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操縦性流体力の過渡特性に関する研究

机动流体力瞬态特性研究

基本信息

批准号：
09651011
负责人：
KARASUNO Keiichi
金额：
$ 2.18万
依托单位：
HOKKAIDO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1999
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09651011/
关键词：
Hydrodynamic forces in maneuvering motion Towing test with ship models Transitional characteristics of hydrodynamic forces 拘束曳航試験

项目摘要

The interim standards of ship maneuverability by IMO are badly in need of the prediction of ship maneuverability at design stage. In this research project for the prediction, we measured the transitional characteristics of hydrodynamic forces acting on ship hulls and tried to estimate the hydrodynamic forces in steady state from the transitional characteristics. First, we studied a method to estimate the added mass of a model ship, which is indispensable to analyze hydrodynamic force acting on the ship in motion. From this study, we developed a simple method to measure the added mass by a model experiment and made out a quick chart of the added mass estimation for block type ship. We also developed a method to estimate the added mass by using CFD, which does not need to carry out model experiments. Next, we studied about a component-type mathematical model of hydrodynamic forces in maneuvering motion to comprehend the mechanism of the forces. In this research project, we carried out oblique towing tests of several ship models to understand the transitional characteristics of hydrodynamic forces. From the analysis of time histories of hydrodynamic forces by using the component-type mathematical model, we got the following concluding remarks.1. The cross flow drag component is a significant factor of the transitional effect. At the beginning of constant velocity in motion, the cross flow drag of the ship that has a rectangular cross section, reaches quickly to a steady state. On the other hand, the cross flow drag of more practical ship needs much time to be stead state.2. The transitional effect of the viscous lift component is more prominent at the bow rather than the stern. But the effect is very little in total hydrodynamic force.3. From the results described above, it seems to be possible to estimate roughly the hydrodynamic forces in steady state from the transitional characteristics in the oblique towing motion.

国际海事组织（IMO）制定的船舶操纵性暂行标准迫切需要在设计阶段对船舶操纵性进行预报。在本预报研究项目中，我们测量了作用在船体上的水动力的过渡特性，并试图从过渡特性估计稳态水动力。本文首先研究了模型船附加质量的估算方法，这是分析运动中船舶所受水动力所必需的。在此基础上，提出了一种简单的模型试验附加质量测定方法，并编制了分段式船舶附加质量估算速查表。本文还提出了一种不需要进行模型试验的计算流体力学附加质量的估算方法。其次，我们研究了机动运动中水动力的分量式数学模型，以理解力的机理。在本研究计画中，我们进行了几个船模的斜拖试验，以了解水动力的过渡特性。利用分量式数学模型分析水动力时程，得到以下结论：1.横流阻力分量是影响转捩效果的重要因素。在匀速运动的初始阶段，具有矩形横截面的船舶的横流阻力很快达到稳定状态。另一方面，实际船舶的横流阻力需要较长的时间才能达到稳态.粘性升力分量的过渡效应在船首比在船尾更突出。但对总水动力的影响很小.根据上述结果，似乎可以根据斜拖运动的过渡特性粗略估计稳态水动力。