Prediction of Hydroelastic Behavior of a Very Large Floating Structure in Waves and Current

波浪和海流中超大型漂浮结构的水弹性行为预测

• 批准号: 12450223
• 负责人: MATSUI Tetsuya
• 金额: $ 8.19万
• 依托单位: Nagoya 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-12450223/
• 关键词: very large floating structure; wave; current; hydrodynamic force; motion response; hydroelastic response; mooring force; forward speed; 浮体式海洋構造物

Theoretical and experimental investigations have been performed with the purpose of establishing a method of prediction for the hydroelastic behavior of a very large floating structure in waves and current (or equivalently advancing with forward speed in waves). The results of the research are summarized as follows :1. A boundary integral equation method was developed to predict the hydroelastic response of a very large floating structure in waves and current A potential flow theory is employed with low current speed assumption. This permits the velocity potential be expanded in a perturbation series of forward speed. Retaining the leading-order terms in the forward speed, the boundary-value problem is reduced to two sets of integral equations which only contain the zero speed Green's function. The solution can be obtained efficiently by applying the boundary element technique which is well-developed for zero speed case.2. The theory was applied to predict the hydroelastic behavior of a circular plate advancing with forward speed in waves. It was shown that the hydroelastic response of the plate is significantly influenced by the presence of small forward speed. Its effect is more significant for the bending strain than the displacement. The approximate prediction taking only account of Doppler's effect is found to underestimate the forward speed effect.3. In order to validate the theoretical approach wave tank tests have been performed using a small scale model of a very large floating structure in waves (without current). Agreement was found to be satisfactory between theory and experiment, thus confirming the validity of the theoretical prediction.

为了建立一种预测超大型浮式结构物在波浪和水流中（或在波浪中以向前速度等效前进）水弹性行为的方法，进行了理论和实验研究。主要研究成果如下：1.采用势流理论和低流速假设，建立了一种边界积分方程法，用于预测超大型浮式结构物在波流作用下的水弹性响应。这允许速度势在前进速度的扰动序列中展开。在保留前向速度的首阶项的情况下，将边值问题转化为两组只包含零速绿色函数的积分方程。应用边界元技术可以有效地求解零速情况下的问题.应用该理论预测了在波浪中以正向速度前进的圆板的水弹性行为。结果表明，小的前进速度的存在下，板的水弹性响应的显着影响。它对弯曲应变的影响比位移的影响更大。发现仅考虑多普勒效应的近似预测低估了前向速度效应.为了验证理论方法的波浪水槽试验已使用一个非常大的浮动结构在波浪（无电流）的小比例模型进行。理论与实验结果吻合较好，证实了理论预测的正确性。