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  1. #1
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    Body aerodynamics

    I just watched antoine albau's speed run at Luderitz. It's evident that they are getting more efficient in as much as they are doing it in relatively lighter winds but it begs a question:
    The most draggy inefficient part is the sailor's body. Has anybody tried fairing the body, arms, legs etc like the speed skiers do?. Surely it must be worth a couple of knots?

  2. #2
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    At the ( relatively) slow speeds they are doing it is likely the biggest drag is in fact coming from the sail. I think the next step in terms of speed is likely to be some way of managing the airflow coming off the leech of the sail.

  3. #3
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    And cavitation of the fin and drag on the board. Don't think there is too much drag in the sail by comparison or ice sailors would not be able to go so fast. I would love to hear your thoughts on that.

  4. #4
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    board drag is the big issue, we need a small upward component of force to reduce board drag, you dont have to fully fly just reduce the board drag a little. tiny foils do it.

    Not sure how to approach the body drag issue, not sure we should either, the closer it is kept to a windsurfer the better.... If you want to build the ultimate speed sailing machine it will not be windsurfer shaped, so then a windsurf speed record should be done on something that looks like and is a windsurfer.

  5. #5
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    I,m working towards a more rounded shape bonus of which is I don't need a weight belt either. ��

    Been looking into landyachts and speaking with bloke that builds/designs them reckoned laying prone as opposed to sitting up was worth minimum of 10 mph . ( the 5.6 model can be uses seated or laid down)

    H had a class 5 yacht which he,d done 72 mph on. Sail wasn't special at all. Low tech at side of ours.

    I,d guess body drag is main reason boards seem more efficient in lighter winds..bigger sail less relative body drag ? Certainly an area worth looking into.

  6. #6
    Junior Member Wing 11's Avatar
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    At 50 kts drag distribution is:

    board 50%
    sail 30%
    fin 10%
    body 10%

    also note:

    -planning board has almost constant drag /nearly indepedent of speed

    -hydrofoils drag increase with square of speed
    Last edited by Wing 11; 12th September 2017 at 05:14 AM.

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