Flying A-Class Project (maybe with wing)

Discussion in 'Projects & Proposals' started by Luk937, Oct 8, 2015.

  1. Luk937
    Joined: Oct 2015
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    Location: Germany

    Luk937 Junior Member

    Hello Community,
    this is my first post, also my english is really broken.

    My project is to fully design and build an A-Class Catamaran strictly along the rules, but also build some new and funny things to make the "ride" more extrem.
    (Like self controlling foils, with flaps to de- or increase the lifting surface. Or the Wing Sail mention at the top)

    My current sate is:
    The design is nearly finish, I "build" an 3d Model in SketchUp.

    I need help with:

    The foils,
    hopefully an cfd analysis to improve the Design,
    And Feedback


    The first pictures are from an old Design state.

    I Hope you could help me with it.
     

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  2. Stumble
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    Stumble Senior Member

    Are you just designing it or planning on building one? If building then I would really recommend starting with an inexpensive used boat. Specifically one with bonded cross beams and canted hulls. These are the two major factors in if a design is worth converting to a foiler.

    As for the foils. First you will need to add a cassette to handle the foils. Exploder has them for sale for about $300 a set. Out of Poland, or I think DNA sells them for about the same.

    The foils themselves are where the real work will come in. There is a crew in Australia working on insert from the bottom foils that would be worth checking out, and there are some guys in the US that are working on oversized foils. The big question is if you are going to try L foils or J foils?

    For rudders I would probably just grab a set of DNA L rudders for about $2,000 a set.
     
  3. Luk937
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    Luk937 Junior Member

    Thanks for your feedback!

    At first the design and improvement process is the important part.

    And the howl project is to design and build it ;)

    Canted Hulls are coming in the next design step (as I mentioned, this is an old state)
    What did you mean with bonded cross beams?
     
  4. Luk937
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    Luk937 Junior Member

    Oh and which crews work on these foils?

    Something like "insert from below" or/and "oversized" foils are what I had in mind.
     
  5. Doug Lord
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    Doug Lord Flight Ready

    Dario Valenza is offering uptip foils: these are foils with intrinsic altitude control designed to be sailed with the windward foil retracted most of the time.
    The are different from "L" foils in terms of heave stability(stable altitude control).
    http://www.carbonicboats.blogspot.com.au/
    Good luck with your project-sounds like fun!
     
  6. Doug Lord
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    Doug Lord Flight Ready

    ================
    Greg, just out of curiosity, why do you think canted hulls are important for a design to be converted to a foiler?
     
  7. Luk937
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    Luk937 Junior Member

    Canted Hulls are faster, therefore it is Simpler to start to foil.
     
  8. Stumble
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    Stumble Senior Member

    This is a big issue on the A-Cat, there is no other crew. Between driving and trim adding the complexity of adjusting foils has so far proven to be slower than just sailing with them down. Which is part of why they haven't been adjusted on the water.

    I think it is possible to rig the boat in such a way that as you move to the traps the windward foil automatically comes up, but it would take some practice to get working right. I haven't messed with it yet because I don't have any foils to try it on. But if you make the foils I am happy to give it a try and I have a friend here wit set of DNA J foils to bench mark them against. :p

    By bonded cross beams I mean ones that are epoxied in place, and not just bolted on. Most of the modern boats are built this way, but there are some designed to break down for transport.

    Doug, the reason to start with canted hulls is that they a) are faster, and b) have less wetted surface just before the boat starts to fly. So they take off sooner.


    Figure a good condition canidate for this type of conversion will run $6-8,000. Then add in a few hundred bucks on the new cassettes. Then whatever you choose to build for the foils.
     
  9. Doug Lord
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    Doug Lord Flight Ready

    Thanks Greg! I was thinking that with these 4 foil boats that you'd want to keep it flat to maximize the vertical lifting area of the foils for takeoff?
     
  10. Luk937
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    Luk937 Junior Member

    As mentioned above, the main goal is to design and construct every little thing.
    So that the last step is: call the compositi sellsman and start building;)

    And also from the beginning to the end, that means: hulls, beams, ruders, foils and so on..
     
  11. Stumble
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    Stumble Senior Member

    Nope. First you fly a hull, causing the canted hull to work properly, then the reduced area and speed gets you flying. we aren't talking a lot of cant here however. I think my hulls are set such that at around 4-6" of hull flying the leeward hull becomes verticle. Any more and you are just bleeding speed.

    It isn't a huge amount but it is noticeable. I would guess 10 degrees or so.


    Luk,

    Trying to build everything yourself is going to not just be incredibly expensive, but also very very slow. Just for instance, my cross beams are autoclaved prepeg high modulus CF tubes. To make these at home would require you to first build an over capable of the tolerances needed, then a non-tapered mandrel to form the tube around, a freezer large enough to store the pre-peg... Then you need a seperate mandrel for the rear beam, a third to make the boom, the list just goes on and on.

    Unless you are planning on going into commercial production I would really suggest buying the bits, and focus your efforts on the foils if that's where you want to experiment. If you then choose to expand your design efforts great, but at least you will have a working package to start from.

    I am not saying it can't be done, but I am not aware of anyone who has attempted to build everything and been successful. The practical realities of trying to build a 30' autoclave for the mast just don't work for a one off build.
     
  12. Luk937
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    Luk937 Junior Member

    Sorry I Misses this Part..
    I work for an boatbuilder xD with two 40" freezer and so on.

    The thing that I want to build was the hulls. The foils or the wing are secondary in this term.

    the problem with the foils is that I need help to design them ;) also to design an wing sail capable of been trimmed as much as possible to stand against every wind ;)

    Also I'm happy to hear feedback for the hull, it is Angeled (around 3-5°),
    The new design has an smaller nose, to decrease the drag when diving.
     
  13. Stumble
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    Stumble Senior Member

    Ahh,

    In that case things get easier.

    Right now either the eXploder to the DNA are probably leading the pack in terms of design, but I would look very seriously at Arno Terra's Flying Carpet design. It should be coming out of molds soon, and is attempting to be the first upwind foiling design. Low volume hulls, shorter mast, less wetted surface, and a new foil design all focused on getting out of e water as quickly as possibly.

    The race is really about how to get up on foils as quickly as possible these days. Aero drag, air tight tramps, tramp sweeping sails, etc... The gains to be made from being the first on up on foils are so huge it is worth sacraficing almost anything to get up first.
     
  14. Luk937
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    Luk937 Junior Member

    Therefor I need someone how would run CFD test with the hull to improve it in aero and hydro Dynamic way. Or tips to improve it my self.

    And did you know where I could ask him ( Arno Terra )
     

  15. Luk937
    Joined: Oct 2015
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    Luk937 Junior Member

    now, the (not really finish) Hull mk6.

    with canted Hulls...

    oh and My plan was to build the Beams direct to the Hulls, (bonded Beams) to reduce the weight.

    could someone help me with the layers (or the plan for them, where I need to laminate and what? )
     

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