物流信息系统

Directions The management interviews identified six initiatives that the firms have used to overcome these basic problems: (1) boundary spanning, (2) education and training, (3) measurement perspective, (4)information substitution, (5) decision integration, and (6) process reengineering. Some of the initiatives are relatively easy and can be implemented in stages. Others, however, require a substantial up-front investment prior to implementation.     

Decarbonization of Ship Operations

<正>The need to reduce the trends associated with climate change imposes measures to reduce the emissions of greenhouse gases to the atmosphere and increase the efficiency of the use of energy. The International Maritime Organization(IMO) has been active since 1997 in promoting the implementation of measures that lead to more efficient ship operation with less fuel consumption and less emissions(Tadros et al., 2023a). The measures include improved ship design and improved operational practi...     

Window to China

China is to apply for joining IMO voluntary audit scheme next year to protect the interests of Chinese shipping industry and the good image of a large shipping country, China plans to apply for joining IMO voluntary audit scheme in the second half of 2007…     

2050 for the shipping industry

正On April 13,2018,London,United Kingdom,the 72nd Meeting of the IMO Maritime Environment Protection Committee(MEPC72)finally formed and adopted the first initial strategy in shipping industry history to reduce shipping CO_2 and greenhouse gas emissions.For the shipping industry emission reduction targets that are of particular concern to the industry,there are three main conclusions:First,to further implement and     

17000载重吨油船结构疲劳分析的快速估算方法(英文)

Fatigue cracks and fatigue damage have been important issues for ships and offshore structures for a long time.However,in the last decade,with the introduction of higher tensile steel in hull structures and increasingly large ship dimensions,the greater attention should be paid to fatigue problems.Most research focuses on how to more easily access the fatigue strength of ships.Also,the major classification societies have already released their fatigue assessment notes.However,due to the complexity of factors influencing fatigue performances,such as wave load and pressure from cargo,the combination of different stress components,stress on concentration of local structure details,means stress,and the corrosive environments,there are different specifications with varying classification societies,leading to the different results from different fatigue assessment methods.This paper established the Det Norske Veritas(DNV) classification notes "fatigue assessment of ship structures" that explains the process of fatigue assessment and simplified methods.Finally,a fatigue analysis was performed by use data of a real ship and the reliability of the result was assessed.     

上风向与下风向风机气动力性能数值计算分析（英文）

Although the upwind configuration is more popular in the field of wind energy, the downwind one is a promising type for the offshore wind energy due to its special advantages. Different configurations have different aerodynamic performance and it is important to predict the performance of both downwind and upwind configurations accurately for designing and developing more reliable wind turbines. In this paper, a numerical investigation on the aerodynamic performance of National Renewable Energy Laboratory(NREL) phase VI wind turbine in downwind and upwind configurations is presented. The open source toolbox Open FOAM coupled with arbitrary mesh interface(AMI) method is applied to tackle rotating problems of wind turbines. Two 3D numerical models of NREL phase VI wind turbine with downwind and upwind configurations under four typical working conditions of incoming wind velocities are set up for the study of different unsteady characteristics of the downwind and upwind configurations, respectively. Numerical results of wake vortex structure, time histories of thrust, pressure distribution on the blade and limiting streamlines which can be used to identify points of separation in a 3D flow are presented. It can be concluded that thrust reduction due to blade-tower interaction is small for upwind wind turbines but relatively large for downwind wind turbines and attention should be paid to the vibration at a certain frequency induced by the cyclic reduction for both configurations. The results and conclusions are helpful to analyze the different aerodynamic performance of wind turbines between downwind and upwind configurations, providing useful references for practical design of wind turbine.     

海岸桩结构布置对波浪参数影响的数值模拟研究（英文）

In this study, the passage of waves through pile groups with different arrangements is investigated using a three-dimensional(3D)numerical model. For the simulations, waves of three different heights of 36, 58, and 81 mm, a fixed period of 0.88s, and a fixed wave length of 1.128 m were used. To simulate the waves and flow pattern through the piles, Reynolds-averaged Navier–Stokes(RANS) equations of fluid motion were solved based on the finite volume method(FVM). Piles were defined as obstacles in the rectangular domain using the fractional area/volume obstacle representation(FAVOR) method. The volume-of-fluid(VOF) and re-normalization group(RNG) methods were used to simulate the free surface and turbulence phenomenon, respectively. By performing different numerical simulations, the effect of coastal pile arrangements on wave pattern was studied and was compared with existing experimental data, and an acceptable agreement was achieved.     

两种直接波浪能转换系统性能的比较:阿基米德波浪摆和波能浮筒(英文)

Many wave energy conversion devices have not been well received. The main reasons are that they are too complicated and not economical. However, in the last two decades direct conversion systems have drawn the attention of researchers to their widely distributed energy source due to their simple structure and low cost. The most well-known direct conversion systems presently in use include the Archimedes Wave Swing (AWS) and Power Buoy (PB). In this paper, these two systems were simulated in the same conditions and their behaviors were studied in different wave conditions. In order to verify the simulations, results of the generator of the finite element computations were followed. An attempt was made to determine the merits and drawbacks of each method under different wave conditions by comparing the performance of the two systems. The wave conditions suitable for each system were specified.     

