Subject: [harryproa] Re: Harryproa website
From: "Robert" <cateran1949@yahoo.co.uk>
Date: 11/19/2006, 8:55 PM
To: harryproa@yahoogroups.com.au
Reply-to:
harryproa@yahoogroups.com.au

-The wind vane is set according to the wind angle but, as the boat
accelerates and the apparent wind moves forward, the pressure
decreases in the venturi as it is moving faster through the water.
This change in pressure, through a spring loaded piston and arm,
changes the relative angle of the vane. The details are still a bit
vague but a low pressure tube to a piston is the basic principle.
Whether a sealed piston or one designed for continuos leakage I am
not sure, but a continuous controlled leakage could be a means of
adjustment and would avoid problems of water sucking back into the
cylinder. Have a suite of them and you can have a friction reducing
bubble layer (;<) .
How to mount the venturi? Possibly a simple tube at right angles to
the flow on the lw of the lw hull below where there is ventilation
and out of the boundary layer. It doesn't have to be a great deal of
force if there is a long enough arm on the steering as the force is
continuous. I am sure there are more sophisticated methods such as
specially designed hoods to accelerate the flow past the tube and
control the angle

Another possibility is to have the velocity component feedback with a
bibbed fishing lure, minus the hooks, attached to a lever arm. The
bib keeps it below the surface until it picks up a plastic bag or
piece of weed. Generally at a reasonable depth there is no problem
with picking up garbage. Leave the hooks on and you will immediately
luff up when you get your dinner. The big problem is that you will
have a hard time with bite offs so a matt black colour scheme and
wire trace is in order.
regards,
Robert

ahoogroups.com.au, "Rob Denney" <proa@...> wrote:
>
> How would it work?
>
> regards,
>
> Rob
> ----- Original Message -----
> From: Robert
> To: harryproa@yahoogroups.com.au
> Sent: Friday, November 17, 2006 7:50 AM
> Subject: [harryproa] Re: Harryproa website
>
>
> Ticking over the difficulties of apparent wind against direction
and
> thought about feedback for the boat velocity component. How about
a
> venturi providing a feed back system? Avoids the problems of
waves
> for any surface piercing arms, but is susceptible to aeration.
> Robert --- In harryproa@yahoogroups.com.au, "Robert"
> <cateran1949@> wrote:
> >
> > -Tricky balancing velocity in the water against wind direction,
> > but theoretically doable. good luck. Robert-- In
> > harryproa@yahoogroups.com.au, "Rob Denney" <proa@> wrote:
> > >
> > > G'day,
> > >
> > > It is the self steering vane, which doubles as the emergency
> > steering oar. Ideally, the blade should be vertical for the
self
> > steering, but I will try it horizontal first.
> > >
> > > No idea yet if the self steering will work, especially
downwind.
> > Should be fun finding out. Even if it is not perfect, it will
> still
> > be a whole lot better than a gen set and fuel or the solar
panels
> an
> > electric auto pilot needs. It is also a lot easier to fix.
> > >
> > > regards,
> > >
> > > rob
> > >
> > > From: Robert
> > > To: harryproa@yahoogroups.com.au
> > > Sent: Wednesday, November 15, 2006 10:59 AM
> > > Subject: [harryproa] Harryproa website
> > >
> > >
> > > Good to see the Harryproa website recovering. Interested to
see
> > the
> > > TransPac Harry and work out what that funny looking oar like
> > member is
> > > between the hulls.
> > > Robert
> > >
> > >
> > >
> > >
> > >
> > >
> > > ----------------------------------------------------------
> --
> > ----------
> > >
> > >
> > > Internal Virus Database is out-of-date.
> > > Checked by AVG Free Edition.
> > > Version: 7.1.385 / Virus Database: 268.11.5/426 - Release
Date:
> > 8/23/2006
> > >
> >
>
>
>
>
>
>
> ----------------------------------------------------------
----------
>
>
> No virus found in this incoming message.
> Checked by AVG Free Edition.
> Version: 7.1.394 / Virus Database: 268.14.6/536 - Release Date:
11/16/2006
>

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