you notice the ribbon behind the propellor?
>
> That was to prove it was moving faster than the wind.
To examine this in detail: note that at 1:25, the kart has already started
moving (and the propeller spinning), yet the ribbon is still blowing
forwards. By about 1:39, the ribbon is hanging fairly limply, so the kart is
roughly matching the wind speed.
And by 1:49, the ribbon is consistently being blown backwards. From this
point on, the kart is maintaining a speed greater than that of the wind.
Lawrence D'Oliveiro
a33f1a...@f18g2000prf.googlegroups.com>, Matty F wrote:
> The guy sounded like a crank so I didn't bother trying to work out
> everything he was doing.
Why do you think he “sounded like a crank”? He was careful to go through the
treadmill test in particular, to demonstrate that there was no trickery
involved.
> If he comes up with something useful that works I'm sure will will
> hear about it one day. I'm not holding my breath.
Lots of people have invented similar mechanisms, and got them to work.
There’s no secret knowledge only available to a select circle of initiates,
no suppressed patents, no hidden research projects that the oil companies
bought up to shut down. It’s all just ordinary everyday science.
Me
> In message <he2a5f$q1i$1...@news.albasani.net>, Me wrote:
>
>> Lawrence D'Oliveiro wrote:
>>
>>> In message <he06rs$hbc$1...@news.albasani.net>, Me wrote:
>>>
>>>> You're back to the "downwind faster than the wind" video, which I don't
>>>> believe.
>>> Why not? I have explained how it works; you have yet to explain why it
>>> cannot possibly work.
>>>
>> No you haven't!
>
> Read my posting
> <http://groups.google.co.nz/groups?selm=hdt416$km0$1...@lust.ihug.co.nz>.
>
>> You've shown links to some dodgy video "evidence".
>
> Nothing dodgy about it. Both the outdoor footage of the kart on the road,
> and the indoor footage on the treadmill, was as clear as can be.
> Particularly the indoor footage--notice how he kept pushing the kart back,
> but it kept regaining speed and coming forward, purely under its own
> propulsion. How do you explain that?
Oh FFS - I already did explain it. He held the cart back with his
finger until prop speed was recovered, and inertia from the rotating
prop drove it "forward". When I pointed that out, you revert to using
the outdoor example, which is dumb, blurry, and proves nothing.
>
>>> Lots of people have built these sorts of machines, and got them to work;
>>> do you really believe they’re all part of a gigantic conspiracy against
>>> you?
>
> Well?
Nobody has built the machine (wind propelled - faster downwind than the
wind). There's no conspiracy.
Me
Have you ever considered the possibility that windspeed on planet Earth
is not constant.
Lawrence D'Oliveiro
> Lawrence D'Oliveiro wrote:
>
>> Particularly the indoor footage--notice how he kept pushing the kart
>> back, but it kept regaining speed and coming forward, purely under its
>> own propulsion. How do you explain that?
>
> Oh FFS - I already did explain it. He held the cart back with his
> finger until prop speed was recovered, and inertia from the rotating
> prop drove it "forward".
But he did it more than once, over and over. Where was the prop speed
“recovered” from, exactly?
> Nobody has built the machine (wind propelled - faster downwind than the
> wind). There's no conspiracy.
Lots of people have done so, and demonstrated them.
Lawrence D'Oliveiro
So it’s not that the kart was moving faster than the wind, but the wind was
moving slower than the kart?
Me
Me
not recorded in a manner from which you can tell anything much at all.
Lawrence D'Oliveiro
> Lawrence D'Oliveiro wrote:
>
>> In message <he2skl$had$1...@news.albasani.net>, Me wrote:
>>
>>> Lawrence D'Oliveiro wrote:
>>>
>>>> In message <hdv99h$spr$5...@lust.ihug.co.nz>, Lawrence D'Oliveiro wrote:
>>>>
>>>>> In message <hdtvaa$1epu$1...@adenine.netfront.net>, Pooh wrote:
>>>>>
>>>>>> Did you notice the ribbon behind the propellor?
>>>>>
>>>>> That was to prove it was moving faster than the wind.
>>>>
>>>> To examine this in detail: note that at 1:25, the kart has already
>>>> started moving (and the propeller spinning), yet the ribbon is still
>>>> blowing forwards. By about 1:39, the ribbon is hanging fairly limply,
>>>> so the kart is roughly matching the wind speed.
