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

Fire Arrow Foiler / MPX Foil System Testing and Development

Gary, Thebault , Larsen, Bradfield and others spent substantial time testing and evaluating the results they achieved with their RC models. The RC model is an excellent tool for those who can't afford to throw money at the problem.
You're in no position to say that I've "overstayed my time"-you have no idea what I'm up against and making a comment like that is simply ludicrous.
I worked with Dr. Sam one summer when he was testing foils for SKAT on an RC platform I built for him. He was a pioneer in hydrofoil design and development and thought that using an RC platform to test foil configurations was a great idea. It's obvious Paul Larsen and Greg Ketterman feel the same way-you're way, way off base ,Gary-and just plain wrong!

 

All these guys together spent far less time with RC models than ....



pogo

 

Doug, are you implying that you are a sick man and that I am a callous brute to criticize your RC playthings - attempting to destroy your raison d'etre?
I am not knocking your health problems, if that is the case.
But I am suggesting that your fixation with toys and writing about them is way over the top imbalanced.
This is a colossal thread ... and any interest sailing readers may have had with foils (except for some modelling enthusiasts) has turned to complete disgust. You are killing the fascination of flying yacht development
Well, actually you're not, because it is an ongoing thing that won't stop. But you've done a good job in urinating a lot of people off.
And don't misconstrue my "overstaying your time" statement - I'm talking about this insane thread ... not your time upon this planet. You're being pathetic.
Okay, build your models, have a good time ... but how about halting your nutty hourly postings until something of importance and interest occurs.
And then we may read your conclusions and genuinely enjoy the full flight videos?

 

Fire Arrow Foiler / MPX Foil System Testing and Development

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Gary, I disagree with you emphatically!!! You're dead wrong.

 

Fire Arrow Foiler / MPX Foil System Testing and Development

Hugh Welbourn on the Fire Arrow and radio controlled models for testing:

 

The only conclusion is to build a real boat.


pogo

 

Fire Arrow Foiler / MPX Foil System Testing and Development

Paul Larsen, with his radio controlled model of SailRocket discussing the scale models he has and will use for SailRocket 3:

 

Fire Arrow Foiler / MPX Foil System Testing and Development

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No, the point is that many accomplished designer/inventors realize that an RC Test Model is a real boat and capable of imparting lots of information about the scaled up full size boat, particularly if it is a foiler. Ignoring this fact is just plain uninformed.

 

Doug ,
nobody said that testing concepts with RC models is a bad way.
But , all these above mentioned guys went after a certain period over to real boats.
I think with models they proofed only that their concepts aree working.
Finetuning can only be done w. real boats.

Trying to make a concept perfect via a model, and another one, and modifications, and, ......becomes selfsufficient playing.


pogo

 

Fire Arrow Foiler / MPX Foil System Testing and Development

Fire ArrowTest Model Specifications---latest update: 6/8/15

A) Name- Fire Arrow

B) LOA-79" (6.58')-including bowsprit

1. mainhull-66.19" (5.52') (The reasoning behind and the story of the added hull length can be found in posts 1177,1187-88,1195-1198)4/30/14

2. mainhull+ rudder and gantry(no bowsprit)- 69.125" (5.76')

3.planing portion of ama=34in. (2.83')

4.ama LOA=50.75in.(4.23')

C) Beam-81.6"(6.8')

D) Mast 103in. (1.75"chord wing mast / 8.58')5/1/14

E) Sail Area:
1. Main+ Mast + Jib= 3390.9sq.in.( 23.5 sq.ft.)5/1/14

2. Main+ Mast + Code Zero= 4087 sq.in.( 28.38 sq.ft. )5/1/14

3. Main + Mast-no jib= 2690 sq.in ( 18.7 sq.ft.)8/14/14

4. Reefed Main + jib= 2796 sq.in ( 19.4 sq.ft.)8/14/14

5. Reefed main + mast= 2096 sq.in.( 14.5 sq.ft.)8/14/14

F) Foils(all foils updated 8/14/14)

1. Main foil area was increased from 50 sq.in. to 84sq.in. which gives it a foil loading of .188lb/sq.in. which is identical to the F3 and equal to about 75% of the total sailing weight. For earliest takeoff the lift from the ama foil is discounted to make sure the main foil alone can lift the boat. Span was increased from 23 to 29" with a 7.6/1 aspect ratio. Initial foiling was done with a mainfoil angle of incidence of 2.5 degrees.

