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
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    Location: Cocoa, Florida

    Doug Lord Flight Ready

    Fire Arrow Foiler / MPX Foil System Testing and Development

    .
    ======================
    The list of mods below was changed 9/22/14-#9 added.
    ======================
    Here is a list of the modifications made since the First Foiling video on July 24th,2014. I've included page and post references:
    ---
    1) Changed the wand tension system to allow maximum force on the wand when it is down(flap generating downforce).-page 111, post 1662
    --
    2) Painted small black section on hull immediately behind each wand(as viewed from the side) to help the white wand to show up better in the video.
    -page 111, post 1661.
    --
    3) 5 full length battens added to main,GCD removed and mast extention added, peak halyard and downhaul purchase increased. -page 109,posts 1631 and 1632.
    --
    4) A reefing system is now incorporated in the rig with a removable mast section and velcro fasteners to hold the rolled up main.-page 109, post 1633-1634 and page 110, post 1642.
    --
    5) i-Flap removed from port foil(still on stb foil) to see if I missed a step in ama foil development by not trying more area before I tried the i-Flap. The resulting foil has the same planform area as the foil with the i-Flap and a few degrees of washin towards the tip. -page 108,posts 1617 and 1618 and page 109 posts 1626 and 1630. Once I have these results I'll either add the i-Flap back to the port foil or remove it from the starboard foil. Then the process of changing the foil angle of incidence,first, and second changing foil area can start-modifying one foil at a time. The focus will be in reducing drag as much as possible within the constraint of light air takeoff which is the main focus of the Fire Arrow project.
    --
    6) Considered adding aero drag reduction measures to the crossarms but postponed that due to a suggestion from Steve Clark,-page111, post 1653.
    (While I greatly appreciate Steve's suggestion regarding aero improvements, I disagree with his assessment of the level of success achieved by the Fire Arrow in her first foiling video. My response to that: -page 116, post 1740)
    --
    7) Added experimental endplates to the outboard ends of the partial span mainfoil flap. -page 112, posts 1667 and 1668.
    --
    8) Added mount for a Velocitek Speed Puck to use to calibrate the i-GOTU* GPS tracker used since day one. -page 112, post 1670.
    * see picture of the tracker and its installation on the boat page 113, post 1682.
    --
    9) Moved the mast step aft as well as adding a second jib attachment point aft of the original. -see post 1772
    ====================

    So the major experiment for the next test sail is the port ama foil with the i-Flap removed compared to the starboard ama foil still using the i-Flap.
     
  2. Doug Lord
    Joined: May 2009
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    Location: Cocoa, Florida

    Doug Lord Flight Ready

    Fire Arrow Foiler / MPX Foil System Testing and Development

    For ease of reference to new and old followers of this project:

    Next-God willing and the creek don't rise a knockout all foiling video......

    Pictures: the boat and Coach Dan Burkes Pirates Team* logo and now the Fire Arrow good luck charm:
    * So far Dans Team has a winning season!
     
    Last edited: Oct 3, 2014
  3. Doug Lord
    Joined: May 2009
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    Location: Cocoa, Florida

    Doug Lord Flight Ready

    America's Cup 62 and the D4Z Prototype

    I am involved with a project to build a sort of scale model of the AC 62 for radio control. I've mentioned the prototype I'm working on while testing the Fire Arrow is on hold in a couple of earlier posts. I don't want to post all the info in this thread so if you'd like to know what the project is all about I've started a new thread under "Projects and Proposals" here: http://www.boatdesign.net/forums/pr...rnational-ac-62rc-class-51540.html#post706793

    and the main thread on rc groups:http://www.rcgroups.com/forums/showthread.php?t=2180752 start on the last page--
     

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    Last edited: Oct 4, 2014
  4. Doug Lord
    Joined: May 2009
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    Doug Lord Flight Ready

