非结构化网格浸入边界法的流固耦合数值模拟

This paper presents an improved unstructured grid immersed boundary method. The advantages of both immersed boundary method and body fitted grids which are generated by unstructured grid technology are used to enhance the computation efficiency of fluid structure interaction in complex domain. The Navier-Stokes equation was discretized spacially with collocated finite volume method and Euler implicit method in time domain. The rigid body motion was simulated by immersed boundary method in which the fluid and rigid body interface interaction was dealt with VOS (volume of solid) method. A new VOS calculation method based on graph was presented in which both immersed boundary points and cross points were collected in arbitrary order to form a graph. The method is verified with flow past oscillating cylinder.     

周期性波动管流的压降研究

Experiments were conducted to study characteristics of flow when flow is fluctuating. The experimental results showed a phase difference between the flow rate and the pressure drop fluctuations. This phase difference between the fluctuating flow rate and pressure drop was analyzed for laminar flow. Analysis showed that the phase difference changes with the period of the flow fluctuation, the pipe radius, the density and the dynamic viscosity of the liquid. Fluctuating pipe flow was then numerically simulated. Results of the numerical simulation were compared with theoretical values and experimental results. It was shown that, when the flow rate fluctuates with time as a sine wave, the pressure drop fluctuates with the same periodicity, and there is a phase difference between them.     

结构动力学基于摄动法的高阶非线性随机有限元方法研究

Several algorithms were proposed relating to the development of a framework of the perturbation-based stochastic finite element method (PSFEM) for large variation nonlinear dynamic problems. For this purpose, algorithms and a framework related to SFEM based on the stochastic virtual work principle were studied. To prove the validity and practicality of the algorithms and framework, numerical examples for nonlinear dynamic problems with large variations were calculated and compared with the Monte-Carlo Simulation method. This comparison shows that the proposed approaches are accurate and effective for the nonlinear dynamic analysis of structures with random parameters.     

水工作业船舶的安全监督管理

随着我国经济的发展和水上货物运输的增加,"十一五"计划不断推动水上工程的建设和发展。港口、桥梁等大型水工作业逐年增加,参加工程建设的水工船舶也在不断增加,有效监管水工作业船舶,对维护水上安全形势,保护良好的通航环境,构建和谐社会至关重要。     

欧盟“低硫燃油法令”露锋芒

<正>根据欧盟法令,自2010年1月1日起,所有停靠欧盟港口的船舶,其燃油含硫量不得超过0.10%的最高限制。据了解,中国目前有400多艘船舶远航欧洲。那么,这一法令的实施,将对这些中国船公司产生哪些影响?采取哪些措施才能完全满足欧盟的这一"环境规则"呢?     

The enforcement of shipping standards under UNCLOS

This article discusses the enforcement of shipping standards, with a particular focus on Part XII of UNCLOS. Section 6 of Part XII contains the only comprehensive set of vessel-related enforcement provisions in the Convention, but the Part’s scope is limited to “the preservation and protection of the marine environment.” Therefore, not all shipping standards fall clearly within Part XII’s ambit, including those centered on safety, security, and crewing considerations. The enforcement provisions of Section 6 are favorable to flag states and their vessels, and Section 7 contains a number of safeguards for their benefit, so it is in the interests of these parties to have coastal state enforcement governed by Part XII. However, the ability of coastal states to establish and enforce shipping standards that apply within the territorial sea extends to more than just environmental matters. The result is that different standards give rise to different enforcement powers, depending on the maritime zone in which a vessel is located, even if those standards arise from the same international agreement. It is suggested that to remedy these problems, UNCLOS would need to be amended in order to provide a comprehensive enforcement regime for the enforcement of shipping standards.     

洋口港污水排海工程排污口选划研究

在综合已有大最研究成果和工程经验的基础上,通过分析排污口选划方法原则、初步方案的选取、海域水动力和水环境影响、泥沙场泥沙冲淤及工程技术经济性等选划因素,确定了洋口港污水排海工程的最佳排污口位置.结果表明,综合考虑各种影响因素的选划方法,有利于实现排污工程的环保排放.     

基于变频器的舰用恒压供水装置控制系统设计

变频恒压供水装置是将交流变频、可编程控制等技术应用于水泵自动控制的新型供水装置.鉴于目前船艇广泛采用的传统压力水柜供水方式存在严重缺陷,设计了基于变频器的舰用恒压供水装置,较好地实现了恒压供水,并可实现电机软启动、平滑加减泵、自动休眠和唤醒等功能,实验测试证明其满足设计要求且性能良好.     

Hydroelasto-plasticity approach to predicting the post-ultimate strength behavior of a ship’s hull girder in waves

Dynamic collapse behavior of a ship’s hull girder in waves is investigated; post-ultimate strength behavior is the focus. Firstly, a simulation method is proposed. Assuming that a plastic hinge is formed during the collapse of the hull girder, the whole ship is modeled as two rigid bodies connected amidship via a nonlinear rotational spring. The post-ultimate strength behavior, such as the reduction of load carrying capacity due to buckling and yielding, is reflected in the model. Hydrodynamic loads are evaluated by using nonlinear strip theory to account for the effect of large plastic deformations on the loads. A scaled model for validation of the simulation is designed and fabricated. Then a series of tank tests is conducted using the scaled model to validate the simulation results. Post-ultimate strength behavior characteristics in waves are clarified by using the numerical and tank test results. It is shown that the hull girder collapses rapidly after reaching ultimate strength, and then the plastic deformation grows until unloading starts at the collapsed section. Finally, several parametric dependencies of the extent of the collapse behavior are discussed based on a series of the simulations.     

Accessing the global seafaring labour market

As a global labour market exists for international shipping, a challenging issue facing this industry is to get access to reliable, accurate and timely information of seafarers’ demand and supply. Related to the deregulation environment and great variety in the availability and quality of relevant information, an enquiry into the global seafaring labour market is more complex than a national labour force survey. To cope with the challenge, a novel approach has been developed by the Seafarers International Research Centre (SIRC) at Cardiff University. Viewing capital (ship), labour (seafarers) and services (cargo or passengers) as interconnected and interwoven to each other, it collects and analyses crew lists from main ports world-wide, resulting in the creation of the first global seafarers database. The purpose of this paper is explain its methodological principles, and to illustrate its application potential. Taking the cruise sector as an example, research findings and methodological implications are highlighted.