海底电缆观测系统的研究现状与发展趋势

随着世界各国对海洋研究和开发的高度关注,海底电缆观测系统越来越为人们所重视。首先简要介绍了海底电缆观测系统的定义及其发展史,并与其它海洋观测系统进行了对比,然后对各国海底电缆观测系统的发展现状进行了概述,指出了海底电缆观测系统的关键技术,最后讨论了海底电缆观测系统的发展趋势并给出相关建议。     

Study on Collision Characters for SPAR Platform

This paper presents the research on the external mechanism of collision characters for a SPAR platform. The collision characters of SPAR platform have not attracted so much attention as that of ships in the past, because short of this kind of collision accidents reported. But with the increasing number of SPAR platforms in the world, the possibility of such kind of accident also increases. Therefore, it is necessary to master the character of SPAR collision. Model test technique is employed to study the external mechanism. The collision scenario is a ship colliding with a SPAR platform moored in the site with 1500 meters water depth. The striking ship hits the SPAR platform on the hard tank near water surface in its longitudinal direction. The specifics of the SPAR＇s motions and the tension forces of the mooring lines are collected to summarize the hydrodynamic characters in the collision scenario. It is found that the maximal displacements and the maximal pitch angles of the SPAR platform, and the maximal tension forces of mooring lines are all linearly proportional to the initial velocity of the striking ship basically. Mooring lines play elastic roles in the collision course.     

Multidisciplinary Design Optimization of A Human Occupied Vehicle Based on Bi-Level Integrated System Collaborative Optimization

The design of Human Occupied Vehicle (HOV) is a typical multidisciplinary problem, but heavily dependent on the experience of naval architects at present engineering design. In order to relieve the experience dependence and improve the design, a new Multidisciplinary Design Optimization (MDO) method “Bi-Level Integrated System Collaborative Optimization (BLISCO)” is applied to the conceptual design of an HOV, which consists of hull module, resistance module, energy module, structure module, weight module, and the stability module. This design problem is defined by 21 design variables and 23 constraints, and its objective is to maximize the ratio of payload to weight. The results show that the general performance of the HOV can be greatly improved by BLISCO.     

On the Interaction of Surface Waves with An Elastic Plate of Finite Length in Head Seas

An eigen-function expansion method based on a new orthogonal inner product is proposed by Sahoo et al. (2000) for the study of the hydroelastic response of mat-type VLFS in head seas. However, their main emphasis is on the effect of edge conditions and they assume that the plate is of a semi-infinite length. In reality, the plate is of finile length. For consider-alion of the finite length effect, the reflection and transmission from the other end must be considered. The effect of this reflection and transmission on the hydroelaslic response of VLFS is of interest for praclical application. Furthermore, the physi-cal meaning of the new inner producl was not given in their paper. In this paper, it is shown that the new inner product can be derived from the governing equation and the bottom boundary conditions. Then the same eigen-function expansion method is adopted for the study of the hydroelastic response of an elastic plate of finite length in surface waves. Delailed comparisons are made between the     

Comparison of Linear Level I Green-Naghdi Theory with Linear Wave Theory for Prediction of Hydroelastic Responses of VLFS

Very Large Floating Structures (VLFS) have drawn considerable attention recently due to their potential significance in the exploitation of ocean resources and in the utilization of ocean space. Efficient and accurate estimation of their hydroelastic responses to waves is very important for the design. Recently, an efficient numerical algorithm was developed by Ertekin and Kim (1999). However, in their analysis, the linear Level I Green-Naghdi (GN) theory is employed to describe fluid dynamics instead of the conventional linear wave (LW) theory of finite water depth. They claimed that this linear level I GN theory provided betler predictions of the hydroelastic responses of VLFS than the linear wave theory. In this paper, a detailed derivation is given in the conventional linear wave theory framework with the same quantity as used in the linear level I GN theory framework. This allows a critical comparison between the linear wave theory and the linear level I GN theory. it is found that the linear level     

超大型浮体水弹性分析的平板格林函数法

采用Eatock Taylor ＆ Ohkusu提出的一种矩形平板的挠度格林函数进行超大型浮式结构物在波浪中的水弹性响应分析，计算结果与试验结果比较，相当吻合，证实此平板挠度格林函数可以用于超大型浮式结构物的水弹性分析。     

Path Following Control of A Deep-Sea Manned Submersible Based upon NTSM

In this paper, a robust path following control law is proposed for a deep-sea manned submersible maneuvering along a predeterminated path. Developed in China, the submersible is underactuated in the horizontal plane in that it is actuated by two perpendicular thrusts in this plane. The advanced non-singular terminal sliding mode （NTSM） is implemented for the design of the path following controller, which can ensure the convergence of the motion system in finite time and improve its robustness against parametric uncertainties and environmental disturbances. In the process of controller design, the close-loop stability is considered and proved by Lyapunov＇ s stability theory. With the experimental data, numerical simulations are provided to verify the control law for path following of the deep-sea manned submersible.     

Dynamic Modeling and Investigation of Maneuver Characteristics of A Deep-Sea Manned Submarine Vehicle

A deep-sea Manned Submarine Vehicle (MSV) is usually required to move at a low forward speed and a low rotational speed when it executes investigation tasks. In this condition, the motion is in large drift angles, and the maneuverability hydrodynamic forces cannot be expressed properly in the conventional mathematical model of submersible motion. In this paper, firstly, a general equation of MSV with six-freedom motion is presented, and the numerical simulation of descent/ascent motion and helix motion is c...     

自动剖面浮标研究现状及展望

回顾了自动剖面浮标的发展历程,自动剖面浮标由Swollow提出的中性浮子发展而来,演变到现在的PROVOR型、APEX型、SOLO型等自动剖面浮标。文中介绍了Argo计划中几种主要的自动剖面浮标,其浮力调节原理主要是通过改变浮标在水中的排水体积实现自动沉浮,从而测量水的温度、盐度、深度等数据。对常规(2 000 m)和深海(2 000 m)自动剖面浮标进行比较,大部分深海自动剖面浮标耐压结构已经采用球形设计,浮标受压后变形小且可减轻浮标自重;单冲程柱塞泵改变为体积较小的液压泵,提供超高压的同时可以充分利用球体空间。目前,常规自动剖面浮标已广泛应用到海洋环境数据的调查、收集,而深海自动剖面浮标仍处于研发与试验阶段,面临诸多的技术挑战,对浮标的可靠性提出了更高的要求。