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Old 03-02-2007, 08:26 PM
BennyWailer BennyWailer is offline
 
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metacentric height

hi,
I'm using Freeship to model a canoe. I want to find the metacenter at 15 deg of heel at a load. The program outputs stability cross-curves as KN*sin(theta)(ft).

Is there a formula to I can use to find the metacenter.

Cheers
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Old 03-03-2007, 01:41 AM
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Guillermo Guillermo is offline
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I recommend you the reading of: http://web.nps.navy.mil/~me/tsse/NavArchWeb/1/toc.htm
Cheers.
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Old 03-09-2007, 09:01 AM
BillyDoc BillyDoc is offline
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That's a very good link, Guillermo, thanks!

BillyDoc
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Old 03-09-2007, 10:47 AM
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RANCHI OTTO RANCHI OTTO is offline
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Very usefull link! Thank you G.
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Old 03-09-2007, 03:54 PM
BillyDoc BillyDoc is offline
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And another one I just stumbled onto, a low-level Navy course with pdfs of the chapters. Click on "Contents.pdf" and then ch01.pdf, etc. This is very basic stuff well explained. Just what I need most of the time!

http://www.usna.edu/naoe/courses/en200/
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Old 04-02-2007, 11:08 AM
knowme knowme is offline
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If I am right at 15 deg heel your metacenter M will coincide with your N. Hence you can find your metacenter from cross curves of stability. If I am wrong somebody correct me please.
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Old 04-03-2007, 12:56 AM
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Guillermo Guillermo is offline
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Quote:
Originally Posted by knowme View Post
If I am right at 15 deg heel your metacenter M will coincide with your N.
Nope. Have a look at the attached figure.
Just a clue: KN = KM * sin θ
Attached Thumbnails
metacentric height-curves.jpg  
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Old 04-03-2007, 09:09 AM
EAP EAP is offline
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Mr G,
Something Dosent Jive Between The Diagram You Posted And The Kn*sin(theta) Given In The Cross Curves Cals Of Freeship. Actually The Diagram Makes Sense To Me, What I Dont Understand Is What The Vertical Axis Of The Freeship Diagram Is Telling Us. It Seems That The Freeship Diagram Should Either Say Kn -or- Km*sin(theta) As Giving The Righing Lever.
Any Thoughts???
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Old 04-03-2007, 04:13 PM
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Guillermo Guillermo is offline
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Could you post the Freeship diagram, please? I do not use that program. Maybe it's a typo or a diferent meaning of notation there. Have you gone through the manual?
Righting lever GZ is equal to KN-KG sin(theta) in the notation I'm used to.
Cheers.
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