High Performance MPX Foil/Self-righting Trimaran-The Test Model

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UPDATE!-Was informed today(4/15/15) that tests have shown that I did NOT have a heart attack. It's simply mindblowing that I was lead to believe that I had. I do have treatable heart disease but no where near as serious as I was lead to believe. The discomfort of the last two weeks is not heart related and more or less typical of the operation.
And I have the go ahead to start testing by the end of May from my doctor- I'll see if the cardio guy agrees Monday.
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See post 1972 for summary of July 24,2014-first full flying foiling as well as all videos. These pictures were taken that day and proved:
1) that the boat would foil in a 5mph breeze,
2) that the unique and different dual altitude control systems worked perfectly,
a-Ama altitude control: each ama uses my own design UptiP foil based loosely on the TNZ main foil in 34. The foil controls the altitude of the ama regardless of load or speed and worked perfectly on port and starboard.
b-The wand controlled main foil worked perfectly to fly the main hull in the very light air. The main and rudder T-foil work together to control pitch of the whole boat and the ride angle of the ama foil. The dual wand system can be adjusted to change the angle of heel of the whole boat by adjusting the altitude of the main hull. The faster the boat goes the more the main foil is unloaded and the ama foil loaded which allows tremendous reserve control power for pitch control. If the boat exceeds the preset wand altitude setting, the wands will cause the mainfoil to develop downforce and therefore extra righting moment. This can be set up as an automatic gust response.
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We still have testing to do in heavier air as well as tests to refine foil area and the iFlap but the basic functionality of the foil system was proven beyond a shadow of a doubt on July 24,2014. Now it's refinement to increase speed w/o sacrificing light air takeoff, and practice, practice, practice to learn to gybe on foils and to learn to sail the boat better. The boat showed, in the long video, that it wanted to foil upwind-the wind was just too light. I expect her to foil well upwind above 6-7 mph wind speed.

click for much better view:

 

Fire Arrow Testing / D4Z Testing

Last year we had to wait a long time(most of June) for light enough wind to do the initial Fire Arrow testing. This year they'll be two boats-the Fire Arrow and D4Z cat. On very light air days ,initially it will be the D4Z-on days with wind it will be Fire Arrow. So there should be no missed days as long as I make the right call in the morning of which boat to take.
Some great video coming!!

 

Doug, thank goodness you're health is not as bad as you first thought, and i hope you totally recover.

I have a question about square/over-square.

Is square/over-square an absolute necessity for a trimaran to lift or fly on foils.

Catamarans that fly, or are well lifted by foils, are not square.

Yet Dr. Bradfield's trimaran 'Osprey' and your own 'Fire Arrow' are square/over-square.

I want to build a fast cruiser trimaran that can at least foil assist and provide some foil pitch control, but i can't afford to engineer such wide cross beams.

 

MCM, the advantage of greater beam is particularly apparent when using wand controlled lifting foils like the Osprey and the main foil of the Fire Arrow.
When there are two wand controlled main foils(Osprey) the loading on the foils is significantly reduced by more beam. It doesn't mean the boat won't foil on a narrower platform, just that IF the foils are wand controlled they will have more work to do to keep the boat level. The Fire Arrow is designed to work at an angle of heel but still uses the wand controlled main foil to keep it at that angle. The FA main foil works more efficiently with more beam, especially when developing downforce.
Most tri's are not square or over square but a boat with that kind of beam is much better off with a foil system like the Fire Arrow that allows tremendous pitch control while allowing the main foil to unload to the point of zero lift and then, automatically develop down force which can increase RM a lot.
In my opinion, the trimaran platform allows for greater beam than does a cat and the Fire Arrow foil system allows that beam to work safely. The same is true to an extent with the Osprey foil system except that since it doesn't heel there is a limit on the size waves it can work with. The Fire Arrow system can be adjusted for different wave conditions.
The Whisper is a relatively narrow wand controlled cat that does not appear to use the dual wands for creating extra RM because it has two guys on trapezes-in other words, a wand based system can work on a narrow boat IF the wands aren't allowed to cause the foils to develop RM(extra lift on the lee foil ,downforce on the windward foil). The "movable ballast" on the Whisper keeps those foils working efficiently.
I don't think the Fire Arrow system would work well on a boat much narrower than square.
If you look at the Exocet 19 ads below you can see that the amas each have one UptiP foil and one rudder t-foil. But the main hull has no foils which means that they have to wait for the main hull to clear the water before the lee UptiP foil+rudder T-foil begin to work efficiently . That probably means a lot of wind before the boat flys.(And is the main reason the FA main hull has a wand controlled main foil and a rudder t-foil!)
There are a lot of options for "foil assist" but the biggest problem with a narrow tri using foil assist(or not,for that matter) is the angle of heel of the boat when the main hull just flys. There's a thread here about that(see below) and the range is something like 13 degrees to an amazing 26 degrees. And the controlling factor is .....beam. The wider the less angle of heel when the boat just flys the main hull. The FA sails at an angle of heel of 10 degrees when flying.
Ask away if this doesn't cover your questions....
PS-why a tri and not a cat? If you are beam constrained a cat may be a better choice. Going with a tri about the same width as a wide cat probably isn't a good idea for a full flying boat and even foil assist is less likely to work well on such a narrow boat.

http://www.boatdesign.net/forums/multihulls/trimarans-angle-heel-main-hull-takeoff-39553.html

 

Thanks Doug, for the info and the link to the heeling angle thread.

