Well, here you were...again!
 

Loco;

--------------------------------------------
Two, any wing keel must not contribute any force in any direction since
that force would only slow the boat down.
______________________________

What kind of a stupid statement is that?
Any an all keels creates force and slows a boat down but they are a
necessary evil to give direction and stability. With or without wings.
A fixed keel is a creation of drag as well as lift.

I can only thing of the saying; " No one is as blind as a person who
refuses to see!"




http://community.webtv.net/tassail/ThomPage

Well, here you were...again!
 

"Ringmaster" wrote in message
ps.com...

Thom Stewart wrote:

Loco, I think it's time for you to examine all the fact once again. I
do believe you're missing something

I have done some reading on wing keels over the years. I
particularly remember Paul Yates writings on this type of foil. Paul
Yates was the designer of the Merit line of sailboats and the only 3
time winner of the MORC International Championships. He designed a
wing keel for the Merit 23. This was a full race version of the 22
(actually the same hull) He stated a number of facts with 2 that stick
out in my mind. One, the winged keels that have appeared on every
production boat have NOTHING to do design wise or performance wise with
the winged keels that were used on the 12 meter AC boats. Two, any
wing keel must not contribute any force in any direction since that
force would only slow the boat down. [snip]

Loco,
Good discussion!
Isn't it all about forces (i.e., producing and manipulating them)? If no
force is contributed, in any direction, what is the point in the wing keel?
Even a lead weight produces a useful force.
Scout

Well, here you were...again!
 

Thom Stewart wrote:
You're the only one talking about get a hull on plane. I showed you a
picture of my 2nd boat with a semi planning Hull.

That isn't what I'm talking about. I'm talking about the lifting force
created down wind, the righting force created when heeled.

Sailboats need righting force when going downwind too. If
there were none, they would tip over.

A wing keel does not make a boat go any faster by lifting it
out of the water. You don't get lift for free. Lift comes at
the expense of drag, remember? The drag created by the wing
in the process of generating lift would be greater than any
drag saved by lifting the boat... otherwise you'd have a
perpetual motion machine.

Thom, you also stated that you angled the wings down to aid
the boat going upwind... how is that suddenly going to lift
the boat when going downwind? Adjustable flaps?



The Wing Keel works. You have to know how and why it works and then
learn to sail your vessel accordingly.

Wing keels work a bunch of different ways. One is that they
get more mass down low, improving stability and
sail-carrying power. More power = more speed. Another way
they "work" is to reduce drag at the keel tip by reducing
what's called the tip vortex: a large mass of water that is
swirled at the bottom edge & tip of the keel because of the
merging of the high and low pressure zones on the leeward &
windward sides of the keel. It takes a lot of energy to get
this mass swirling, that energy comes from the boat's
forward motion and is felt by the boat as drag.

Thom I was impressed that you remembered the Aussies passing
Dennis Conner on the downwind leg. That was actually the
biggest advantage Australia 2 had over Liberty; downwind she
could go lower & faster in the same pressure.


....Is it faster; probably not, but
it is a more comfortable ride and a decent wind is equal to or better
than a straight Fin. It has to have a flow over it.


One way I think a wing keel helps is to dampen pitching.
I've noticed this on several different boats... this can
make the boat faster as well as more comfortable.

A big disadvantage of wing keels here in the Southeast is
that they get stuck in the bottom. I have also proven that
you can take a 5' draft fin keel boat into places that a
4.5' wing keel can't go. And once stuck, wing keels are
harder to get free.

Fresh Breezes- Doug King

Well, here you were...again!
 

Ringmaster wrote:
I have done some reading on wing keels over the years. I
particularly remember Paul Yates writings on this type of foil. Paul
Yates was the designer of the Merit line of sailboats and the only 3
time winner of the MORC International Championships. He designed a
wing keel for the Merit 23. This was a full race version of the 22
(actually the same hull) He stated a number of facts with 2 that stick
out in my mind. One, the winged keels that have appeared on every
production boat have NOTHING to do design wise or performance wise with
the winged keels that were used on the 12 meter AC boats.

True. The wing keels on some racing boats are very complex
with more computer design work and testing than the average
moon rocket.


.....As it stands at the present I don't know of one planing
sportboat that uses a winged keel.

The new Moths?
http://moth.iointegration.com/

But I don't think they are sportboats, officially.

Fresh Breezes- Doug King

Well, here you were...again!
 

"Capt" Rob wrote:
Our wing has 19% more wetted surface than the standard 6 foot keel.



According to who?



BeneteauUSA. E-mail them if you like. Or simply use your head and look
at the two keels. The wing is a foot shorter, but it carries the wings,
side surface + flat keel bottom.



RB
35s5
NY

Well, here you were...again!
 

OzOne wrote:
Doug, IIRC, The biggest advantage Benny achieved with his wing was as
a 'cheater'.

Oh, I dunno... Dennis Conner and the New York YC certainly
thought it was cheating. Everybody else thought it was cool.

