I will leave JT ot explain about the biplane
rig.
The tornado guys I am sailing against on Sunday are
the challengers for the next Little America's Cup, to be held here next
year. I am trying to persuade them that for a heavy air venue such as
Perth, they need an Atlantic proa. They are fixated on foils.
However, they have the 3 piece wing rig from the last challenge so we will see
what can be done. I offered to pay for a set of hulls and beam (only one
needed for an AP) for a 5.5m version to test it out, but there were no
takers.
The foil proa is still happening, just waiting for
the owner to pay some money, although I am not sure exactly what it will look
like yet.
Elementarry's speed hump at 16.8 knots may or may
not exist. Should have a better idea in 20 knots (new forecast) on
Sunday. I tried a planing hull on U. The boat would not climb over
the bow wave, just sailed on the front part of the rocker. Probably needs
some more work, although pointed sterns are not conducive to
planing.
regards,
rob
----- Original Message -----
Sent: Friday, March 10, 2006 7:37
PM
Subject: SV: Re: SV: [harryproa] some
more Elementarry data points
JT,
I like the concept. Why not connect the wings with
an
endplate at the top? I imagine that together with very
little or no
gap between bottom end of wing and deck
should give a very nice effective
A/R. Using constant
profile foils for easy production and having
the
biplane wings rotate around a common axis would rid u
of quite a bit
of mechanics. I like your idea about
using a teleflex cable, but why not
attach the wing
rudder directly to the wings with a rod and then
control
AOA for the wing from the helm positition with
the teleflex cable?
I don't think this concept is all novel, recall seeing
something
similar somewhere on the web. What I have
not seen is someone putting
something like that on a
100 kg, 7.5 m, l/b=20 Proa! This is the first
time a
rigid wing could really show it's benefits outside
the
category "very_expensive_and_fragile_speed_machines".
About the
real fun - I think Elementarry must be able
to leave displacement mode in
order to improve
Elementarrys upper speed range much above 16
knots.
Considering it's round bilge, double ended lee hull
will it
plane? Would not CLR moving, transitioning
from displacement cause
problems?
I think that to plane - Elemetarry needs either a
flat
bottom - 'Dory style' to possibly take it into
plane(Crew weight on
flying or planing ama should help
here).
Or take the hull out
of the water - Foils! A set of
nice foils, dimensioned to take the hulls
out of the
water @13-14 knots or so, should make the resistance
curve
look horisontal from liftoff into silly speeds,
compared to without foils.
From what I read, Mark is
working on a hydrofoil solution? An update would
be
nice.
Elementarry has obviously proven itself to be a
rocket
despite an undersize rig. I am so impressed by both
the potential
for this concept, as well as by what is
already
achived!
/Kenneth
--- jjtctaylor <jtaylor412@cinci.rr.com>
skrev:
> Kenneth,
>
> I have suggested to Rob a rigid
Biplane wing set
> which is functionally easier to use, and a
>
symmetical foil is really not a complicated effort.
> Just takes time
to fab. Chain or pulley
> set inside the LW hull gangs the wings
together so
> only a single air rudder is needed.
> Simple
teleflex cable to the rudder controls wing
> angle of
attack. Rob has an aeronautical
> engineer friend who has a
foil shape that would
> work. Only technical effort is what Rob
> does best, optimize the wing spar for weight and
>
strength.
>
> Wings size is 4 x 20 ft each for proper
aspect ratio
> and satisfactory performance. The
>
real fun comes if he can overcome the downwind
> velocity loss (bubble)
by accelerating at a
> beam reach then bearing off downwind as he
moves
> faster than downwind air, moving the
> air forward as he
bears off. Wings can do that if
> the hull efficiency is
right. Then you have
> true screamer, upwind and down !
>
> JT
>
> --- In harryproa@yahoogroups.com.au,
Kenneth
> Hernemalm <hernemalm@y...> wrote:
> >
>
> Congrats Rob, that is quite a feat!
> > Maybe not that
surprising about the Una rig
> working so
> > well -
Elementarry being a low drag boat is
> obviously
> > well
matched with a low drag rig. Good move! Will
> be
> > very
interesting to see how it works out with more
> > canvas. Optimizing
for low drag with a wing mast
> > should pay off. Can't help thinking
a rigid wing
> would
> > be cool on Elementarry, but i guess
that would not
> > make Elementarry very elementarry ;)
> >
> > Still planning for a Europe tour this summer?
> >
> > Good luck to leaving Tornados in the wake!
> >
>
> /Kenneth
> >
>
>
>
>
>
Bästa hälsningar
Kenneth Hernemalm
om du vill ringa
finns jag på 0701-593302 eller 031-552121
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