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Re: Surf foil self-sailing up wind

Posted: Mon Dec 16, 2019 11:27 am
by merl
Peter_Frank wrote:
Sun Dec 15, 2019 8:52 pm
I have the very opposite experience.

In light winds say 7-9 knots (at 10 m height), where there is hardly ANY wind down at the surface, most hydrofoil combos will sink down to board flat either fast if heavy aluminium, or really slow if light carbon and big wings, .
....

If you got a foil that ALWAYS sits on its side when put into this position, in "no" wind also, you got a problem indeed :(

8) Peter
I think my combo will sit on its side indefinitely. RL Orca, which is a 663 copy Wing only slightly heavier than the original, and a relatively light and short (75cm) alu mast. But I think the thing that makes it worse is a low volume board. The rail sinks deeper so the mast is more horizontal to the water in a very stable position.

Re: Surf foil self-sailing up wind

Posted: Mon Dec 16, 2019 11:41 am
by Herman
If the centre of lateral resistance (water) aligns with the centre of effort from the windage it will sail along. If the centre of effort is behind the centre of lateral resistance it will turn into wind, in front, it will bear away. If the centre of effort moves forward as it heads up to align with the centre of lateral resistance and vice versa you will get more body dragging practice. Just my theory. Somebody had the idea of adjustable buoyancy which would help.