测量浮标长效锚泊系统的研究

文章以近年来国内外锚泊系统失效事例调查为基础,论述了浮标锚系设计中,除风、浪、流外力计算之外的常被人们忽视的其它因素,从而提出测量浮标长效锚泊系统的设计方案。     

浅海环境观测专用浮标和潜标锚泊系统的研究

文中着重介绍为改进浅海环境观测专用浮标和潜标锚泊系统所做的三件工作。一是提高水面标志浮标的抗台风、抗倾覆和抗沉能力以及连接件的流线型化;二是通过理论计算和水池试验,选用抗风能力强的配套的浮标／潜标系统系列;三是应用设计新型的打捞钩,及时而方便地将丢失在海底的仪器等打捞回来。     

水下锚泊系统计算──一种单链动力分析的数值方法

以悬链线理论为基础，采用集中质量法分析了水下锚泊系统单链动力特性，得出了在强迫振荡时锚链的开关及链动张力历时曲线。计算结果同实验结果吻合良好，说明该方法是可行的．     

内波吸引子的数值模拟

密度稳定层结的流体中产生的内波沿着由内波固有频率、流体浮力频率等因素所确定的特征线(或内波射线)传播。边界上的反射不改变内波的频率,从而也不改变反射后的内波特征线与重力方向所成的夹角。侧边界倾斜的封闭容器内,内波能量沿特征线传播的过程中经侧壁、表面和底面的反射可能会集中在一个封闭的轨道上,形成内波吸引子。该现象已经得到水槽试验、线性理论和数值试验的验证。本文利用非线性非静压的环流模式MITgcm,模拟了二维封闭区域中(1,1)-吸引子和(2,1)-吸引子的形成过程,并讨论初值条件对它们的影响。稳定的(1,1)-吸引子其极限环两侧流速出现很强的剪切流。当减小地形的坡度时,由于线性因素的增加,吸引子的结构不变,但吸引子厚度在相空间中的收缩速度加快。对于(2,1)-吸引子,由于轨道所成的两个环中间的节点耗散了部分能量,吸引子的收敛速度较慢。节点处,流体速度始终为0,但存在强烈混合,流体浮力频率呈现振幅较大的周期变化。     

有效吸收和传递波浪能的锚泊系统的设计制作

将传统定位浮标加以改进,可以形成一种能有效吸收和传递波浪能的锚泊系统。此系统的最上端是漂浮着的海面浮标,海面浮标下端连着锚泊钢缆,锚泊钢缆下端到海底之间又依次连有张紧锤、储链和重物锚块。锚泊系统中的海面浮标随波浪同步上下起伏,从而带动与其连在一起的由张紧锤绷直的锚泊钢缆上下振动,于是海面浮标吸收波浪能并由引导缆向下传递。20 m长的储链可以保证整个装置在涨潮、退潮的极限水深情况下,仍旧可以有效地传递海表面波浪能;合适的重物锚块可以起到为整个系统定位的功能。最后给出了一个实际应用波浪能的例子。设计制作的锚泊系统可以有效吸收和传递波浪能,为波浪能的利用提供了一种行之有效的方法。     

吕宋海峡内波吸引子的三维数值模拟

Internal waves propagate along wave beams that are inclined with respect to the horizontal plane. It is conjectured that the internal waves generated in the Luzon Strait may be confined between the double ridges in the strait and concentrate to a closed trajectory, the so-called internal wave attractor, due to the reflection of wave beams from the lateral boundaries, sea surface and bottom. This work carried out two experiments using a three dimensional non-hydrostatic general circulation model, MITgcm, to investigate the possibility that the ridges in the Luzon Strait allows for internal wave attractors. Baroclinic current in both of the experiments demonstrate the forming of ring-like patterns in some section around 20° and 21°N, indicating that the development of the internal wave attractors are allowed in the Luzon Strait. The different resolutions and initial conditions in the two experiments also reveal that the internal-wave-attractor phenomenon is robust in this region.     

深海抗风浪网箱锚泊系统的设计

通过对网箱框架、网衣在风、浪、流作用下的受力分析 ,建立网箱锚泊系统缆绳受力计算的数学模型。以国家十五“86 3”计划课题—“深海抗风浪网箱的研制”所设计的网箱为例 ,选定山东荣成市寻山海域 1 0年一遇的灾害海况为设计计算条件 ,根据 Morison公式 ,采用 Goodman- L ance方法求得单个网箱的锚泊力为 6 5 .6 7k N。在此基础上对网箱的锚泊系统进行设计 ,确定了锚泊系统每只锚重 2 5 0 kg,锚链重为 1 5 0 kg,缆绳长度为 33m。     

基于AQWA的漂浮式海洋装置载体锚泊系统耦合分析

文章基于波浪力时域频域的运动理论,采用变换锚链夹角的方法,通过水动力软件AQWA进行仿真耦合分析的方式,得出针对特定研究对象即双浮筒漂浮式浪流发电装置的最佳锚泊方案,进而探讨类似的漂浮式海洋装置载体锚泊系统方案的设计。     

TLP平台锚泊系统和锚固基础的发展状况

我国是海洋石油资源比较丰富的国家,尤其是我国的南海海域,更有"第二个波斯湾"的美誉.     

