Experimental and numerical analysis of a fishing vessel motions and stability in a longitudinal seaway

Motions and stability of a typical B.C. fishing vessel were experimentally and numerically investigated in a longitudinal seaway condition. The experimental model was self-propelled, radio-controlled and equipped with an on-board data acquisition system. Pitch, roll, yaw, surge, and heave responses to regular waves of predetermined frequencies and amplitudes generated along a 220-ft model basin were obtained. Different displacement conditions and GM configurations were tested. The numerical model for the dynamic analysis of the fishing vessel motions has been implemented using strip theory. A computer program was developed to study the nonlinear motions of the vessel. The velocity dependent coupling terms, responsible for a major part of the nonlinear behavior, were included. A time dependent component analysis of the roll damping has been performed. Regular linear and nonlinear waves were used. A parametric study of the fishing vessel stability has been carried out by considering its dynamic response in waves of varying characteristics. Unstable behaviour was found to be closely related to waves of length of similar magnitude to the ship length. The effects of wave amplitude and rudder usage were found to be of capital importance in the capsizing process. Experimental and numerical results showed good agreement.Applied Science, Faculty ofMechanical Engineering, Department ofGraduat