【作者】 张祥伟；

【导师】 任俊生；

【作者基本信息】 大连海事大学 ， 交通信息工程及控制， 2012， 硕士

【摘要】 拖船协助在船舶靠离码头过程中发挥着重要的作用。拖船作业过程中,拖船与被拖船之间会产生水动力相互作用,船间水动力作用对拖船作业会产生直接影响,甚至会造成船舶操纵困难而产生危险。研究船间水动力作用对拖船操纵安全和拖船作业效率的提高有着重要意义。在拖轮模拟器中加入船间水动力作用模块是必要的。针对拖船的滑流效应和船间效应,本文进行了如下三个方面的工作：1.基于最小二乘法建立拖船螺旋桨滑流效应的数学模型。文中用F检验法对所建立的模型进行显著性检验,检验结果表明所建立的模型是合理的；然后又对建立的模型用Matlab进行了仿真,仿真结果与柯恩达效应和流体的驻点压力对滑流效应的解释是一致的。2.基于势流理论建立拖船所受船间效应的数学模型。首先在拖船与被拖船首尾线上布置一些源(汇)来取代船体对来流的扰动,源(汇)的强度根据拖船与被拖船的船体水下几何形状确定,由分布的源(汇)即可求得速度势,接着根据速度势求得船体对周围流体的诱导速度,再利用伯努利方程求得拖船船体附近流体的压强,最后用辛普生积分求出拖船受到的横向力和转首力矩。计算结果与试验结果对比表明所建立的模型是合理的。3.用Visual C++6.0搭建仿真平台,对船间水动力作用数学模型在测试平台上进行仿真测试。文中做了三组仿真：一是对拖船拖带被拖船前进运动仿真；二是对拖船拖带被拖船转向运动仿真；三是对拖船受到的船间效应作用进行仿真。前两组是对拖船的滑流效应进行的测试,第三组是对拖船受到的船间效应进行的测试。仿真结果表明所建立的模型是合理的。更多还原

【Abstract】 Tugboat assistance plays a significant role in ship berthing or unberthing. Tug-ship interactions which occur in tugboat operations will directly act on tugboat. Due to tug-ship interaction, tugboat likely becomes maneuveringly difficult and dangerous. So research on the tug-ship interaction is of great importance. It is also necessary to integrate the tug-ship interactions into the towage model in tug simulator.The main contributions of the thesis focus on the tugboat’s slipstream effect and ship-ship interaction, and are summarized as follows.1. The mathematical model for tug’s slipstream effect is estbabished based on least-square algorithm. F test is done for the mathmetical model, which demonstrates that the mathematical model is reasonable. The Matlab simulation results about the mathematical model can embody the effect of the tug’s slipstream.2. Ship-ship interaction on the tugboat is built based on potential-flow theory. Firstly, the source or sink is arranged on the tugboat and towed-ship to replace the ship hull disturbance to the incoming flow. The strength of the source or sink is arranged according to the geometry of the ship body. Secondly, the induced velocity of the tugboat and towed-ship are obtained on the basis of the arranged source or sink. Thirdly, the pressure around the tugboat body surface is caculated in accordance with the induced velocity by use of the Bernoulli equation. At last, the lateral force and yawing moment acting on the tug is caculated by Simpson integration.3. The simulation platform is established using the Visual C++6.0for testing. Three simulations are carried out in the thesis, namely, tugboat towing towed-ship forward motion, tugboat towing towed-ship yawing, and ship-ship interaction between tugboat and towed-ship. The former two tests are related to tug slipstream effect. The third test is about ship-ship interaction effect. The tests demonstrate the effectivness of the tug-ship interaction model.更多还原