Research on the Estimation of Ocean Wave Spectra Based on Running Ship Motions

基于行船运动的海浪谱估计研究

• 批准号: 63550326
• 负责人: HIRAYAMA Tsugukiyo
• 金额: $ 1.54万
• 依托单位: Yokohama National University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1988
• 资助国家: 日本
• 起止时间: 1988 至 1989
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-63550326/
• 关键词: Ship Motion; Ocean Wave Statistics; Irregular Waves; Spectrum; Directional Spectrum; 方向スペクトル

There is no need to say that for the design and management of ship or floating bodies it is important to grasp the real state of ocean waves in quantitative manner. It is also important on the view point of preventing abnormal sea disaster. Usually instrumental measurement of ocean waves is made by ships in standing condition or moored floating bodies and it is very difficult to measure waves from running ship, so even today main source of ocean wave statistics is owed to visual observation.So,in this research we aimed to estimate directional spectrum of ocean waves in real time, introducing micro computer on board and using information on ship motions.On the first stage of this project, we conducted towing ship experiment in our towing tank which can generate directional spectrum waves and comparing those results with theoretical calculation, we examine the reliability of theoretical calculation of ship motions in directional spectrum waves.In the next, we developed a system which can estimate directional spectrum waves in real times by obtaining ship motions from sensors on board. In this system the frequency response functions of ship motions are given theoretically. Those functions are examined in the first stage and then we made numerical simulation on this system.Finally, we applied this system in real ship experiment and it was found that this system can be used practically.

不必说，对于船舶或浮体的设计和管理来说，以定量的方式掌握海浪的真实的状态是重要的。从预防异常海洋灾害的角度来看，这也是重要的。由于海浪的测量通常是由船舶在静止状态下或系泊的浮体进行的，而船舶在航行状态下的测量是非常困难的，所以直到今天，海浪统计的主要来源还是靠目视观测。因此，本研究的目的是在真实的时间内估计海浪的方向谱，在船舶上引入微型计算机，利用船舶运动信息。在这个项目的第一阶段，在能产生方向谱波的拖曳水池中进行了拖曳船试验，并将试验结果与理论计算结果进行了比较，本文首先验证了船舶在方向谱波浪中运动理论计算的可靠性，然后开发了一个利用船上传感器获取船舶运动信息的系统，该系统能够在真实的时间内估计船舶的方向谱波浪。在该系统中，从理论上给出了船舶运动的频响函数。首先对系统的功能进行了验证，然后对系统进行了数值模拟，最后将系统应用于真实的实船试验，结果表明该系统具有一定的实用价值。