Ship Maneuvering Simulation In Winds& Waves

Based on the ship maneuvering mathematical model on water surface, the thesis built up ship maneuvering mathematical model. The model took the rolling coupling and the effect of interference forces and moments by winds, waves and sea currents during maneuvering into account. Moreover, this article has made a further research of ship's rolling characteristic in wind and waves after maneuvering.When building up the mathematical model, the following factors have been considered: the forces and moments acted on ship's hull, propeller, rudder and interrelationships; the ship's movement on water surface and the rolling moment coupling; the rolling forces and moment by maneuvering; the recovery forces and moments of buoyancy; the ship's hydrodynamic forces and moments; the rolling damping forces and moments; the ship's inertia forces and moments; the interference forces and moments of winds and waves; and the interacting relationship of them. The paper applied the calculating method-the Runge-Kutta method to calculate the equation of maneuvering mathematical model, and simulating calculated for the trials on the ship's maneuverability by Visual C++ programming language. The thesis presented a quantitative analysis to the relationships between the rolling angle and the ship's different maneuvering scheme in wind and wave. And put forward the assessment curves of maximum rolling angle and maneuvering rudder angle by calculation in case of the dangerous situation caused by transversal wind and wave.By the researching, we can draw the following conclusions:During turning in the winds and waves, it may cause a larger rolling angle acted by the rolling moments in winds and waves and the rolling moments by maneuvering. The calculated results showed that the magnitude of the ship's maximum rolling angle caused by maneuvering and waves has some relationship with the rolling phases caused by waves and turning rudder. When the phases are same, the rolling angle will be larger; on the contrary, it will be smaller. It may cause an obviously rolling under the effect of waves even turning a smaller rudder angle.The results of this thesis can provide the reference guides to the captains and the officer to maneuver the ships in practice. And put forward a certain theoretical method to simulate the ship's maneuverability in waves at same time.