Time Domain Simulation Of The Hydrodynamic Forces Acting On A Ship Advancing In Following Seas

In this paper, the hydrodynamic forces acting on a body are investigated by employing a semi-nonlinear time domain model for the three-dimensional radiation and diffraction problem with a free surface. The body boundary condition is applied on the instantaneous body surface while the free surface condition is linearized. The initial value problem is then solved for the velocity potential using a panel method on the moving body. After that, an "integral" method developed by Duan is employed to calculate the hydrodynamic forces on bodies of arbitrary geometry undergoing large amplitude motions.In order to validate the reliability of these theory and codes, some comparisons are made between the author's results and known semi-analytical solutions, numerical results and experimental data, including the added mass and damping coefficient associated with a floating hemisphere undergoing forced periodic oscillations and a submerged sphere undergoing large amplitude periodic motions, the wave resistance problem of a submerged spheroid, the diffraction problem of a submerged sphere with forward speed and a Wigley hull with forward speed. The results show excellent agreements between them. Thus, the present method is applied to study the diffraction problem of a Wigley hull with a forward speed in following seas.