asymmetrical fin

Discussion in 'Boat Design' started by phum, Nov 4, 2010.

  1. phum
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    phum Junior Member

    Hello all,
    Where would I find a drawing/ offsets for a asymmetrical fin section?
    Peter
     
  2. PAR
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    PAR Yacht Designer/Builder

  3. phum
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    phum Junior Member

    Now I have too many choices, What would be a common section used?
    Peter
     
  4. PAR
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    PAR Yacht Designer/Builder

    Foils sections selections are based a several variables. What is your target Reynolds number range?
     
  5. phum
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    phum Junior Member

    chord length .5 Mt.
    speed 3 Mt. a second
    Renolds number approx 100,000.
    Does that sound right?
    Peter
     
  6. PAR
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    PAR Yacht Designer/Builder

    Okay, now what do you want this foil to do? It's application?
     
  7. phum
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    phum Junior Member

    one of a pair of bilgeboards.
    Peter
     
  8. PAR
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    PAR Yacht Designer/Builder

    That's not telling me much. What level of preformance do you desire? What make, model and year boat? Are there specific needs or issues you're looking to solve? What where the previous sections employed and why didn't you like them? Etc., etc., etc.
     
  9. phum
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    phum Junior Member

    I am looking at replacing an existing lifting fin with 2 bilgeboards. The object of the exercise is to free up floor area in the cabin. lifting bilge boards would be built into bunks so floor area will be clear. The main reason for seeking a efficent section is minimise size and maximise lift.
    Peter
     
  10. PAR
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    PAR Yacht Designer/Builder

    Well you still haven't told me much, so I'll just offer up some sections that preform well at low Reynolds numbers and you can research them and pick the one you like.

    Naturally, the first one would be the bench mark E387, next on the list would be the FX 63-137, followed by the SD 7003 and SD 7037.

    Then again you can fall back on one of the NACA 63 series like the 63-209 or try the Selig S3021.
     

  11. phum
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    phum Junior Member

    Thanks very much for the info.
    Peter
     
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