how is the helm balance of this configuration of foils and sails? does the wing have much area forward of the mast step? if not, i would think the COE would be fairly far aft of the CLR of the centerboard, and a lot of weather helm would result. like a unarig.
that's one advantage of rob's double big rudders: you can move the CLR aft by raising the front one.
ben
> I have shown a centreboard and two rudders under the lw hull. This
> overcomes some of the vortex shedding issue I envisaged with two
> larger bi-directional rudders intended for leeway prevention. The
> centreboard is cambered with small radii edges. The intention is
> that it will work over a very narrow range - the goal is to have it
> at zero angle of attack. It needs to be elevated and lowered to
> achieve this to balance leeway forces from the wing and hulls. The
> rudders do not do much work so are also bi-directional with small
> radii edges but non-cambered. All the underwater control surfaces
> are under the hull to lower risk of ventilation and sudden changes in
> control. I expect the leading rudder will ventilate in waves but
> this should only result in a slight reduction in drag not sudden
> changes in control forces.
>
> I have shown a wing over a flat elevated deck that works as a bottom
> end plate for the wing and will increase L/D over a wing without end
> plate.