    RC Foiler Development

    I discovered this accidentally-two more video's from Ian Holt in Australia-max speed 22 kilometers an hour(13.67 mph) and an experimental one meter trimaran with wand controlled foils: (Interesting that Ian is using the same tracker I am on the Fire Arrow and it also shows his altitude changing like mine does-it has shown the Fire Arrow going as high as 100' while it actually never left sea level. Must be some glitch in the built in software? )

    https://www.youtube.com/watch?v=VNHVufhBb3Y&index=2&list=UU0Olp6vZzdP4D2yPJ85jS1A



    And this one is the experimental addition of wand controlled foils to a one meter trimaran. Rather than the wand controlling a flap as on my F3, he, apparently, is using the wand to control the whole foil-it's kinda hard to tell. You can see the windward wand doesn't drop close to vertical so it's probably not developing much downforce. When he gets it right it will be rock steady in that breeze:
    https://www.youtube.com/watch?v=N_vprFOK3WE&list=UU0Olp6vZzdP4D2yPJ85jS1A
     
  5. Jim Caldwell
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    Jim Caldwell Senior Member

    If he is using the wand to control the foil isn't it backwards, when the wand comes down it angles the foil up ( video at 1.14 ). I can't figure it out either. Maybe Ian will chime in?
     
  6. Doug Lord
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    Doug Lord Flight Ready

    RC Foiler Development

    I can't tell-the wand should be at max lift when all the way back and max down force when near vertical. I wish Ian would chime in...
     
  7. Jim Caldwell
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    Location: Cleveland, Ohio

    Jim Caldwell Senior Member

  8. Doug Lord
    Joined: May 2009
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    Location: Cocoa, Florida

    Doug Lord Flight Ready

    RC Foiler Development

    ============
    I PM'd him about this and the AC 62 this morning.......
     
  9. Doug Lord
    Joined: May 2009
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    Location: Cocoa, Florida

    Doug Lord Flight Ready

    Fire Arrow Foiler / MPX Foil System Testing and Development

    While this project is on very temporary hold,I've been having fun the last week or so working on the feasibility of starting an AC 62RC Class and doing the technical analysis for that boat as well as talking to people from all over about it. And while I think it could be a great RC racing class the technical potential of an AC 62RC cat pales in comparison to a radio control race boat, say 48" or so LOA, built light and using the Fire Arrow MPX foil system. It simply lends itself to pushing hard with tremendous RM in stronger wind as well as great performance around a course. And it makes me think........
     
  10. Doug Lord
    Joined: May 2009
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    Location: Cocoa, Florida

    Doug Lord Flight Ready

    Fire Arrow Foiler / MPX Foil System Testing and Development

    As I've mentioned before, I've had time to work on other projects while waiting for my "crew"(Dan) to be available. Many of you will remember that the Fire Arrow is a scale test model of a high performance 19.5' "sport" trimaran. So the idea is to be able to foil easily, flying in as little as 5mph of wind. That was why the TNZ invented UptiP foils were so important-the version I designed requires no adjustment while sailing over a wide speed and load range-and has worked 100% perfectly. In fact, if the wind went from zero to max pressure there would have to be only one AOI adjustment while sailing thru all those conditions!
    That brings me to the wand based main foil. As good as I think wands are and as well as they work they are a pain on a boat that touts itself as very simple to sail. However, for years I've tried to come up with a way to ditch the wands on a "sport" version of this boat. Because of all the foil work I've been doing lately, I guess, I had a brain storm tonight. The drawing below shows the idea. The two red circled areas of the foil are "high lift" sections to help fly the main hull early just like the wand does by lowering the mainfoil flap.The faster the boat goes and the more load taken by the ama foil, the higher the new foil rises until the high lift sections are clear of the water! With the foil below, there is no flap-no moving parts at all.
    The "real" version would retract under the main hull just like the wand based mainfoil would.
    Definitely going to have to test this!!
    Also inspired by the i-Flap....(right, below)
     