>>>>
>>>> And by 1:49, the ribbon is consistently being blown backwards. From
>>>> this point on, the kart is maintaining a speed greater than that of the
>>>> wind.
>>>
>>> Have you ever considered the possibility that windspeed on planet Earth
>>> is not constant.
>>
>> So it’s not that the kart was moving faster than the wind, but the wind
>> was moving slower than the kart?
>
> Not for a sustained period, not in constant wind speed/direction ...
So is there any point in the video, once the kart on the road has got up to
speed, at which the ribbon is ever blown forwards?
And what about the treadmill test, conducted indoors in still air? Where are
the changes in wind speed coming from there?
Lawrence D'Oliveiro
> Lawrence D'Oliveiro wrote:
>
>> In message <he2rvr$gfv$1...@news.albasani.net>, Me wrote:
>>
>>> Lawrence D'Oliveiro wrote:
>>>
>>>> Particularly the indoor footage--notice how he kept pushing the kart
>>>> back, but it kept regaining speed and coming forward, purely under its
>>>> own propulsion. How do you explain that?
>>>
>>> Oh FFS - I already did explain it. He held the cart back with his
>>> finger until prop speed was recovered, and inertia from the rotating
>>> prop drove it "forward".
>>
>> But he did it more than once, over and over. Where was the prop speed
>> “recovered” from, exactly?
Well?
>>> Nobody has built the machine (wind propelled - faster downwind than the
>>> wind). There's no conspiracy.
>>
>> Lots of people have done so, and demonstrated them.
>
> Prove it.
That’s what I’ve been doing, carefully explaining how it all works, how it’s
based on sound physical principles, how the phenomena in the video do stand
up to scrutiny. Whereas all your denials have just been “no it can’t, no it
can’t, no it can’t”. You are the one showing a lack of understanding of
basic, everyday physics and the simplest of machines.
Me
> In message <he35nh$u6l$3...@news.albasani.net>, Me wrote:
>
>> Lawrence D'Oliveiro wrote:
>>
>>> In message <he2rvr$gfv$1...@news.albasani.net>, Me wrote:
>>>
>>>> Lawrence D'Oliveiro wrote:
>>>>
>>>>> Particularly the indoor footage--notice how he kept pushing the kart
>>>>> back, but it kept regaining speed and coming forward, purely under its
>>>>> own propulsion. How do you explain that?
>>>> Oh FFS - I already did explain it. He held the cart back with his
>>>> finger until prop speed was recovered, and inertia from the rotating
>>>> prop drove it "forward".
>>> But he did it more than once, over and over. Where was the prop speed
>>> “recovered” from, exactly?
>
> Well?
>
>>>> Nobody has built the machine (wind propelled - faster downwind than the
>>>> wind). There's no conspiracy.
>>> Lots of people have done so, and demonstrated them.
>> Prove it.
>
> That’s what I’ve been doing, carefully explaining how it all works,
Rubbish - every time you're challenged you change subject - or show bad
video as proof, and that video originates from a single troll posting to
various physics blogs.
Nobody has "demonstrated so" at all.
The troll evades testing his device on a long "travelator" by claiming
that the wheels would get stuck in the grooves. There are plenty of
other solutions.
Lawrence D'Oliveiro
> Lawrence D'Oliveiro wrote:
>
>> In message <he35nh$u6l$3...@news.albasani.net>, Me wrote:
>>
>>> Lawrence D'Oliveiro wrote:
>>>
>>>> In message <he2rvr$gfv$1...@news.albasani.net>, Me wrote:
>>>>
>>>>> Lawrence D'Oliveiro wrote:
>>>>>
>>>>>> Particularly the indoor footage--notice how he kept pushing the kart
>>>>>> back, but it kept regaining speed and coming forward, purely under
>>>>>> its own propulsion. How do you explain that?
>>>>>
>>>>> Oh FFS - I already did explain it. He held the cart back with his
>>>>> finger until prop speed was recovered, and inertia from the rotating
>>>>> prop drove it "forward".
>>>>
>>>> But he did it more than once, over and over. Where was the prop speed
>>>> “recovered” from, exactly?
>>
>> Well?
Still waiting for this. Are you going to explain your mumbo-jumbo
pseudoscientific gobbledygook, or not?
Me
What "pseudoscientific gobbledygook"?
If you want it expressed more correctly, then:
He pushed the cart back with his finger until prop speed increased to
the maximum rotational speed possible from the geared drive and belt
speed, and when he removed his finger, inertia from the rotating prop
drove the cart "forward".
