NUMERICAL EVALUATION OF SHIP MANEUVERING PERFORMANCE IN WAVES

This paper considers a numerical computation of ship maneuvering performance in waves. For this purpose, modular type maneuvering model (MMG model) is adopted and wave drift forces and moments are included in maneuvering equation of motion. Wave drift forces ware calculated using a seakeeping program based on higher-order Rankine panel method. When calculating the wave drift force acting on a ship, the forward speed, wave heading, wave period and drift angle of the ship are considered as key parameters. It means that ship's lateral speed is also included to calculate wave drift force. Numerical simulations are carried out in regular waves using S175 containership and computation results are validated by comparing them with results of free-running model test. Using the developed program, numerical simulation in irregular waves are, also, conducted and discussion is made on the sensitivities of time signal of wave elevation on turning performance.