Analyses |
 
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Analyses |
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In the initial model setup, properties of the ocean, pipeline, seabed, installation vessel and internal fluid are assigned. The water depth is 50m at the initial vessel position, and increases to 150m as the vessel moves horizontally. The lower end of the pipeline is fixed at the seabed, and the upper end is connected to the vessel. The pipeline is filled with seawater. The file 3D_Seabed.fcsbd specifies the seabed topography.
Due to the operation of the meshing algorithm, which attempts to maintain element length consistency between adjacent line sections, some elements in the upper region of the pipeline are quite short. In order to lengthen these elements, a static restart analysis is performed. Specifically, elements 87 to 98 were extended to all use a standard element length. A further static analysis is also performed to adjust the total length of the pipeline to compensate for the increase in pipe length from the previous analysis.
The model includes three winch element sets, named WinchA, WinchB and WinchC. Winch velocity as a function of time is specified for each set. Vessel motion is specified in terms of a series of horizontal displacements at various times in a file called Vessel_motion.incx.