It would have eventually slowed down, stopped and gone back the other
way, but the experiment was designed very poorly, as the length of the
belt was too short. The person conducting the experiment knew that, so
on other forums he made up all sorts of excuses as to why he couldn't
use a longer belt, "travelator", conveyor belt in a factory etc.
The outdoor video shows nothing particularly interesting, as variables
weren't controlled or measured, in particular wind direction and how
constant the wind velocity was.
If something had actually been demonstrated that really appeared to show
that sustained "sailing directly downwind faster than the wind" was
possible, then it might be worth thinking about how principles of
physics could explain what was observed. But as it wasn't ever
demonstrated, there's nothing to discuss.
Gobbledygook - whatever - you've been trolled beautifully.
JohnO
> Lawrence D'Oliveiro wrote:
I'm surprised that Larry is really so credulous that he'd believe
everything he's seeing on a youtube video.
Mind you, they say there's one born every minute.
Lawrence D'Oliveiro
> He pushed the cart back with his finger until prop speed increased ...
Prop speed DECREASED when he pushed the cart back on the treadmill. The prop
was geared to the wheels. So when the wheels slowed down, so did the prop.
If you didn’t understand this point, then you’ve understood nothing.
Lawrence D'Oliveiro
d49265...@f1g2000prf.googlegroups.com>, JohnO wrote:
> I'm surprised that Larry is really so credulous that he'd believe
> everything he's seeing on a youtube video.
I don’t. I went over it quite carefully before realizing it was genuine. As
I have been carefully explaining.
Me
You need to think a bit harder on what you say above Larry.
Take a 3 year old's "push + go" toy car, and think whilst you play with it.
Me
Lawrence D'Oliveiro
> Lawrence D'Oliveiro wrote:
>
>> In message <he4nqd$e4g$1...@news.albasani.net>, Me wrote:
>>
>>> He pushed the cart back with his finger until prop speed increased ...
>>
>> Prop speed DECREASED when he pushed the cart back on the treadmill. The
>> prop was geared to the wheels. So when the wheels slowed down, so did the
>> prop.
>
>> If you didn’t understand this point, then you’ve understood nothing.
>
> You need to think a bit harder on what you say above Larry.
Go and look again at the machine. The prop is fixed rigidly to a shaft that
rotates freely in a long tube. At the bottom, front, end of the tube, there
is a gear on the end of the shaft, that meshes with another gear fixed to
the axle carrying the front wheels.
So when one spins, the other has to spin. When the wheels spin forward, the
propeller pushes air to the rear.
It really is that simple.
Me
... and there's 100% traction with no slippage/loss between wheels and
the treadmill?
BTW, what are typical losses when transferring torque 90 deg from the
axle to the shaft driving the prop?
Yep - it really is that simple - it doesn't work!
ChristianKnight
> Lawrence D'Oliveiro wrote:
> in position until the propellor achieves direct-driven speed, when
> released it advances, but that advance (driven by inertia in the prop
> drive mechanism) is limited by the length of the treadmill. If the
> treadmill was long enough, it would fall back to below wind speed.
Maybe worth giving it a chance and not closing the door completely to
the concept as solar winds could give amazing propultion if speed
could me magnified with the right capture. The more boats and buggies
that give this theory a try the quicker advancements mutate to change
the currant laws of physics. Surely science once sincerely put forward
the idea it is not possible for two people to talk to each other miles
apart through little rectangle plastic things.
Christ's love
Me
May I suggest that you work more closely with Larry on perfecting your
theories, if you could agree to work with him in a GPL non-commercial
environment.
JohnO
> Lawrence D'Oliveiro wrote:
>
> >>>> He pushed the cart back with his finger until prop speed increased ...
> >>> Prop speed DECREASED when he pushed the cart back on the treadmill. The
> >>> prop was geared to the wheels. So when the wheels slowed down, so did the
> >>> prop.
> >>> If you didn’t understand this point, then you’ve understood nothing.
> >> You need to think a bit harder on what you say above Larry.
>
> > Go and look again at the machine. The prop is fixed rigidly to a shaft that
> > rotates freely in a long tube. At the bottom, front, end of the tube, there
> > is a gear on the end of the shaft, that meshes with another gear fixed to
> > the axle carrying the front wheels.
>
> > So when one spins, the other has to spin. When the wheels spin forward, the
> > propeller pushes air to the rear.
