On Sun, 14 Oct 2007 14:17:54 +0100, Andy Champ
wrote:

Steve Firth wrote:
Wilbur Hubbard wrote:

It's good to see a
Brit is the first to insert his foot into his mouth.

Ah no, that would have been you, as usual, Craptain. I bet you think
that ice yachts can't reach 146mph either.

Wilbur seems to have it right this time. Either the article is
misquoted, very badly written, or just plain wrong.

An apparent wind from dead ahead can add nothing but a force directly
astern.

The case where a true wind from ahead can be used to drive a windmill
that can drive a propeller to propel the vessel is different; but this
requires a true wind.

BTW ice yachts cannot make 146mph *directly* upwind.

Andy

This is got to be one of the stupidest threads I have ever read.
Anyone who has ever been in a boat motoring directly into the wind
knows that the sail produces no forward force. I can only assume that
the individuals who argue otherwise have never been a boat under those
conditions.

In this one (and perhaps only) instance I must admit that I agree with
Willie.

BTW ice boats (yachts?) don't do 146 MPH directly down wind either.




Bruce in Bangkok
(brucepaigeATgmailDOTcom)

wrote:
On Sun, 14 Oct 2007 14:17:54 +0100, Andy Champ
wrote:

Steve Firth wrote:
Wilbur Hubbard wrote:

It's good to see a
Brit is the first to insert his foot into his mouth.
Ah no, that would have been you, as usual, Craptain. I bet you think
that ice yachts can't reach 146mph either.
Wilbur seems to have it right this time. Either the article is
misquoted, very badly written, or just plain wrong.

An apparent wind from dead ahead can add nothing but a force directly
astern.

The case where a true wind from ahead can be used to drive a windmill
that can drive a propeller to propel the vessel is different; but this
requires a true wind.

BTW ice yachts cannot make 146mph *directly* upwind.

Andy

This is got to be one of the stupidest threads I have ever read.
Anyone who has ever been in a boat motoring directly into the wind
knows that the sail produces no forward force. I can only assume that
the individuals who argue otherwise have never been a boat under those
conditions.

The advertisement never claimed to impart forward force going directly
into the wind. All they claimed was that they could somehow decrease the
load on the motor or increase the efficiency of the system. Even the
slightest lift on the hull could produce this, a heel to a more
effecient hull shape could also do it.

We can't tell if it's true with this boat because we don't really know
what they are talking about, but it seems very very possible, though
almost surely the effect will be trivial. So the advertisement is
probably true.

Stephen

On Sun, 14 Oct 2007 20:37:22 -0700, Stephen Trapani
wrote:

The advertisement never claimed to impart forward force going directly
into the wind. All they claimed was that they could somehow decrease the
load on the motor or increase the efficiency of the system.

Those two sentences mean the same thing. Raising a sail when headed
directly into the wind will increase the aerodynamic drag acting on
the boat, and reduce speed.

Casady

Richard Casady wrote:
On Sun, 14 Oct 2007 20:37:22 -0700, Stephen Trapani
wrote:

The advertisement never claimed to impart forward force going directly
into the wind. All they claimed was that they could somehow decrease the
load on the motor or increase the efficiency of the system.

Those two sentences mean the same thing. Raising a sail when headed
directly into the wind will increase the aerodynamic drag acting on
the boat, and reduce speed.

Putting wings on a plane increases aerodynamic drag acting on the plane,
yet it increases the speed, right?

Stephen

Stephen Trapani wrote:

Putting wings on a plane increases aerodynamic drag acting on the plane,
yet it increases the speed, right?

Stephen

I don't know that much but I think this statement is incorrect.

Putting the wings on a plane does not increase the speed. It creates
vertical lift which makes the plane go upward but it has to add to the
drag and in fact slow the plane down. The reduced speed is of no concern
to the plane as long as it doesn't slow it down enough to loose the
lift. It can compensate for the loss of speed by putting more power
anyway and getting more lift in the process which is what it is trying
to do in the first place. As it goes further up it reaches thinner air
which will cause less drag...

