工程背景下《海洋工程环境学》课程教学模式研究

随着我国"海洋强国"战略的不断推进,国家对发展海洋经济越来越重视,相关产业对船舶海洋工程专业应用型人才的培养提出了新的要求。《海洋工程环境学》课程是一门船舶与海洋工程类学生的专业必修课,课程主要侧重于工程实际应用,进一步激发学生对本专业的学习兴趣,培养其独立处理、解决问题的能力。文章针对这一课程教学存在的问题和不足,在工程背景下对其课程教学模式进行了研究,旨在为培养解决工程实际问题的高素质应用型人才提供借鉴。

《海洋工程今日要闻》Subsea 7获得道达尔巴西海上项目服务合同2019年9月3日刊

英国油田服务商Subsea 7公司宣布获得道达尔巴西海上Lapa东北油田的开发服务合同。该油田距离圣保罗州海岸约300千米,位于桑托斯盐下盆地2150米。据悉,合同价值5000万到1.5亿美元,包括安装和预调试35千米长的柔性管道、在卡拉瓜塔图巴浮式生产储卸油装置和5口勘探井之间建立连接等.

《海洋工程今日要闻》BP向阿塞拜疆投资60亿美元2019年4月22日刊

BP将和合作伙伴一起,投资60亿美元开发位于阿塞拜疆近海的ACG大型油田项目。BP表示,将在ACE项目新建一个深水开发平台以及多个配套设施,2023年建成投产后预计可新增产量10万桶/日,累计产量将达到3亿桶。自1994年签署首个产品分成合同以来.

《海洋工程今日要闻》 沙特阿美扩大海上油气产能 2019年7月10日刊

近日,沙特阿美授出34份设计、采购、施工(EPC)合同,总价值达到180亿美元,主要用于提升Marjan和Berri油田的产能。沙特阿美计划通过进一步开发,将这两个油田的原油日产量提高55万桶,天然气日产量提高25亿标准立方英尺。目前,沙特阿美能保持的最大产量为1200万桶/日。EPC合同内容包括建设新的海上油气分离装置,以及24个海上油气平台。

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第七届亚太地区海岸国际会议(APAC2013)征文通知

The 7th International Conference on Asian and Pacific Coasts（APAC2013）will be held in Bali,Indonesia in September 2013（http：//apac2013.org）.The aim of the conference is to promote scientific advancement,technological progress,information exchange,and cooperation among engineers and researchers in coastal,port,

Steady State Analysis of Towed Marine Cables

Efficient numerical schemes were presented for the steady state solutions of towed marine cables. For most of towed systems,the steady state problem can be resolved into two-point boundary-value problem,or initial value problem in some special cases where the initial values are available directly.A new technique was proposed and attempted to solve the two-point boundary-value problem rather than the conventional shooting method due to its algorithm complexity and low efficiency.First,the boundary conditions are transformed into a set of nonlinear governing equations about the initial values,then bisection method is employed to solve these nonlinear equations with the aid of 4th order Runge-Kutta method.In common sense,non-uniform (sheared) current is assumed,which varies in magnitude and direction with depth.The schemes are validated through the DE Zoysa's example,then several numerical examples are also presented to illustrate the numerical schemes.

Depression and elevation internal solitary waves in a two-layer fluid and their forces on cylindrical piles

Both large amplitude depression and elevation internal solitary waves （ISWs） were observed on the continental shelf of the northwest South China Sea （SCS） during the Wenchang Intemal Wave Experiment. In this study, we investigate the characteristics of depression and elevation ISWs based on comparisons between observational results and internal wave theories. It is suggested that the large amplitude depression wave is better represented by the extended Korteweg-de Vries （EKdV） theory than by the KdV model, whereas the large amplitude elevation wave is in better agreement with the KdV equation than with the EKdV theory. Wave-induced forces on a supposed small-diameter cylindrical pile by depression and elevation waves are also estimated using the internal wave theory and Morison formula. The wave-induced force by elevation ISWs is rarely reported in the literature. It is found that the force induced by the elevation wave differs significantly fi＇om that by the depression wave, and the elevation wave generally produces greater force on the pile in the lower water column than the depression wave. These results show that ISWs in the study area can present a serious threat to ocean engineering structures, and should not be ignored in the design of oil platforms and ocean operations.

