Analysis Summary |
 
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Analysis Summary |
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The base node of the riser is fixed in the 3 translational degrees of freedom. Vessel boundary conditions (BCs) are specified in the translational DOFs at the ends of the two winches, and for the moonpool rigid elements. The initial positions of the two vessel reference points and the RAOs are also input. The SCR is specified as being full of seawater.
A regular wave of amplitude 3.21 m and period 5.75s is specified. The BCs remain unchanged and are carried through automatically from preceding analyses. Since vessel BCs and RAO data have previously been input, dynamic motions are automatically applied with the onset of wave loading.
The payout of the installation winch takes places at 2.2 m/s over a 65s interval, including ramping up and down intervals of 5s. The pull-in of the FPU winch takes place at 1.25 m/s over 92s, again with 5s ramping up and down intervals. These values are for demonstration purposes only, to give an analysis of reasonable duration. Much longer winching times would be used in reality.
Adequate clearance of the winches from their respective moonpools has to be ensured. This is checked here using Clear, the Flexcom postprocessor for clearance/interference calculations. Note that two rigid beam elements are included in the model to represent the edge of the moonpools on the two vessels, for the purpose of the clearance analyses.