Veal Heel for Multihull Foilers

Can we roll this discussion back one step - I want to clarify the distinction between righting moment (RM - with lots of thoughts above) and lift to windward (not discussed yet I don't think). I have got some of the ideas on the table here a bit confused between the two...

When the Moth heels to windward (no matter what the skipper's name ;-) the foils provide lift both vertically (up out of the water) and horizontally (to windward).

I had previously thought this was the major benefit of the "___heel" - which a level multihull platform is going to be hard pushed to emulate with standard tee foils. Assymetric foils used separately will achieve it of course.

The role of RM seemed to me to be subservient to the lift to windward (LW - is that an accepted acronym, or another neologism? ;-) Isn't this LW the main benefit? Surely RM is just a sideshow in comparison.

Then there is another beneficial side effect from inclining the rig to windward, a la sailboards, as yet unexplored here.

Dog, B.

 

With veal heel extra RM is generated by the fact that the CG of the boat+ crew is to weather of the center of lift of the foils. The RM can be as high as 1.2 times the RM with the boat level and is ,essentially, free righting moment. In my opinion the gain in RM trumps everthing else though they all are dependent on and intertwined with each other.

From a previous post:

The advantages of veal heel on a bi-foiler:
1) produces side force from the lifting foils that can unload the vertical fin reducing the chance of ventilation. (major)
2) increases RM regardless of altitude(as long as hull structure is clear of the water).(major-very significant-approx. 20% increase in RM)
3) produces lift component from the sail that reduces foil loading.(minor)
4) shifts helmsman closer to the water decreasing the impact of his wind shadow on the sail and putting him in a slower moving portion of the wind boundary layer.(minor)

This rough sketch shows how a multihull using one power foil at a time would work.
-The angles shown are the angles from the vertical of the mast/mainfoil strut and the angle from vertical of the powerfoil strut.
-In this application both the mainfoil,rudderfoil and power foil contribute to lateral resistance and their respective vertical foils are unloaded.
-the sketch is one half of a trimaran.

 

Let's just assume, for a moment, that this "concept" can actually work as advertised in a static environment. Yes, that's right... I said assume. We have to assume this possibility since the craft in question does not exist. But, let's just go ahead and do that for sake of conversation.

We are sitting here looking at a boat layout that allows for more righting moment. So, what are the advantages?

Can we carry more sail in any given wind condition?

Will the sailor be able to sit further inboard, rather than hike the craft, such as those already known and well tested?

Is the boat going to be heeled by manual ballast movement, (hiking) initially, until the outboard foil grabs and then the ballast gets to slide back inboard?

Will the boat actually go faster, or will it always be in a state of seesawing, never able to reach a state of balanced equilibrium?

Will it be adversely susceptible to water conditions that are not within its narrow, static bandwidth of operation?

How does the sailor maintain an upright condition when the outboard foil comes free and loses flow over the surface?

How does the sailor operate all the various controls to allow the boat to function as designed AND keep a wary eye for collisions, wind shifts, wave action, groundings of exposed foils, etc.?

How does the boat function repeatedly with such enhanced levels of maintenance required without high levels of invested time?

Looking out ahead of the curve, just a bit... How does the builder compensate for the added cost of very expensive foils?

Lastly, how does one argue for more complexity, more maintenance, more susceptibility to damage and more overall weight when there are boats already that will perform better for far less invested cash and time?

Yes, folks, before you all get up on your hind legs to argue that this is only speculative talk; That a boat of this type has not been built at all and that there are no real world proofs that it can work well enough to actually sail in a broad range of conditions... I get it. It's a what-if scenario.

And truly.. that is the point all along. It's vapor, non-existent, only on a squiggled sheet of paper. One other guy's take on the proposal is as valid as he who orginally made said proposal. When you only argue air, then we all stand at the same podium. Now, if said craft were built, tested and proved in a wide variety of conditions, (I'm thinking Rave, Trifoiler, etc., here) then it stops being a mental ************ exercise and enters the world of, "hmmmmm?, maybe this could actually work, OR Geeez, what in the hell was I thinking? This thing stinks."

What I see above is an exercise in the patting of one's own back, all while ignoring that there are inherent limitations within the design that are being totally glossed-over in favor of what supposedly will work. This is, The Emperor’s New Clothes, being branded as a boat. Until the hard questions get just as much value in the argument as the so-called skimming of the cream elements, this is a doomed concept.

That's a very tidy description of fantasy.

