New Wing Sail

Discussion in 'Multihulls' started by Manfred.pech, Apr 9, 2017.

  1. bjn
    Joined: Jul 2014
    Posts: 99
    Likes: 1, Points: 8, Legacy Rep: 16
    Location: Stockholm

    bjn Junior Member

    This is probably true. The wing can create more lift. But because of tip losses in limited span, the difference is smaller than in infinite span. So I think it's impossible to get a ratio of 2.

    This report shows a lift coefficient of 1.6 for a windsurf sail. So that would need a lift coefficient of 3.2 to double the lift. Which I think is near impossible in infinite span. And very much impossible with the aspect ratio of a windsurf sail. I think a wing will not be able to have a lift coefficient of more than 2 with the aspect ratio of a windsurf sail.
    http://people.eng.unimelb.edu.au/imarusic/proceedings/13/Alexander.pdf

    I'm wondering what will happen to these soft wings in really strong winds? They might deform. I hope they have tested that.

    I think this is wrong. A wing will never be sailed dead downwind. It will be sailed at an angle to the true wind to get the apparent wind at 90° or more forwards.
     

  2. bjn
    Joined: Jul 2014
    Posts: 99
    Likes: 1, Points: 8, Legacy Rep: 16
    Location: Stockholm

    bjn Junior Member

    The endplates will act to increase the effective span/aspect ratio. Effective span will more or less increase like if the span was increased by the length of the endplates (within limits, of course). The endplates in question are very small, and will barely change the effective span at all. So will not stop the induced drag=)

    It's not possible to stop the induced drag. You can only decrease it a bit with the endplates, or by increasing the span/aspect ratio.
     
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