Bow Wave and Kelvin Wake

Discussion in 'Hydrodynamics and Aerodynamics' started by WilliamP, Oct 21, 2012.

  1. Ad Hoc
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    Ad Hoc Naval Architect

    D

    Oh dear, what a sorry paper.

    In the abstract it mentions “hull speed”. That set the tone. No serious hydrodynamicist would ever use the nonsensical bullocks term “hull speed”. And to follow this up with “..its pointed forebody would slice into a head or an oblique wave separating the wave to the right and left…”…ugh!

    As for his theorems….oh dear. Obviously never seen a high L/D ratio hull form. ;)

    His complex equations reduced to a simple 1 liner..which if you use “0 degree” as an input makes it rather silly…but then uses this simple 2D equation to arrive at 3D flow results!!

    45% reduction of power at 10 knots!!....:eek::eek:

    It is just meaningless drivel I am afraid. I could go on..but its 10mins of my life I won’t get back. :(
     
  2. gonzo
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    gonzo Senior Member

    Is this where the bow bulbs make a difference at the design speed? Do they change the angle of the bow wave because they are submerged or is the effect completely unrelated?
     
  3. Ad Hoc
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    Ad Hoc Naval Architect

    It is :
     
  4. Ad Hoc
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    Ad Hoc Naval Architect

    Indeed. Nowt like favouritism to support an "objective" discussion :D:D
     
  5. Leo Lazauskas
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    Leo Lazauskas Senior Member

    You just have to be sure to find really, really good ones to trot out. :)

    Lamb, Ursell, Newman, Wehausen and a few others will be remembered as truly
    great in their field.
    Whittaker is just not in the same class. Demonstrably so, now that you have
    shown us his elementary mistake. :p
     
  6. Leo Lazauskas
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    Leo Lazauskas Senior Member

    It's a question of time management, John.
    Here, let me sing it for you...

    You've got to know when to hold 'em.
    Know when to fold 'em
    And throw 'em in the bin.
     
  7. Ad Hoc
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    Ad Hoc Naval Architect

    I am indebted to you for your sagacious words and insight... :p
     
  8. Leo Lazauskas
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    Leo Lazauskas Senior Member

    If I can save you 5 minutes next time, then my work is not in vain.
    It was a truly poor paper.
     
  9. Ad Hoc
    Joined: Oct 2008
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    Ad Hoc Naval Architect

    After reading the drivel in just the 3rd line of the abstract, i was ready to throw in the towel. But, D asked me for my opinion on the paper, so i'll blame him for not getting back 20mins of my life in reading it :D
     

  10. daiquiri
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    daiquiri Engineering and Design

    Hey guys, you cannot always eat candies, ok? :D
     
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