A new ship energy management algorithm to the smart electricity grid system

In this paper, a new energy management algorithm has been suggested for the ships connected with alternative energies considering the smart electricity grid features. The algorithm focuses on the use of optimum energy source on the shipboard based on the priorities of authorities such as the most economic, environmental, or both criteria at the ports. The algorithm is performed in MATLAB, and several case studies are simulated to validate the results. The 5 maritime nations, which are at different regions: United States, Belgium, Turkey, China, and Australia, are taken into account in the case studies. The actual data of a bulk carrier ship have been used to achieve tangible results in the simulations. The results of the case studies are compared to determine the changes of energy cost and released emission to meet demand of electricity on the ships. Capital cost of the proposed concept is also given to make an economic evaluation. The results show that the ship energy management algorithm provides the significant economic and environmental advantages. This paper aims to contribute to the importance of the ships in the smart electricity grid concept for the maritime and electricity sector representatives.     

Consideration of influence factors between small‐scale specimens and large components on the fatigue strength of thin‐plated block joints in shipbuilding

Shipbuilding in blocks, as being usual on all larger shipyards, requires that the blocks will finally be welded together manually or semi‐automatically, that is, with butt‐welds in transverse direction that have to withstand relatively high dynamical loads. Modern shipbuilding aims at lightweight construction with thin plates that may have a plate thickness down to 4 mm. Previous investigations showed that manually produced butt‐welds in such thin structures did not reach the calculated fatigue life as required in the rules. Up to the present, this problem has not yet been solved, and it is questioned if all influence factors on the fatigue behaviour of real structures are correctly considered as no damage cases at butt joints that are known yet. In the investigation described here, results from small‐scale specimens tested with cyclic loads will be transferred to large components, considering the effects of recorded pre‐deformations induced by welding as well as measured differences in residual stresses between small‐scale specimens and large components, thus clarifying how far for instance a detrimental stress ratio should be taken into account by the rules for thin plates.     

Investigations for indications of deliberate blasting on the front bulkhead of the ro-ro ferry MV ESTONIA

The roll-on-roll-off passenger ferry MV ESTONIA sank during the night of 28 September 1994 in the Baltic Sea. In October 2000, divers recovered two palm-sized test pieces from the front bulkhead of the wreck. The investigators analysed these specimens to determine whether there were any indications of deliberate blasting. Since the wreck had been submerged for almost six years, it was clear that chemical traces would not be present on the surfaces of the test pieces. Therefore, the investigators performed comparative tests on shipbuilding steel to find a microstructural criterion that exclusively characterises a blast. The shipyard Jos. L. Meyer, Germany, had built the ESTONIA and supplied shipbuilding steel plates similar to that used for building the vessel in 1979/1980. The comparative tests comprised mechanical tests, shot peening tests and blasting tests using different explosives. Testing demonstrated that blasting always formed twinned ferrite grains in the microstructure over the whole cross-section of each of the 8 mm thick comparative plates. Although one of the original test pieces of the ESTONIA showed deformation twins, this was only confined up to 0.4 mm underneath the surfaces and not spread over the whole cross-section. Comparative shot peening tests produced the very same pattern of subsurface deformation twins. Therefore, the twins detected in the microsection of the test pieces of the ESTONIA wreck traced back to the shot peening process performed by the shipyard in 1979/1980 and not to a deliberate blast.     

基于Android系统的船舶行业移动办公的研究实现

基于现代网络技术的发展和移动终端的发展前景,为了更好地发展船舶行业,从而实现移动办公,本文采用了智能移动终端开发了一款查询软件,主要从用户的角度进行功能分析、权限设计、接口设计和测试。通过测试,可以看出该软件可以实现远程访问数据库,查询信息和收发信息。在一定程度上,这一功能的实现推进了移动办公的速度,同时加速了船舶行业的数字化进程,如果把该软件推广到其他行业,依然可以完成相似的功能,有更广阔的发展前景。     

提高50Mn-C材质船用锻件质量的措施

本文主要介绍了50Mn-C材质船用锻件在生产过程中,有效控制了锻件草状波、性能不合格等问题的发生,提高了锻件一次探伤及性能的合格率。     

四分之一波长间距阵抗拖船干扰研究

为改善拖曳线列阵声呐的尾向探测能力,降低拖船噪声对半波长间距阵尾向探测性能的制约,本文关注四分之一波长间距阵对连续波信号和带限噪声的响应。研究表明,四分之一波长间距阵具有非对称的端向指向性,与半波长间距阵相比有约20 d B的空间抑制能力,能有效抑制拖船辐射噪声干扰。本文还提出用零陷权组合传感器构成四分之一波长间距阵,理论上其抗拖船噪声干扰的效果比四分之一波长间距阵更好。     

基于天线分集和空-时编码的抗舰载卫星天线指向损耗方法研究

本文针对舰载卫星天线指向损耗问题,将接收分集和空-时编码技术应用于舰艇卫星通信中。构建了舰船卫星通信信道模型,分析了舰载天线随机指向损耗特点,研究了接收分集和空-时编码技术,进行了舰船卫星MIMO通信性能仿真。研究结果表明,将MIMO技术应用于舰艇卫星通信可以有效改善舰载卫星天线指向损耗的不良影响。     

高动态临近空间飞行器海上组网测控方案设计

为解决高动态临近空间飞行器海上测控对测量船数量需求较多、现有船队规模无法满足的难题,在分析测控需求特点的基础上,提出了一种基于测量船与临近空间飞艇组网测控的新模式。结合近中程、远程飞行试验分别进行了测控总体方案设计,并讨论了海上组网测控需要研究的关键技术。相关研究对我国后续开展高动态临近空间飞行器海上测控系统建设具有一定的参考价值。     

内爆炸作用下舰船多舱室破坏的数值模拟

内部爆炸条件下爆炸波受舱室壁面多次反射叠加作用,其破坏作用大大加强,破坏机理也与空中（自由场）爆炸有明显区别。对内部爆炸作用下舰船多舱室结构的破坏效果进行数值模拟分析,结果表明：舰船十字形舱室的舱壁和甲板对爆炸能量具有导向作用,爆轰产物压力分布与破坏范围均呈比较明显的十字形分布;内爆炸作用下爆点所在舱室的舱壁可能发生整体冲切破坏,在爆轰产物推动下,冲切破坏的舱壁能够达到较高的飞行速度,并在飞行过程中对相邻舱壁造成碰撞破坏;具有泄爆孔和外侧加强筋的舱壁其破坏程度可有效降低,而内侧加强筋对舱壁则无加强效果,同无配筋情况相比,设内侧加强筋的舱壁的破坏程度要稍大。