Dynamic Response Analysis of Towed Cable During Deployment/Retrieval

A numerical approach was developed to analyze the transient behavior of towed cable during ac- tively controlled deployment/retrieval (DR).The cable motion is described by the lumped parameter method, its corresponding boundary conditions are presented.In view of its varying length during DR,two auxiliary arguments are introduced to describe its continuous varying length and discrete number of nodes(equations), the length is determined by the pay out(or reel-in) rate,which is then used to determine the node number by a logic relation.For the discrete mathematical model of towed cable,an algorithm was developed to deal with the discrete governing equations.The simulation results indicate that the cable experiences more com- plex motions due to its varying length,and tension fluctuates seriously in the startup and ending stage of deployment/retrieval.The effect of towing ship's motion in waves on cable during deployment/retrieval is also considered via numerical simulation.

Magnetic Detection Method for Seabed Cable in Marine Engineering Surveying

The detection and identification of the seabed cable is becoming an important task in the marine engineering. The features of the magnetic anomaly can be used to detect the existence of the seabed cable. The magnetic field model is presented, and the consistency of the magnetic anomaly distribution between the simulation of the model and the observed data is verified. The comparison shows that the seabed cable can be effectively detected and identified with reasonable method.

Grouting Control for Deep-Water Jacket Skirt Pile

Deep-water jacket skirt pile grouting is a critical step in ocean platform construction. Because of the complexity of the skirt pile structure and grouting pipeline, the calculation of grouting pressure and the control of output pressure are involved. Beginning with the jacket skirt pile grouting construction scheme, grouting pressure is estimated on the basis of engineering fluid mechanics theory and variable frequency control technique. Programmable logic controller is the center of grouting pressure control system, which accomplishes the flow control of cement buffer tank, water buffer tank, additive buffer tank, cement metering tank, water metering tank, additive metering tank, mixer and agitator. Based on PROFIBUS-DP network, the output pressure of the slurry pump is controlled by the inverter. This method has been applied successfully in JZ20-2 Nor. high spot jacket platform construction.

Marine Structures: Future Trends and the Role of Universities

This paper emphasizes some of the challenges and trends associated with the future development of marine structures. Its main focus is on ways to improve the efficiency of energy-consuming ships, and on design challenges related to energy-producing offshore structures. This paper also discusses the analysis tools that are most needed to enable sustainable designs for future ships and offshore structures. The last section of the paper contains thoughts on the role of universities in education, research, and innovation regarding marine structures. It discusses curriculum requirements for maritime-technology education, basic research activities, and international cooperation.

Sanders＇ Mid-long Cylindrical Shell Theory and its Application to Ocean Engineering Structures

The cylindrical shell is one of the main structural parts in ocean engineering structures.These cylinders are mostly of medium length,which means that the radius of the cross section is significantly smaller than the length of the cylindrical shell.From the viewpoint of the shell theory,they belong to the mid-long cylindrical shell category.To solve mechanical problems on this kind of structure,especially a cracked cylindrical shell,analysis based on shell theory is necessary.At present the generally used solving system for the mid-long cylindrical shell is too complicated,difficult to solve,and inapplicable to engineering.This paper introduced the Sanders' mid-long cylindrical shell theory which reduces the difficulty of the solution process,and will be suitable for solving problems with complicated boundary conditions.On this basis,the engineering applications of this theory were discussed in conjunction with the problem of a mid-long cylindrical shell having a circumferential crack.The solution process is simple,and the closed form solution can usually be found.In practical engineering applications,it gives satisfactory precision.

