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

WOLF- design specs compared with the 16' ASTUS trimaran:
LOA- WOLF 15.46'----Astus 16'
--ama LOA-WOLF(two stage ama) 11.5'----Astus 14'
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Beam- WOLF 18.75'----Astus 12'
---Wolf folds to a trailerable beam of 8'.
---Astus uses telescoping beams for a trailerable beam of 8.2'.
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Sail Area-
--upwind- WOLF 217sq.ft----Astus 160sq.ft.
--downwind- WOLF 367sq.ft----Astus(sport) 36o sq.ft.
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Weight-WOLF target-275lb*---Astus 462lb
* mostly carbon
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Ama buoyancy-WOLF(two stage ama) 270lb----Astus 1130lb
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Mast length- WOLF 25'----Astus 26'
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Comments-
Astus appears to be designed to be sailed by two people-WOLF is a singlehander that can take a second person.
WOLF will be a full flying foiler with takeoff in a 5mph wind(target). WOLF, singlehanded, has an exceptionally large righting moment( 5402.5ft.lb.+ 1500ft.lb. from mainfoil downforce) compared with the Astus RM of 516oftlb with two people on board(main hull apparently does not fly before ama buries).
Astus 16:

 

Progress on the D2 here:

Dominion 2-HW ,a Self-Righting Foiling RC Keelboat/ One-off Design & Build Project - Page 37 - RC Groups https://www.rcgroups.com/forums/showthread.php?2434531-Dominion-2-HW-a-Self-Righting-Foiling-RC-Keelboat-One-off-Design-Build-Project/page37

 

Fire Arrow/WOLF , Maserati and Active/Passive Foil Control
Maserati will soon be racing in the 2017 Transpac with her 3pt foil system that is basically the same as the Fire Arrow/Wolf foil system. Both Fire Arrow and WOLF use UptiP ama foils or in Maserati's case"L" foils that work like UptiP foils with automatic altitude control. Both boats have an adjustable AOI(angle of incidence) foil on the daggerboard and both use a single rudder T-foil with adjustable AOI. Both boats allow adjustment(if required) of the AOI of the ama foils.
The biggest difference between them is that Maserati is 70' LOA-Fire Arrow 5' and WOLF 15'. Along with that there are differences in control systems directly related to the size and mission of the two boats. Fire Arrow/ Wolf controls the flight altitude of the main hull with a wand surface sensor set to allow the boat to fly at an angle of heel of 10 degrees. This is done to allow the UptiP ama foils to stay down rather than have to be retracted/deployed with every tack or gybe like every other boat that uses UptiP ama foils and drastically reduces crew workload on a small sport tri like WOLF. The wand allows the main foil to automatically develop downforce and additional RM as required. The mainfoil and rudder T-foil work together to control pitch of the boat including pitch of the ama and ride angle of the ama UptiP foil. Maserati uses two rudder t-foils , one on each ama with the windward one retracted. Fire Arrow/WOLF uses a single rudder t-foil on the main hull which is never adjusted(but could be).
Maserati uses manual/hydraulic control of the mainfoil . The Maserati mainfoil is also capable of providing downforce. Maserati's rudder T-foil is equipped with flaps that allow manual control of the lift(and/or pitch trim adjustment of the boat) .
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Both boats use active and passive flight altitude control at the same time.
Active control is when the lift of the foil is controlled by a surface sensor( mainfoil on Fire Arrow/WOLF) or manually/hydraulically(mainfoil on Maserati). Maserati may use active control of the rudder T-foil lift though this foil may also be set to work passively with no manual control.
Other examples of active control: AC 50 main foil, Whisper, Rave, S9, Hobie Trifoiler.
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Passive control is when the shape and design of the board provides the altitude control required. This is true of the UptiP ama foils that control ama flight altitude on the Fire Arrow/ WOLF and of the ama "L" foils on Maserati. "L" foils don't have the intrinsic altitude control of UptiP foils but, on Maserati, because of the angle they have in each ama they work like UptiP foils when immersed .
The rudder t-foil on Fire Arrow/WOLF is a passive trailing foil that works automatically.
Other examples of passive control: Hydroptere, Quant 23, Flo 1 and others with surface piercing foils, most UptiP foils where leeway coupling or leeway coupling combined with tip breach control altitude . Most trailing rudder T-foils.

Fire Arrow:




Maserati:

 

Super Slick Paint---
I found this stuff around 1965 in Popular Science or Popular Mechanics. It was a paint that was very slick and contained molybdenumdisulfide(?) powder-gray in color. I used it on my Windmill just before the Southeast Districts in Montgomery, Alabama. My crew and I trained for 6 months before and we won 4 out of 5 races with a lead approaching a mile in 2 or 3 of the races. My brother used it too which saved me since I was protested for using the paint. I won and he got third.
It was called "Super Glide" and I haven't been able to find it since the 60's.
Thanks to PAR, I've found a new bottom paint from Pettit that may be as good called "Black Widow": Black Widow - New for 2017! http://www.pettitpaint.com/product.asp?id=300
It's available from West Marine for around $120 a quart........

Me and my Windmill about 1965:

 

Follow Maserati(foil system designed by Guillaume Verdier) using the same basic foil configuration as Fire Arrow/WOLF in the Transpac starting 4:30pm Eastern today here: Maserati-- 70' Ocean Racing Foiler https://www.boatdesign.net/threads/maserati-70-ocean-racing-foiler.57254/page-3 posts 32 and 33
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UPDATE- Maserati finished third behind Phaedo and Mighty Merloe-see the thread for the story...

