another nail in the coffin of the balestron, huh? first crappy jib luff tension, and now needing both rudders down for helm balance.
so the idea is that... there is less total drag with a single high-aspect foil than there is with two foils that provide the same leeway resistance and turning moment. that makes sense-- only one tip vortex.
it seems then that rudder placement becomes critical, because you need to balance sideslip from the sail with the weather helm caused by the ww hull. all without fine-tuning the CLR with the rudders. too much towards the ends and you geta big turning moment but not much leeway prevention. just the opposite if too much towards the mast.
is it all just guesswork or is there engineering software that can help? i only know of jSDN yacht designer. from a 3D CAD drawing it can calculate COE, CLR, COG, COB, etc. it's not clear to me though if it can compute drag and weather helm and leeway. maybe in the paid version.
woohoo about five proas in the competition! very much looking forward to seeing them all.
ben
--- In harryproa@yahoogroups.com.au, Rob Denney <harryproa@...> wrote:
> 2) It [balestron rig] will have lee helm if you only sail with one rudder. Bi
g deal, at
> least it will steer with 2, I hear you say. And I agree, but once you have
> sailed with one, it becomes pretty compelling, particularly as the bows lift
> up rather than get depressed by the drag on the rudder.
> Look forward to the details. Should be a fun competition. I have now seen
> 4 harryproa entries, plus mine. Plus I bet there will be a bunch of non
> harry proas as well.
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