Evaluation of Hydrodynamic Coefficients of Ships Oscillating in A Numerical Wave Tank

A technique for the evaluation of the hydrodynamic coefficients of ships is outlined for ship oscillating in a numerical wave tank, which is established on Computational Fluid Dynamics (CFD) theories. The numerical simulation of ship sections and bodies forced oscillating in the tank are carried out. The added mass and damping coefficients are obtained by the decomposition of the computational results, which agree well with the corresponding ones of potential theories.     

A Unified Computational Method for Simulating Dynamic Behavior of Planing Vessels

High speed planing hulls have complex hydrodynamic behaviors. The trim angle and drafts are very sensitive to speed and location of the center of gravity. Therefore, motion simulation for such vessels needs a strong coupling between rigid body motions and hydrodynamic analysis. In addition, free surface should be predicted with good accuracy for each time step. In this paper, velocity and pressure fields are coupled by use of the fractional step method. On the basis of integration of the two-phase viscous f...     

我国海岸线确定和管理模式研究

文章归纳总结了我国海岸线确定和公布的模式．提出了海岸线确定后的海岸线修订、海岸线区划、海岸线使用和海岸线信息化管理等方面的问题．并对其进行了具体的研究和探讨,为我国海岸线的管理提供了有益的参考。     

防火隔热材料在海洋船舶上的应用研究

研制耐火度高且无毒的防火隔热材料,增强船舶结构的防火能力.对于确保船舶的安全运营具有重要意义.文中深入分析了国内船舶防火隔热材料的性能、优缺点及其应用情况.介绍了国外绿色船用材料的研究现状和性能,对船用防火隔热材料的研发具有一定的参考价值和指导意义.     

基于北斗卫星的海洋测量数据传输系统

针对目前我国海洋测量船上测量数据无法实时传输的现状,采用我国自主研发的北斗卫星导航系统为无线信道单元,结合数据压缩及长报文通信协议等技术,设计了基于北斗卫星的海洋测量数据传输系统,解决了海洋测量船上测量数据实时传输的问题。     

Computation of inertial and damping characteristics of ship sections in shallow water

Hydrodynamics of 2D contours representing ship sections is considered for the case of small harmonic oscillations with a modification of a boundary-integral-equation method implemented earlier for the deep-fluid case. Alterations of the algorithm required by the finite-depth case are described in the present study and a number of numerical results are given.These include comparison with another code for the case of flat horizontal bottom and comparative calculations made for the case of the abrupt change of depth near the ship (stepped bottom). The results can be used for estimation of the bottom's influence on the manoeuvring and seakeeping qualities of ships.     

A Non-Linear Rheological Model of Soft Clay and Its Application in Settlement of Sunk Ship

A one-dimensional consolidation-creep model test on the creep deformation of soft muddy clay in the littoral area of Tianjin is performed. A nonlinear rheologic model is established and the model coefficients are determined, in consideration of the characteristics of soft muddy clay. Furthermore, a settlement equation is deduced from the theologic model and verified by the field settlement measurements of Beitang Reservoir dam in Tianjin littoral area. Finally, the settlement e- quation is applied in calculating the settlement of ＂FAIRWAY-＂ suction dredger, which sunk in the external channel of Tianjin Port, induced by the soft clay consolidation of seabed. These results provide useful information for the decision of salvage plan.     

北极海缆路由工程地质勘察问题探析

跨北极海缆以其铺设成本低、海缆传输距离短、信息传输速率高等优点成为多个国家优先选择的海缆线路。文章简要介绍了环北极国家和我国的北极海缆建设现状。探讨了海冰对工程地质勘察区域的限制、海冰对工程地质调查取样的影响、海雾对工程地质勘察进度的影响和北极地缘政治对工程地质勘察的制约。提出增强调查船舶破冰性能、加速勘察技术革新、提升海冰气象预报能力和深化国际合作等建议,以提升我国北极区域海上综合勘察能力。     

船基系统海气通量测量方法研究

海气通量交换是海洋学和气象学许多领域共同研究的内容,是气候形成和变化的重要机制之一。文章通过比较测量海气通量的几种方法,提出了在船基仪器上使用直接协方差法测量海气通量的方法,并给出了船体运动造成测量结果误差的校正算法。     

船体结构腐蚀检测规划的成本及效益分析

建立了基于风险的船体结构腐蚀优化检测规划的成本-效益分析模型。以费效比作为选择最优检测策略的标准,最优的检测策略是在保证结构设计工作寿命期内的可靠指标大于最低可靠指标的基础上,使得结构生命周期内总的费效比最大。在此基础上,以受点腐蚀损伤的船体构件为例,对其检测策略进行了成本-效益评估,并对计算结果进行了敏感性分析。结果表明,基于风险的成本及效益分析方法可以将检测规划的经济性和可靠性有效地结合起来,能够在风险与成本之间达到一种平衡,它在优化检测策略时是有效的。