防风单点系泊系统系泊力试验研究

通过物理模型试验,得到了3种船型在不同工况组合下的偏荡幅度、偏荡周期以及系泊力实测数据。试验得出了船舶在台风与波、浪、流共同作用下,单点系泊力的主要影响因素为风速、流速、波浪、船舶种类、水线上下侧投影面积比和系泊系统的刚性。选出了本文理论意义明确合理的适合单点系泊系统使用的防风系泊力表达形式,即奎因公式。采用系泊力试验数据在奎因公式的基础上导出的防风系泊系统系泊力计算公式,并给出了公式中的重要参数表达式。     

A Time Domain Computation Method for Dynamic Behavior of Mooring System

A quasi-steady time domain method is developed for the prediction of dynamic behavior of amooring system under the environmental disturbances,such as regular or irregular waves,winds and cur-rents.The mooring forces are obtained in a static sense at each instant.The dynamic feature of the moor-ing cables can be obtained by incorporating the extended 3-D lumped-mass method with the known shipmotion history.Some nonlinear effects,such as the influence of the instantaneous change of the wettedhull surface on the hydrostatic restoring forces and Froude-Krylov forces,are included.Thecomputational results show a satisfactory agreement with the experimental ones.     

新型深海系泊系统及数值分析技术

随着海洋油气资源开发逐渐向深海转移,传统的悬链式系泊系统在技术和经济上遇到难以逾越的障碍。作为一种新型的适用于深水和超深水环境的系泊系统,绷紧索系泊系统面临广阔的应用前景。文章对这种新型系泊系统的发展情况进行了介绍,基于有限元数值分析技术,对系泊系统的两个关键特性,即系缆的绷紧-松弛特性以及纤维系缆的动刚度特性进行了分析和处理,通过算例考察了深海平台运动引起的系缆力响应。     

Design Curves for Mooring Lines of Turret Mooring Systems

This paper presents a series of design curves to aid in the selection of turret mooring systemsfor tankers based Floating Production Storage and Offloading(FPSO)systems.These curves are appropri-ate to water depths ranging from 100m to 600m.The curves can be used as a preliminary design tool,al-lowing the designer to quickly evaluate alternative mooring system configurations,including the numberof mooring lines,the characteristics of chain and wire rope to be deployed and the initial tension.With aknowledge of the total environmental force and vessel motion characteristics,the designer can determinethe appropriate system for closer evaluation.     

Theoretical Model and Dynamic Analysis of Soft Yoke Mooring System

As a popular solution for mooring an FPSO （Floating Production, Storage and Offloading） permanently in shallow water, the soft yoke mooring system has been widely used in ocean oil production activities in the Bohai Bay of China. In order to simulate the interaction mechanism and conduct dynamic analysis of the soft yoke mooring system, a theoretical model with basic dynamic equations is established. A numerical iteration algorithm based on error estimation is developed to solve the equations and calculate the dynanfic response of the mooring system due to FPSO motions. Validation is conducted by wave basin experimentation. It is shown that the numerical simulation takes only a few iteration times and the final errors are small. Furthermore, the calculated results of both the static and dynamic responses agree well with those ones obtained by the model test. It indicates that the efficiency, the precision, the reliability and the validity of the developed numerical algorithm and program are rather good. It is proposed to develop a real-time monitoring system to further monitor the dynamic performance of the FPSO with a soft yoke mooring system under various real sea environments.     

Investigation of Performance of Turret Assembly in Inboard Turret Mooring System

To fulfil the need of development of offshore oil floating production system, the performance of turret assembly in an inboard turret mooring system has been investigated in the paper. By means of systematic evaluation, the optimal structure of the turret for single-point mooring systems has been determined. Through model tests of a turret mooring system, several groups of data such as forces, moments and displacements under different environmental conditions have been obtained. Stresses and strains of the turret structure have been calculated by means of the finite element method corresponding to the situation in the model experiment. The study shows that the selected turret structure and the designed turret assembly are technically feasible.     

海底地磁日变观测站的设计与应用

采用布设海底地磁日变观测锚系的技术方法,可解决远海区磁测日变改正观测资料问题。重点介绍设立海底地磁日变观测锚系中观测设备的技术特性、锚系设计及这一技术方法在国内的首次应用情况。     

Study on Ship Automatic Berthing System with Mooring Lines

This study describes an automatic berthing system with mooring lines. It is designed to be berthed by using mooring device on the upper deck of a ship. It is to berth once maintaining parallel with the quay by controlling both forward and aft breast lines. Berthing method is used through length adjustment of mooring lines connected between ship and quay by controlling the angular velocity and the torque of hydraulic motor in mooring device. The study is conducted under three changing conditions of draft, such as even-keel, rise of the gravity center and trim to stern. Variables affecting berthing stability are determined based on the control performance of each condition. Bond graphs method is used to model the system. Controller is designed as PID control method of reference-model algorithm. The control program is composed of synchronous control system based on the equations derived with the numerical analysis. The tank test is conducted to verify the usefulness of the control program.