Blowhards Sailing Downwind

There sure seems to be a lot of people in need of remedial
reading-for-content involved in the thread about sailing downwind.

First of all, in all the posts that I can stand to read, John Larkin is
NOT saying that his wind-propelled object would move FASTER than the
tailwind, just that it WOULD move in the direction of the tailwind.

Second, some people seem to misinterpret John's comments and argue against
their erroneous interpretation of John's comment, or seem to say (*seem
to*, because some of their rants are not very coherent) that an object
cannot be wind propelled at all by a tailwind, regardless of the
contrivance (e.g., windmill driving a gearbox).

Third, I don't know why John hasn't set these people straight, nor do I
understand why this thread has forked in two:

Direct Downwind Faster Than the Wind (DDWFTTW)

vs

Direct Downwind NOT Faster Than the Wind (ddwNfttw).

Those that are arguing against ddwNfttw probably would argue that an
electrical generator cannot supply the electricity that powers its own
field ELECTROmagnets.

Sheesh!

--- Joe

In article
none-3107101753220001_at_dialup-4.231.172.30.dial1.losangeles1.level3.net>,
none_at_given.now (Joe) wrote:

There sure seems to be a lot of people in need of remedial
reading-for-content involved in the thread about sailing downwind.

First of all, in all the posts that I can stand to read, John Larkin is
NOT saying that his wind-propelled object would move FASTER than the
tailwind, just that it WOULD move in the direction of the tailwind.

Second, some people seem to misinterpret John's comments and argue against
their erroneous interpretation of John's comment, or seem to say (*seem
to*, because some of their rants are not very coherent) that an object
cannot be wind propelled at all by a tailwind, regardless of the
contrivance (e.g., windmill driving a gearbox).

Third, I don't know why John hasn't set these people straight, nor do I
understand why this thread has forked in two:

Direct Downwind Faster Than the Wind (DDWFTTW)

vs

Direct Downwind NOT Faster Than the Wind (ddwNfttw).

Those that are arguing against ddwNfttw probably would argue that an
electrical generator cannot supply the electricity that powers its own
field ELECTROmagnets.

Sheesh!

--- Joe

Gulp!

I read too much of that thread and became addled. What John said is so
amazingly simple and obvious, and the people that were arguing against it
so confused, that it seems to have rubbed off on me.

John merely said that an object could be wind propelled directly into a
headwind by way of say, a windmill turning a gearbox and some wheels.

As long as the widmill is allowed to orient itself into the wind (they
usually swivel) the wind powered wheeled vehicle can go in *any*
direction.

On Sat, 31 Jul 2010 18:12:26 -0700, none_at_given.now (Joe) wrote:

In article
none-3107101753220001_at_dialup-4.231.172.30.dial1.losangeles1.level3.net>,
none_at_given.now (Joe) wrote:

There sure seems to be a lot of people in need of remedial
reading-for-content involved in the thread about sailing downwind.

First of all, in all the posts that I can stand to read, John Larkin is
NOT saying that his wind-propelled object would move FASTER than the
tailwind, just that it WOULD move in the direction of the tailwind.

Second, some people seem to misinterpret John's comments and argue against
their erroneous interpretation of John's comment, or seem to say (*seem
to*, because some of their rants are not very coherent) that an object
cannot be wind propelled at all by a tailwind, regardless of the
contrivance (e.g., windmill driving a gearbox).

Third, I don't know why John hasn't set these people straight, nor do I
understand why this thread has forked in two:

Direct Downwind Faster Than the Wind (DDWFTTW)

vs

Direct Downwind NOT Faster Than the Wind (ddwNfttw).

Those that are arguing against ddwNfttw probably would argue that an
electrical generator cannot supply the electricity that powers its own
field ELECTROmagnets.

Sheesh!

--- Joe
Gulp!

I read too much of that thread and became addled. What John said is so
amazingly simple and obvious, and the people that were arguing against it
so confused, that it seems to have rubbed off on me.

John merely said that an object could be wind propelled directly into a
headwind by way of say, a windmill turning a gearbox and some wheels.

Yes, I did say that. It's fairly obvious. What I don't know is how
fast it could move windward, and whether it could actually move faster
upwind than the wind speed. Apparently people have hit numbers like
60% or some such.

