Hydrodynamic Phenomenon and Its Effects in Large Scale Floating Structures

大型漂浮结构中的水动力现象及其影响

基本信息

批准号：
05302056
负责人：
YOSHIDA Koichiro
金额：
$ 13.63万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for Co-operative Research (A)
财政年份：
1993
资助国家：
日本
起止时间：
1993 至 1994
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-05302056/
关键词：
semisubmersible wave load wind load interaction hydrodynamic phenomenon simulation wave tank test wind tunnel test

项目摘要

In this study, first of all, the accuracy of the analysis method of wave load, which has been developed in the laboratory of the head investigator, was discussed by comparison with experiments of a model of semisubmersible with a large number of columns connected by lower hulls. An interesting phenomenon of generation of standing wave was found out in the numerical simulation by the above analysis method and confirmed by the experiments in the case where the incident wave has some particular direction and frequency for the model composed of densely allocated large number columns with large diameter.In the case of large scale semisubmersibles, the rigidity with respect to deformation in the vertical direction is, generally speaking, much smaller than that in the horizontal direction. Therefore, an analysis method for vertical elastic deformation including rigid motion was developed by combining the 3D-matrix method with the wave load analysis method mentioned above and the high accuracy was confirmed by comparison with experiments of a model. It can be said from the results obtained that hydroelasticity should be taken into account in the case of large scale semisubmersible with a large number of column elements.On the other hand, regarding wind, an experimental study on wind load was carried out. Using the wind tunnel for full span model test belonging to the department of Civil Engineering of the University of Tokyo, element-wise drag and lift foyces of a model of a large scale semisubmersible were measured. Especially, in some cases, combination models of the semisubmersible structure and a solid wave surface with high wave height were used to measure the effect of existence of waves on wind loads. The results showed that the wind load is not so small and may be considerably large especially, in the case of combined model mentioned above.Therefore, it is considered to be important to study further the effect of wind on behaviors of large scale semisubmersibles.

在这项研究中，首先，通过与下船体连接的大量柱子相比，讨论了在头部研究员实验室中开发的波载分析方法的准确性。在数值模拟中通过上述分析方法发现了一种有趣的现象，并通过实验确认，在事件波在数量上具有特定方向和频率的情况，对于由较大的大规模分配的大小直径分配的密集分配的大型柱组成。大规模半毛体的情况下，相对于ver方向而言，相对于近距离的刚性，相比，较小的方向相比，该方向较小。因此，通过将3D-Matrix方法与上述波载分析方法相结合，通过将3D-Matrix方法与上述波动载荷分析方法相结合，并且通过与模型的实验进行比较确认了高精度，从而开发了一种垂直弹性变形的分析方法。可以从获得的结果中可以说，如果大规模半得出的情况，应考虑使用大量的列元素，应考虑到水力弹性。另一方面，关于风，对风负载进行了实验研究。测量了属于东京大学土木工程系的全面跨度模型测试，测量了元素的拖放式磁力障碍，该模型的模型是大规模半无效的模型。尤其是在某些情况下，使用半熟悉结构的组合模型和具有高波高度的实心波表面来测量波的存在对风负荷的影响。结果表明，风负荷并不那么小，尤其是在上面提到的组合模型的情况下可能很大。因此，进一步研究风对风对大规模半潜水行为的影响很重要。