Worldwide Approximations of Current Profiles for Steel Riser Design: The WACUP Project

This paper describes the objectives and methodology of the WACUP (Worldwide Approximations of Current Profiles) Joint Industry Project. The project goal is to establish best practice for reducing large current profile databases into a smaller, representative set of profiles for riser design. We studied the use of the following three techniques for comparing and reducing measured in-situ databases: Empirical Orthogonal Function (EOF), Self Organizing Maps (SOM) and classical Current Profile Characterisation (CPC). We evaluated the skill of these three techniques in estimating Vortex Induced Vibration (VIV) fatigue damage to a Steel Catenary Riser (SCR). Our measure of skill was the comparison of the results from the reduced data sets with results from the original complete database. The standard techniques were modified and accuracy was improved. The role of numerical current models to complement in-situ measurements in riser design was also assessed.