Re: [PSUBS-MAILIST] Re: []

["Dale" <heinzind@cadvision.com>]

-----Original Message-----
From: Danny Campbell <danny.campbell@usa.net>
To: personal_submersibles@psubs.org <personal_submersibles@psubs.org>
Date: Wednesday, February 28, 2001 11:53 AM
Subject: [PSUBS-MAILIST] Re: []


  Bernoulli's Law applies
>in water just as in air... If two particles hit the leading edge of a foil
>section and separate, one going over the top and one going along the flat
>bottom, the one that has to travel the greater distance must travel faster
to
>meet up with the other particle at the trailing edge.  The faster the flow
the
>lower the pressure.
>
>Rudders and things like that are typically symmetrical since you're not
trying
>to get lift per se, just a force due to redirecting the mass flux of the
water
>going by.  I've never looked into it but I'm sure there are applications
for
>true foil sections used while submerged, whether it be for "flying" a
>submarine or for the lifting wings of a hydrofoil.
>
>Hope that answers your question Dale.  We'd love to see some more pictures
of
>your boat and know how your adventures are going!
>
>Danny
>


I was not sure if the principal (higher speed equals lower pressure) applied
equally in water as it does in air..I was musing about this today, and
thought because water does not compress, if you move an airfoil through it,
you must be lifting the upper column of water,(up over the airfoil) and
hence the whole weight of the column of water would be bearing down.
destroying any lift....if the airfoil was upside down, then there would be
no where for that column of water to go, and it would push you up.. kind of
the opposite of what you wanted...  anyways, thanks all for the answers..

I will be conducting the deep test on my sub next month (March).. I plan to
send it down to 400 feet without me in it..only a camera looking out at a
pressure gauge to record the feat, leave it down there for a while..(perhaps
an hour) and then bring it back up..Ill be taking some pictures and will
post the best ones (if It survives)   I will then be ready for a summer of
subbing..or summer fixing, or summer of recovery ,depending on the
outcome...

dale