The straight downwind, faster than the wind, case probably works too.
It is sure counter-intuitive.

As long as the widmill is allowed to orient itself into the wind (they
usually swivel) the wind powered wheeled vehicle can go in *any*
direction.

Yup.

John

There sure seems to be a lot of people in need of remedial
reading-for-content involved in the thread about sailing downwind.

On Jul 31, 11:27 pm, John Larkin
jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
On Sat, 31 Jul 2010 18:12:26 -0700, n...@given.now (Joe) wrote:
In article
none-3107101753220...@dialup-4.231.172.30.dial1.losangeles1.level3.net>,
n...@given.now (Joe) wrote:

There sure seems to be a lot of people in need of remedial
reading-for-content involved in the thread about sailing downwind.

First of all, in all the posts that I can stand to read, John Larkin is
NOT saying that his wind-propelled object would move FASTER than the
tailwind, just that it WOULD move in the direction of the tailwind.

Second, some people seem to misinterpret John's comments and argue against
their erroneous interpretation of John's comment, or seem to say (*seem
to*, because some of their rants are not very coherent) that an object
cannot be wind propelled at all by a tailwind, regardless of the
contrivance (e.g., windmill driving a gearbox).

Third, I don't know why John hasn't set these people straight, nor do I
understand why this thread has forked in two:  

Direct Downwind Faster Than the Wind (DDWFTTW)

vs

Direct Downwind NOT Faster Than the Wind (ddwNfttw).

Those that are arguing against ddwNfttw probably would argue that an
electrical generator cannot supply the electricity that powers its own
field ELECTROmagnets.

Sheesh!

---  Joe

Gulp!

I read too much of that thread and became addled.  What John said is so
amazingly simple and obvious, and the people that were arguing against it
so confused, that it seems to have rubbed off on me.

John merely said that an object could be wind propelled directly into a
headwind by way of say, a windmill turning a gearbox and some wheels.

Yes, I did say that. It's fairly obvious. What I don't know is how
fast it could move windward, and whether it could actually move faster
upwind than the wind speed. Apparently people have hit numbers like
60% or some such.

The straight downwind, faster than the wind, case probably works too.
It is sure counter-intuitive.



As long as the widmill is allowed to orient itself into the wind (they
usually swivel) the wind powered wheeled vehicle can go in *any*
direction.

Yup.

John

So, what did you conclude about sailing downwind faster than the wind?
I read quite a few posts but still didn't figure it out. It seems the
propeller prop extracts kinetic energy from the moving car and propels
it faster, but that doesn't seem to provide any gain of kinetic
energy. How does the car accelerate faster than the wind going
downwind? Eventually, there would be a headwind if the car moved
faster than the wind, which would provide a drag. How do you explain
it in simple terms?

-Bill

On Sat, 31 Jul 2010 18:12:26 -0700, n...@given.now (Joe) wrote:
In article
none-3107101753220...@dialup-4.231.172.30.dial1.losangeles1.level3.net>,
n...@given.now (Joe) wrote:

There sure seems to be a lot of people in need of remedial
reading-for-content involved in the thread about sailing downwind.

First of all, in all the posts that I can stand to read, John Larkin is
NOT saying that his wind-propelled object would move FASTER than the
tailwind, just that it WOULD move in the direction of the tailwind.

Second, some people seem to misinterpret John's comments and argue against
their erroneous interpretation of John's comment, or seem to say (*seem
to*, because some of their rants are not very coherent) that an object
cannot be wind propelled at all by a tailwind, regardless of the
contrivance (e.g., windmill driving a gearbox).

Third, I don't know why John hasn't set these people straight, nor do I
understand why this thread has forked in two:  

Direct Downwind Faster Than the Wind (DDWFTTW)

vs

Direct Downwind NOT Faster Than the Wind (ddwNfttw).

Those that are arguing against ddwNfttw probably would argue that an
electrical generator cannot supply the electricity that powers its own
field ELECTROmagnets.

Sheesh!

---  Joe

Gulp!

I read too much of that thread and became addled.  What John said is so
amazingly simple and obvious, and the people that were arguing against it
so confused, that it seems to have rubbed off on me.

