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

Discussion in 'Multihulls' started by Doug Lord, Dec 28, 2010.

  1. Doug Lord
    Joined: May 2009
    Posts: 16,580
    Likes: 298, Points: 93, Legacy Rep: 1362
    Location: Cocoa, Florida

    Doug Lord Flight Ready

  2. Doug Lord
    Joined: May 2009
    Posts: 16,580
    Likes: 298, Points: 93, Legacy Rep: 1362
    Location: Cocoa, Florida

    Doug Lord Flight Ready

    WOLF with Welbourn foils-they represent a 46% increase in righting moment should they be used:

    WOLF W Foil 3-30-19 001.JPG
     
  3. Eric Lundy
    Joined: May 2017
    Posts: 21
    Likes: 4, Points: 3
    Location: Vermont

    Eric Lundy Junior Member

    Doug, your passion for sailing is unparalleled. I like your foiler, yet I have a question. I believe it would be more efficient if your leward AMA and foil gave you excessive support to windward. My point is I want your central T foil to be tilting to windward. This means extending the foil arm on the leward ama to create a windward tilt overall.
    -eric
     
    Doug Lord likes this.
  4. Doug Lord
    Joined: May 2009
    Posts: 16,580
    Likes: 298, Points: 93, Legacy Rep: 1362
    Location: Cocoa, Florida

    Doug Lord Flight Ready

    Eric, thanks! One of the key design elements of the Fire Arrow and WOLF is that she sails with a 10 degree angle of heel which keeps the windward UptiP foil clear of the water so that the ama foils don't have to be retracted when tacking or gybing-a big labor saver compared to other boats that use uptip foils. For racing the boat would be equipped with a canting mast to maximize rig power.
    When flying in conditions in which downforce on the main foil is used, there is an element of lift to windward from the main foil. And the lee UptiP foil vertical is twisted to a positive angle of incidence as opposed to the daggerboard which is at zero degrees AOI and unloaded under sail.

    MPX Downforce - Copy.jpg


    MPX_Fire Arrow-3D SAILING-7-24-14 009 (4) - Copy - Copy.JPG
     
    Last edited: Sep 25, 2019
  5. Doug Lord
    Joined: May 2009
    Posts: 16,580
    Likes: 298, Points: 93, Legacy Rep: 1362
    Location: Cocoa, Florida

    Doug Lord Flight Ready

    WOLF daughter of fire arrow- I've been working on a different folding system than the one I've posted earlier here. The earlier system required SS hinges and a sliding tube inside the cross arm. The potential new system is, in essence, a "plug-in" system with a difference: as the two-stage ama is unplugged it can be slid out and then folded thanks to a flexible tube attached to the inside of the plug-in tube. It would be a lot lighter and equally as quick to fold.
    old system:
    Folding System-Wolf,Dream Flyer.jpg
     
  6. Doug Lord
    Joined: May 2009
    Posts: 16,580
    Likes: 298, Points: 93, Legacy Rep: 1362
    Location: Cocoa, Florida

    Doug Lord Flight Ready

    WOLF daughter of fire arrow
    Specifications

    Latest Update 10/18/19---Design 99% complete--ready to build!
    Design by Doug Lord--- with a little help from my friends
    Inspired by Fire Arrow
    System usable on trimarans from one meter LOA to 100+'.
    Note significant changes to improve performance with two crew. Still basically a singlehander but can take off in light air with a 350lb crew.

    ==================
    A) WOLF specs(tentative) :
    LOA 16' 9"
    Max Beam 20'
    CL ama hull to CL ama hull-18'
    Target weight 272lb
    SA-(mast length 28' all carbon wing mast)
    --upwind: 215.2 sq.ft
    --downwind: 300 sq.ft
    --max pressure before depowering/reefing:
    -----WOLF= 1.45 lb per sq.ft. sail area singlehanded(220lb).
    -----1.98 lbs per sq.ft. sail area doublehanded(350lb)
    * NOTE-see "F)" below for max pressure comparison with an F18.
    -----------------------------------
    SAIL LOADING- an indicator of hydrofoil performance. Divide weight in pounds by SA in sq.ft( reference: Moth= 2.97lb. per sq.ft. sail loading w 180lb crew).
    WOLF- upwind SA 215.2, downwind SA 300. Weights using highest estimated boat weight* + 220lb for one person and +350lb for two people(MAX).
    * 190lb
    ------
    upwind-one person=2.28 lb. per sq.ft. sail loading @ 492lb total flying weight
    two people=2.89 lb. per sq.ft. sail loading @ 622lb total flying weight
    --
    downwind-one person=1.64 lb. per sq.ft. sail loading @ 492lb total flying weight
    two people=2.07 lb per sq.ft. sail loading @ 622lb total flying weight
    ------------------------------------------------
    B) Advantages:
    1-Singlehander- Excellent upwind and downwind performance with 220lb crew. Minimum crew weight 120lb*. Two people for daysailing-max about 350lb.
    *Righting moment supplemented by mainfoil downforce.
    --
    2- Will foil in 5 knots of wind with 220lb and close to that with 350lb crew .
    --
    3- Carbon rotating wing mast, carbon cross arms and carbon foils.
    --
    4- Retractable foils(from cockpit). Mainfoil retracts flush with bottom and tips are designed to not dig into sand. Rudder foil retracts above bottom. Ama foils retract above waterline when boat is level.
    --
    5- Extremely comfortable sliding seat* on each side. Allows crew to move 1.75' outboard very quickly.
    * see picture below-
    --
    6- Uses the Fire Arrow Foil System(like Fire Arrow, Gitana 17, Banque Pop, Macif , Macif jr(24'Diam tri) and Maserati)-- the same as the original system first used on the Fire Arrow Test Model- except the larger boats use two rudder t-foils on each tack. WOLF has two UptiP ama foils-one used at a time-and one wand controlled mainfoil for very early takeoff and capable of substantial downforce- all working with a single rudder T-foil. Downforce can be virtually instantaneous adding RM in response to gusts. UptiP foils stay down-no adjustment when tacking or gybing.
    (see #16 below)
    --
    7- Foiling throughout the wind range -including very light air-the essence of 3D SAILING!
    --
    8- Assy Spin/Screecher retracted under the front deck.
    --
    9- Boat folds from max beam to trailerable width in about 4 minutes. No waterstays.
    --
    10- Mid (wish)boom mainsheet so sheet* is always in forward hand and extension tiller always in aft hand.
    *uses variation of the Swift Solo main +jib sheeting system=single sheet.
    --
    11- Quickly self-draining cockpit-large scuppers with backflow flap.
    --
    12- Planing ama hulls designed for incidental contact with water at speed and for inadvertent contact at slow speed.
    Adjustable angle of incidence of planing surface of each ama simultaneously on prototype. Angle of incidence of ama foil has to be changed when this is done. Planing surface starts at +4 degrees.
    Uses Two-Stage Amas-see attachments below. They consist of a planing ama hull(Stage One) coupled to a "curved piece"(Stage Two) that provides extra buoyancy in the event of a knockdown. Curved piece facilitates high dihedral crossarms which keep the crossarms clear of the water.
    --
    13- Planing main hull.
    --
    14- Aerodynamic surfaces added to forward and aft crossarms. Adjustable flaps added on rear cross each side. Jib foot and forward part of main foot to be sealed to deck.
    --
    15- Automatic Foiling: no foil adjustments required after shoving off the beach and lowering the foils.
    --
    16- Adjustable crossarm dihedral for prototype to facilitate testing.
    [​IMG]

