Large amplitude ship motions and bow flare slamming pressures in regular head seas

In this paper, the motion equations incorporating nonlinear terms due to large amplitude motions and bow flare slamming pressures are described in regular head seas. Numerical predictions of ship motions based on a small amplitude linear theory and large amplitude nonlinear method and experimental data are compared with each other in the frequency and time domain. The nonlinear restoring force, nonlinear damping force and nonlinear fluid momentum force are considered in predicting ship motions. The frequency dependent added mass and damping coefficient are computed at the instantaneous submerged sections of the ship. The momentum slamming theory and Wagner theory are used to predict the bow flare slamming pressure. The total impact pressure is expressed as the sum of water immersion impact pressure and wave striking impact pressure. There is a satisfactory agreement between theoretical predictions and model test measurements.