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  11. Madrc570
    Joined: Aug 2013
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    Location: Australia

    Madrc570 Junior Member

    Hi Doug,

    I think you might have some ventilation issues with this design both at high speed and when you're heeling. From what I gather this is basically a 2 stage surface piercing foil that should behave like a more efficient form of a ladder foil(?). As soon as the wing tips come out of the water you will still have water flowing over them and flying up from them thus affecting the working foil surface below. I'm imagining an extreme form of what happens to the AMA foils. Because this is happening there will be a far higher chance of ventilation and/or stalling and a fair amount of drag. That is at least from what I understand.

    Also when you heel you have the force vectors from the main parts of the foil acting against the angular parts which could cause havoc.

    Not saying it wont work but I think there are more efficient solutions.:)

    -Curtis
     
  12. Doug Lord
    Joined: May 2009
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    Location: Cocoa, Florida

    Doug Lord Flight Ready

    Fire Arrow Foiler / MPX Foil System Testing and Development

    Well, you may be right, Curtis. But this is a sort of double version of i-Flap which worked perfectly(with relatively high drag). May need to change the shape a bit, we'll see.
    The real problem with it( that I'm sure about)is that it doesn't automatically create downforce like the wand system does. That's a big deal because the wand system acts to maintain the preset angle of heel which is also essential for the very strong pitch control the system has now.
    How are you doing with your boat?
     
  13. Doug Lord
    Joined: May 2009
    Posts: 16,679
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    Location: Cocoa, Florida

    Doug Lord Flight Ready

    Fire Arrow Foiler / MPX Foil System Testing and Development

    Here are two more rough sketches showing the boat level and then heeled as seen in the video. I'm close (I think) to solving the downforce problem. The two simplest solutions:
    1) if the main foil gets too "light" ease off or reef,
    2) Use a lever to "shift" the AOI of the foil midsection to slightly negative.
    These aren't really satisfactory because, again, the wand system is 100% automatic. But there may be another way.
    I think that it may be possible to fly the main foil just above the waves, reducing drag. It would still put the brakes on any pitch excursion that might occur. Probably worth testing because of the great simplification in removing the dual wands. Unfortunately, that simplicity is (so far) replaced by the daggerboard within a daggerboard to allow full retraction on the full size version.
    Interestingly, Mode 2 shows something I hadn't even considered-the heeled foil develops some lift to windward.
    Remember, this is not a racing configuration-the intention is to simplify sailing the full size boat........
    This is a bit off the wall and needs careful study but, as the boat goes faster, the bow is going to drop so it may possible to tailor the appropriate portion of the middle of the foil to be very close to zero AOA when the foil is in equilibrium at the surface so that as it speeds up this same portion of the foil goes slightly negative to develop downforce. Might work. Or even going as far as using an upside down asymmetrical section for that portion of the foil. It would still lift positively at takeoff pitch up but as the boat levels off it would come closer and closer to developing downforce-completely automatically.
    Added version 3 10/7/14:
     
  14. Madrc570
    Joined: Aug 2013
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    Location: Australia

    Madrc570 Junior Member

    That sounds better Doug- the section change in the foil, and the 2d profile is deeper which should solve what I pointed out.

    My boat hasn't changed much in the past couple of weeks of holidays but the foil moulds on the other hand are 70% complete!! I've only had about 2 days over this time period- Went surfing for the first week. and have been really sick for the last week, we did get out on our boat though. :/ not too much fun for me...

    As soon as I'm well enough to deal with saw dust and epoxy fumes I'll be back at the moulds. I'll send you pic

    -Curtis
     

  15. Doug Lord
    Joined: May 2009
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    Location: Cocoa, Florida

    Doug Lord Flight Ready

    Fire Arrow Foiler / MPX Foil System Testing and Development

    Well, get well,man! Thanks for your comments-I appreciate them...
     
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