THE PREDICTION OF WAVE-INDUCED MOTION AND MOORING FORCES FOR FLOATING OFFSHORE STRUCTURES

海上浮动结构的波感运动和系泊力的预测

基本信息

批准号：
61460177
负责人：
MATSUI TETSUYA
金额：
$ 4.61万
依托单位：
NAGOYA UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1986
资助国家：
日本
起止时间：
1986 至 1987
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-61460177/
关键词：
Floating offshore structures Irregular waves Moored vessel Wave drift force 長周期運動

项目摘要

A series of theoretical and experimental investigations have been conducted to predict the slow drift motion and mooring line forces for floating structures in irregular sea waves. The resluts obtained from this project are summarized as follows:(1) An exact method for simulating the slow drift motion and mooring line forces for floating offshore structures has been proposed within the framework of the second order potential flow theory. The method has been applied to understand the slow drift behaviour of such structures as an articulated column and a moored semi-submersible. It was confirmed that the simulated time histories of the slow drift motion of the semi-submersible are in fairly good agreement with the measured ones in model tests, if the viscous damping term is evaluated appropriately, say by means of the Morison formula.(2) A specific instrument for the random forced oscillation test has been manufactured to measure the hydrodynamic forces on an articulated column model in the low frequency motion. The effects of the high frequency motion of the column and the incoming waves on the hydrodynamic forces have been investigated in dateil. The conclusions arising from the test are listed in the following:a) The hydrodynamic damping of the articulated column in the low frequency motion is mainly due to viscous effects.b) Such damping forces are strongly influenced by the presence of the high frequency motion of the column as well as the incoming waves. Due to small number of the measured data their significant scatter observed. it is difficult at the present stage to predict quantitatively the hydrodynamic forces on the column in the low frequency motion. This will be a matter for future research.

已经进行了一系列的理论和实验研究，以预测不规则海浪中浮动结构的慢速移动线和系泊线力。从该项目中获得的重新升压总结如下：（1）在二阶电势流理论的框架内提出了模拟慢速运动和浮动线结构的系泊线力的确切方法。该方法已应用于理解诸如铰接式柱和系泊半缩的结构的缓慢漂移行为。 It was confirmed that the simulated time histories of the slow drift motion of the semi-submersible are in fairly good agreement with the measured ones in model tests, if the viscous damping term is evaluated appropriately, say by means of the Morison formula.(2) A specific instrument for the random forced oscillation test has been manufactured to measure the hydrodynamic forces on an articulated column model in the low frequency motion.已经研究了日期的柱子和传入波对流体动力的影响。测试产生的结论列出了以下内容：a）低频运动中铰接式色谱柱的流体动力阻尼主要是由于粘性效应。由于少量的测量数据，它们观察到了显着的散射。在目前阶段很难在低频运动中定量地预测柱上的流体动力。这将是未来研究的问题。