Angle of attack?

Forums Chop Shop and DIY gear Angle of attack?

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    jt
    Participant

    What angle of attack are you DIY wing makers using for both front and tail wings please? Also do they differ from normal to high aspect wings too? Thanks.

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    HSfoils
    Participant

    Just to split hairs quickly- Angle of Attack (AoA) is the angle at which the foil attacks the water while under way, this varies with speed and how many pies you ate first.

    Angle of Incidence (AoI) is the angle at which the wings are set relative to a horizontal line (zero deg.) We generally assume this to be parallel to the fuselage.

    Usually the front wing is set at zero degrees, that is if you draw a line through the foil from the apex of the leading edge to the trailing edge it will be zero degrees, parallel with the fuse. This isnt to be confused with AERODYNAMIC ZERO, When the wing is producing zero lift. this usually requires an AoI in the negative 1-5 degree range.

    Tail wings obviously differ greatly but anywhere from -2 (zero lift) to +5 degrees (gofoil maliko levels of downforce) will work depending on your skill and paticular wing. I find roughly +2 degrees to be a happy average with my setup, does everything from flat water paddle starts to head high drop ins

    jt
    Participant

    Thanks HSfoils. Sorry meant angle of incidence. I’ve been using a E-Flite Angle Pro II 5 in 1 Digital Incidence Meter using the plate mount on the mast as my 0 degree reference point. Seems most Axis front wings are set at about 2 to 3 degrees up whilst the tail is 0 to -1 degree.

    surfcowboy
    Participant

    I’ll rough measure mine this week but when I was building a diy wing I was advised to aim for 1 or 2° for front wing.

    Curious to see what brands do. Paging KD…

    surfcowboy
    Participant

    Just checked and my Gong XL is dead flat measuring by my ultra accurate iPhone and clamp with a groove in it method.

    Kane DW
    Moderator

    2 degrees difference between front back wings is pretty standard, most brands use varying combinations of front and rear wing angle to get it.

    Ive heard Armstrong and axis use around +2 in the front but that could be less on the newer wings, naish about +1 front on their new wings.

    The amount of front wing angle is basically a trade off between high and low speed efficiency. The goal is to Keep the fuselage parallel with the flow for max efficiency, but foils run such a wide range of aoa it ends up being a choice of what speed you want the fuse straight at. In some cfd runs I’ve done, a 1300cm2 wing with an 85cm span at 11% thick runs about 0.5 degrees at 15mph with an 80kg rider. The same wing in pump could hit 5-15 and at top speed is probably at 0 or even -0.5.

    Personally I like 0 in the front wing the most, I spend a lot of time going fast and any angle in the front feels like the foil rides nose down. My newest wings are as fast as anything and so far so work great!

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