Nature, Source and Composition of Volcanic Ash in Surficial Sediments Around the Zhongsha Islands

Volcanic detrital sediments are a unique indicator for reconstructing the petrogenetic evolution of submarine volcanic terrains. Volcanic ash in surficial sediments around the Zhongsha Islands includes three kinds of volcanogenic detritus, i.e., brown volcanic glass, colorless volcanic glass and volcanic scoria. The major element characteristics show that bimodal volcanic activity may have taken place in the northern margin of the South China Sea, with brown volcanic glass and colorless volcanic glass repre- senting the mafic end-member and felsic end-member, respectively. Fractional crystallization is the main process for magma evolu- tion. The nature of the volcanic activity implies that the origin of volcanic activity was related to extensional tectonic settings, which is corresponding to an extensional geodynamic setting in the Xisha Trench, and supports the notion, which is based on geophysical data and petrology, that there may exist a mantle plume around the Hainan Island.

The ultimate strength of doubler plate reinforced Y-joints under compression loading

It is common practice in the offshore industry to solve the punching shear problem due to compression by using doubler plate. The finite-element method is a useful tool for studying this problem. The aim of this paper is to study the static strength of doubler plate reinforced Y-joints subjected to compression loading. The finite-element method is adopted in numerical parametric studies. The individual influences of the geometric parameters βand τd （doubler plate to chord wall thickness ratio） and ld/d1（dubler plate length to brace diameter ratio） on the ultimate strength are made clear. The results show the size of plate may have important effects on the strength of reinforced joints. It is found that the ultimate strength of Y-joints reinforced with appropriately proportioned doubler plates can be greatly improved nearly up tothree times to un-reinforced Y-joints.

Dynamics of Anchor Last Deployment of Submersible Buoy System

Submersible buoy systems are widely used for oceanographic research,ocean engineering and coastal defense.Severe sea environment has obvious effects on the dynamics of submersible buoy systems.Huge tension can occur and may cause the snap of cables,especially during the deployment period.This paper studies the deployment dynamics of submersible buoy systems with numerical and experimental methods.By applying the lumped mass approach,a three-dimensional multi-body model of submersible buoy system is developed considering the hydrodynamic force,tension force and impact force between components of submersible buoy system and seabed.Numerical integration method is used to solve the differential equations.The simulation output includes tension force,trajectory,profile and dropping location and impact force of submersible buoys.In addition,the deployment experiment of a simplified submersible buoy model was carried out.The profile and different nodes' velocities of the submersible buoy are obtained.By comparing the results of the two methods,it is found that the numerical model well simulates the actual process and conditions of the experiment.The simulation results agree well with the results of the experiment such as gravity anchor's location and velocities of different nodes of the submersible buoy.The study results will help to understand the conditions of submersible buoy's deployment,operation and recovery,and can be used to guide the design and optimization of the system.

An investigation of the performance of an electronic in-line pump system for diesel engines

WIT Electronic Fuel System Co.,Ltd.has developed a new fuel injector,the Electronic In-line Pump(EIP) system,designed to meet China's diesel engine emission and fuel economy regulations.It can be used on marine diesel engines and commercial vehicle engines through different EIP systems.A numerical model of the EIP system was built in the AMESim environment for the purpose of creating a design tool for engine application and system optimization.The model was used to predict key injection characteristics under different operating conditions,such as injection pressure,injection rate,and injection duration.To validate these predictions,experimental tests were conducted under the conditions that were modeled.The results were quite encouraging and in agreement with model predictions.Additional experiments were conducted to study the injection characteristics of the EIP system.These results show that injection pressure and injection quantity are insensitive to injection timing variations,this is due to the design of the constant velocity cam profile.Finally,injection quantity and pressure vs.pulse width at different cam speeds are presented,an important injection characteristic for EIP system calibration.

A Study of Oceanic Reverberation Modeling Based on a Nonlinear Low-Dimensional Dynamic System

Acoustic reverberation signals generated by an experimental explosive source are analyzed by nonlinear dynamical methods. Three characteristic parameters, i.e., the correlation dimension, the largest Lyapunov exponent, and the Kolmogorov en- tropy, are estimated in the reconstructed phase space. The results indicate that the reverberation signals are nonlinear. The Volterra adaptive prediction method is introduced to model the oceanic reverberation signals. The reverberation time series can be predicted in short term with small prediction errors. A preliminary conclusion can be reached that the nonlinear low-dimensional dynamic sys- tem model is more suitable for modeling oceanic reverberation than the classical random AR model.