Re: [PSUBS-MAILIST] Ratio of ballast tank holes

["Jens Laland" <laland@artematrix.org>]

Frank

** Most soft ballast tanks are made from sheet metal and not meant to handle
** much pressure differential.

I browsed through a paper awhile ago... although, I don't know if it's
applicable to the rupture or collapse of air filled ballast tanks while
still being submerged... but anyway, here is an interesting quote from it:

"In the case of implosion problems, the structural failure of an
implodable volume leads to the compression of the air inside. The pressure
can become thousands of times greater than the atmospheric pressure and
much greater than the hydrostatic pressure. The differential of pressures
between the air and the water forces the air bubble to expand, generating
a shock wave that travels throughout the water. Since the implodable
volumes are usually mounted to the submarine hull, the shock wave?s
emission point is very close to the submarine and its strength is only
slightly decreased before it reaches the submarine hull. Thus, it may be
the effects of the implosion that lead to the failure of the submarine
hull rather than the initial shock wave induced by the explosion."

>From "A Multiphase Fluid-Structure Computational Framework for Underwater
Implosion Problems", by Arthur Seiji Daniel Rallu [2009], ref

http://stanford.edu/group/frg/research_team/arthur_thesis/ThesisRallu.pdf

Best regards,
Jens Laland




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