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 Classic30 09-19-2012 10:59 PM

Moment curves

I came across this amongst the pile of plans.. Can anyone tell me exactly what it's trying to tell me? :confused:

http://i1136.photobucket.com/albums/...ps0450264a.jpg

Thanks,
Cameron

 tdw 09-20-2012 12:38 AM

Re: Moment curves

whoa ... did all the pans come with her C ? That is wonderful.

Now as for me I have no idea what that actually means but how about the wave created by the boat at the nominated angles of heel at max hull speed ?

 tdw 09-20-2012 12:39 AM

Re: Moment curves

but I think I'd be totally wrong ....

though that illuminates my poor dim mind not one iota.

 tdw 09-20-2012 12:46 AM

Re: Moment curves

Try this ....

Understanding monohull sailboat stability curves | M.B. MARSH DESIGN

Seemingly absolutely nothing to do with wave motion and all to do with stability.

May I go back and remove my first post please ?

 Faster 09-20-2012 01:05 AM

Re: Moment curves

Quote:
 Originally Posted by tdw (Post 924269) .....though that illuminates my poor dim mind not one iota.
I looked at that link... that must make us 'dim' and 'dimmer'.....:confused:;)

 SloopJonB 09-20-2012 02:38 AM

Re: Moment curves

Quote:
 Originally Posted by Faster (Post 924273) I looked at that link... that must make us 'dim' and 'dimmer'.....:confused:;)
Add me and we have "dimmest". :D Unless it's Steven Hawking speaking I can usually grasp the concept but that link was totally ununderstandable. :confused:

 Classic30 09-20-2012 03:00 AM

Re: Moment curves

1 Attachment(s)
Quote:
 Originally Posted by tdw (Post 924268) whoa ... did all the pans come with her C ? That is wonderful.
..and not just the plans but the specification also!! :D - including the following statement which explains why it's all so rare.

Do Jeff and Bob write stuff like this? I'd be curious to know:

Attachment 12191

That the original owner ignored that statement and that the previous owner was an architect (and document hoarder!) is one of the reasons the ANMM catalogued her. :)

 Classic30 09-20-2012 03:03 AM

Re: Moment curves

Quote:
 Originally Posted by SloopJonB (Post 924286) Add me and we have "dimmest". :D Unless it's Steven Hawking speaking I can usually grasp the concept but that link was totally ununderstandable. :confused:
At least now I know I'm not the only one! :D

From Wikipedia: "The convex hull of any finite set of points on the moment curve is a cyclic polytope.[3] Cyclic polytopes have the largest possible number of faces for a given number of vertices, and in dimensions four or more have the property that their edges form a complete graph. More strongly, they are neighborly polytopes, meaning that each set of at most d/2 vertices of the polytope forms one of its faces. Sets of points on the moment curve also realize the maximum possible number of simplices, among all possible Delaunay triangulations of sets of n points in d dimensions.[4]"

Repeat that quickly at your next dinner party and your 'neighbourly polytopes' will tie you up in white canvas and pack you off to the local looney bin!! :laugher :laugher :laugher

(..so I'm secretly hoping one of the Design Gurus around here can teach us something before we all go barmy. :eek:)

 svHyLyte 09-20-2012 10:48 AM

Re: Moment curves

Quote:
 Originally Posted by Hartley18 (Post 924233) I came across this amongst the pile of plans.. Can anyone tell me exactly what it's trying to tell me? :confused: Thanks, Cameron
I believe that is a graphic of the moments of the immersed area taken about a longitudinal axis of the hull at the indicated heeling angles.

 bobperry 09-20-2012 11:46 AM

Re: Moment curves

Those are very interesting curves but they don't tell me anything. I just need a more simple explanation other than the Wiki one. I would think a more useful set of curves would be immersed volumes at various heel angles. For my simple approach to design that would be a more tangeable way to look at immersed heeled volumes. I've been around the world of yacht design professionaly now for 45 years and I have never seen them before. Maybe Jeff can explain them. Now I really want to know.

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