Calculations of the Hydrodynamic Forces Acting upon a Ship with Large Amplitude Motions (1st Report)

In order to solve nonlinear hydrodynamic problems of a ship with forward speed, a nonlinear calculation method of two-dimensional hydrodynamic problems is developed. The free surface boundary conditions are linearized, but an exact body boundary condition permits large amplitude motion of the body. Appling the multi pole expansion method, a calculation procedure which gives an exact solution of the boundary problem mentioned above is developed. Ignoring the effect of the free surface on the bi-harmonic component of the velocity potential, an approximate calculation method is proposed. Calculated results are compared with measured ones. The approximate method gives fairly good estimations.