    --
    17-Total buoyancy of the "curved piece" +ama hull(two-stage ama) is 207lb.
    ==================
    C) ---Memorable quote from JG Baker, Designer and Builder of the Monitor foiler in the 1950's:
    " The main need is to lower the wind velocities required for flying in order to increase the opportunities for high speed travel"

    D) ---VPLP on the daggerboard main foil:
    " On these big boats, when you ease a sail, it is a pain because it takes so long to grind it back in. But here you press a button and the angles of incidence change. And with the foil on the daggerboard you can use it to alter the flight according to the wind*. If it builds, rather than easing the sheet you increase the righting moment by increasing the angle and conversely, as it eases you can reduce it and let it fly more."
    * done 100% automatically on Fire Arrow/ WOLF with wand controlled main foil.

    ================
    E) --- Fire Arrow Foil System-first of its kind on any trimaran. Elements developed first by Fire Arrow include:
    1) the first trimaran in history to use UptiP* ama foils,
    *invented by Team New Zealand
    ---
    2) the first trimaran in history to use a single wand controlled main foil capable of downforce,
    ---
    3) the first trimaran in history to use Two Stage Amas.(see below for Two-Stage Ama pictures)*

    =======================================================
    F) Max pressure for F18 and WOLF before depowering or reefing :
    1)-The max pressure for an F18 based on 229 sq.ft. upwind SA, CE at 16.9', 2-180lb crew on trapezes and 5320 ft.lb. RM is 1.39 lb/sq.ft..
    ---
    2) ---Max pressure for WOLF with 215.2 sq.ft. upwind SA, CE at 14.65', one 220lb crew sitting in a comfortable sliding seat, and 4572.4 ft.lb RM* is 1.45 lb/sq.ft..
    ---

    ===========================================================
    G) *The Two Stage Ama Design offers a lot both Statically and Dynamically:
    1-Statically- the boat is sitting still and hit by a hand of God gust. It is theoretically possible that the boat could be knocked over with the mast horizontal but the two stage ama offers reserve buoyancy after the ama hull itself is immersed by the immersion of Stage Two("curved piece") . It is enough, however, to right the boat and/or prevent a 90 degree capsize.(see #17 in Section "B" above)
    2-Dynamically-the ama hull has two levels of dynamic vertical force:
    a. first and foremost the ama lifting foil that works from very low speed on up,
    b. Second, and a sort of back up at speed, is the planing hull design of the ama. To start with on Fire Arrow/WOLF, the planing surface only comes into contact with the surface at very low speed with the ama starting to fly before the main hull does. And when the boat is flying the ama performs as reserve lift during incidental surface contact at speed.
    *Also see here for more on two stage ama theory: High Performance MPX Foil/Self-righting Trimaran-The Test Model https://www.boatdesign.net/threads/high-performance-mpx-foil-self-righting-trimaran-the-test-model.36058/page-191

    [​IMG] [​IMG]
    ======================================================
    UptiP Ama Altitude Control-pictures A & B----
    Note that the ama is flying before main hull-note ama flight altitude:
    [​IMG]

    Now that the main hull is flying and speed and load are significantly greater than in "A" above, note that ama flight altitude is the same! And that's due to the ama UptiP foil design(no moving parts) :
    [​IMG]
    =======================

    [​IMG]

    [​IMG]

    WOLF Trimaran Foiler
    Last edited: 10/18/19
    yes, it is a Revolution
     
  7. Doug Lord
    Joined: May 2009
    Posts: 16,580
    Likes: 298, Points: 93, Legacy Rep: 1362
    Location: Cocoa, Florida

    Doug Lord Flight Ready

    Interesting comment by Michele Petrucci, designer of the S9 cat: "Acat must continuously depower above 7 knots of wind.."
     

  8. Doug Lord
    Joined: May 2009
    Posts: 16,580
    Likes: 298, Points: 93, Legacy Rep: 1362
    Location: Cocoa, Florida

    Doug Lord Flight Ready

Loading...
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.