Computation of the Linear and Nonlinear Hydrodynamic Forces on Slender Ships with Zero Speed in Waves : Infinite-Depth Case

In the present paper, an infinite-depth unified theory is applied to the computation of the linear and second-order hydrodynamic forces on slender bodies. No forward speed is assumed, which is valid for some types of ships, like FPSOs and shuttle tankers. Strip theory solution, which is essential for the extension to theory is extended to unified theory, was obtained using NIIRD program developed at MIT. The linear theory is extended to the computation of the second-order mean-drift forces and moment. Furthermore, Aranha's formular is applied to the prediction of wave drift damping coefficients. From this study, it is proved that unified theory provides an accuracy comparable with 3D panel method for the second-order forces as well as the linear solution with much less computational effort.