Vessels and Vessel Motions |
 
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Vessels and Vessel Motions |
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The various program options for modelling vessels and associated vessel motions are discussed in the following sections:
•Basic Vessel Concepts introduces the various vessel motion categories and the vessel local axis system.
•Combining Vessel Rotations discusses the available methods (both large and small angle theories) for combining vessel rotations from a number of sources.
•Vessel Offsets discusses the application of static offsets.
•Low Frequency Drift Motions describes the application of second order drift motions.
•High Frequency RAO Motions describes the application of first order (wave frequency) motions.
•Combined High and Low Frequency Motion Timetraces describes the facility to combined low and high frequency vessel motions into motion time histories.
•Summary of Vessel Motion Options summarises the various vessel motion categories, and valid combinations of those divisions.
•Calculating Vessel RAO Response outlines the basic principles underlining the operation of the Flexcom vessel RAO facility.
•RAO Conversions describes the available options to define conventions with respect to the specification of vessel RAO data.
•RAO Layouts describes the different schemes for laying out the data in the RAO file.
•Moonpool Data describes the specification of the vessel moonpool, which is used in the computation of hydrodynamic loading within the moonpool.
•*VESSEL,INTEGRATED is used to specify all information pertaining to a vessel or vessels.
•*VESSEL is used to specify the initial position and undisplaced orientation of a vessel.
•*RAO is used to specify Response Amplitude Operators for a vessel.
Note also that the old *VESSEL and *RAO keywords have effectively been superseded by the new *VESSEL,INTEGRATED keyword, which accepts RAO data also, thereby eliminating the need for a separate *RAO keyword – hence the ‘integrated’ nature of the new keyword.
•*OFFSET is used to specify an offset of an attached vessel from its initial position.
•*DRIFT is used to define vessel drift motions.
•*VESSEL TIMETRACE is used to specify that the combined high and low frequency motions of a vessel are to be read from an ASCII timetrace data file.
•*RAO FORMAT is used to define custom RAO conversion settings.
•*MOONPOOL is used to define the location and extent of the vessel moonpool.
If you would like to see an example of how the *VESSEL,INTEGRATED keyword is used in practice, refer to any of the standard Flexcom Examples.