As long as you all know it as that, then there's no problem. I happen to like playing pretend as much as the next guy. There is, however, a way to alter the existing paradigm...

Build a working example and get it on the water in front of lots of peers with substantive well-shot video and still imagery to support the argument... or debunk it, as well.

Dreamschemes are not for the risk averse.

 

I believe your understanding is superior to some who think they are "experts" and love to claim that the rest of us "don't understand" what is happening.

 

Doug, you're cornered mate, show us your plans of say, a 9 metre fast ballasting bi foiler - with no lead keel either please.

 

Oh, and I forgot to add, plans to build - because your are backed hard against the wall now - don't have to be super detailed - just so we know what is going to come out of your boat shed. Also the 9 metre length is non-binding - you have a choice, but it has to be larger than 8.5 m. Cheers.

 

Cornered hell! This thread is about a brand new idea for which no plans exist other than to test it on my new boat-read the thread!
How about the technical specs of a 60 footer? If it needs to be selfrighting it will require a canting keel. For an AC type to compete with DZ and CZ eliminate the canting keel and add Power Foils. Simple and very,very fast.
As for bi-foilers(without power foils) I have done preliminary design work(numbers)on a 60 foot self-righting bi-foiler and several self-righting Sportboat foilers and they could be adapted to the Power Foil concept.

Quote from the first post of this thread: "I think there may be a better way on a high performance trimaran that would use very small "amas" like the Rave but with a major difference: the new boat would use two foils-like a Moth- for boat speeds up to say, 20 knots. After that the boat would deploy(retractable) very small foils from the vicinity of the windward ama that would generate downforce to increase RM."

--------
--60' Moth self-righting bi-foiler: http://www.boatdesign.net/forums/sa...acing-monofoiler-design-discussion-15143.html Also see post 104 of the 60' Moth thread for an analysis of my preliminary calculations by R Hough.
--Sportboats: Design for Flight http://www.boatdesign.net/forums/sailboats/sportboats-design-flight-14606.html

 

Beg to differ.
And apparently you do too according to your last post.
The foils allow the good use of windward heel you like so much, duh.
"Veal heel, veal heel," you say, and say.

You pointed out yourself there would not be much benefit of windward heel
in these particular craft without them.
Their design and embodiment therefore obviously contribute to the RM developed.
But I can still call it John Wayne heel, or Elton John heel, or Elton Brown heel, if I want to.
But if you keep trying to put me down in such a high handed way,
I might have to slap some Chris Brown heel up in your grill.
What do you think, I was born yesterday?
Did you think I was imagining some mysterious torque
generated by a critical mass of carbon fibers?
(rhetorical, no answer needed)


You ought to be reminded as well of the role of the sail in holding the boat up,
which you seem to have forgotten in your last ad hominem misfire
If you don't believe me about the sail next time you are hiking out on your foiler :lol:
or windsurfer or kiteboard (or sunfish for that matter) try dumping the sheet
and see what is entirely supporting you.
By the way that nifty hydrofoil lift and stability will drop you quick too -sure you have seen some moths crash.
Hopefully you have a lifejacket.

No I don't think I "equated" anything.
My main point (again) is with little highly loaded foils you have to worry about them ventilating, spinning out, stalling, etc.

But even if I had equated your design with another, my response would be, "So what?"
Little problems like trim changes and loss of foils' lift do tend to keep cropping up here and there in sailing, you know.
They are worth thinking about. I hoped the sailrocket picture might suggest to you to consider
how it can go when foils' lift is affected by sudden changes like ventilation, attitude and pressure changes, etc.
It is a dramatic example, no?

Your concept has interesting features, but no easy solutions. Not to say it's impossible.

In response to questions and challenges like you get when you present ideas on the forum,
at such an early design concept stage, some people might say:

"Yes I understand these problems, and they will be addressed through tuning and foil selection,
blah blah blah, etc, once a prototype is built, but right now
I am at the concept stage so I have other things to figure out first,
like my weights and costs...."

Rollin' out of here with my Jay Z heel on....

 

The Lord's ability to prepare plans and actually design/engineer can be seen in post #32 (above), and added here in case it gets deleted from the other post.

 

---------------------------------
1)The design and embodiment of the foils is not related one iota to veal heel as long as they support the boat 100%-as best I can tell now.

2) I think I posted at least twice that the lift from the sail is one of the benefits of veal heel. I also posted the paper by Bill Beaver that states the same thing. Its really difficult to quantify just how much the foil loading is reduced but you're 100% right -it is reduced.

