FAST2011 Conference Papers Available

Discussion in 'Hydrodynamics and Aerodynamics' started by Leo Lazauskas, Mar 13, 2012.

  1. Leo Lazauskas
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    Leo Lazauskas Senior Member

    I'm not sure what you mean by the "plateau" in the drag curve.
    My predictions, and Lawry's, and the (scaled) experimental results show a
    dip at about 23 knots for the uniform cushion case, but no plateau as such
    after that.
    However, compared to the catamaran the SES is far superior with about
    half the resistance at 50 knots. It's hard to do better than that, except with
    a segmented cushion with unrealistic pressures.

    In the graphs, the first set are for the single cushion case.
    h100c0 means 100% support from sidehulls (i.e. a pure cat).
    h20c80 means 20% sidehull support, 80% from cushions.
    The other set of graphs are for a segmented cushion case (with three
    subcushions).
    Except for a narrow band around 19 knots, drag is worse than the single
    cushion case.
     

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  2. BMcF
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    BMcF Senior Member

    I should have said "and/or plateau". What is often overlooked in both the model testing and theoretical world is that the drag hump is not as pronounced in the real world..often not nearly so. You do not 'put the craft on full lift" and then proceed ahead i the real world; you only do that in the model tank. The actual..the practical..drag curve is much more benign in the hump region, as the skilled skipper slowly adds lift as he adds propulsion power. Thus, in actual practice, the drag 'hump' becomes in reality a 'ledge preceeding a plateau'.;)
     
  3. Ad Hoc
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    Ad Hoc Naval Architect

    Just the same occurred with SWATHs too...some very unpublicised disasters out there!
     
  4. BMcF
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    BMcF Senior Member

    I know..I was 'there' too.:rolleyes:

    Ruh roh. In hindsight,,my presence at the scene of so many 'NA disasters' might be interpreted as a 'trend'...
     
  5. Ad Hoc
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    Ad Hoc Naval Architect

    Bigger than this baby??

    TNSL-01.jpg TNSL-2.jpg
     
  6. Ad Hoc
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    Ad Hoc Naval Architect

    :eek::eek::eek:
     
  7. Leo Lazauskas
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    Leo Lazauskas Senior Member

    Thanks, Bill.
    That's another good reason to produce resistance curves at various levels of
    cushion support. Lucky I don't use CFD for those sort of calculations :)
     
  8. Leo Lazauskas
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    Leo Lazauskas Senior Member

    Is that beast in service now?
    There seemed to have been several stops and starts to the project before it was finally launched.
     
  9. Ad Hoc
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    Ad Hoc Naval Architect

    As far as I know, still laid up. But I think they used her during the Tsunami evacuations last year. But can't find confirmed reports of this. I read on one Japanese site/journal....my Japanese is very rusty at best! :(
     
  10. BMcF
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    BMcF Senior Member

    I forgot all about that thing. It's easy for me to forget because..

    1. It was an operational failure.

    2. The design was based heavily on a 'gratis' USN to Japan '3KSES Data Dump' that some of us thought innapropriate.

    3. I was not brought in and never received a dime on that project..see 2 above. :p


    The largest SES projects that I was involved in that 'nearly' proceeded to a complete vessel were the German SES-700 (850-ton FLD) and the Italian SEC (1100 ton FLD). The former was cancelled at 'last moment' as consequence of German reunification costs and the latter was never completed due to financial collapse of the shipyard involved. As for designs that never emerged beyond paper and maybe a tanks model, I could not begin to count them all; but the largest would have been the most recent..the USN HSSL at over 1000' LOA.
     
  11. Leo Lazauskas
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    Leo Lazauskas Senior Member

    Sadly, the FAST 2011 papers are no longer available from the link I posted.
    Someone read boatdesign.net, passed on the information, and then I received
    an email from someone involved with the T-Craft that I hadn't heard from in
    about 8 years. Apparently, the papers shouldn't have been there.
     
  12. BMcF
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    BMcF Senior Member

    "shouldn't have been there"? Odd. Is that because the proceedings are supposed to be published only for sale?
     
  13. Leo Lazauskas
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    Leo Lazauskas Senior Member

    It wouldn't surprise me if that's the underlying reason. The conference and
    proceedings were prohibitively expensive (for me) back in 1997.
    All I got from my acquaintance was that:
    "...X was surprised to see them there when I notified him."
     
  14. BMcF
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    BMcF Senior Member

    They were 'free' if you attended.:D

    I attended all of the early ones from Trondheim through Yokohama...but as the activity in AMV/HPMV areas fell steadily off, so did my enthusiasm for spending a lot of money to attend that conference series. The annual international Fast Ferry conference was another 'must attend' that long since dropped off my radar, I'm afraid.
     

  15. Leo Lazauskas
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    Leo Lazauskas Senior Member

    The conference was free, if you hung around looking like a janitor. :cool:
    The proceedings were free if you had a friend who refereed the papers. :)
     
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