FLNG/FPSO Vessel Movement

Discussion in 'Hydrodynamics and Aerodynamics' started by ChemEnger, Oct 2, 2015.

  1. ChemEnger
    Joined: Oct 2015
    Posts: 1
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    Location: Edinburgh

    ChemEnger New Member

    Hi all, I am a chemical engineering final year student in Edinburgh, Scotland. I am currently researching the effect of motion on top side equipment for an FLNG vessel. I am a little bit overwhellmed by obtaining vessel pitch and heave data. I've been looking at RAOs but am struggling how to use them.

    I believe if I have a significant wave height of 4m, then my wave amplitude is ±2m and if the time period of the wave is 10 seconds, I then use the RAO chart and see where the curve intersects at 10 seconds to read off my heave (m/m) or pitch (deg/m). Using this number I multiply it by the wave amplitude to get the heave or pitch. Is this approach correct?

    The next problem I have is determining the period of the vessel for a given degree of freedom. Is it simply (in the case above) 10 seconds?

    Thanks for your help and patience with this noob!
  2. NavalSArtichoke
    Joined: Oct 2013
    Posts: 431
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    Location: GulfCoast

    NavalSArtichoke Senior Member

    Things are not as simple as you believe in trying to determine the effect of motions on FPSO vessels. Trying to give you a crash course in ship motion analysis in a blog post is out of the question. I suggest you seek out a naval architect who has experience with ship motion analysis and ask him to give you a tutorial in how to understand the ship motion data you have and how to apply it.
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