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  #1  
Old 09-14-2010, 03:43 AM
nikezz nikezz is offline
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Minimum engine horsepower required, at a given speed, displacement and hull form?

I have found rule of thumbs for hull speed, but it seems to be for amateurs and is grossly incorrect.

V = 1.34 (LWL)^(1/2)

I've also found rule of thumbs for hp to displacement

1 hp to 450-500 lbs

I was wondering if there were more accurate ways to find the hp required for a certain design, if you were only given

a. Hull form
b. Speed required (in knots)
c. Displacement (in tonnes)
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Old 09-14-2010, 10:25 AM
Eric Sponberg's Avatar
Eric Sponberg Eric Sponberg is offline
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Nikezzm,

Go to this link,

center of flotation calculation and implications?

and to post #264 to download "The Design Ratios", which we discussed on this forum earlier this year. This document of the sum of all my "lecture" posts on that thread. In chapter 4 and in chapters 11 and 12 I discuss the speed/length ratio and the various speed prediction equations.

Eric
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Eric W. Sponberg
Naval Architect
Sponberg Yacht Design Inc.
St. Augustine, Florida
www.sponbergyachtdesign.com
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Old 09-15-2010, 03:36 AM
nikezz nikezz is offline
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Quote:
Originally Posted by Eric Sponberg View Post
Nikezzm,

Go to this link,

center of flotation calculation and implications?

and to post #264 to download "The Design Ratios", which we discussed on this forum earlier this year. This document of the sum of all my "lecture" posts on that thread. In chapter 4 and in chapters 11 and 12 I discuss the speed/length ratio and the various speed prediction equations.

Eric
Thank you very much.
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