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Re: [PSUBS-MAILIST] Submerged speed calc
A couple of years ago Peter Madsen wrote about Kraka and her snorkeling performance. His comments:
...the primery problem that hits a classic shape during
high underwater speed is a "nose up" tendency. Kraka has a hull that has this
tendency since most of the drag inducing superstructure is above the center of
thrust, causing a rising torque as uw speed increases. At some 6 knots the boat
( expected ) goes out control, since at this speed the dive planes are 15
degrees down - yet the boat still rises. That is the limit of the
design.
Great that Kraka just rises for him when going out of control. At the time he seemed to really like running on snorkel and was getting into work on his UC3 boat which has a modern shape more optimized for submerged speed.
http://www.bluesky-services.dk/submarine/pages/page_050_uk.html
take care-
Paul