Re: [PSUBS-MAILIST] gelcoat

[Carl Kem <dustyut@lasal.net>]

I recall the German XVIIB used peroxide.  Tons of it were used without incident.
After WW2 the Brits had the sub and renamed it HMS Meteorite (was U-1407).  If I
remember correctly, the USN also did some experimenting with peroxide, but that
never came to much.
Carl


Carsten Standfuß wrote:

> Hmm, have heard something of a new russian test torpedo called "the big
> one"
> with a kerosin / peroxide drive. Was on board "Kursk". Very effective,
> can reduce a 30.000 ts warship in a view seconds to under 15.000 ts...
>
> Was delivered from the factory with a handbook, page 1 :
> Do not store/use onboard of any russian naval vessel until its wartime
> and all other torpedos are allready fired and war-luck went badly down..
>
> Maybe simillar thing like walter-peroxide rocketengine torpedo (1944)
> called "Mondfish" (G7ur = Rückstoßtorpedo/Rockettorpedo later T XIV).
> But this was a small unit developt for midgets, runs just 50 knots
> for 1200 m with the rocket engine at the stern.
> Test report conclusion was : Some test shoots with "different luck"...
>
> If you build some rocketengines on the forward end of the torpedo -
> like the rescue rockets system on Apollo spacecraft -
> the peroxide/kerosin engine produce a hell amount of CO2 and steam ..
> its maybe very fast underwater - but control is maybe another point.
>
> Carsten
>
> John Pier schrieb:
> >
> > The new Russian torpedo, still under development goes 200 miles an hour
> > under  the water, yes 200 miles / h
> > however it is kind of a rocket more than a torpedo and  to reduce the huge
> > drag at this speed , the torpedo releases a "skin" of gas between the water
> > and its hull. No sand paper here !!!
> > Herve Jaubert
> >
> > ----- Original Message -----
> > From: Tim Curtis <navark@yahoo.com>
> > To: <personal_submersibles@psubs.org>
> > Sent: Tuesday, February 27, 2001 11:58 AM
> > Subject: [PSUBS-MAILIST] gelcoat
> >
> > > The idea behind all of this is to reduce the amount of
> > > flow that is touching the surface in question.  Like
> > > you said, laminar flow is better for as much of the
> > > hull (wing) as possible in terms of drag.  There will
> > > almost always be turbulent flow over the majority of
> > > the hull though.  These turbulent vortices suck energy
> > > from the hull to maintain their motions.  If you were
> > > to place micro-grooves along your hull that were
> > > matched to 80-90% of the diameter of these turbulent
> > > vortices, then you would have a reduction in drag.
> > > The reason being, is that the turbulent flow actually
> > > touches less of the hull this way - if you picture two
> > > triangles, like two mountains next to each other, with
> > > a huge sphere/cylinder supported by the two points.
> > > The sphere is too large to fall into the valley
> > > between the mountains, so it only touches at two
> > > points.  If you can get your turbulent flow to only
> > > touch at two points instead of dragging completely
> > > across the body, you will decrease your drag.  This is
> > > probably poorly worded, and I apologize.  It is much
> > > easier to describe with diagrams.
> > >
> > >    -Tim
> > >
> > >
> > >
> > >
> > >  I seldom post anything but often take a look in to
> > > see what is going
> > > on.  Now I am truly puzzled.  First, I am not a fluids
> > > engineer, but I do
> > > know some facts about aerodynamics from years of
> > > studying airplanes.  I
> > > think you fellows are talking about turbulent boundary
> > > layer.  As air flows
> > > over an airplane wing the velocity of the air
> > > approaches zero as it comes
> > > in contact with the wing itself.  In an airplane an
> > > undisturbed boundary
> > > layer is very important.  This creates laminar flow
> > > down to the wings
> > > surface and greatly reduces drag.  One reason that the
> > > P-51 in WWII was so
> > > fast was that they could maintain this laminar flow
> > > well past a third of
> > > the wings cord.  The British gained advantage with
> > > this effect also until
> > > they started painting their Spitfires with a rough
> > > dull finish camouflage
> > > paint which disturbed the laminar flow and caused
> > > greatly increased
> > > drag.  Everything I have studied suggests that you
> > > want to minimize
> > > turbulent boundary layer flow to reduce drag.  I have
> > > no doubt that putting
> > > something like course sandpaper on the hull of a sub
> > > would be a massive
> > > mistake.
> > >      Perhaps there is some finish that promotes a type
> > > of turbulent flow
> > > that is benificial but before anyone goes for the
> > > rough look I think you
> > > need to research this extensively.
> > >
> > > G, Boucher
> > >
> > >
> > > __________________________________________________
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> > > http://personal.mail.yahoo.com/
> > >
> > >

--
"In times like these, it helps to recall there have always been times like
these."-Paul Harvey