Mathematical Model For Ship Manoeuvring And Its Application In Navigation Safety Evaluation

With the development of ship enlargement, the research on safe navigation in the waterway of port and river is becoming more and more important. There are only some general regulations on the flow field in most technical codes of different countries for port and river projects while there are few specific regulations especially on the nonstationary and nonuniform flow. So the ship manoeuvring simulation has become an important tool to evaluate safe navigation in complex flow field and to choose good layout design plan of port and structure type. In the present thesis, a coupled ship manoeuvring and tide-current mathematical model is developed. On the basis of model validation, the coupled model is used to assess manoeuvring safety of different plans for Longkou Port waterway design. The main contents and conclusions are as follows:Firstly, the force and moment on the ship body, propeller, rudder and the interaction with each other in the mathematical model for ship manoeuvring are considered separately. The Ronge-kutta method is employed to solve the governing equation and the effect of tide-current is also taken into consideration to simulate the manoeuvring movement in a complex flow field. So a simulation system for safe navigation is presented.Secondly, the simulation system is applied to compute the flow field and to evaluate the safe navigation of different plans for Longkou Port waterway design. The results indicate that the ship of 60,000 ton can't enter the harbor safely in the design speed of 6kn without the breakwater due to strong cross current along the channel, while it can when the flow fiels is improved after the breakwater being built. The ship can also enter the harbor safely when the modified plan is applied.Thirdly, different ships are simulated in a specified flow field. The results show that the maneuverability of bigger ones is worse in the same flow field. As the ship is becoming larger and larger, the navigation safety deteriorates. So the evaluation of safe navigation will play more and more important roles in the future development of ports.