John merely said that an object could be wind propelled directly into a
headwind by way of say, a windmill turning a gearbox and some wheels.

Yes, I did say that. It's fairly obvious. What I don't know is how
fast it could move windward, and whether it could actually move faster
upwind than the wind speed. Apparently people have hit numbers like
60% or some such.

The straight downwind, faster than the wind, case probably works too.
It is sure counter-intuitive.



As long as the widmill is allowed to orient itself into the wind (they
usually swivel) the wind powered wheeled vehicle can go in *any*
direction.

Yup.

John

Imagine you're in the car and the groundspeed of the wind is 10 MPH.
The car is moving downwind at 10 MPH. The relative wind, what you
feel, is zero. You have a big lazy pusher propeller on a pylon, and it
sees zero relative wind.

So connect a generator to one wheel and make electricity. And use that
to turn a motor to spin the prop, in the push-the-car-downwind
direction. (Or use a mechanical linkage, same thing.) The wheel is
spinning fast, so generates a decent amount of power. You only have to
turn the prop a little to make thrust. The result is acceleration
downwind.

The trick is that the prop is pushing against the tailwind, and
against a zero relative wind. It doesn't have to work very hard to
make a goodly chunk of thrust... less than the wheel drag needed to
make the power.

Another way to look at it: instead of a tailwind, imagine a

So, what did you conclude about sailing downwind faster than the wind?
I read quite a few posts but still didn't figure it out. It seems the
propeller prop extracts kinetic energy from the moving car and propels
it faster, but that doesn't seem to provide any gain of kinetic
energy. How does the car accelerate faster than the wind going
downwind? Eventually, there would be a headwind if the car moved
faster than the wind, which would provide a drag. How do you explain
it in simple terms?

Really???
Rather than a prop, use another wheel, a 5th one, driving against the
pavement. Why not?

On Jul 31, 11:27 pm, John Larkin
jjlar...@highNOTlandTHIStechnologyPART.com> wrote:

On Sat, 31 Jul 2010 18:12:26 -0700, n...@given.now (Joe) wrote:

In article
none-3107101753220...@dialup-4.231.172.30.dial1.losangeles1.level3.net>,
n...@given.now (Joe) wrote:

There sure seems to be a lot of people in need of remedial
reading-for-content involved in the thread about sailing downwind.

First of all, in all the posts that I can stand to read, John Larkin is
NOT saying that his wind-propelled object would move FASTER than the
tailwind, just that it WOULD move in the direction of the tailwind.

Second, some people seem to misinterpret John's comments and argue against
their erroneous interpretation of John's comment, or seem to say (*seem
to*, because some of their rants are not very coherent) that an object
cannot be wind propelled at all by a tailwind, regardless of the
contrivance (e.g., windmill driving a gearbox).

Third, I don't know why John hasn't set these people straight, nor do I
understand why this thread has forked in two:

Direct Downwind Faster Than the Wind (DDWFTTW)

vs

Direct Downwind NOT Faster Than the Wind (ddwNfttw).

Those that are arguing against ddwNfttw probably would argue that an
electrical generator cannot supply the electricity that powers its own
field ELECTROmagnets.

Sheesh!

--- Joe

Gulp!

I read too much of that thread and became addled. What John said is so
amazingly simple and obvious, and the people that were arguing against it
so confused, that it seems to have rubbed off on me.

John merely said that an object could be wind propelled directly into a
headwind by way of say, a windmill turning a gearbox and some wheels.

Yes, I did say that. It's fairly obvious. What I don't know is how
fast it could move windward, and whether it could actually move faster
upwind than the wind speed. Apparently people have hit numbers like
60% or some such.

The straight downwind, faster than the wind, case probably works too.
It is sure counter-intuitive.




As long as the widmill is allowed to orient itself into the wind (they
usually swivel) the wind powered wheeled vehicle can go in *any*
direction.

Yup.

John


So, what did you conclude about sailing downwind faster than the wind?
I read quite a few posts but still didn't figure it out. It seems the
propeller prop extracts kinetic energy from the moving car and propels
it faster, but that doesn't seem to provide any gain of kinetic
energy. How does the car accelerate faster than the wind going
downwind? Eventually, there would be a headwind if the car moved
faster than the wind, which would provide a drag. How do you explain
it in simple terms?

