无线传感器网络(WSN)在智能交通系统中的应用

无线传感器网络在智能交通领域的应用在国外刚刚开始,美国麻省理工学院媒体实验室、英国伦敦大学BERBECK学院、比利时布鲁塞尔自由大学的COMO实验室都在政府或民间的基金支持下开展WSN的专项研究。本文从介绍交通传感器技术入手,剖析WSN在车辆检测、车速测定、路基路况实时探测的应用技术、并对传感器的设计构造,网络的传输协议算法等有关WSN的国际先进技术信息进行披露。     

福仕达前舱线束电气盒电路图解

介绍海马福仕达豪华型微型客车的线束部件配置明细,并根据全车线束产品图纸,对前舱线束中电气盒的连接电路作出图解。当车载某电气设备不能正常工作时,本文可以作为参照,便于对连接电器设备的线束电路进行查找及故障的排除。     

基于嵌入式服务器的多模航行信息接收系统设计

文章设计了一种基于嵌入式服务器的多模航行信息接收系统,具有自动接收船舶识别信息、航行告警信息和气象传真信息的功能,同时具备了通过多功能显示器和热敏打印装置进行集中显示和图像打印的功能。文中给出了系统硬件组态及相应软件设计流程,测试和试用结果显示系统具有极高可靠性和实用性,具有很大的市场推广价值。     

动态斜面式撇油器结构优化及数值模拟

基于对现有动态斜面式撇油器工作原理和结构性能的分析，提出了“双重拖带”的概念，即表层传送带的拖带作用和底层水流的拖带作用。结合N—S方程，对“双重拖带”的作用机理进行了数值模拟。结果表明：“双重拖带”比传统拖带的作用收油效果更好，适用的溢油粘度范围也更广。     

Forging penetration efficiency of steel H13 stepped shaft radial forging with GFM forging machine

The numerical thermal mechanical simulation of radial forging process of steel H13 stepped shaft with GFM (Gesellschaft fur Fertigungstechnik und Maschinenbau) forging machine was carried out by three-dimensional finite element code DEFORM 3D. According to the effective plastic strain, the mean stress and the mean plastic strain distribution of the radial forging, the forging penetration efficiency (FPE) was studied throughout each operation. The results show that the effective plastic strain in the center of the forging is always greater than zero for the desirable larger axial drawing velocity. The mean stress in the center of the workpiece is proposed to describe hydrostatic pressure in this paper. There is compressive strain layer beneath the surface of the workpiece to be found, while there is tensile strain core in the center of the workpiece. These results could be a valuable reference for designing the similar forging operations.     

基于事故树分析法的船舶LNG燃料加注火灾防控研究

文章采用事故树分析法,对船舶LNG燃料加注时可能引起火灾的事件进行了分析,提出了相应对策,为LNG动力船舶燃料加注的安全管理提供了参考。     

关于二维混合浪周期问题的初步探讨

在沿海港口工程采用的《海港水文规范》（JTS145—2—2013）中,并未就常见的混合浪给出波浪周期的计算公式,以致实际工程设计中混合浪周期的选取比较困难。本研究基于小振幅波理论,利用能量法推导二维混合浪周期的计算公式,可供工程设计参考。     

Numerical study on flow-induced noise for a steam stop-valve using large eddy simulation

The noise induced by the fluctuant saturated steam flow under 250 °C in a stop-valve was numerically studied.The simulation was carried out using computational fluid dynamics（CFD） and ACTRAN.The acoustic field was investigated with Lighthill＇s acoustic analogy based on the properties of the flow field obtained using a large-eddy simulation that employs the LES-WALE dynamic model as the sub-grid-scale model.Firstly,the validation of mesh was well conducted,illustrating that two million elements were sufficient in this situation.Secondly,the treatment of the steam was deliberated,and conclusions indicate that when predicting the flow-induced noise of the stop-valve,the steam can be treated as incompressible gas at a low inlet velocity.Thirdly,the flow-induced noises under different inlet velocities were compared.The findings reveal it has remarkable influence on the flow-induced noises.Lastly,whether or not the heat preservation of the wall has influence on the noise was taken into account.The results show that heat preservation of the wall had little influence.     

3D numerical modeling of wave forces on tandem fixed cylinders using the BEM

In this paper a 3D numerical model was developed to study the complicated interaction between waves and a set of tandem fixed cylinders.The fluid was considered to be inviscid and irrotational.Therefore,the Helmholtz equation was used as a governing equation.The boundary element method（BEM） was adopted to discretize the relevant equations.Open boundaries were used in far fields of the study domain.Linear waves were generated and propagated towards tandem fixed cylinders to estimate the forces applied on them.Special attention was paid to consideration of the effect on varying non-dimensional cylinder radius and distance between cylinders,ka and kd on forces and trapped modes.The middle cylinder wave forces and trapped modes in a set of nine tandem cylinders were validated utilizing analytical data.The comparisons confirm the accuracy of the model.The results of the inline wave force estimation on n tandem cylinders show that the critical cylinder in the row is the middle one for odd numbers of cylinders.Furthermore the results show that the critical trapped mode effect occurs for normalized cylinder radiuses close to 0.5 and 1.0.Finally the force estimation for n tandem cylinders confirms that force amplitude of the middle cylinder versus normalized separation distance fluctuates about that of a single cylinder.     

智能交通在城市交通中的应用探讨

智能交通的研究课题是如何把现代的高科技与交通联系起来.结合实际阐述了智能交通系统在城市交通管理中的作用和重要性,针对我国交通现状提出了一些建议,并对智能交通未来的发展进行了探讨.