Estimation of current loads on offshore vessels

Abstract

Current loads acting on offshore structures, particularly side-by-side moored vessels are important factors for predicting the hydrodynamic and structural responses of the structures. Unfortunately there are only a few standardized current load data for single offshore vessels setting aside side-by-side moored vessels. In this study, current loads on only single vessels are studied as an intermediate step for estimating current loads acting on multi vessels. Current load coefficients for three hull shapes are calculated using a CFD code, which is well known in the field of shipbuilding industry. In order to validate the proposed approach, a typical VLCC is taken as an example and resulting current coefficients are compared with experiments and with the OCIMF(Oil Companies International Marine Forum) data. The comparison shows a good agreement in qualitative sense. Two additional models considered herein are a shuttle tanker and a FPSO under deepwater condition (WD/T ≥ 6). It is found that the current force is very sensitive to the hull shape. The present numerical approach is expected to be applicable for practical design of offshore vessels. Copyright ？ 2005 by The International Society of Offshore and Polar Engineers.