Hello Jonathan
Herve Jauvert send me some photos of his "Inturder" wet sub that uses an outboard. I have them posted on my web site, www.submarineboat.com Look about half way down the " Evolution of Design" page. The SEALS also have a Surface Planing Wet Submersible. See the side bar at the bottom of the same page. I'd love to see some design details for that one. My design is for a 2-person, Surface Planing Dry Ambient and you can look through my insanity on the rest of the site. I welcome your input and look forward to hearing more about your design as you progress along.
Kindest Regards
Doug Jackson
Tulsa, Oklahoma.
In a message dated 5/21/2004 2:24:28 PM Central Daylight Time, Asmyth@changepoint.com writes:
Jonathan,
I love creative designs. This one has elements that have been done
before, but it wouldn't be an easy one to pull off. Especially the
retracting fins bit, that sounds pretty cool yet hard!
As for the first part about a high-speed planning wet sub hull, Herve
Jauvert of Seahorse Submersibles recently did just that, and sells it as
a special forces military sub. However, rather than retracting the
outboard, I believe he is pressure-compensating it and leaving it
outside during dives. I haven't asked him, but I surmise that from
photos.
On the topic of an X tail, I don't know anyone who has implemented it.
However, my own project has a V tail, which from a control perspective
is very similar. The only way I could find to implement it was with
independent electrical servos moving each control surface, and the
signals being electronically processed. There must be a mechanical way
to do this, as the Beechcraft Bonanza proves, but the mechanical
approach stumped me. I first implemented this with oversized toy servos,
but Ian Roxborough is currently writing software to do the servo control
on a Unix platform with industrial servos instead. If you can make your
way to the 2004 convention, I think you'll get some detailed info on the
approach.
Cheers,
Alec
-----Original Message-----
From: Jonathan Huntoon [mailto:jonathanhuntoon@hotmail.com]
Sent: Friday, May 21, 2004 2:10 PM
To: Personal_Submersibles@psubs.org
Subject: [PSUBS-MAILIST] Wet-sub propulsion stability and X-tail
Hello Everyone,
I have been an avid reader of the psubs website for quite
sometime. My
purpose in this email is two fold. First, I have decided to join the
mailing
list, and I thought I would make my formal introduction. I currently a
college student and I have been interested in submersibles since my
senior
year of High School. I undertook an ambitious project to build a one-man
wet
submersible. Using trolling motors, batteries, plywood and PVC, I
created
what many considered a death trap, but it worked! Due to problems with
electrical insulation, the system only performed admirably in fresh
water,
going 5 or 6 knots. I vowed, that if I ever had the time, money, and
inclination, that I would go back and try building another wet sub,
correcting all the problems with the first design.
My second purpose in this email is to ask a few questions. I
have done my
best to go back and read all the topics applicable to my situation. I
found
very little information however, on my specific questions. I think the
best
thing to do would be to give everyone a little background into my new
project, in hopes of giving you a picture of my ideas. I am majoring in
engineering, and I have experience in CAD. So someday I can attach some
design pictures.
I case you haven't figured out by this point, I have decided to
make a new
submersible. I was comforted to know I was not alone in my efforts. Most
people couldn't believe I made my first sub, so I thought they would not
be
surprised when I started another. I was wrong (It is difficult sometimes
when everyone thinks you're completely nuts).
I have made every effort in my new sub to follow hydrodynamics.
As I
mentioned before my sub is a wet sub, it will hold two people. The sub
design is 14' long and 4' diameter at the widest point, which is 5'6"
down
the length. The sub follows a tear drop contour and is as
hydro-dynamically
sound as I can make it and still keep the project manageable.
I wanted to make my project unique, and so I decided to try to
come up with
one solution to the age old question of sub endurance and speed. Because
my
vehicle is a wet sub, the driver must wear SCUBA gear to operate it.
Therefore it is not practical to drive the vehicle out to the dive site.
I
wanted a way to quickly get the sub to the dive site, dive down,
surface,
and then quickly drive the vehicle home. As I am sure you all know the
ideal
hydrodynamic shape underwater performs very poorly on the surface. As
waves
pile up on the hull, the vehicle looses all efficiency. I asked myself
how
to fix this many times, and the solution seemed to be staring me in the
face. One of the advantages that wet subs have is their weight. I can
make
my hull out of fiberglass. What would happen if I added enough power to
the
vehicle to get the whole hull to hydroplane out of the water? The way
the
sub is contoured it might work.
I have designed my sub to (hopefully) hold a 40HP e-start
outboard motor.
When the sub is on the surface, the outboard will propel the entire sub
out
of the water at a high rate of speed. I can drain the hull and close it
making it a surface boat. Underwater I will withdraw the outboard into
the
hull and store it in a pressure compensated compartment. This minimizes
flooding issues with the motor, and eliminates the hull protrusion.
When I was faced with the obstacle of how I would steer my
submersible, I
immediately drawn to the cruciform arrangement. I am a big proponent of
the
KISS principle. Underwater steering can be accomplished with the
cruciform,
but when the sub is hydroplaning the tail presents a problem. Even if I
extend the tail through some means so that a section of the rudder is
underwater, when the boat travels at high speed there could be a real
instability. Realistically the hull could be completely out of the
water. I
was originally only going to have the motor stationary, but even if I
rigged
it to turn a little, is there a danger of the sub getting out of
control? I
have seen too many movies of those high speed boats flipping out of
control
and hurting people. I know I am inside the sub, but it can still hurt me
it
flips at 30+ mph.
I decided a way I might combat this instability it to use an
X-tail. Some
navies around the world have opted for the tail because it gives 25%
tighter
turns. I like it because I am considering using a piston to extend the
lower
fins of the X into the water when the sub is at high speed, effectively
giving me 3 points of a stable tripod. Does this idea sound crazy? I
could
turn the sub, but also adjust the hull pitch up and down.
My last question is if anyone has experience dealing with X tail
control
systems. Due to the complexity, I would need all four fins to be
actuated
separately. I would need joystick control, and some sort of motor
control
that could take my stick position and turn it into the proper fin
position.
The trick is the forces off the fins are additive, so all four fins need
to
work together.
I realize this is a long email, but I look forward to reading
anyone's
insights on the matter.
Best Regards,
Jonathan Huntoon
|