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*Moonpool |
 
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*Moonpool
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*Moonpool |
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To define the location and extent of the vessel moonpool at solution initiation, for the purpose of applying hydrodynamic loading on elements of the structure contained within the vessel moonpool.
Refer to Moonpool Hydrodynamics for further information on this feature.
A block of two lines repeated as many times as necessary.
VESSEL=Vessel Name
X0, Y0, Z0, θ, b
A vessel cannot have more than one moonpool.
Input: |
Description |
Vessel Name: |
The name of the vessel whose motions define the motion of the moonpool. |
X0: |
The global X-coordinate of the origin of the vessel moonpool at solution initiation. See Note (a). |
Y0: |
The global Y-coordinate of the origin of the vessel moonpool at solution initiation. See Note (a). |
Z0: |
The global Z-coordinate of the origin of the vessel moonpool at solution initiation. See Note (a). |
Theta: |
The initial yaw orientation of the moonpool in degrees measured anticlockwise from the global Y-axis. See Note (a). |
Width: |
The moonpool width, and overall height of the transition region. See Notes (a) and (c). |
(a)The vessel moonpool entrains a volume of seawater that is assumed to translate and rotate with the vessel in question. The water particle velocities and accelerations within the area enclosed by the moonpool are calculated from the vessel motions, as opposed to from the ambient wave field. The moonpool is assumed to be square in cross-section and extends from the origin of the moonpool (which would typically be at the same level as the vessel keel) to above the mean water level, as shown below.
The initial location of the volume enclosed by the moonpool is defined by specifying the global X, Y & Z coordinates of the moonpool origin, which is located at the centre of the square that forms the bottom face of the volume enclosed by the moonpool. The orientation of the volume enclosed by the moonpool in the global YZ-plane at solution initiation is defined by θ, which is the angle between the local moonpool y-axis and the global-Y axis (measured anticlockwise from the global-Y axis). In most circumstances, this would be the same as the initial vessel yaw orientation. At solution initiation, the volume enclosed by the moonpool is assumed to be orientated vertically (that is, the local moonpool x-axis is aligned with the global X-axis).
(b)The initial location and orientation of the volume enclosed by the moonpool corresponds to the initial position of the vessel with which the moonpool is associated. Any movement of the vessel from its initial position (including movement due to offset, drift, or vessel RAOs) will cause a corresponding movement of the volume enclosed by the moonpool.
(c)As noted above, the moonpool width b also defines the overall height of a transition region between the volume enclosed completed by the moonpool and the ambient wave field. This transition zone, and how Flexcom treats riser element within it, is illustrated and discussed in the notes of the Moonpool Hydrodynamic Properties table. You are referred to that table for further details if necessary.