Safety assessment for a side-by-side offloading mooring system

In order to improve the safety properties of an offloading system with side-by-side (SBS) mooring in which the FPSO is moored by a yoke system in the field of BZ25-1, it is necessary to analyze those properties. According to the experience of similar projects, tow strategies of different offloading arrangements were discussed by using the 3-D radiation/diffraction theory and quasi-static time domain method to assess their respective safety properties. Through the safety assessment analysis of different arrangement comparisons, various ways to improve the safety properties of offloading systems with side-by-side mooring were verified by analyzing the tension in the mooring lines and the fender deflection. Through comparison it can be concluded that by enlarging the key factors properly, including the size of the fenders and the hawsers as well as the number of hawsers, a better safety performance can be achieved.     

优化船用柴油机的性能以减少氧化硫SO_x排放物的形成（英文）

Optimization procedures are required to minimize the amount of fuel consumption and exhaust emissions from marine engines.This study discusses the procedures to optimize the performance of any marine engine implemented in a 0D/1D numerical model in order to achieve lower values of exhaust emissions. From that point, an extension of previous simulation researches is presented to calculate the amount of SO_x emissions from two marine diesel engines along their load diagrams based on the percentage of sulfur in the marine fuel used. The variations of SO_x emissions are computed in g/k W·h and in parts per million(ppm) as functions of the optimized parameters: brake specific fuel consumption and the amount of air-fuel ratio respectively.Then, a surrogate model-based response surface methodology is used to generate polynomial equations to estimate the amount of SO_x emissions as functions of engine speed and load. These developed non-dimensional equations can be further used directly to assess the value of SO_x emissions for different percentages of sulfur of the selected or similar engines to be used in different marine applications.     

Numerical analysis of the high skew propeller of an underwater vehicle

A numerical analysis based on the boundary element method (BEM) was presented for the hydrodynamic performance of a high skew propeller (HSP) which is employed by an underwater vehicle (UV). Since UVs operate at two different working conditions (surface and submerged conditions), the design of such a propeller is a cumbersome task. This is primarily due to the fact that the resistance forces as well as the vessel efficiency under these conditions are significantly different. Therefore, some factors are necessary for the design of the optimum propeller to utilize the power at the mentioned conditions. The design objectives of the optimum propeller are to obtain the highest possible thrust, minimum torque, and efficiency. In the current study, a 5-bladed HSP was chosen for running the UV. This propeller operated at the stern of the UV hull where the inflow velocity to the propeller was non-uniform. Some parameters of the propeller were predicted based on the UV geometrical hull and operating conditions. The computed results include the pressure distribution and the hydrodynamic characteristics of the HSP in open water conditions, and comparison of these results with those of the experimental data indicates good agreement. The propeller efficiency for both submerged and surface conditions was found to be 67% and 64%, respectively, which compared to conventional propellers is a significantly higher efficiency.     

Jotun COSCO:Being the Forerunner of Conventions

With the gradual implementation and promotion of the new coating standard PSPC, IMO has already meant to expand the PSPC application scope from ballast tanks to void tanks and cargo oil tanks. Lately, Maritime Safety Committee MSC87 approved the standard and the draft, which made     

Formal safety assessment and application of the navigation simulators for preventing human error in ship operations

The International Maritime Organization （IMO） has encouraged its member countries to introduce Formal Safety Assessment （FSA） for ship operations since the end of the last century. FSA can be used through certain formal assessing steps to generate effective recommendations and cautions to control marine risks and improve the safety of ships. On the basis of the brief introduction of FSA, this paper describes the ideas of applying FSA to the prevention of human error in ship operations. It especially discusses the investigation and analysis of the information and data using navigation simulators and puts forward some suggestions for the introduction and development of the FSA research work for safer ship operations.     

带吊舱水下机器人运动建模与仿真(英文)

To provide a simulation system platform for designing and debugging a small autonomous underwater vehicle’s (AUV) motion controller, a six-degree of freedom (6-DOF) dynamic model for AUV controlled by thruster and fins with appendages is examined. Based on the dynamic model, a simulation system for the AUV’s motion is established. The different kinds of typical motions are simulated to analyze the motion performance and the maneuverability of the AUV. In order to evaluate the influences of appendages on the motion performance of the AUV, simulations of the AUV with and without appendages are performed and compared. The results demonstrate the AUV has good maneuverability with and without appendages.     