-Bill
Vacuum motors

John Larkin wrote:

Imagine you're in the car and the groundspeed of the wind is 10 MPH.
The car is moving downwind at 10 MPH. The relative wind, what you
feel, is zero. You have a big lazy pusher propeller on a pylon, and it
sees zero relative wind.

So connect a generator to one wheel and make electricity. And use that
to turn a motor to spin the prop, in the push-the-car-downwind
direction. (Or use a mechanical linkage, same thing.) The wheel is
spinning fast, so generates a decent amount of power. You only have to
turn the prop a little to make thrust. The result is acceleration
downwind.

Really???
Rather than a prop, use another wheel, a 5th one, driving against the
pavement. Why not?

The trick is that the prop is pushing against the tailwind, and
against a zero relative wind. It doesn't have to work very hard to
make a goodly chunk of thrust... less than the wheel drag needed to
make the power.

Is this a joke?

Another way to look at it: instead of a tailwind, imagine a

Imagine a calm, no-wind day, and a propeller, powered by a generator
attached to one of the wheels, pushes a car along.

On Sat, 14 Aug 2010 00:06:39 -0700, Beryl <fourl_at_road.net> wrote:

John Larkin wrote:

Imagine you're in the car and the groundspeed of the wind is 10 MPH.
The car is moving downwind at 10 MPH. The relative wind, what you
feel, is zero. You have a big lazy pusher propeller on a pylon, and it
sees zero relative wind.

So connect a generator to one wheel and make electricity. And use that
to turn a motor to spin the prop, in the push-the-car-downwind
direction. (Or use a mechanical linkage, same thing.) The wheel is
spinning fast, so generates a decent amount of power. You only have to
turn the prop a little to make thrust. The result is acceleration
downwind.
Really???
Rather than a prop, use another wheel, a 5th one, driving against the
pavement. Why not?

Because the pavement is moving 10 mph relative to the car.

So it takes a lot of power to push the cart using a driven wheen,

obviously more power than you can extract from a different wheel. But it's easy to
push against the tailwind because it is moving AT THE SAME SPEED as
the car. It's like pushing against the truck in my example.

It's just an impedance matching problem.


The trick is that the prop is pushing against the tailwind, and
against a zero relative wind. It doesn't have to work very hard to
make a goodly chunk of thrust... less than the wheel drag needed to
make the power.
Is this a joke?

To you, apparently.

Another way to look at it: instead of a tailwind, imagine a
Imagine a calm, no-wind day, and a propeller, powered by a generator
attached to one of the wheels, pushes a car along.

Wind-powered cars tend to not work when there's no wind.

The car is WIND POWERED. It extracts energy from the wind. It violates
no conservation principles.

You snipped my truck and electronics examples.

John

On Aug 13, 9:53 pm, John Larkin
jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
On Fri, 13 Aug 2010 21:16:14 -0700 (PDT), Bill Bowden



wrongaddr...@att.net> wrote:
On Jul 31, 11:27 pm, John Larkin
jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
On Sat, 31 Jul 2010 18:12:26 -0700, n...@given.now (Joe) wrote:
In article
none-3107101753220...@dialup-4.231.172.30.dial1.losangeles1.level3.net>,
n...@given.now (Joe) wrote:

There sure seems to be a lot of people in need of remedial
reading-for-content involved in the thread about sailing downwind.

First of all, in all the posts that I can stand to read, John Larkin is
NOT saying that his wind-propelled object would move FASTER than the
tailwind, just that it WOULD move in the direction of the tailwind.

Second, some people seem to misinterpret John's comments and argue against
their erroneous interpretation of John's comment, or seem to say (*seem
to*, because some of their rants are not very coherent) that an object
cannot be wind propelled at all by a tailwind, regardless of the
contrivance (e.g., windmill driving a gearbox).

Third, I don't know why John hasn't set these people straight, nor do I
understand why this thread has forked in two:  

Direct Downwind Faster Than the Wind (DDWFTTW)

vs

Direct Downwind NOT Faster Than the Wind (ddwNfttw).