 

WOLF daughter of Fire Arrow:
I've finalized the design of the ama and main foil trunks and laid out and cut out the ama foil trunk positions and the mainfoil trunk position on the Concept Model. The ama UptiP foils are one foot forward of the mainfoil which allows the center of vertical lift to move forward and outboard as the boat speeds up.
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Below ,is an illustration of the upper and lower "Z" seating for WOLF:

 

WOLF daughter of Fire Arrow- The next week will produce a bunch of stuff on the WOLF concept model: the mast, the curved half-a-wishbone boom, the port and starboard UptiP ama foils and the curved daggerboard main lifting foil. Which brings up a problem.
The daggerboard lifting foil will be curved to match exactly the curve of the bottom of the main hull so it can be recessed when retracted allowing beaching of the boat. So far so good: the problem arises because the mainfoil will have a wand controlled partial span flap similar to the one below used on Fire Arrow EXCEPT that it will be curved. That (so far) throws a wrench into the works because making a curved flap work is extremely difficult-at least it is to me so far. But I'm confident enough of finding a solution by the time I have the boat built that I'm going ahead with a mock-up of the mainfoil and recess on the model.
So if anybody has a brilliant idea how to make the curved flap work I'd like to hear about it.....

Fire Arrow mainfoil roughed in:

 

WOLF quickie molds for concept model:
A) Mainfoil
1-area 3.21sq.'
2-span 5.2', tapered planform: max chord 10" tapering to 6" at tip.
3-30% partial span flap.
4-tentative section- symmetrical(lift+downforce) -no section yet, but relatively thin depending on structural requirements.
5-approx. CL at takeoff .9, flap down.
6- approx. CL at cruise .3, flap neutral.
7- tentative aspect ratio=8.4/1 .
8- all carbon.
9- mainfoil tips are not hydro-dynamically driven as much as they are there to prevent tip from digging in in sand during beaching with foil retracted flush with bottom.
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B) UptiP ama foils
1-projected area for vertical lift=2.3 sq.ft.
2-total length of foil-6-8', nominal chord 8" tapering toward tip.
3-nominal CL at takeoff .6 .
4-nominal CL at cruise .3+ .
5-tentative section: asymmetrical 63412 or a thinner version depending on foil structural requirements.
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--Target: takeoff in a 5mph wind
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C) Half a wishbone boom-similar to TF10

 

Major Big Deal: Gitana 17 will use a lifting foil on the daggerboard -like Maserati and----wait for it--Fire Arrow!!!!!
So very cool! Follow the thread here: Gitana 17-100' Trimaran Foiler-Launch 7/17/17 https://www.boatdesign.net/threads/gitana-17-100-trimaran-foiler-launch-7-17-17.58231/#post-808389

 

Here is the first picture of Gitana's foil equipped daggerboard:

 

One of the most significant elements of the Fire Arrow Foil System is the use of UptiP ama foils which were discovered by TNZ in the lead up to 34. The cool thing about them is that they automatically maintain altitude regardless(for the most part) of speed and with no moving parts. The Fire Arrow was the first trimaran ever to use this type of ama foil.
Watch Guillaume's video(thanks to Corely) where he describes the ama foils for Gitana 17--also based on the TNZ discovery : Yachting World https://www.facebook.com/yachtingworldmagazine/videos/vb.111913865558561/1425355727547695/?type=2&theater

Fire Arrow Foil System UptiP ama foil:

 

WOLF daughter of Fire Arrow-- foils roughed in-
The foils are built with carbon and still need hand finishing. Their area and shape has been carefully designed to allow the fullsize boat to fly at 6mph(5.22 knots) boat speed which should occur in a 5mph(4.35 knots), or less,breeze. The mainfoil(daggerboard T-foil) will support 55% of the load and the UptiP ama foil 25% at takeoff. The rudder T-foil ( not shown ) will support 20% of the total load at takeoff.
Between 10 mph( 8.69 knots) and 15 mph( 13 knots ) boat speed the UptiP ama foil will support 80-90% of the total weight of the boat + crew.
Foil loading at takeoff is interesting: main=70lb/sq.ft., ama=46.6lb/sq.ft.. This low foil loading is key to early takeoff. For reference, the foil loading on a Moth main foil is about 178 lb/sq.ft. with the mainfoil supporting 80% of the load.

 

WOLF daughter of Fire Arrow---
The foil system is looking excellent particularly in that it is clear the these foils will be able to be left down while flying and not have to be raised/lowered with every tack or gybe. At this point this design (and Fire Arrow) are the only foilers employing UptiP foils that can do that.......
The numbers are great in terms of early take off and the automatic unloading of the mainfoil just after the boat crosses the 10mph(8.69 knots) threshold. This unloading will reduce drag a great deal and allow the possibility of using mainfoil downforce as required just after reaching 10mph in boatspeed.

 

WOLF daughter of Fire Arrow--
Two degrees of "up-tip" shown in the roughed in foils below. The one marked "FINAL" is the version chosen for WOLF.

 

Electronic/Radio Control of Foils--Looking forward to the elimination of the dual wands on the mainfoil and finding a way to completely(or even partially) change the ama foils to find a simple way to include ,perhaps, a flap that would allow configuring the ama foils more efficiently throughout the speed range but especially for early (light air) takeoff. The wand/UptiP foil set-up will be the way to go to start but there is such cool stuff available now that big changes to foil control are probably not too far down the line.....
TAKEOFF:
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