AN ANALYSIS OF SOME FACTORS OF THE TRAINING OF CHINESE SAILORS

Ministry of Communications of P. R. China has successfully organized some dozens of classes to train ship officers, and given corresponding tests, which played a very important part in improving the whole educational level of sailors in our country. However, with the development of situation and the application field of science and technology being continuously enlarged, some parts of present training have become too obsolete to satisfy practical need. At the same time, a lot of adverse information fed back from the organizations such as International Maritime Organization(IMO), harbor supervision office, classification society and shipping company. It is necessary to adjust and reinforce the training of sailors in our nation. The following is     

船用玻璃纤维增强复合材料与钢连接结构的力学特性（英文）

The use of a glass-fiber reinforced composite in marine structures is becoming more common, particularly due to the potential weight savings. The mechanical response of the joint between a glass-fiber reinforced polymer(GRP) superstructure and a steel hull formed is examined and subsequently modified to improve performance through a combined program of modeling and testing. A finite-element model is developed to predict the response of the joint. The model takes into account the contact at the interface between different materials, progressive damage, large deformation theory, and a non-linear stress-strain relationship. To predict the progressive failure, the analysis combines Hashin failure criteria and maximum stress failure criteria. The results show stress response has a great influence on the strength and bearing of the joint. The Balsawood-steel interface is proved to be critical to the mechanical behavior of the joint. Good agreement between experimental results and numerical predictions is observed.     

汇合涡流管节气门角度优化的试验研究和三维CFD分析（英文）

Seven adjustments of convergent-type Vortex Tube(VT) with different throttle angles were applied. The adjustments were made to analyze the influences of such angles on cold and hot temperature drops as well as flow structures inside the VTs. An experimental setup was designed, and tests were performed on different convergent VT configurations at injection pressures ranging from 0.45 to 0.65 MPa. The angles of the throttle valve were arranged between 30° to 90°, and the numbers of injection nozzles ranged between 2 and 6. Laboratory results indicated that the maximum hot and cold temperature drops ranged from 23.24 to 35 K and from 22.87 to 32.88 K, respectively, at four injection nozzles. Results also showed that temperature drop is a function of hot throttle valve angle with the maximum hot and cold temperature drops depending on the angle applied. We used graphs to demonstrate the changes in the cold and hot temperature drops with respect to hot throttle angle values. These values were interpreted and evaluated to determine the optimum angle, which was 60°. The CFD outputs agreed very well with the laboratory results. The proposed CFD results can help future researchers gain good insights into the complicated separation process taking place inside the VTs.     

通过光滑空气-水交界面的低频声传播的数值研究（英文）

It is the traditional belief that sound transmission from water to the air is very weak due to a large contrast between air and water impedances. Recently, the enhanced sound transmission and anomalous transparency of air-water interface have been introduced.Anomalous transparency of air-water interface states that the sound generated by a submerged shallow depth monopole point source localized at depths less than 1/10 sound wavelength, can be transmitted into the air with omni-directional pattern. The generated sound has 35 times higher power compared to the classical ray theory prediction. In this paper, sound transmission through air-water interface for a localized underwater shallow depth source is examined. To accomplish this, two-phase coupled Helmholtz wave equations in two-phase media of air-water are solved by the commercial finite element based COMSOL Multiphysics software. Ratios of pressure amplitudes of different sound sources in two different underwater and air coordinates are computed and analyzed against non-dimensional ratio of the source depth(D) to the sound wavelength(λ). The obtained results are compared with the experimental data and good agreement is displayed.     

考虑层流—湍流转捩的近水面AUV水动力流的数值研究（英文）

Nowadays, Autonomous Underwater Vehicles(AUVs) are frequently used for exploring the oceans. The hydrodynamics of AUVs moving in the vicinity of the water surface are significantly different at higher depths. In this paper, the hydrodynamic coefficients of an AUV in non-dimensional depths of 0.75, 1, 1.5, 2, and 4D are obtained for movement close to the free-surface. Reynolds Averaged Navier Stokes Equations(RANS) are discretized using the finite volume approach and the water-surface effects modeled using the Volume of Fraction(VOF) method. As the operating speeds of AUVs are usually low, the boundary layer over them is not fully laminar or fully turbulent, so the effect of boundary layer transition from laminar to turbulent flow was considered in the simulations. Two different turbulence/transition models were used: 1) a full-turbulence model, the k-ε model, and 2) a turbulence/transition model, Menter's Transition-SST model. The results show that the Menter's Transition-SST model has a better consistency with experimental results. In addition, the wave-making effects of these bodies are studied at different immersion depths in the sea-surface vicinity or at finite depths. It is observed that the relevant pitch moments and lift coefficients are non-zero for these axi-symmetric bodies when they move close to the sea-surface. This is not expected for greater depths.     

完全非线性方法的两个三维自由浮体瞬态行为数值模拟研究(英文)

Two floating structures in close proximity are very commonly seen in offshore engineering. They are often subjected to steep waves and, therefore, the transient effects on their hydrodynamic features are of great concern. This paper uses the quasi arbitrary Lagrangian-Eulerian finite element method (QALE-FEM), based on the fully nonlinear potential theory (FNPT), to numerically investigate the interaction between two 3-D floating structures, which undergo motions with 6 degrees of freedom (DOFs), and are subjected to waves with different incident angles. The transient behaviours of floating structures, the effect of the accompanied structures, and the nonlinearity on the motion of and the wave loads on the structures are the main focuses of the study. The investigation reveals an important transient effects causing considerably larger structure motion than that in steady state. The results also indicate that the accompanied structure in close proximity enhances the interaction between different motion modes and results in stronger nonlinearity causing 2nd-order component to be of similar significance to the fundamental one.