Study On Simulation Mathmatical Model Of Ship Maneuvering Motion In Wind And Wave

With the development of the analog technology, the training simulator of ship maneuvering had been rapidly developed. The training simulator can be used to carry out the driving training job for the driver to cultivate the professional skills of the drivers and increase their level of technical operations, to avoid the maritime accidents caused by the improper operation of the drivers. The simulation model of the ship maneuvering motion was the core technology of the training simulator, then building the mathematical model of ship maneuvering motion with the 6 degrees of freedom in wind and wave and researching the ship maneuvering motion in wind and wave had engineering and practical significance.With the dynamics theory of ship motion, based on the idea of the separate modeling of ship maneuvering motion, the ship maneuvering motion equations with the 6 degrees of freedom was derived and established. Based on the hydrodynamic performance of the ship, propeller, rudder separately considered, considering the mutual influence and simplifying the expression of hydrodynamic, the hydrodynamic mathematical model of bare hull, propeller and rudder were established.Based on the assumption that the random wind on the sea was steady, the mathematical model of the wind force was given. According to Froude-Krylov hypothesis assumption, the ship was regard as a box, the mathematical model of first-order wave forces was established. The second-order wave forces was proportional to the wave height and the mathematical model of second-order wave forces was establishedOn the base of the force of the mathematical model, which had been given, the ship maneuvering motion real-time simulation system in wind and wave was developed by using Fortran language. Using the program, the author calculated the ship maneuvering motion under different rudder angle in still water and analyzed the change of the heel angle and the turning trajectory. The author simulated the ship direct motion and the ship turning motion in wind and wave and gave the factors which impact the ship turning trajectory and swaying motions in wind and wave. The author summed up the instance that the ship easily be capsized in wind and wave when the ship was turning, which give the driver some advice to assure the ship is safe when sailing in wind and wave. The simulation program developed by the authour was used to the driver training simulator. The ship motion in wind and wave can be showed and the propellor speed and the conditions of wind and wave can be changed to meet the functional requirements of the simulator.