Studies on a Mathematical Model for Manoeuvering Motions of Ships Moving Slowly in Shallow Waterways.

点击翻译按钮获取中文摘要

In the present report, an attempt is done to establish a mathematical model for manoeuvering motions of ships moving slowly in shallow waterways. The stuties contain the four parts mentioned below.(1) To investigate hydrodynamic properties of ships moving slowly, detailed captive model tests were carried out. Examining carafully the results of the tests, a new mathematical expression for hull forces is derived on the assumption of quasi-steady state from the practical viewpoint.(2) Shallow water effects on hull forces were investigated by captive model tests. The effects on main derivatives are reported.(3)Performances of tugs were studied and the limits of the pushing abili ties were estimated.(4)The procedure to determine hydrodynamic derivatives is discussed and A kind of memory effect on the measured hydrodynamic forces is reported. The quasi-steady mathematical model is recommended from the practical view-point.(5)Manoeuvering motions in harbours are investigated and the concept of elemental manoeuvers is proposed to grasp the ship motions in harbours.