In other words, one doesn't put wings on a plane to make it go faster
but to make it go higher..

Jeannette

Jeannette wrote:
Stephen Trapani wrote:

Putting wings on a plane increases aerodynamic drag acting on the
plane, yet it increases the speed, right?

Stephen

I don't know that much but I think this statement is incorrect.

Putting the wings on a plane does not increase the speed. It creates
vertical lift which makes the plane go upward but it has to add to the
drag and in fact slow the plane down. The reduced speed is of no concern
to the plane as long as it doesn't slow it down enough to loose the
lift. It can compensate for the loss of speed by putting more power
anyway and getting more lift in the process which is what it is trying
to do in the first place. As it goes further up it reaches thinner air
which will cause less drag...

In other words, one doesn't put wings on a plane to make it go faster
but to make it go higher..

The wings take the plane off the ground into a different medium,
reducing resistance, increasing the speed. Same thing happens with a
hydrofoil.

Stephen

In article ,
Stephen Trapani wrote:

Richard Casady wrote:
On Sun, 14 Oct 2007 20:37:22 -0700, Stephen Trapani
wrote:

The advertisement never claimed to impart forward force going directly
into the wind. All they claimed was that they could somehow decrease the
load on the motor or increase the efficiency of the system.

Those two sentences mean the same thing. Raising a sail when headed
directly into the wind will increase the aerodynamic drag acting on
the boat, and reduce speed.

Putting wings on a plane increases aerodynamic drag acting on the plane,
yet it increases the speed, right?

Stephen

Actually, NO, putting wings on the plane does NOT increase its speed,
unless one considers the difference in Drag due to Alltitude. If putting
wings, on increased the speed, then missiles would have wings, which
they don't.

Duh......

You wrote:
In article ,
Stephen Trapani wrote:

Richard Casady wrote:
On Sun, 14 Oct 2007 20:37:22 -0700, Stephen Trapani
wrote:

The advertisement never claimed to impart forward force going directly
into the wind. All they claimed was that they could somehow decrease the
load on the motor or increase the efficiency of the system.
Those two sentences mean the same thing. Raising a sail when headed
directly into the wind will increase the aerodynamic drag acting on
the boat, and reduce speed.
Putting wings on a plane increases aerodynamic drag acting on the plane,
yet it increases the speed, right?

Stephen

Actually, NO, putting wings on the plane does NOT increase its speed,
unless one considers the difference in Drag due to Alltitude.

Bingo. Getting it off the ground decreases resistance, increasing the
speed. Same thing can happen with a boat.

Stephen

On Mon, 15 Oct 2007 07:31:20 -0700, Stephen Trapani
wrote:

Putting wings on a plane increases aerodynamic drag acting on the plane,
yet it increases the speed, right?

Absolutely not. For the highest possible speed you use the smallest
wing you can get away with. You do have to land. A bigger wing is
favored for short takeoff and landing, for example. A bigger wing will
make for a steeper angle of climb, at a slower speed. To increase rate
of climb, more engine power is needed. No free lunch anywhere, a good
rule to remember. The only real way to increase performance in all
areas, is to make it lighter. You can have strong, light, or cheap.
Pick any two.

Casady

Richard Casady wrote:
On Mon, 15 Oct 2007 07:31:20 -0700, Stephen Trapani
wrote:

Putting wings on a plane increases aerodynamic drag acting on the plane,
yet it increases the speed, right?

Absolutely not. For the highest possible speed you use the smallest
wing you can get away with. You do have to land. A bigger wing is
favored for short takeoff and landing, for example. A bigger wing will
make for a steeper angle of climb, at a slower speed. To increase rate
of climb, more engine power is needed. No free lunch anywhere, a good
rule to remember. The only real way to increase performance in all
areas, is to make it lighter. You can have strong, light, or cheap.
Pick any two.

Getting the plane off the ground doesn't decrease it's resistance and
increase it's speed?

Stephen