gigi66 a écrit:
Starboard n’a pas de winglet?
La cassure est moins marqué certes, mais pour moi, ils y sont
https://starboardfoils.com/pages/overview-2019To break the vortex effect the winglet has to have a hard cut, most (if not All) windfoils have curved tips. I think this has more to do woth stability, and mostly with the fact that we always sail with the foil under an angle (banked over). A plane is mostly completely horizontal when going in a straight line.
There is a difference you can feel between flat wings and wings with curved tips, mostly when banking the board and during the jibe the curved tips feel more steady / on rails.
Furthermore, most windfoilwings twist off a little at the end, which has a very similar effect (somehwat diminished maybe, wouldn’t know for sure), that is also one of the main aerodynamic reasons for loose leech /top twist in sails. A very clear example of this would be the F-One Levo900 wing.
Finally, I am starting to see 2 styles in performance wings, straight with curved wingtips, and wings with the curve a little further towards the middle, going back to flat / twisting off wingtips. (Sort of double s shape?) like the select profoil or the levo 900 named above.
Edit: onle last thing, tips curved up at the front wing might (just a thought, no empiric evidence whatsoever) cause distortion around the mast aswell, an airplane doesn’t have this problem.