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*Para Seabed |
 
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*Para Seabed
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*Para Seabed |
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To request summary output of statistics of parameters related to seabed contact.
Refer to Output Parameters for further information on this feature.
A block of lines as follows:
[TITLE=Title Name]
[SCALE=Scale Factor] [, UNITS=Unit]
[PLOT=Plot Option]
DATA1=Set Name or ALL
DATA2=Seabed Parameter
Title Name defaults to blank. Scale Factor defaults to 1. The Unit entry is described in Note (d). Plot Option can be YES or NO (the default). Set Name must be defined using *ELEMENT SETS. Seabed Parameter can be 1 (for seabed clearance), 2 (for length on seabed) or 3 (for maximum span, average gap, and average gap over central third of maximum span).
Input: |
Description |
Element Set: |
The element set for which the summary output is required. |
Parameter: |
The options are Clearance, Length on Seabed, and Maximum Span and Average Gap. The options are largely self-explanatory. See Notes (a) - (c). |
Title: |
A descriptive title to be associated with the output. This entry is optional. |
Scale: |
A scale factor to apply to the data. This entry is optional, and defaults to a value of 1. |
Unit: |
The units to be used for the output. This entry is optional, and defaults to the base units for this output type. See Note (d). |
Plot: |
This option allows you to request a timetrace plot, in addition to the summary output. By default, no plot is created. |
(a)Clearance presents the statistics of clearance between the range of elements and the seabed. What actually happens is that for the element set you specify the program first attempts to identify “sagging” and “hogging” sections within the set. The minimum clearance calculations are then based on the sagging sections and the maximum clearance calculations on hogging sections. Where no such sections can be identified, the calculations cannot be performed, and a zero value is returned by default. Consider for example the case of a free-hanging catenary partly lying on the seabed, where seabed clearance is requested for a set of elements well above the touchdown zone. The summary output will report zero clearance in this case, because no sagging and hogging regions are present. Although this might appear counter-intuitive the program is operating as intended.
(b)Length on Seabed calculates the statistics of the length of riser in the element range lying on the seabed during the analysis.
(c)Maximum Span is defined as the maximum continuous length of pipeline that is not supported by the seabed. Average Gap is defined as the average clearance between the pipeline and the seabed within the region of the maximum span. The Average Gap is also presented over the central third of the maximum span.
(d)The units entry explicitly specifies what units are to be assigned to the output. This entry is optional, and if omitted, Flexcom simply assigns suitable units depending on the base units for the particular output type. If you do explicitly specify a unit, then it must be consistent with the dimension of the output type. For example, length can be specified in metres, inches, etc. The program is quite flexible in terms of accepting unit descriptions – e.g. metres, m, etc. are all equally valid.