|
David,
The reduction in prop noise with CR props is very interesting.
I'm seeking 5 to 8 knots top speed, but may end up adjusting my
expectations. Even with that capability, much of your operation and mine
will still be at 3 knots or less. I'm considering putting the stern planes
and the rudder in the prop stream for greater response and
manouverability. The problem is they get in each other's way. Here
are a couple of videos on how Nemo-100 handled it. You can
pause the first one at 00:20 to get a good look. The second
video is better for observing it in operation. Both videos took
several minutes to load.
I don't know yet what the rear of my sub will look like and may not take
this approach. One other I'm considering is having a single rear main
thruster that rotates up and down, left and right, but that presents its own
problems as well. Due to other responsibilities, it will be several months
before I can seriously work on that design issue. Maybe by then I will
have seen somebody's design that I really like.
What is the basic shape of your design? By the way, I notice that
Volvo uses the term counter- instead of contra- in their description.
Jim
In a message dated 12/30/2010 2:34:46 A.M. Central Standard Time,
dbartsch2236@hotmail.com writes:
In in-water testing near a boat ramp with
early passive sonar hydrophones, I was flabbergasted at how well I could
hear boat motors and props especially when they throttled up to aid in getting
the boat and trailer out of the water.
I was later
dumbfounded when a rather large boat did this and only the engine could be
heard...Later when the boat was out of the water I saw why... It had two
counter rotational props on a single drive shaft outboard! Had it not been for
the gas motor itself, this particular boat would have been an issue with any
collision avoidance sonar system.
If such a
drive system could be installed aboard a small submarine and driven by
an electric motor, I could attain the speed desired for planes control as
well as reduce self generated noise to better aid in passive sonar
searches.
David Bartsch
> Subject: RE:
[PSUBS-MAILIST] counter rotational
> From: MerlinSub@t-online.de
>
To: personal_submersibles@psubs.org
> Date: Thu, 30 Dec 2010 08:20:00
+0000
>
>
> Put the shafts and gear in water and seal just
the motor...
>
>
> "David Bartsch"
<dbartsch2236@hotmail.com> schrieb:
> >
> > Thanks
gang,
> >
> > Torpedo use is definitely out. After a little
thought I think the real problem when using such a drive on a submarine would
be to be able to seal these two separate shafts from leakage from sea
pressure. Still, placing two such props inside a kort nozzle could give some
awesome results...I'll follow up on your provided references.
> >
> > David Bartsch
> >
> >
> > From:
JimToddPsub@aol.com
> > Date: Thu, 30 Dec 2010 02:08:21 -0500
>
> Subject: Re: [PSUBS-MAILIST] counter rotational
> > To:
personal_submersibles@psubs.org
> >
> >
> >
> > David, here are a couple of links re contra-rotating
shafts.
> > -Jim
> >
> >
http://www.springerlink.com/content/t821016235773860/
> >
>
> http://www.maxxprod.com/mpi/mpi-266.html
> >
> >
> > In a message dated 12/30/2010 12:03:38 A.M. Central Standard
Time, dbartsch2236@hotmail.com writes:
> > Anyone have a clue as to
how a single shaft dual rotating propeller gear box works? Drawings?
>
>
> > David Bartsch
> > =
>
>
>
>
>
************************************************************************
>
************************************************************************
>
************************************************************************
>
The personal submersibles mailing list complies with the US Federal
>
CAN-SPAM Act of 2003. Your email address appears in our database
>
because either you, or someone you know, requested you receive
messages
> from our organization.
>
> If you want to be
removed from this mailing list simply click on the
> link below or send
a blank email message to:
>
removeme-personal_submersibles@psubs.org
>
> Removal of your
email address from this mailing list occurs by an
> automated process
and should be complete within five minutes of
> our server receiving
your request.
>
> PSUBS.ORG
> PO Box 53
> Weare, NH
03281
> 603-529-1100
>
************************************************************************
>
************************************************************************
>
************************************************************************
>
= |