Variable Shape Wing

Discussion in 'Hydrodynamics and Aerodynamics' started by WSW2016, Aug 5, 2019.

  1. WSW2016
    Joined: Mar 2016
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    WSW2016 Junior Member

    Hi
    I am working with variable shape wing.
    The wing have internal mast.
    The camber and thickness can be changed.
    The camber can be reversed.
    The wing twist can be applied with variable progression.

    The result the ultimate sail...please check the animations and please make some comments.
    Most interesting will be to get info whats wrong with such approach as I got never
    any comments since 2015 when it was first published on Wind Sun Waves driven sailing machine http://www.wabes2015sailboat.n.nu/ .


    https://youtu.be/0kDEAyLkZwg
     
  2. Barry
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    Barry Senior Member

    Last edited: Aug 5, 2019
  3. WSW2016
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    WSW2016 Junior Member

    Barry - I do agree with you - nothing is new - but NASA-s wing is for aeroplan and is not changing camber or thickness
    and is not reversing the camber either as it is necessary for sailboats.
    There is a question I still do have: whats wrong with my proposal?
    Best Regards
     
  4. BlueBell
    Joined: May 2017
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    BlueBell . . . _ _ _ . . . _ _ _

    WSW,
    Funny how forums don't like to answer questions isn't it!?

    So, what's wrong with your concept?
    Nothing.
    Birds vary their wing shape all the time.
    Nothing new, as Barry pointed out.
    It is hugely valuable, key to hydrofoil advancement.
    Commercial airlines do it pretty effectively with slats and flaps,
    but they don't vary the thickness which could be integral.

    Is that your video?
    What have you done?

    Best Regards
     
  5. BlueBell
    Joined: May 2017
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    BlueBell . . . _ _ _ . . . _ _ _

    WSW,

    Is the link in your first post your link?
    No wonder you don't have any comments, there is no way to comment on the link!
    The ideas presented may be too advanced for this group to comment on anyway.

    Do you have any prototypes or just graphics?
     
  6. WSW2016
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    WSW2016 Junior Member

    BlueBell.
    Yes, the avi files are my own but the question is if you watched two videos ar only one?
    And yes it is important for foiling boats as the speed makes L/D more important.
    Note that proposed wing can be twisted in not linear manner = same like the wind speed from the ground up is increasing.
    Instead of reefing the top of the wing can be made thinner and set at zero lift so the tip vertex gets reduced by 90%.

    I did som models of the ribs controlled by small RC servos - gets soon boring as was working as predicted.
    I have done many flow simulations - not necessary right answers but better than making small models due to Reynolds...
    In general I am not going to use this wing for traditional sailing boat. Most of my time of last 2 years was going to project of foiling boat
    sailing into wind eye - not published anywhere yet.

    I was little joking on my site about Dual Flapping- this is clear that this is not any flapping but I did expect very sharp
    comments but as you was joking about forums "not answering questions"...we can agree that it is some truth in that anyway?

    Note that AC75 got dual skin main but still old fashion D shape mast - so this will end as proposed by me?
    When I sent my wing proposal to Artemis they said that they have a fix design and the teams can not have own designs.
    Note also that I do not have any commercial activity like production or patents - just fun! What is your hobby?

    Best Regards
     
  7. BlueBell
    Joined: May 2017
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    BlueBell . . . _ _ _ . . . _ _ _

    WSW,

    Thank you for the reply.
    Yes, I watched both videos.
    Three in fact, if one includes the kids video on the link.

    My hobby is boats: human powered, kite powered, electric powered, hydrofoils, houseboats, sailboats, commercial boats, and earthquakes.
    Thanks for asking.

    Best Regards
     
  8. WSW2016
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    WSW2016 Junior Member

    BlueBell.
    I do get your point - you are correct there is only a contact for mailing.
    I do understand that people like to be anonymous...
    I believe that we have many clever people on our forum but nobody like to be exposed for the unknown?
    Best Regards
     
  9. WSW2016
    Joined: Mar 2016
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    WSW2016 Junior Member

    BlueBell.
    Your hobby is boats: human powered, kite powered, electric powered, hydrofoils, houseboats, sailboats, commercial boats, and earthquakes.
    My hobby is boats: human powered, ----------------, electric powered, hydrofoils, -------------, sailboats, commercial boats, and ---------------.

    You can always contact me on the contact mail for any more specific discussion.
    And believe me...we do have some small earthquakes in Sweden but there no way to use it for boat propulsion...:)
    Best Regards
     
  10. Barry
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    Barry Senior Member

  11. DCockey
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    DCockey Senior Member

    What will you use for the skin which will be flexible and stretch to conform to the moving ribs but stiff to not deflect from air pressure?
     
  12. WSW2016
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    WSW2016 Junior Member

    Barry.
    Thank you for the video - very informative.
    I do believe that the fighter wings needs to stay for tremendous forces and not only from air related
    therefore it is not easy to compare to wings on sailboats. Sailboat wings are easier I do hope that you agree.
    Yes, I can see that they change the camber as well. Thanks!

    Best Regards
     
  13. WSW2016
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    WSW2016 Junior Member

    DCockey.
    The first materials choice I made was Polypropylene reinforced unidirectional with Hollow Glasfiber.
    Still there are many other material choices as it is not very critical as one might believe. It gets much tougher on aeroplans.

    When one play little with Rib axis position on NACA6513 then we can see that the bending of the surfaces gets minimal.
    This fact makes that the skin can be very stiff vertically with some flexibility horizontally to enable shape change.
    The weight of the skin is stretching it between the ribs, do to gravity, so it is similar to cloth sails.
    However I must admit that the skin is the most difficult part of such variable shape wing for sail boats - not necessary expensive but must be well engineered.

    Best Regards
     
  14. tspeer
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    tspeer Senior Member

    Existing wingsails have variable camber and twist - much more than depicted in the animations. What is the benefit of variable thickness? The thickness of existing wingsails is largely determined by structural stiffness, which requires the full depth and cross sectional area of the D tube. Depending on how much laminar flow one expects to achieve at the intended operating points, there may not be an aerodynamic penalty for the thickness. I don't see how the proposed system provides the required structural stiffness.
     

  15. WSW2016
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    WSW2016 Junior Member

    Hi TSpeer

    Det är difficult to make nice answer without making a new controversy - sorry if so is the case...

    Not many existing wing sails are build as one piece having continuous skin as proposed.
    It is vertically stiff, horizontally soft semi-hard skin.

    Wings are used for fast going sailing boats so the amount of twist requirement is less than on slow sailing boats.
    This is simply vertical wind speed gradient and boat speed vectors - but I know that you understand that.

    Still proposed by me method allow to make wing like NACA 9520 and twist up to 30 degrees but this will be never necessary.
    As I can measure air pressure at each RIB on windward och lee-side of the skin so automatic seeking for biggest difference
    in pressure then the wings curvature and AoA can be adjust for maximum driving force like never before.

    I see that solutions applied to many sailing boats are dictated by different rules or one class requirements
    in order to give all sailors the same chance.
    And you are right: who cares if thickness play role when all are forced to have the same wing design?

    Now the latest AC boat will get D-shaped mast and double-skin soft sail. The D-shaped mast will twist ?
    In my opinion AC shall get also open class version limited by xyz BOX not prohibiting progress of what is possible
    and not using muscles to drive the boat.
    But interesting sport events for masses are also very important so I am not against how they run the AC circus now.

    Still I am satisfied with your answer - good to know how other sailors are thinking - THANKS!
     
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