Abstract: The shipping economy is developing with the continuous expansion of the world trade. The number of merchant ships has been increasing, especially the demand for bulk cargoes, such as oil and ore, has increased sharply. Ships tend to be large-scale. The emergence of ultra-large oil tankers and ultra-large ore ships not only facilitates the maritime transportation, but also increases the risk of maritime transportation. Once an accident occurs, it will cause huge economic losses and immeasurable marine environment pollution. The ship turning is introduced based on the Nomoto mathematical model. The MATLAB simulation of the ship turning test under the certain marine environment interference has been carried out for the teaching practice ship Yukun of Dalian Maritime University, and the simulation curve has been analyzed. At the same time, the speed drop during the ship turning is studied. By taking the speed drop estimation formula that was proposed by Li Zongbo as an example, a 300 000 tonnage oil tanker has been examined to simulate the experimental results of Li Zongbo and others with MATLAB based on the Nomoto mathematical model. The applicability of the speed drop estimation formula to large ships is verified by comparing the simulated results with the actual speed in the turning motion. Finally, it is summarized to present some shortcomings in the current study.

Key words: ship, mathematical model, turning maneuverability, speed drop on turning

摘要： 随着世界贸易的不断扩大,航运经济不断发展,商船数量不断增加,特别是石油、矿砂等大宗货物的需求量急剧增加,船舶趋于大型化。超大型油轮、超大型矿砂船的出现,在便利海上运输的同时,也增加了海上运输的危险性,一旦发生事故,将会造成巨大的经济损失和不可估量的海洋环境污染。文章以Nomoto数学模型为基础,介绍了船舶旋回运动的过程,以大连海事大学教学实习船“育鲲轮”为例,进行了在一定海洋环境干扰下的船舶旋回试验MATLAB仿真,并对仿真曲线进行分析;同时,研究了船舶旋回运动中速降问题,并以李宗波提出的速降估算公式为例,在Nomoto数学模型的基础上,以30万吨油轮为例,对李宗波等人的试验结果进行MATLAB仿真,并与旋回运动中实际速度进行对比,验证了速降估算公式对大型船舶的适用性。

关键词: 船舶, 数学模型, 旋回操纵, 旋回速降