AmCup yachts rating formula took draft and keel weight into
consideration and Benny worked out that he could place the extra
weight in a wing arrangement on a shorter keel and gan measurement
advantages in other areas including sailplan.

There is also a limit on draft in the 12-Meter rule. One of
the 'problems' with the wing is that it is deeper when
heeled, and Australia 2 was protested on those grounds.


When heeled, the wing still gave the depth required for good 'grip'
uphill while giving reduced draft downhill.
Of cousre there were the other advantages, but a lot of work was
required to reduce drag from the possibility of generating an extra
tip vortex on the keel.

As I understand it, the way the tip vortex reduction works
is that the two tips generate counteracting vortices. There
is more turbulent flow, but less loss of differential
pressure from leeward (high pressure) to windward (low
pressure) and less energy transferred into the water. "Less
energy transfer" is a fancy way of saying less drag.


I know there are a couple of excellent studies online, but I just
can't recall them this evening.


Here's a pretty good one, although this begins far beyond
where mass-produced wing keels leave off.

Back to the original:
The international committee in charge of approving the
measurement & rating of 12-Meters had the power to stop
Australia 2 before letting her enter a single race... the
question of how to measure the girth at hull stations,
whether to include the wings in the draft, etc etc...
complex issue, but they decided to let it be decided on the
water.

The funny thing is that Dennis Conner was cheating too, he
had an illegal mast and had Liberty measured in two
different configurations, so effectively she was two
different boats. He whined & bitched about being cheated out
of the Cup, but the truth is he sailed an awesome series and
almost won anyway. If they had been smart, the Race
Committee could have enforced their own draft rule by
putting at least part of the course in water that was deep
enough for Liberty's conventional keel but not quite for
Australia 2's wings (which were very large, something like
18' span IIRC).

BTW I never did understand the name change with Bob Miller.
He was definitely an outstanding genius and a great sailor.

Fresh Breezes- Doug King

Well, here you were...again!
 

A wing keel does not make a boat go any faster by lifting it
out of the water. You don't get lift for free. Lift comes at
the expense of drag, remember? The drag created by the wing
in the process of generating lift would be greater than any
drag saved by lifting the boat... otherwise you'd have a
perpetual motion machine.


Charlie Morgan wrote:
Yeah! That's why no one has ever succesfully built a hydrofoil boat.
And you can stop trying to invent the airplane. too! Sails on a
sailboat will only make it go backwards due to all the drag overcoming
the lift.


So you believe a wing keel does make boats go fster by
lifting it up?

DSK

Well, here you were...again!
 

"DSK" wrote in message
...
Thom Stewart wrote:
You're the only one talking about get a hull on plane. I showed you a
picture of my 2nd boat with a semi planning Hull.

That isn't what I'm talking about. I'm talking about the lifting force
created down wind, the righting force created when heeled.

Sailboats need righting force when going downwind too. If there were none,
they would tip over.

A wing keel does not make a boat go any faster by lifting it out of the
water. You don't get lift for free. Lift comes at the expense of drag,
remember? The drag created by the wing in the process of generating lift
would be greater than any drag saved by lifting the boat... otherwise
you'd have a perpetual motion machine.

" . . . and that stupid perpetual motion machine that Lisa made just keeps
going faster and faster. Lisa! In this house we obey the laws of
thermodynamics!"
Homer Simpson in "Disbanding of the PTA"

Well, here you were...again!
 

... The drag created by the wing in the process of generating lift
would be greater than any drag saved by lifting the boat... otherwise
you'd have a perpetual motion machine.


Scout wrote:
" . . . and that stupid perpetual motion machine that Lisa made just keeps
going faster and faster. Lisa! In this house we obey the laws of
thermodynamics!"
Homer Simpson in "Disbanding of the PTA"


If there was a perpetual motion machine that mowed the lawn,
I'd be in favor of it.

You wanna try to explain the difference between a wing keel
and a hydrofoil to ChuckieM/Krusty/BB? Other than that one
is very heavy and increases stability by use of much lead,
and the other is as light as can be made for the strength
needed?

DSK

Well, here you were...again!
 

DSK wrote:
Ringmaster wrote:
I have done some reading on wing keels over the years. I
particularly remember Paul Yates writings on this type of foil. Paul
Yates was the designer of the Merit line of sailboats and the only 3
time winner of the MORC International Championships. He designed a
wing keel for the Merit 23. This was a full race version of the 22
(actually the same hull) He stated a number of facts with 2 that stick
out in my mind. One, the winged keels that have appeared on every
production boat have NOTHING to do design wise or performance wise with
the winged keels that were used on the 12 meter AC boats.

True. The wing keels on some racing boats are very complex
with more computer design work and testing than the average
moon rocket.


.....As it stands at the present I don't know of one planing
sportboat that uses a winged keel.

The new Moths?
http://moth.iointegration.com/

But I don't think they are sportboats, officially.

looks sporty to me...Wow what a blast, but expect to get wet everytime.
With a dozen gyros and computor it would be fun to make a similar 60
fter

Joe

Fresh Breezes- Doug King