Re: [PSUBS-MAILIST] Going faster (was: gel-coat)

[MerlinSub@t-online.de (Carsten Standfuß)]

My 3 cents - 1 cents each point:

1.) special hull surface - may look for swim suits for olympic swimmers
in the internet, most of the winners of the last olympic sports events
use there swim-clothes from one factory/material - I have forgotten the
name - something 
with shark.. We can cover our subs with that clothes .. if it not work
it is easy to remove it. (But sandpaper will clear not work..) 
To test it will be very easy and unexpensive - two submarine styled
bodys in the size of coca cola bottles on a balance beam - one with the
cover the other without. Or two girls on the balance beam on a rope
behind a boat - one with the swim-clothes - one without .. 

But I am myself are not so much interesst in that stuff because for the 
reason that submarines which stay longer in the water will quickly 
get some floor/flower/shells on their surface and need for this 
reason a layer of anti-flower-paint. 
I remember some years ago the US-navy did some test on a
minesweeper-ship
hull - works well the first 2-3 weeks..

2.) flipper wings for propulsion will work - on surface ships. 
During my study we have one human powered prototype ship during a race
between the europe shipbuilding University's. It was made by dutch 
guys and run well forward - but the reverse thrust was very, very
low. Karl Fuller and I allready discuss this idear 
for submarine purpose last year - and found that the wings will move in
one direction and the sub hull in the other.. not very comfortable in a
submarine
with a hull go fpr example 60 times minutes up and down or left and
right - and
can not go fast to reverse..
For this reason you need at least to flipper wings which runs in
opposite 
direction together.  

3.) Richard your are very welcome - but new idears get criticism all the 
time - criticism will stop if your prototype race over/under the water. 

If somebody offer a idear to this open group - this indicates
that it is a open idear and he want to share - if he don't want to 
share this idear - he should not open a discuss about it. 

E-MHD thrust without moving part will be a great idear 
for subs in saltwater - Richard, maybe make your world wide patent 
in each nation with a coastline - at least in america and europe, 
maybe also in japan - than come back to share the full idear.  
And if your idear is usefull - everybody around you will copy them
- if you want or not - the only way to make big money with that is 
produce them quicker than all the other guys - and better. 

How much for a 40 kilowatt device which a 70% thrust ratio -
like a standard propeller ? Which voltage, how many space inside 
the sub ? Which influence to the computer and instruments inside the sub
? 
Works that with steel hull subs ? 
Which influence to the sub/engine during the time the (steel-) wreck on
the
bottom gets visible close to your portside windows ? 
I can send you some hundreds question more .. but a the moment I can not
belive
that this work with a good power to thrust ratio.. 

Carsten
 

"Michael B. Holt" schrieb:
> 
> Thanks, Tim, for the essay about grooves in the hull.  Somewhere
> around here I have papers about that sort of thing, and there was a
> patent granted for the idea of a grooved hull.
> 
> One of the papers is about the shark and dolphin skin characteristics.
> What I gleaned from the article was that dolphin skin, especially,
> reduced drag by being flexible.  As I recall the paper, bubbles formed
> on the skin, and the dolphin would eject them by sending a wave of
> warm blood along its body while flexing the entire skin in a series
> of pulses.  The bubbles served the same function as the sandpaper, but
> only up to a certain speed; beyond that, they were drag-inducers.
> 
> Of course, figuring out how to send a series of waves long the
> out hull of a submarine might be an engineering challenge ...
> 
> Shark skin is different, being covered with a layer of fibers oriented
> along the flow direction.  That might work, for some speeds, but the
> idea of a submarine covered in plastic fur is, at least, funny as hell.
> 
> Has anyone evdr followed up the idea of the flipper as propulsion?
> There's a canoe builder in Canada who has a pedal-pwoered boat that
> uses a flexible flipper for propulsion.  I'll see what I can find.
> 
> Mike