Re: [PSUBS-MAILIST] end caps [was: what is the diference k250- k600]

["Cliff Redus" <dr_redus@devtex.net>]

Ian.

Nice overall lines!  The drag from the free flooded hydrodynamic shell will
be low do to the streamlined profile and low cross sectional area as seen
from a frontal position.  When you start to do your weight and buoyancy
calculations, it looks from the drawing like your CG will be significantly
displaced aft from the CB.  One way to get around this would to use
syntactic foam aft.  It looks like the orientation of the pressure hull does
get you significant freeboard .  It will be interesting to see from your
calcs  how much freeboard you can actually achieve. From the diagram, it
looks like your calculations will also show a big movement in the CB from
fully blown MBT to fully flooded MBT. Thus, with the current layout, you
would have to find some way to trim longitudinally each dive. It would be
best if CB and CG were displaced only vertically.  Also I did not see a VBT.
How are you planning on doing fine tuning to get neutral buoyancy? What is
the pump for,VBT?  What is the design depth?  It looks like you are going to
use the aft fins for propulsion.  You might want to look at the work being
done at MIT on their robotic tuna project
http://web.mit.edu/towtank/www/tuna/brad/tuna.html.  Keep us appraised of
your progress as you cycle through your design process on this concept.

Cliff