3) You know, I think I have pointed out-perhaps not too clearly- that the concept boat when using the Power Foil upwind-in strong wind only- is very similar to the windward foil on a Rave hydrofoil whose function of "negative lift" has been proven in countless hours of Rave sailing in all conditions. The same thing with the Hobie trifoiler except that the altitude control is different but the net result is the same. My intention was to try to show that adding a Power Foil to each side of a trimaran bi-foiler is based on two different technologies very well proven in their own right. The combination is new and I will experiment with it-there is much to learn even though,again, the concept is based on two PROVEN technologies.

4) I started this thread by asking for comments; I said earlier that I appreciated your comments as I do most comments on this thread. I asked for comments so ,hopefully, I would be challenged about some of my assumptions and my theory-and I have been. I try to answer in as specific a fashion as I can-sorry for the slip-ups but this is a living concept that I learn more about every day. I sometimes respond to what I perceive as an "attitude" with an attitude and that is a mistake that I am trying hard to eliminate from my response. I do screw-up in that regard but I'm working hard to be as factual and as direct as I can be-and to be as clear as possible with no "smartassness" at all. At least that is the goal.

 

Doug, why don't you bite the bullet and draw some plans - and ******* build (I'll reduce the compulsory super Moth to 7 metres, Judge Judy talking and she rules, okay) and enough of this theoretical BS - there comes a time where you have to produce something solid (or lightweight with water ballast in your case) - suck and see and making stupid mistakes and education from empirical knowledge are the way to go, matey - (this could occupy you for years) otherwise you'll mathematics yourself over the moon and just produce ephemeral dreams. Waiting with bated breath for plan drawings. Cheers.

 

Well, gee Gary, after the theoretical part is nailed the concept will be tested on my new boat. Thanks for your input. Really helps me think it out.

 

Veal Heal

For Gary: this is without a doubt the best way to use three foils(in the water) on a multihull-its only part time with just two foils the majority of the time plus:
* 15-20% more RM for free
* improved upwind performance
* earlier takeoff
* lower drag, especially in light to moderate air

 

Hey guys and gals, this boat design forum is exactly that, a boat design forum, it shouldn't be a bun fight about peer pressure to build a said design.

One thing is for sure you can gleem a lot of good ideas from it and for those who are of the inclination, can go and build their own design. If it incorporates ideas from this forum than bloody great as that is exactly what this forum is for, an exchange of ideas.

Doug, keep up the good work, you do amongst many of your replies, have some good ideas and pass on many ideas gleemed from elsewhere on the internet that I may not have found.

 

Wayne,

It's nice of you to moderate the interaction, as it were... but perhaps there is one small, but very important, aspect to what is going on here that you have missed.

Boat design talk, theory tossing, whatever... are all just stuff floating in the air and everyone knows that. It's all great fun, can serve a valid purpose and in some circles, is absolutely vital to the development of rich ideas. The real rub comes when someone starts in with the "it will be like this and it will perfom like this and it will be the best, fastest, most spectacular Wozzle ever seen on the water."

Nobody alive can make predictions such as that without either a great deal of expertise, or having already built said Wozzle and shown it to be of fabulous potential. Since none of that exists when it comes to our resident dreamer, the proof is entirely in the physical presentation of the pudding, as it were. Hey, it would be great if the guy were to actually produce something more than hyperbole. It's been said many times here, by many members... that they'd be the first to say congratulations. Yet, there has not been one thing fabricated that justifies the constant flow of words.

Since work progress is not being shown, it's not entirely out of place to suggest that the rhetoric should be squeezed back about ten notches until such time as a working example as a proof of concept can be shown repeatedly in a public place.

Take a moment to thread your way back through the various and sundry "ultra-important ideas" that have been tossed out here by said dreamer over the last five years... all of them, mind you, just brimming with overly complex concepts, and not one of them has ever been brought to fruition before the experienced sailors here.

Not one

I couldn't care less if Dream Boy ever puts a boat on the water. It would be graciously considerate, though, if our favorite prognosticator were to righteously dial back the endless rattle and humm until such time as this, five years in the making, wonder boat finally shows its mug in public.

Since that isn't going to happen (and looking back through the threads will show you that) one can only "strongly suggest" that Mr. Dream get into the shed and get something completed.

I say, suggest away with any old idea one pleases, Wayne. But, please, have the grace to know when one has overstayed the visit and excuse oneself to the work space. Please tell me that this isn't too much to ask?