Those that are arguing against ddwNfttw probably would argue that an
electrical generator cannot supply the electricity that powers its own
field ELECTROmagnets.

Sheesh!

---  Joe

Gulp!

I read too much of that thread and became addled.  What John said is so
amazingly simple and obvious, and the people that were arguing against it
so confused, that it seems to have rubbed off on me.

John merely said that an object could be wind propelled directly into a
headwind by way of say, a windmill turning a gearbox and some wheels.

Yes, I did say that. It's fairly obvious. What I don't know is how
fast it could move windward, and whether it could actually move faster
upwind than the wind speed. Apparently people have hit numbers like
60% or some such.

The straight downwind, faster than the wind, case probably works too.
It is sure counter-intuitive.

As long as the widmill is allowed to orient itself into the wind (they
usually swivel) the wind powered wheeled vehicle can go in *any*
direction.

Yup.

John

So, what did you conclude about sailing downwind faster than the wind?
I read quite a few posts but still didn't figure it out. It seems the
propeller prop extracts kinetic energy from the moving car and propels
it faster, but that doesn't seem to provide any gain of kinetic
energy. How does the car accelerate faster than the wind going
downwind? Eventually, there would be a headwind if the car moved
faster than the wind, which would provide a drag. How do you explain
it in simple terms?

-Bill

Imagine you're in the car and the groundspeed of the wind is 10 MPH.
The car is moving downwind at 10 MPH. The relative wind, what you
feel, is zero. You have a big lazy pusher propeller on a pylon, and it
sees zero relative wind.

So connect a generator to one wheel and make electricity. And use that
to turn a motor to spin the prop, in the push-the-car-downwind
direction. (Or use a mechanical linkage, same thing.) The wheel is
spinning fast, so generates a decent amount of power. You only have to
turn the prop a little to make thrust. The result is acceleration
downwind.

The trick is that the prop is pushing against the tailwind, and
against a zero relative wind. It doesn't have to work very hard to
make a goodly chunk of thrust... less than the wheel drag needed to
make the power.

Another way to look at it: instead of a tailwind, imagine a truck
behind you, going 10 MPH and pushing your car. You pull out a big
hydraulic jack and arrange to mount it on your car and push against
the truck. Get the hydraulic pressure to pump the jack off one of your
spinning wheels. Wheel spins, pumps jack, pushes the car and the truck
apart. Now the car is moving faster than the truck, ahead of the
truck. Same idea: push against the tailwind instead of the truck, use
a prop instead of a jack.

You can do this in an electronic circuit, too:

http://www.panoramio.com/photo/38968555

Imagine the 12 volt battery is equivalent to a 12 MPH wind. Suppose
the DC/DC converter inputs 17 volts (on the right) and outputs 5 volts
(on the left). The stacked 12v battery and 5v dc/dc output make 17
volts, namely V+. The 17 volts (17 to ground!) powers the input of the
dc/dc converter. The voltage stepdown allows a current step-up, so
there's plenty of V+ amps available to power the converter input.
Tricky, but no paradox, no violation of conservation of energy. You
could buy a $6, 12v to 5v isolated dc/dc converter from Mouser and
build this.

You can push that around a little

http://www.panoramio.com/photo/38968667

and simulate a car that uses a propeller to drive the wheels and move
into the wind.

Cute trick, but not worth getting obsessed about. As some people are.

John

Yes, good ideas. But it the case of the truck pushing the car, there
seems to be some energy storage prior to using the jack to push the
car away from the truck and go faster than the truck.

the same idea and run a generator to charge a battery for a couple
hours (while being pushed by the truck), and then use a motor to go
much faster than the truck. So, it appears possible to go much faster
than the wind downhill, using some energy storage technique supplied
by the wind.

On Fri, 13 Aug 2010 21:16:14 -0700 (PDT), Bill Bowden



wrongaddr...@att.net> wrote:
On Jul 31, 11:27 pm, John Larkin
jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
On Sat, 31 Jul 2010 18:12:26 -0700, n...@given.now (Joe) wrote:
In article
none-3107101753220...@dialup-4.231.172.30.dial1.losangeles1.level3.net>,
n...@given.now (Joe) wrote:

There sure seems to be a lot of people in need of remedial
reading-for-content involved in the thread about sailing downwind.

