Delft series

Discussion in 'Boat Design' started by willfox, Aug 28, 2009.

  1. willfox
    Joined: Oct 2008
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    willfox Junior Member

    I am currently workng on a delft series excel program. I am using the regression coefficients which were based on pre 1992 yachts as i am designing a heavier displacement classic cruiser. Im not too sure if I have got the correct equation.

    has anyone got a link to this equation. I seem to be getting silly figures such as 1500kN at a Fn of 0.35 for a 13 m lwl and 20 odd tonne yacht?!! :confused:
     
  2. terhohalme
    Joined: Jun 2003
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    terhohalme BEng Boat Technology

    The residual resistance number is more or less on the spot but not kN, just N. Don't forget viscouse resistance.

    Terho
     
  3. Ad Hoc
    Joined: Oct 2008
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    Ad Hoc Naval Architect

    can you post the output?
     
  4. Alik
    Joined: Jul 2003
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    Alik Senior Member

    I always use 2-4 methods for resistance prediction (of course, proper methods with matching parameters). Never trust only one method to predict the resistance...

    For heavy displacement boat - try trawlers/tugs series. Delft series is known to underevaluate resistance of heavy motorsailers, while formally parameters of series match.
     
  5. Alik
    Joined: Jul 2003
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    Alik Senior Member

    This is sample for 16m trawler-style boat powerboat, calculated by same software.

    Need to say that formally boat fits in parameters of Delft series, but resistance is very different due to variations of hull shape.
     

    Attached Files:


  6. willfox
    Joined: Oct 2008
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    willfox Junior Member

    Im not too sure how i would attach the spreadsheet unless i could get email numbers?
     
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