Wingsail Monohull

Rcsailing.net Technology Discussions
41

Sorry, if you got me wrong.
And please - don´t take me too serious.
But my point of view also belongs into here!

What I want to point out is the reason,
WHY the wingsails have been banned for most of the monohull classes and WHO banned them.

  1. Class officials maybe because of cost explosions or to keep the class “clean”. - Whatever.
    That´s not the point.

  2. But Designers mainly because of technical/physical reasons.

    If wingsails don´t work properly on monohulls - except on foil assisted Moths - then why try to use them there?
    If wings only bring a real advantage for fast multihulls - like it´s proofen since decades in the Little America´s Cup/the C-class catamarans - then because they belong there.

If softsails don´t work as good as solid wings on fast multihulls - as poofen in the 33rd America´s Cup -
why should THEY be used there? (Just to show the opposite).

So we could probably agree on this:
Soft sails make sense on 99% of the monohulls and on most mediumspeed multihulls,
but solid wings only make sense on 1 % foil assisted monohulls and on the highspeed multihulls.

And as a result of the said above:
The youtube links I posted last time simply show where the best designers on this planet want to go in the future - in which direction.
They want more efficient multihulls, with even more efficient solid wings.
Bigger, lighter, faster, more relyable, more exciting - simply MORE.
They want to explore what is possible today and tomorrow - not go back in time.

I don´t want to say monohulls are running out of fashion -
it´s just something different.
And you wouldn´t want to install nowadays race tires on a Ford T, right?
Wouldn´t make sense to me either.

Just my 5 cents

42

I dont see why you say they only work on a fast monohull like a foiling moth. The article presented was of a M from the 50’s and it worked. Now you may not get all the benefits of a wing sail on slower monohulls, but that doesnt mean they dont work.

43

Quote:
“And you wouldn´t want to install nowadays race tires on a Ford T, right?”

Race tires would also “work” on a Ford T.

But - would you install them there?
That´s my point!

And I didn´t say they don´t work at all.
I said they don´t work properly.

You just don´t get a benefit out of them, which is in relation to the invested effort.

44

I like the empirical method:

  1. Make one,put it on yacht; if it works, great.
  2. If it doesn’t, put it on a land yacht, and you have another toy to play with when the water gets hard.

Edward.

45

Firstly, I don’t take your seriously at all, I find it some what entertaining, that you say out of your mouth that you “don’t want to say mono-hulls are out of fashion” and then from the other end of your anatomy you say, “why put race tires on a model T Ford ?” I love a good debate :stuck_out_tongue:

I totally disagree with you … solid wings do make sense on 100% of Moths, but do all moth owners want wings ? well maybe as it is still in early phase of this open development class, time will tell, but as wings start proving to be advantageous in this mono-hull class (if they are not banned) then this would be a perfect case of any class benefiting from using a wing.

Given that we are talking about RC sailing here (not crewed boats here) wings have been proven to work on mono-hulls with keel & bulbs (do you bother to read Mr Reynolds article? Post #6 in this thread) and proven to be faster than 1:1 to soft sail areas in mono-hull class.

The sad part about wings in any class, is that the moment they prove to more effective than the status quo, rules are quickly drafted-up to limit their sail area to handicap their use, as noted in Mr. Reynolds article.

A wing is a lot easier to build at home than soft sail plan, look at how many plane modelers make’em, compared to the black secret art of making a good set of soft sails.

Further, it is far easier to build, sail & race a RC 1 meter mono-hull than a RC 1 meter multi with a wing, from my limited understanding of RC Multi’s they need to be at least 2 meter hulls before you can have any real sailing stability and then … you need big trailer to take it to the lake and is it going to be close or exciting racing …!?

A quote from Mr. Reynolds article: “Using our wind-tunnel data I first put a small wing sail on a pair of catamaran hulls of my own design, calling her “Katy Kat.” But I soon discovered that cats are no damn good on small closed courses. Because of their light weight and low inertia they tend to lose headway on turns across the wind for tacks and buoys, ending up dead in the water or drifting aft.” This is the reason why I and many others, like RC mono-hulls over multi’s.

To use your car analogy: If you want just “straight-line speed” build & race a dragster, if you want something that goes “faster around a course with close & exciting racing” build & race a F 1 Car.

Back to sailing, it’s relative to mono & multi hulls both benefit from wings…That’s my point !!

Here I’m interested in discussing about a wing on a mono-hull, if I ever want to think about a wing on a multi-hull, I will drop into the multi forum and gladly dissuss it there.

Cheers Alan :zbeer:

46

I also think this is good entertainment and
a good debate is allways worth spending my time.

I just need to know, where it leads to - if it leads to anywhere at all.
I´ve seen too many debates here going in circles and leading nowhere.

But I know I got my point across and it´s time for me to lean back and
just watch, what you - and others - can get done here in this forum.

Meanwhile I will work on plans for a new 2 meter catamaran
with a solid wing like the 34th AC boat will probably have.
At least that´s what I´m aiming for.

