Development of a Very Large Floating Structure with a Submerged Plate

超大型水下板漂浮结构的开发

• 批准号: 12555280
• 负责人: TAKAKI Mikio
• 金额: $ 5.44万
• 依托单位: HIROSHIMA UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-12555280/
• 关键词: VLFS; submersed plate; reduction effect of oscillation; elastic deflection; modal analysis; eigenmode; breaking wave phenomenon; negative added mass; 流体力相互干渉; 流体力の増加; ドライ固有モード; 大型浮体構造物; 付加質量の増加; 減衰力の増加; 波数分裂; 消波効果; 高次流体力成分; MAC法

We have proposed a new very large floating structure with a submerged plate for the purpose of developing a very large floating structure (VLFS) with a conventional breakwater system, and have performed the following studies.1. We have developed the numerical computing program for estimating the hydrodynamic forces on the submerge plate and the fore part of the very large floating structure with the submerged plate, and have performed the experimental studies. The following conclusions are obtained.(1) The breaking waves are generated on the submerged-plate in short wave periods, and it dissipates the incident wave energy. As a result, all of the wave exciting forces on the fore part of VLFS are decreasing.(2) The added mass on the submerged-plate oscillating near VLFS is slightly larger than the one on the submerged plate only for all oscillation frequencies, while the damping forces coefficients increase with the oscillation frequencies. Thereby, it has been made clear that the incre … More ase of the total hydrodynamic forces on submerged plate is induced by the increase of damping force in the high frequency range.(3) The added mass on the submerged plate takes the negative value in the long oscillation periods, and the damping force coefficients increase at the same time. Therefore, the characteristics of these hydrodynamic forces are useful for reducing the elastic deflection of VLFS in long wave periods.2. We have applied the modal analysis method to the elastic deflection of VLFS, and have made clear the effect of the submerged plate on the elastic deflection of VLFS in waves. The following new information is obtained in this study.(1) The wave exciting forces rather than the radiation forces strongly affect the reduction of the elastic deflection of VLFS.(2) The submerged plate strongly affects on the wave exciting forces rather than the radiation forces. In particular, the submerged plate is useful for reducing the elastic deflection of VLFS for short wave periods.(3) The submerged plate strongly affects the hydrodynaraic forces with the mode of less than the 8th, and it scarcely affect the ones with the higher modes.From the above studies, we are sure that the proposed method is useful is useful for reducing the elastic deflection of VLFS in waves. Less

我们提出了一种新的超大型浮式结构与淹没板的目的是开发一个非常大的浮式结构（VLFS）与传统的防波堤系统，并进行了以下研究。本文编制了计算超大型浮式结构物的浮板和前部水动力的数值计算程序，并进行了试验研究。得出以下结论。(1)在短波周期内，潜板上产生破碎波，并耗散入射波能。因此，VLFS前部的波浪激振力均减小。(2)在VLFS附近振荡的潜板上的附加质量仅在所有振荡频率下略大于潜板上的附加质量，而阻尼力系数随振荡频率的增加而增加。因此，已经明确， ...更多信息 阻尼力的增加在高频范围内会导致作用在水下平板上的总水动力的减小。(3)在长周期振动过程中，淹没板上的附加质量取负值，阻尼力系数增大。因此，这些水动力的特性对于减小超长浮体在长波周期的弹性变形是有用的.本文将模态分析方法应用于超大型浮体的弹性变形分析，明确了波浪作用下潜板对超大型浮体弹性变形的影响。本研究获得了以下新信息。(1)波浪激振力而不是辐射力对VLFS弹性挠度的减小有很大影响。(2)水下平板对波浪激振力的影响较大，而对辐射力的影响较小。特别是，淹没板是有用的，以减少弹性变形的VLFS的短波周期。(3)潜板对8阶以下模态的流体动力影响较大，对高阶模态的流体动力影响较小，因此，本文提出的方法对减小超大型浮体在波浪中的弹性变形是有效的。少

项目成果

Mikio Takaki: "Hydrodynamic Forces on a Submerged Plate"Proceedings of the 11th International Offshore and Polar Engineering Conference 2001, Stavanger. III. 518-524 (2001)

Mikio Takaki：“水下板块上的流体动力”2001 年第 11 届国际近海和极地工程会议论文集，斯塔万格。

Masahiko Fujikubo: "A New Type VLFS Using Submerged Plates : SUB-PLATE VLFS ---Part 3 Structural Response and Strength ---"Proceedings of 20th International Conference on Offshore Mechanics and Arctic Engineering OMAE 2001. OMAE-01-5019(CD-ROM). (2001)

Masahiko Fujikubo：“使用水下板的新型 VLFS ：SUB-PLATE VLFS ---第 3 部分结构响应和强度 ---”第 20 届国际海上力学和北极工程会议记录 OMAE 2001。 OMAE-01-5019(CD

Mikio Takaki: "Effect of a Submerged-Plate on Hydrodynamic Forces Acting on a Very Large Floating Structure"Transaction of the West-Japan Society of Naval Architects. 103. 195-204 (2002)

Mikio Takaki：“水下板块对作用于超大型浮动结构的水动力的影响”西日本造船学会会刊。

M.Takaki: "A New Type VLFS Using Submerged Plates : SUB-PLATE VLFS ---Part 1 Basic Concept of Systems ---"20th International Conference on Offshore Mechanics and Arctic Engineering OMAE 2001. OMAE-01-5017(CD ROM). (2001)

M.Takaki：“使用水下板的新型VLFS：SUB-PLATE VLFS ---第1部分系统的基本概念---”第20届国际海上力学和北极工程会议 OMAE 2001. OMAE-01-5017(CD ROM)

Mikio Takaki & Msatoshi Nishikawa: "Hydrodynamic Characteristics of a Submerged Horizontal Plate"西部造船会会報. 第101号(印刷中). (2001)

Mikio Takaki 和 Msatoshi Nishikawa：“水下水平板的水动力特性”，西方造船工程师学会公报第 101 号（印刷中）。