2. Rudder foil area was increased from 26 sq.in to 49.8 sq.in. and is now 59% of mainfoil area with an aspect ratio of 8/1. Span increased from 18.74 in. to 23.25 in.. Rudder foil loading is.106 lb/sq.in. and equal to about 25% of total sailing weight at takeoff. Loading on this foil automatically changes from takeoff to near zero to negative(pulling down). Initial foiling as done with the rudder foil set at 0 degrees angle of incidence. But if you watch the videos you'll see that the boat initially pitches up during takeoff giving a positive angle of attack to the rudder foil before leveling off.

3. Ama foil(s) area is 68.62 sq.in. which will change as it is refined. The effective area(projected) for vertical lift is 52.9 sq.in. or 77% of total area. One foil is still using the i-flap, described earlier, while the other foil has had the flap removed but retains the same projected area for vertical lift. The idea is to test whether or not the foil can achieve early take off as well as the foil with the i-flap-or at least close enough to justify the reduced drag by the removal of the i-flap. The effective aspect ratio of the foil includes both the horizontal component and the vertical(curved) component and is 6.4/1.
IMPORTANT NOTE- In the last 7+ min foiling video it is clear that it would be ideal to have the model foils retractable and that for sure, as always planned, the full size foils will be retractable. But when they are retractable they will also be about a foot deeper(3.375" on the model) which would help in waves when on the foils. Not possible on the model, at least any time soon.

4. All Foils change their loading as the boat speeds up:

a. Mainfoil begins to unload right after takeoff until it's primary function is pitch control(with the rudder) and maintenance of the main hull altitude(boat angle of heel). If the heeling force causes the main hull to rise past the preset wand altitude set point( that is, if the angle of heel increases), the main foil will develop substantial downforce adding to the righting moment of the boat.This is a particularly important feature of this foil configuration.

b. Rudder foil starts with a maximum vertical lift of 25% of the total load(5.28 lbs) minus the pitching moment created by the rig. It will change loading automatically until it pulls down, if necessary. Rudder foil works with the main foil to control the pitch angle of the boat. See F2 above.

c. Ama foil begins to load up right after takeoff until it carries the majority of the load. Ama foil angle of incidence is preset for the conditions apparent at the time of launch. On the full size boat the ama foil angle of incidence will be adjustable while sailing but such adjustment will be very infrequent. Ama foil angle of attack is controlled by the main foil and rudder foil working together. Ama foil angle of incidence is preset in the range of 0 degrees to +7 degrees. Initial foiling was done with the AOI set at + 7 degrees. From the results of the early foiling, it appears that the AOI may be able to be substantially reduced-depending on the comparison tests of the two ama foils-one with the i-flap and one without. Independent pitching of the ama foil is physically impossible since ride angle is controlled by the main foil and rudder foil, again, together.

d. Angle of incidence of every foil is measured in reference to the static design waterline which is parallel to the flight waterline soon after takeoff.

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Fire Arrow Foiler / MPX Foil System Testing and Development

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You misunderstand: the whole point of this Test Model is to build a full size version later on when funding can be found. In the meantime, all the testing that's possible will be done within the constraints of needing two people and two vehicles to test and record video. It's a slow process but no less meaningful than any other Test Project. These guys ,especially Paul Larsen and Hugh Welbourn have spent years developing their concepts without regard to how long it takes. That's the point here: testing will proceed when it can without any concern whatsoever for how long it takes.
This is the first trimaran configuration of its type in the history of mankind. This is the first trimaran of any size to use UptiP foils on the amas, and the first one to use a two stage ama.The first trimaran, of any size, to use a wand controlled variable lift main foil. There is no rush-we're already way ahead of the game.
You would understand that if you'd read the thread........

 

Silly, silly me. It's like flatulating against a volcanic eruption of horse defecation.

 

Put your raincoat on Gary. There's another eruption coming.

 

I'm gasping, Doug, struggling to stay alive under this heinous, overpowering onslaught.
Because I've failed to introduce any sort of balance in this endlesss treadmill tirade.
In fact I'm a near dead shell, beaten to a burnt and charred substance.
No one, Doug, on this planet can compete with your gigantic and volcanic word spewing obsession. No one.

 

Gary-why don't you just give it up-this accomplishes nothing. You're not going to change my mind and I'm not going to change yours.