>
> > It really is that simple.
>
> ... and there's 100% traction with no slippage/loss between wheels and
> the treadmill?
> BTW, what are typical losses when transferring torque 90 deg from the
> axle to the shaft driving the prop?
>
> Yep - it really is that simple - it doesn't work!
Never mind that. Even state of the art wind turbines are only about
30% efficient.
Me
> On Nov 20, 8:55 pm, Me <u...@domain.invalid> wrote:
>> Lawrence D'Oliveiro wrote:
>>> In message <he55cm$c...@news.albasani.net>, Me wrote:
>>>> Lawrence D'Oliveiro wrote:
>>>>> In message <he4nqd$e4...@news.albasani.net>, Me wrote:
>>>>>> He pushed the cart back with his finger until prop speed increased ...
>>>>> Prop speed DECREASED when he pushed the cart back on the treadmill. The
>>>>> prop was geared to the wheels. So when the wheels slowed down, so did the
>>>>> prop.
>>>> You need to think a bit harder on what you say above Larry.
>>> Go and look again at the machine. The prop is fixed rigidly to a shaft that
>>> rotates freely in a long tube. At the bottom, front, end of the tube, there
>>> is a gear on the end of the shaft, that meshes with another gear fixed to
>>> the axle carrying the front wheels.
>>> So when one spins, the other has to spin. When the wheels spin forward, the
>>> propeller pushes air to the rear.
>>> It really is that simple.
>> ... and there's 100% traction with no slippage/loss between wheels and
>> the treadmill?
>> BTW, what are typical losses when transferring torque 90 deg from the
>> axle to the shaft driving the prop?
>>
>> Yep - it really is that simple - it doesn't work!
>
> Never mind that. Even state of the art wind turbines are only about
> 30% efficient.
there's still plenty of mileage left in the small stuff!
Lawrence D'Oliveiro
> Lawrence D'Oliveiro wrote:
>> In message <he55cm$ch$1...@news.albasani.net>, Me wrote:
>>
>>> Lawrence D'Oliveiro wrote:
>>>
>>>> In message <he4nqd$e4g$1...@news.albasani.net>, Me wrote:
>>>>
>>>>> He pushed the cart back with his finger until prop speed increased ...
>>>> Prop speed DECREASED when he pushed the cart back on the treadmill. The
>>>> prop was geared to the wheels. So when the wheels slowed down, so did
>>>> the prop.
>>>> If you didn’t understand this point, then you’ve understood nothing.
>>> You need to think a bit harder on what you say above Larry.
>>
>> Go and look again at the machine. The prop is fixed rigidly to a shaft
>> that rotates freely in a long tube. At the bottom, front, end of the
>> tube, there is a gear on the end of the shaft, that meshes with another
>> gear fixed to the axle carrying the front wheels.
>>
>> So when one spins, the other has to spin. When the wheels spin forward,
>> the propeller pushes air to the rear.
>>
>> It really is that simple.
>
> ... and there's 100% traction with no slippage/loss between wheels and
> the treadmill?
How does that affect the numbers?
Lawrence D'Oliveiro
c6bbfa...@u16g2000pru.googlegroups.com>, JohnO wrote:
> Even state of the art wind turbines are only about 30% efficient.
And in the road test in the video, the kart is managing maybe only a 20%
boost on the wind speed. So what’s the problem?
Lawrence D'Oliveiro
ae1a-0c1...@y32g2000prd.googlegroups.com>, ChristianKnight wrote:
> The more boats and buggies that give this theory a try the quicker
> advancements mutate to change the currant laws of physics.
But there is NO new physics involved in this—it’s just the same old law of
conservation of energy, plus principles of basic machines that humans have
known about for millennia.
That’s the point that so many people find difficult to understand—they think
these machines are “impossible” because they seem to violate physics. In
fact the only thing violated is their misunderstanding of physics.
Robin Halligan
> In message <he06rs$hbc$1...@news.albasani.net>, Me wrote:
>
>> You're back to the "downwind faster than the wind" video, which I don't
>> believe.
>
> Why not? I have explained how it works; you have yet to explain why it
> cannot possibly work.
>
> Lots of people have built these sorts of machines, and got them to work; do
> you really believe theyοΏ½re all part of a gigantic conspiracy against you?
And lots of people have created videos of cell phones popping popcorn does
this mean next time i want a bowl of popcorn i just toss my celly in and
call myself?