But doesn't that mean no lift at all, because won't a wand adjusted for pitch control cause the foil to develop RM automatically whether I want it to or not.

I haven't decided yet.
I have enough red cedar, doug fir, fiberglass, epoxy and shed-space to build up to 52' (16m) whether cat or tri. But i can't spend much on carbon fiber or i'll be short on sails and hardware.
That's why i worry about beams or masts that i can't engineer out of wood/epoxy and fiberglass.
Also, my beams will have to be demountable, as i'm 8 miles from the launch ramp.

 

Wands are never "adjusted for pitch control"* that I know of. A boat with dual ,independent forward wands will develop RM if there is no movable ballast.
Movable ballast that is used to keep the boat level will prevent RM from the foils. Righting moment is caused by the boat rolling and the differential position of the wands that results from that. If the boat is kept level ,then the wands cause the foils to lift the same on each side.
*Dual, independent wands can be adjusted for roll control by causing the foils to generate righting moment.

Click on the picture and note that the lee wand is angled further back than the windward wand which means the lee foil is developing more lift than the windward foil. On a boat with movable ballast you'd move the crew further outboard until both wands were the same angle. On this particular boat the crew can sit anywhere since the foils will keep the boat more or less level. However, it's faster to use movable ballast, if you have it to keep the thing level.
The second picture is of Whisper, an 18' wand controlled cat that uses movable ballast instead of differential foil lift for RM. it's much narrower than the same length Osprey:

 

So U-tips are not exactly self adjusting by T-rudder and pitch, because they need to be raked as well ?
But what about T-foils - the dagger is always stationary, and only the horizontal flap adjusts its angle of attack ?

 

Foils

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Kinda tough to understand. Many(but not all) UptiP foils will have the rake adjusted for a takeoff AOI(around 6 degrees) and a cruise AOI-around 3 degrees or slightly less). Rake adjustment on the newest UptiP foils is very little after that.
"self adjusting by T-rudder and pitch" doesn't make sense to me. The rudder T-foil is set at about zero degreesAOI to the static waterline IF it is parallel to the cruise flight waterline. The rudder foil AOI requires very little, if any, in flight adjustment, depending on the boat.
T-foils I have set up have the main or rudder foil attached at exactly 90 degrees(except on the surface piercing T's on the D4Z) . Main T-foils have the bottom raked forward so that the main foil has an AOI of 2.5 degrees. Rudder foil=zero degrees.
It's good practice on any foiler to have everything adjustable but the values above have worked right off the bat on dozens of foilers.
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If you look at the Exocet foil configuration and the new Gitana foil configuration, they have one UptiP foil on each ama and one rudder T-foil. That means they have to have enough wind to fly the main hull before full foiling. It can also mean the boat won't foil in light air though ,being an ocean racer,Gitana will rarely lack wind. But the Exocet is handicapped with that configuration, in my opinion. The Fire Arrow has a main wand controlled lifting foil and one rudder T-foil on the main hull. It(model and fullsize) is designed to fly in as little as 5mph(4.3 knots) of wind as the model proved last year. By having excellent light air foiling ability the boat will have more use in the US where its 10 knots or less in many places much of the time. The other advantage of the foils on the main hull is that they control the ride angle of the ama UptiP foil and prevent it from any pitch excursions whatsoever.
The Fire Arrow UptiP ama foils also incorporate a twisted uptip portion of the foil with an "iFlap" which is just a fixed flap to help with early takeoff w/o having to rake the foil. Much written about that in this thread and referenced in the last few pages. The testing coming up will allow the iFlap to be reduced in area(probably) for the greatest efficiency.

 

Fire Arrow and D4Z

Back at it starting today! Got the radio set up and programmed so that it switches over between the Fire Arrow and D4Z. Tested it.
Finish programming servos and winches on D4Z tomorrow.
Feels good......

 

I am just catching up on email and ran upon this post. A day or two earlier I saw a video of this boat capsizing.

http://www.sailingworld.com/video-gunboat-capsize-les-voiles-de-st-barth

If this has already been discussed -sorry.

My comments
G4 is a very interesting application of technology. It does offer some accommodation, but it is accommodation by my standards -and other people like me that cannot afford the boat and it's maintenance/attrition. I can see some potential for exciting racing and a place for crew to sleep (the owner would stay on shore in swank hotel).

