http://www.vacantisw.com/foildesign.htm

actual intelligent discussion of keel design, the various
factors influencing how keels work, and a very clear
explanation of the Reynolds number.

I suggest that certain people read it very very studiously
to find the answer as to whether wing keels lift the boat.
Yes or no?

DSK

DSK wrote:
http://www.vacantisw.com/foildesign.htm

actual intelligent discussion of keel design, the various
factors influencing how keels work, and a very clear
explanation of the Reynolds number.

I suggest that certain people read it very very studiously
to find the answer as to whether wing keels lift the boat.
Yes or no?

DSK

Someone think at 8 kt a lead wing is going to provide lift?
Would both side of the wing provide equal lift on a heel?
Wouldent that cause the boat to heel more?

I know nothing about winged keels. I just thought it was a better way
to put weight down low and keeping a shallow draft. Sorta like thoses
boats that have two keels.

Joe

Doug,

Your article by Vacanti talks volumes of LIFT. You should be able to
answer your own question. Does all the LIFT describe in the article
LIFT the boat? Of course not. Does it help increase Speed? Maybe. Maybe
Not.

Doug, I've spent a life time in the Oil refinery measuring liquid flows.
Orifice Plates designed using Reynold numbers
You and Vacanti have not made mention of the large "Gray Area" of the
Reynolds #
between laminar flow and turbulent flow. It is right in this area that
our keels live.
You also ignored the "Newtonian" factor and just talked Reynolds and
Bernoulli. Let us not forget that each created lifting force has a equal
and opposite force. It is important to identify these forces.

A wind tunnel isn't necessary for the speeds we are dealing with. A
level of water, in the bath tub and shaker of talcum powder on the
surface of the water will show these actions and how they are shedded.

A "Wing Keel" works but in needs motion to make it work. Motion thru the
water. In a "Drifter" a straight fin will outperform it but as motion
increase it will increase its effect and yes it will be more effective.

I think I've said enough for an Old Beached Sailor. I'll back out of
this discussion




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

Thom Stewart wrote:

Doug,

Your article by Vacanti talks volumes of LIFT. You should be able to
answer your own question. Does all the LIFT describe in the article
LIFT the boat?

That's why I used the word "up"


Doug, I've spent a life time in the Oil refinery measuring liquid flows.
Orifice Plates designed using Reynold numbers
You and Vacanti have not made mention of the large "Gray Area" of the
Reynolds #
between laminar flow and turbulent flow.

Actually it does. Almost all foils will have at least a
small section of laminar flow, some rather odd foils are
designed to work almost entirely in laminar flow... even
odder ones with none. Ever seen a super-cavitating prop?


You also ignored the "Newtonian" factor and just talked Reynolds and
Bernoulli.

Actually, I didn't. I didn't write that web page


... Let us not forget that each created lifting force has a equal
and opposite force. It is important to identify these forces.


Forces are not always equal & opposite, though. If they
were, nothing could ever move. For example, the force
exerted by the wind on the sails heels the boat & drives it
forward. The boat goes faster *until* it creates enough drag
to equal the drive. At that point, forces are equal.

Have you worked on control systems that cycled or hunted? An
example of how difficult it can be to get forces to equalize
smoothly?

Fresh Breezes- Doug King

Yes Doug,
---------------------------------------------
Have you worked on control systems that cycled or hunted? An example of
how difficult it can be to get forces to equalize smoothly?
-------------------------------------------------
That is why PB, Reset, & Dev have been added to those systems




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

Thom Stewart wrote:
Yes Doug,
---------------------------------------------
Have you worked on control systems that cycled or hunted? An example of
how difficult it can be to get forces to equalize smoothly?
-------------------------------------------------
That is why PB, Reset, & Dev have been added to those systems


Proportional Band also known as Gain

Reset rate can be a very effective way of stopping the
system from hunting, but can also be over done so that the
system is either too fast or too slow... ask Bobsprit which,
after all I've been busted for talking gibberish.

Get him to explain what Dev stands for and what it does too.
I'd like to read that myself.

Regards
Doug King

Doug,

I think you have Reset & Deviative mixed up but maybe not.
Proportional Band limits the amount of response to the original Off Set
or a proportional amount.

PB will keep cycling down but has a tendancy to "Droop" Not return to
its original value. RESET will make additional correction to return to
original point but with a new correction force.

Deviative (Like Pepper) needs to be added carefully. It is a ampilifier
of the original off set. It forces the PB to a greater correction force.

Doug, that is a rather quick and dirty explaination. If you want more
contact me off line




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