47

I don`t agree that you got your point across at all, unless it was the fact that multi’s and mono’s are different fish that drink the same water.

I’m sitting on the fence about AC 34, I have to see it…to believe it. AC 33 was a sleeper the only thing that made it anywhere near interesting was the wing !

Wishing you the very best with your 2 metre cat with wing & look forward to seeing what you get done there too, I’ll work on my IACC 120 with wing mast (not sail) to start with and see where it goes from there…

1000% positive we’ll both enjoy and have lots of fun with our respective classes.

Cheers :drink:

P.S Mullti’s have a bigger % gain using a wing than a Mono.

48

But that WAS my point!

“Multi’s have a bigger % gain using a wing than a Mono”

I just went one step further:

“If I can get more % gain out of a multi using a wing,
then WHY build a mono to put a wing on it?”

(For me this sounds like going three steps ahead
and then two back.)

PS:
And thats true as well:
“AC 33 was a sleeper the only thing that made it anywhere near interesting was the wing!”

49

schluss !!!

50

Sounds like you´re running out of analytical arguments.

I was just getting started and you are allready pushing the red button.

Boring.

Just because some (unknown to me) Mr.Reynolds is stating his personal point of view -

  • which is totally ok for me -
    I still don´t see any reason, why I - or anybody else - shouldn´t make his own experiences.

As you mentioned earlier:
“I have to see it to believe it.”
I can agree to that.

And I want to see it myself.
That´s why I´m going my own way.
And allways did.

One more thing:
Why should I repeat an experience,
somebody else has experienced allready?
I´m looking/aiming for NEW experiences.

And I don´t do, what others expect me to do.
I do, what I expect of myself.

51

You criticise others for not following your opinion …and then contradict yourself, you must be a Politician right ??

I would like to experience a RC mono-hull with a wing, YES it will not be as fast a RC multi with a wing, but everyone knows that … don’t they !? …smell the flowers man, to use your words … It’s my experience :wink:

52

Oh bugger !! some more analytical arguments for you…:slight_smile: Mr. Reynolds credentials you forgot to read.

[i]Mr. Reynolds is an engineer and a corporate and private technical inventor who holds a number of patents. The patent rights to one of his inventions, a digital decoder and memory invented for multiplexing the remote control of a model fireboat, were later sold to Boeing and used to control the BOMARC national-defense missile. His other personal technical efforts have included ornithopter development and hydrofoil-rotor marine vehicles.

Reynolds has lectured nationally, including at NASA Goddard, and at a number of universities. For years he taught evening courses on inventing at the University of Washington, at Community Colleges, and at Boeing. Prior to “retirement” he held Engineering Management positions on many Boeing programs.

He has a degree in Mechanical Engineering from the University of Washington and is a Registered Professional Engineer. He is an Associate Fellow of the American Institute of Aeronautics and Astronautics, and has been elected to the Hall of Fame of the Academy of Model Aeronautics.[/i]

Sorry I didn’t catch-it if you said it before… but who are you again ?

53

I am NOT going to be pulled into this discussion, other than to offer the following website and a good performance comparison of soft single ply sails against a double ply “wing sail” that is also “soft” (more or less) when mounted and tested on a 37 foot monohull. I would suppose one could make contact and discuss finer points of the “discussion” with the designer and others who have tested it.

While NOT a true solid wing sail as normally accepted, it does begin to show performance improvements (even for a monohull) that a wing shape can provide.

http://www.omerwingsail.com/

http://www.omerwingsail.com/air-flow/

http://www.omerwingsail.com/yach-world/

And the benefit this has over the “hard” or rigid wing sails is it can be reefed - or completly lowered for in-port mooring.

Enjoy - and regards, and why not give it a try?

Dick

54

Thanks Dick …not planning to port moor my 120 except maybe the bath :lol:

55

Hi guys,

Firstly an apology, I found this web page a long time ago when a friend of mine built an RC land sailer with a solid wing mast and I just re-discovered it in my bookmarks folder…
He was experiencing that the wing was very on/off and with the wind having a constantly changing angle of attack it was impossible to sail 100% all the time and I was looking for a solution to the problem…
This is a design solution for a freely rotating wing with a control vane that ‘sets’ the wing at the optimum angle of attack.
It has polars,sketches and photos with a more than adequate description of the design and suggestions for improvements… All on a mono hull!
www.ivorbittle.co.uk/Articles/The%20model%20wing-sailed%20yacht/The%20wing-sailed%20yacht%20for%20the%20web.htm

