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Air temperature data, compared with the 2oC above ambient recommended limiting temperature criterion.
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Turbulence intensity compared with a recommended turbulence criterion.
Although no formal criteria currently exist, it is also sometimes helpful to present:
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Longitudinal velocity data at 25m/s free stream velocity (an indication of the extent of shear in the flow).
There are a number of key issues that should be appreciated when this data is presented, and is plotted or tabulated in terms of wind heading:
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The convention is that wind headings are always presented in terms of the heading FROM which the wind is blowing. Nevertheless, labelling of tabulations and plots should always include the words wind direction (from) in order to remove any chance of misunderstanding
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The heading reference being used should always be explicit on every tabulation and plot
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For fixed platforms in the early phases of design it may be convenient and useful to present results in terms of headings relative to Platform North. However, in later stages when data is being used in operability assessments, or is being prepared for the production of a summary for operations (see Section 10.10.3), then it is likely to be much more useful if presented in terms of True North
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Installations such as mobile drilling rigs and FPSOs that can change their heading as a result of the weather conditions or for operational purposes should have their wind heading data presented relative to their primary axis. Again the direction of this primary axis should be explicit
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In all the above, a small annotated plan view sketch alongside the table or plot should be used to avoid any possibility of misunderstanding by the reader.
In the future this is likely to be augmented by: It is recommended that data is presented at two levels, firstly a detailed level which shows quantitatively the parameters of interest in relation to the acceptance criteria (see Figures 10.19, 10.20 and 10.21 below), and secondly at a simpler summary level, which illustrates the extent of non compliance with the limiting criteria as a function of wind speed and direction (see Figures 10.22 to 10.24).
The tabular presentation of the data should comprise results from a polar survey taken above the landing spot together with results from lateral surveys. The lateral surveys should correspond to the worst-case wind directions identified in the polar surveys. Typical examples of a tabular presentation are shown in the tables in Figures 10.19 and 10.20.
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