Hydrodynamic Numerical Study On The Ship's Side Thrusters In Restricted Waters

In recent years, in order to realize the construction of marine power and marine resources development strategic target, our country accelerates the development of marine engineering equipment research, deep-sea oil exploration, and also rises a great mass favor of the south China sea reef reclamation and expansion. In the construction of south China sea reef expansion, as the main force in building construction, lots of advanced propulsion technology engineering ships are equipped with bow and stern thrusters. In restricted waters, like the lagoon or near the reef, they would get better excellent manipulation performance in compare with the traditional ships. In the restricted waters like the narrow waterway, waters near the pier, the force of the sailing ship will make a great change because of the shallow water effect and the bank effect. The opening of bow and stern thrusters would provide more excellent course adjustment ability than the traditional rudder equipment. But the jet of the bow and stern thrusters would make great difference with the performance under low speed or in unrestricted waters because of the influence of the hull wake, water conditions or the ship speed. The thrust performance of the side thrusters will also make great difference with the ideal parameters in the operation instruction of the side thrusters.This paper first introduces the research of thrusters' performance and ship's maneuvering in restricted waters at home and abroad. It calculates the viscous flow field and the resistance of the 54 m marine engineering ship by using general software platform based on viscous flow theory, and also the ship structured grid and two phase flow model are adopted. Then this paper works on open water numerical simulation test and verify by using KP505 type propeller, witch got extensive and reliable test data, to verify the validity of the grid form and the numerical method after by comparing with the tank test results.And further, this paper uses the data of hull drawings for ship and side thrusters to proceed geometry modeling. Then it builds the whole ship flow field including the bow and stern thrusters by adopting a hybrid grid form which consists of tetrahedron and hexahedron mesh. And it studies the transformation law of the influence of the thrust performance generated from the propeller speed and ship speed, by taking hull interaction into account in unrestricted waters.In the final, this paper calculates the transverse force and gyroscopic moment generated from bank effect in various ship speed by constructing the working condition of shallow-offshore water. It studies the opening strategy of side thrusters and analyzes the failure speed range of the side thrusters. Then it calculates the stress distribution of the ship after opening the bow and stern thrusters. and compares the difference of the side thrusters' performance in restricted waters and unrestricted waters, providing a beneficial reference for the safety of ship's manipulation.