catamaran series

Discussion in 'Boat Design' started by sorooshghaderi, May 17, 2009.

  1. sorooshghaderi
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    sorooshghaderi Junior Member

    Hi
    I'm a MSc student in marine Engineering.
    I want to test catamaran models from 64 , 89 , ... series.
    but I haven't non dimension table offset from these series.
    please help and guide me
    thanks a lot
     
  2. Ad Hoc
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    Ad Hoc Naval Architect

    sorooshghaderi

    There are not offset tables in the series 64 paper that I ahve, just lots of small body plans. These are relatively easy to scale off and then faired in later. Would these help?
     
  3. sorooshghaderi
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    sorooshghaderi Junior Member

    thanks Ad Hoc
    but I want to build some models from standard series and test it.
    then I must optimize the body hull for my final project.
     
  4. Ad Hoc
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    Ad Hoc Naval Architect

    Soroo...

    What will you "optimise" it for?..the series is a very efficient hull form.
     
  5. Guest625101138

    Guest625101138 Previous Member

    If you want to design an optimum displacement hull for a given displacement and design speed then you can use Michlet/Godzilla:
    http://www.cyberiad.net/michlet.htm

    It has the ability to rapidly iterate hull forms to achieve the lowest drag hull. In a few minutes it will analyse thousands of iterations and continually selects the hull with the lowest drag until a stable form is reached.

    This software has been used to optimise olympic rowing sculls, US Navy vessels, world record setting surf skis, world record human powered boat, low wave river cats and many more.

    Rick W
     
  6. daiquiri
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    daiquiri Engineering and Design

    Ad hoc, Rick, I was looking for the paper entitled "Series 64 Resistance Experiments on High-speed Forms", but with no success. Do you perhaps happen to have it? And if yes... well, you know... ;)
     
  7. Ad Hoc
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    daiquiri

    Yes i do ahve it..use it for almost all our boats.

    Will do.
    It is an old copy the photocopying isn't that good..Ive had it years...hope it comes out ok...
     
  8. Ad Hoc
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    Ad Hoc Naval Architect

    The question asked is in the emphasis is on "I must.."

    What is the point of using a software program when the aim is to do it manually?..using software doesn't help him one bit!
     
  9. daiquiri
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    daiquiri Engineering and Design

    Thanks in advance. :)
     
  10. Ad Hoc
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    Ad Hoc Naval Architect

    Soroo...
    which univeristy in Iran are you studying at?
     
  11. Guest625101138

    Guest625101138 Previous Member

    daiquiri
    If you are looking for the lowest drag hull you should be aware that the 64 series produces hulls having approximately 40% higher resistance than what Godzilla arrives at as the optimum for a given design speed.

    Playing around with the three variables available in the series does not offer the flexibility possible with Godzilla even using the 8 function version.

    You may find this paper of greater value on the hull series as it provides a method to apply the test results:
    http://www.dtic.mil/cgi-bin/GetTRDoc?AD=AD624688&Location=U2&doc=GetTRDoc.pdf

    You arrive at the best hull shape you can using the series and I will compare it with what Godzilla can produce.

    I should add that I have evaluated the results of Godzilla on boats considerably larger than the models that the Series 64 is based on and can confirm the accuracy of the results in the Froude numbers of interest.

    The other aspect of the series data if used for catamarans is that it does not consider hull interactions and these can be a few percent.

    Rick W
     
  12. Ad Hoc
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    Ad Hoc Naval Architect

    Daiquiri

    Ive scanned it in, finally, hasn't come out too bad. Took me ages to scan it in though..do you want me to send it to you PM?

    Mind you you could just ignore it and everything else in naval architecture, as the 'holy grail' has been found, it is a press the button software, no more studying required, ever!!
     
  13. daiquiri
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    daiquiri Engineering and Design

    I've sent you a PM with my e-mail address. Thanks a lot!

    I can feel a slight touch of sarcasm, or was it a cynism, in your words... ;)
     
  14. daiquiri
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    daiquiri Engineering and Design

    That link was useful, thanks a lot, Rick. :)
     

  15. Ad Hoc
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    daiquiri

    Just sent it to you.

    No cynicism at all. I never knew the holy grail had been found and all tank test houses are all redundant and unemployed scratching their heads thinking why didn't we do that... since the holy grail has been found, no more research required. Just press the button and hey presto...oppps, which button was that again?
     
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