First of all, in all the posts that I can stand to read, John Larkin is
NOT saying that his wind-propelled object would move FASTER than the
tailwind, just that it WOULD move in the direction of the tailwind.

Second, some people seem to misinterpret John's comments and argue against
their erroneous interpretation of John's comment, or seem to say (*seem
to*, because some of their rants are not very coherent) that an object
cannot be wind propelled at all by a tailwind, regardless of the
contrivance (e.g., windmill driving a gearbox).

Third, I don't know why John hasn't set these people straight, nor do I
understand why this thread has forked in two:  

Direct Downwind Faster Than the Wind (DDWFTTW)

vs

Direct Downwind NOT Faster Than the Wind (ddwNfttw).

Those that are arguing against ddwNfttw probably would argue that an
electrical generator cannot supply the electricity that powers its own
field ELECTROmagnets.

Sheesh!

---  Joe

Gulp!

I read too much of that thread and became addled.  What John said is so
amazingly simple and obvious, and the people that were arguing against it
so confused, that it seems to have rubbed off on me.

John merely said that an object could be wind propelled directly into a
headwind by way of say, a windmill turning a gearbox and some wheels.

Yes, I did say that. It's fairly obvious. What I don't know is how
fast it could move windward, and whether it could actually move faster
upwind than the wind speed. Apparently people have hit numbers like
60% or some such.

The straight downwind, faster than the wind, case probably works too.
It is sure counter-intuitive.

As long as the widmill is allowed to orient itself into the wind (they
usually swivel) the wind powered wheeled vehicle can go in *any*
direction.

Yup.

John

So, what did you conclude about sailing downwind faster than the wind?
I read quite a few posts but still didn't figure it out. It seems the
propeller prop extracts kinetic energy from the moving car and propels
it faster, but that doesn't seem to provide any gain of kinetic
energy. How does the car accelerate faster than the wind going
downwind? Eventually, there would be a headwind if the car moved
faster than the wind, which would provide a drag. How do you explain
it in simple terms?

-Bill

Imagine you're in the car and the groundspeed of the wind is 10 MPH.
The car is moving downwind at 10 MPH. The relative wind, what you
feel, is zero. You have a big lazy pusher propeller on a pylon, and it
sees zero relative wind.

So connect a generator to one wheel and make electricity. And use that
to turn a motor to spin the prop, in the push-the-car-downwind
direction. (Or use a mechanical linkage, same thing.) The wheel is
spinning fast, so generates a decent amount of power. You only have to
turn the prop a little to make thrust. The result is acceleration
downwind.

The trick is that the prop is pushing against the tailwind, and
against a zero relative wind. It doesn't have to work very hard to
make a goodly chunk of thrust... less than the wheel drag needed to
make the power.

Another way to look at it: instead of a tailwind, imagine a truck
behind you, going 10 MPH and pushing your car. You pull out a big
hydraulic jack and arrange to mount it on your car and push against
the truck. Get the hydraulic pressure to pump the jack off one of your
spinning wheels. Wheel spins, pumps jack, pushes the car and the truck
apart. Now the car is moving faster than the truck, ahead of the
truck. Same idea: push against the tailwind instead of the truck, use
a prop instead of a jack.

You can do this in an electronic circuit, too:

http://www.panoramio.com/photo/38968555

Imagine the 12 volt battery is equivalent to a 12 MPH wind. Suppose
the DC/DC converter inputs 17 volts (on the right) and outputs 5 volts
(on the left). The stacked 12v battery and 5v dc/dc output make 17
volts, namely V+. The 17 volts (17 to ground!) powers the input of the
dc/dc converter. The voltage stepdown allows a current step-up, so
there's plenty of V+ amps available to power the converter input.
Tricky, but no paradox, no violation of conservation of energy. You
could buy a $6, 12v to 5v isolated dc/dc converter from Mouser and
build this.

You can push that around a little

http://www.panoramio.com/photo/38968667

and simulate a car that uses a propeller to drive the wheels and move
into the wind.

Cute trick, but not worth getting obsessed about. As some people are.

John