Study On The Slope-bank Effect Of The Ship In Restricted Water

Recently with the continuously increasing of the density of the vessels in the restricted waters,many accidents such as collision,stranding and grounding occur occasionally,which attract much attention to the ship-maneuvering in the restricted waters.The article mainly studies the impacts of the slope-bank effect when the ship navigates in restricted waters,and carries out a simulation to the major influential factors,such as the width of the waterway,depth,speed,the distance off centerline and slope angle.According to Japan MMG's ship maneuvering mathematical model theory,the formulas for calculating hull hydrodynamic force,rudder force and propeller force are presented,and the hydrodynamic interaction among them.The article provides a ship maneuvering mathematical model in restricted water which combined the Kijima model and Yoshimura model.The ship maneuvering mathematical model in restricted water is suitable for the entire maneuvering range including normal speed,low speed,small and large drift angle and so on.Considering the effect of shallow water,the conclusions researched by Kijima is adopted.On the base of the above-mentioned mathematical model,the paper fully takes the influence of wharf suction and push torque into consideration when ship sails close to the coast,applies the fourth-order Runge-Kutta to compute the mathematical model,and simulates the ship movement in restricted waters with Simulink toolbox in MATLAB.At last,the paper studies the major influential factors on Slope-bank effect,and gives the ship movement state on the corresponding condition,the simulation result is identical to the qualitative analysis.This research provides a reference not only for the ship steerers and the pilots on safe control of the vessel in restricted waters,such as narrow channel and canal,but also for the waterway designers and the dredge operators,and brings forward a theoretical foundation to the research and development of Ship Handling Simulator.