Again sorry for sitting on this, it was not intentional…

Cheers, Jim

56

Intriguing thread. I think “disabled” has his argument wrong about why put a wing sail on a single hull. A single panel sail works on a pressure differential as does a wing sail, however a wing sail, either hard or soft, will have a greater pressure differential than a single panel. Wing sails can also be tailored to the wind speed, with thickness, front and trailing edge thickness and camber, so for a given area you get more power. With displacement hulls, you reach terminal speed more quickly, getting ahead of the competition. With skimming single hulls and multis, you can reach a higher speed. So, taking the displacement hull, you have to design the wing sail for wider set of conditions and wind speeds than the the faster monos and multis. This is a basic exercise in airfoil design, wider set of conditions require more thickness, faster speeds thinner sections. I would imagine for most sailing , one would want a soft wing sail to adapt to wider conditions. One must remember that your are transfering a force from moving wind pressure to a relatively non-moving and thicker-water - medium. There has to be some give or you will have controllability problems. Look how tender the fast multis are with the hard wing sails. Same with the Moths, one little bit off, and into the drink you go.
Now, as to the sails design, I have been thinking a lot about wire cutting a foam board for the wing on my marblehead. Haven’t tackled any of the airfoil design yet, but a foam core would be flexible and give you the shape you want. The other idea I had was the bubble wrap between two layers, specifically the bigger bubble packs that are about as big as your hand. I imagine there is a way to make specially designed bubble packs with simple heat sealers to any shape you want, have to look at the kitchen sealers available.
Ok, what does everyone think? NEXT!

57

Thanks for the link Jim, very interesting read, the subject of using a vane pop-ups again, which gives me impression there is some sensitivity to finding the right angle of attack with wings …I’ll cross this bridge when I get there, having no experience with wings at all, I’ve been studying all I can find & will firstly build something and then learn my way around it as I go.

1957250s – I thought about making foam core wing and toyed with the idea of using monokote foil, this is the stuff the fly guys use to cover their plane wings by tacking it onto a surface with hot iron and then using hot-air to shrink the surface to the wing shape… just my two cents worth.

Wing terminology is open to different interruption, I made up definitions graphic to explain my own interruption (if wrong, please let me know)

  1. Soft-Wing, Claudio was working on something and used his graphics (hope you don’t mind)
  2. Mast-Wing, this is hard mast foil shape where you can use varying chord % for the foil from 5-50% with normal sail material making up remainder of the chord
  3. Hard-Wing, this is where the wing can be made up of 2-3 solid components along the chord.

I wish to start with a Mast-Wing firstly to learn the variables, if successful I may later move up to a hard-wing, wanna learn to walk before I can run if you know what I mean.

Being a winter project (K1W1ng-Mast) planning so far is that I’ve finally decided to use 56 dm2 sail plan which is maximum plan for rig 1 on a AC 100 and is suitable for rig 2 on a AC 120, so I can move them between hulls and compare performance to normal sail plans for both classes.

Main sail height is 1,440 mm and using 80 mm gap between Mast-Wing ribs I end up with 19 ribs, using 8 mm O.D CF tube near the front edge, the Mast-Wing takes up 50% of the chord which tapers.

Planning to cut 2 mm balsa to make foil shaped ribs, bottom rib # 1 is therefore has chord of 172 mm and is 29 mm wide and rib #19 at the head on the Mast-Wing has chord of 64 mm and is 11 mm wide.

Thanks for throwing whole heap of variables at me :confused:…just what I needed to start doubting myself :lol:

Question I like to ask is that with my plan of a mast-wing, presented here, do you think this concept would cover wide set of conditions?

My doubting thoughts:

  • Taper Mast-Wing profile ?
  • Straight Mast-Wing profile ?

I welcome any “constructive feed-back”, as this is a totally new experience that I like to try on RC mono-hull.

Cheers Alan

58

Hey Alan,

My 2 cents:
I am interested on another level as I’m probably building the full sized version soon…
I would start withe the NACA 0012 - 64 profile suggested in the article I posted.
It has been tested and known to work.
I have a hunch that using a tapered section lowers the C of E and the wing will have a wider ‘stall range’ a bit like a tapered chord for a fin…
All the high performance ‘Solid’ wing masts for full sized yachts used a ‘trapezoidal’ section, this may not be that important in the beginning, but I’m sure that once this catches on, and people learn more, then designs will mimic the full scale units.
Cheers, Jim.

59

Just wanted to add -
With wings or sails, it is all about the angle of attack. From the land-yacht experience, the hard part with solid sails is there is no way to tell if you are sheeted correctly. It either went like a rocket or it crawled along.
The smallest adjustments made a big difference, add some distance to the equation and it got even harder.

Our conclusion was a vane for self trimming is a very practical solution here…

60

For the solid wing, I have noticed many two element wings with a pivot like this drawing as opposed to a solid hinge along the trailing edge of the front element. I assume this idea is to help keep flow attached to the trailing section with a slotted flap idea. Some slow flying airplane wings use leading edge slots like this. Control horns attached to the lead element and the joining plate could control the slot and trailing section offset.

The full sized Oracle wing also had different trailing edge sections that could each be trimmed at a different angle to the leading edge to provide twist to the upper wing. I would think this would be way more important to do with a monohull wing than the multihull wing, due to the hull speed difference.

Maybe build three different wings that could all be slipped over a 1/2" carbon tube, and all rotate independently. The top sections can twist to a different angel to the section below by use of a “pin in slot” arrangement where the two stack on top of each other.