Estimation of hydrodynamic loads of an offshore supply vessel in uniform current

摘要

Simple approaches to estimate uniform flow current loads on a ship are expressed aiming for preliminary design stage. Surge, sway and yaw load coefficients at different current incident angles are investigated for an offshore supply vessel. Two different methods of Faltinsen and Leite are presented and compared. The effect of interaction of transverse and longitudinal current components to each other is shown. It is demonstrated that the surge force can be strongly affected by transverse current component which deserve consideration. Generally, both methods have the same trend but the Leite results tend to have higher values. The novelty of work is estimation of the ship cross-flow coefficient by applying the existing test result of simple shapes in incompressible wind tunnel to strip theory. On this base, the ship sections are replaced with equivalent sections such as ellipse, rectangle and diamond. The effect of edge sharpness and bilge radius is considered.