PREDICTION OF HYDRODYNAMIC FORCES AND MOMENTS ACTING ON SHIPS IN HEAVING AND PITCHING OSCILLATIONS BY MEANS OF AN IMPROVEMENT OF THE SLENDER SHIP THEORY

A method of prediction of hydrodynamic forces and moments acting on a ship in heaving and pitching oscillations is presented. It is based on a revision of the slender ship theory, which can interpolate between the original slender ship theory at low frequencies and the strip theory at high frequencies. Numerical computations are carried out for Series 60 models and results are compared with experiments by Gerritsma and Beukelman. Much better agreement between computer and measured results is observed when compared with results of the strip theory.