ON THE HYDRODYNAMIC COEFFICIENTS OF HIGH SPEED VESSELS WITH VERTICAL MOTIONS

A method to calculate the vertical hydrodynamic forces acting on a high speed vessel with vertical motions is described. It is based on the Chapman formulations. The radiation condition is treated by following the method of Yamasaki & Fujino in which a more relaxed Sommerfeld's radiation condition is imposed on an artificial open boundary. As an application of the method, the diagonal and cross-coupling added mass and damping of heave and pitch for a high-speed boat as well as a fishing boat are calculated and compared with experimental results. Calculations following a nonlinear OSM are also conducted for comparison. The comparison showed that the vertical hydrodynamic coefficients of high speed vessels can generally be evaluated with more accuracy using this method.