The Simulation Study On The Functions Of The Schilling Rudder While Berthing And Unberthing

Because of the large-scale, specialised, and high-speed development of the modernised ships, relevant personnel’s demand for manoeuvrability has been increasing steadily. Rudder effect, which fundamentally affects the ships, has always been one of the concerns, and the corresponding researching works is ever on the way. As a new rudder type, Schilling Rudder has gradually come into application, especially common onboard full form ships, such as some large-scale oil tankers, together with large-scale container ships, and some other ships’ forms. Its excellent hydrodynamic features win overall recognition, and lay solid foundation of its further promotion. The theories of berthing and unberthing with the aid of Schilling Rudder are mostly acquired from actual ship experiments, and the qualitative and the quantitative analyses are relatively scarce. Therefore, the analysis on the effects of Schilling Rudder plays a critical and practical role while taking into practice.The thesis adopts MMG modeling thought, and establishes individual models on the bases of hull, screw, bow thruster and rudder’s particular performance, together with the interference. Meanwhile, comparison has been made between the expressions of the ordinary rudder and Schilling Rudder, and complies them into the ship simulation model one by one. It provides such a relatively sensible, integrated mathematical model which combines the Kijima model and the Yoshimura one, and compatible for almost the whole maneuvering aspects (including low speed, normal speed, small and large drift angle, etc.). When drift angle is over30degrees (big drift angle), the Yoshimura model is applied; when less than20(small drift angle), the Kijima one is applied; within20and30, the interpolating method is applied. Under the consideration of the shallow water effect, the conclusions are reached out through the Yoshimura one. Simulation platform is developed on the basis of MATLAB mathematical language. With the appliance of the fourth order Runge-Kutta method, the ship simulation movement formulas are resolved. Ship maneuverings in harbor, especially the berthing and unberthing handling, are simulated with the usage of Simulink toolbox. On the ground of the validity insurance of the simulated ships, many simulation experiments are carried out on the Schilling Rudder ship with different rudder angles, loading conditions, the use of the bow thruster, etc. By the comparison of trajectories, changes in heading, and heading change rate and so on, many factors which influence the Schilling Rudder effects are analyzed. When coming into practice, especially the self-berthing and self-unberthing with Schilling Rudder and bow thruster, the conclusions might be the references to the relevant personnel.