In addition to the safety problem (a big boat that has higher loads relative to the human power trying to control it) I wonder about mundane things like surface quality and marine growth. This is a shiny bottom boat -no ablative coating. Does it need to come out of the water a couple times a month to be cleaned -a slave to the crane. Does anyone know what effect surface roughness has on foil performance? I may be wrong but my requirement for any foiling boat that can not fit on a trailer is that the foils can easily be lifted out of the water (from above).

 

Fire Arrow Foiler / MPX Foil System Testing and Development

Skyak, I'm not sure what Gunboat's thoughts are on this except that they offer two different types of foils-UptiP foils for performance and "C" foils for foil assist(retractable fully). I would imagine some of the owners would dry sail the boat at their club-or estate and/or use a floating ramp dock to keep the boat out of the water.
There are two long threads-mostly BS-but with some interesting nuggets on SA
and this thread here: http://www.boatdesign.net/forums/multihulls/gunboat-g4-uptip-foils-50397-11.html
The Fire Arrow is ,of course, trailerable, and can be sailed off a beach with a dolly like the cats use.

 

AC 4.8RC Foiling Cat

A bit more progress on the D4Z: http://www.boatdesign.net/forums/pr...-americas-cup-catamaran-52931.html#post734265

 

Fire Arrow Foiler / MPX Foil System Testing and Development

"Lost" ama foil pictures. These might help anyone considering an UptiP ama foil since we know they work. I had forgotten about these pictures:

click for best view:

 

Fire Arrow Related Testing: The D4Z Foils(Batfoils!)

The testing of the Fire Arrow is about to resume but the testing of the foils for the D4Z cat is also about to start. These unique "Curved Twisted Surface Piercing T-Foils" or Batfoils for short started out as an idea for what could be a simple replacement of the the main wand controlled foil on the Fire Arrow. That replacement foil may use a center section featuring an upside-down asymmetric section capable of generating downforce as the boat speeds up and pitches down.
But the concept of a surface piercing T-foil using the iFlap on each side is very unique and worth testing. IF the testing, soon to be done on the D4Z, works out then the Batfoil will have definite use on the Fire Arrow , particularly if the asymmetric section will work. The Batfoil, w/o asymmetrical section, has tremendous potential on a foiling cat where the foils are mounted with a 10 degree cant(bottom outboard) that allows the windward foil to fly clear of the water at just a 4 degree angle of heel!
More reading on the genesis of these foils:
1) p120, post 1795--the first incarnation of the idea,
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2) p121, post 1803,
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3) p123, post 1831- downforce!
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4) p123, post 1837- downforce!
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5) p125, post 1871
NOTE: each Batfoil is equipped with two iFlaps, one at each tip. The idea ,in testing, is to gradually reduce the iFlap area w/o impacting low windspeed takeoff significantly. The first mention and description of the iFlap is here, referring to the Fire Arrow ama foils-each equipped with one iFlap. Initial tests showed that the iFlap worked perfectly in aiding low speed takeoff.
iFlap- p105, post 1561
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Pictures, L to R, 1-4 Batfoils just pulled from quickie mold showing the iFlap at each tip, 5-7 Batfoils attached to D4Z daggerboard showing white flight waterline marks. Drooped "L" rudders are shown as well. Batfoils are twisted from zero degrees at center to +3+iFlap at each tip. They are installed on the daggerboard with the center at +3 degrees. The whole point of the twist and iFlap is allow early takeoff with no adjustment of the foil-100% automatic.

 

The HYDROcontest is a quest to design and build energy efficient vessels of the future. We will be representing AMC in 2015.

https://www.kickstarter.com/project...-for-international-competition?ref=nav_search

A team of undergraduate engineers from the Australian Maritime College have entered the 2015 HYDROcontest to be held in Switzerland this coming July. Large amounts of work have been put into designing and building innovative remote controlled boats to race against university teams from all over the world. We require help with funding in order to allow us to compete on the world stage in Switzerland this year as shipping and travel make up the majority of the overall costs for this project.

The HYDROcontest, the brainchild of the HYDROS organisation, focuses on the development of technologies that can assist in increasing the energy efficiency of the vessels of tomorrow, and hence reduce their dependence on fossil fuels. The contest aims to showcase research and innovation in the area of maritime transport through a series of three challenges: a heavyweight transport vessel that must race with 200 kg of cargo, a lightweight vessel race with a load of 20 kg, and a long distance race to determine the most energy efficient vessel design. Further details on both HYDROcontest and HYDROS may be found using the links below.

http://www.hydrocontest.org

Team AMCAT had a very successful competition at the inaugural HYDROcontest in 2014. We managed to walk away with the best design award in the lightweight category for our hydro foiling catamaran (in photos and videos above). With the knowledge and skills obtained from last year and a fresh dose of new team members we believe that we have the ability to not only design and produce new and innovative boats that will help shape the vessels of the future but also be very competitive in this years competition. We also believe that we can provide a team and product that ourselves, our university and our sponsors can be proud of.