SWAN和MOHID联合模型在连云港港30万吨级航道建设中的应用

根据连云港海域的特点,建立能考虑风浪影响的三维潮流、泥沙数学模型,对真实的"韦帕"台风作用下的潮流场和泥沙场进行模拟,力求更合理地反映近岸泥沙运动规律。数学模型计算得到的流场、含沙量场和航道回淤结果与现场实测资料进行验证,二者吻合较好。在此基础上,对连云港港30万吨级航道在"韦帕"台风作用下的回淤情况进行了预测,给出了航道的沿程淤强分布,为航道的设计提供依据。     

Formal Safety Assessment: an updated review

The method of Formal Safety Assessment (FSA) was devised several years ago with the intent to help the International Maritime Organization (IMO) and other policy makers formulate policies and regulations by the proper use of the scientific method in matters pertaining to maritime safety and the protection of the marine environment. A host of FSA studies have been submitted over the last several years and have been reviewed by the IMO. Also, progress has been recently accomplished as regards incorporating environmental risk evaluation criteria within FSA. On the basis of these developments, revisions of the FSA guidelines have been proposed and adopted. This paper presents a review of the FSA method in light of these developments. This review updates an earlier review of FSA by Kontovas and Psaraftis [Marine Technol 46(1):45?C59, (2009)]. It also takes this opportunity to identify some deficiencies of FSA, either due to an incorrect application of the method or to the method itself, and makes some suggestions for further action in this area.     

余弦载荷作用下圆锥壳的动力屈曲研究

本文采用数值方法对圆锥壳在余弦载荷作用下的动力屈曲问题进行了探讨.利用非线性几何方程建立了锥壳的基本动力屈曲方程.采用级数展开和伽辽金法等方法对方程进行了简化,使之成为常微分方程.方程的求解则采用龙格库塔法,最后给出临界冲击载荷值.     

Performance of Two Types of Mooring Systems in the Heave Motion of a Two-body Floating Wave Energy Converter

Journal of Marine Science and Application - This work investigated the influence of two types of mooring systems on the hydrodynamic performance of a two-body floating wave energy converter (WEC)....     

有轨电车综合指挥调度系统中列车运行的控制与监视

介绍国内有轨电车的发展现状,结合苏州有轨电车2号线综合指挥调度系统(tramway integrated dispatching system,TIDS)项目,对TIDS主要的系统功能进行简要说明,对有轨电车TIDS系统自动监控功能进行详细的功能模块划分,并围绕列车位置的监视与追踪,提出一种新的基于冗余策略的列车追踪方法和列车定位矫正算法,用于列车定位和显示。方案可在确保线路运行安全和运营安全的前提下,提升效率、提高稳定性,对后续有轨电车综合指挥调度系统方案建设具有一定的参考价值。     

PFI增压汽油机机油稀释试验研究

在一款1．0 L 气道喷射增压汽油机上研究了机油稀释的分布区域及其产生机理,发现机油稀释严重的区域主要集中在高速大负荷工况。通过对喷油器喷孔直径、喷油相位、VVT 动作角、空燃比、水泵流量、机油冷却器散热量、曲轴箱强制通风系统 PCV 阀补气量等相关特性参数的调整验证,发现喷油相位靠后、空燃比过浓是机油稀释严重的主要原因,水泵流量、PCV 阀补气量、VVT 动作角、机油冷却器散热量对机油稀释也有一定的影响,喷油器喷孔直径的变化对机油稀释无影响。最终在该款发动机上综合采用优化喷油相位、水泵流量、PCV 阀补气量、机油冷却器散热量的措施,最大机油稀释水平控制在5％以下。     

Clamping performance of fastener in windshield wiper assembly using theoretical and experimental methods

Improper clamping of wiper arms can cause problems in the operation of the wiper. An excessive clamping force can cause damage to the wiper arm head. On the other hand, an insufficient clamping force can cause self-loosening of the nut. Given the lack of direct research on the clamping force of the fastener in wiper assembly, this study verifies the existing clamping performance of the fastener in windshield wiper assembly by theoretical and experimental methods. The theoretical calculation results show that all the clamping performance are satisfied under the general snow load condition. However, under the critical load condition, maximum assembly preload and safety margin against slipping are in disagreement with the standard values. This problem is solved by increasing the strength grade of the bolt. The experimental results show a reducing tendency of the clamping force during the snow durability test. However, this reducing clamping force during the 60,000 test cycles is acceptable. In the case of nut reusing more than two times possibly cause a problem of its loosening because of insufficient clamping force. Therefore, it is recommended that the nut should not be reused more than two times.     

Design process to minimize roof surface defects using a flexural function and Finite Element analysis

The appearance and exterior precision of passenger cars aesthetics has become an important factor in the automotive industry. During vehicle assembly, the curvature of the roof can change slightly and create cosmetic defects that affect the exterior appearance. The critical factor causing curvature change on the roof is the thermally driven expansion of an elastomer-based mastic sealer which is applied between the exterior roof panel and support rail during the frame assembly process. Therefore the expansion of the mastic sealer was modeled to predict the curvature change in the roof panel. In order to evaluate the causes and predict the curvature change quantitatively, a Finite Element (FE) simulation of the oven heating and mastic curing was performed. Validation of the simulation model was performed by comparing the local deformation and amount of the curvature change on the roof obtained from the actual process. In order to minimize the curvature change, the Taguchi method was used in conjunction with the FE model where a total of eight factors were chosen to perform a sensitivity analysis. In order to exclude the deformation due to residual stress resulting from the oven process, it was selected as a noise factor. Response was taken as the maximum curvature change calculated by a flexural function which was used to distinguish absolute curvature that is not affected by the horizontal or vertical movement of roof panel. A total of 18 cases were analyzed with length of each sealer, pitch of sealer, and rail location being identified as the most influential factors affecting the curvature change. Using the optimum values, the amount of curvature change in the roof panel was reduced by 12 percent.     

Assessing the Potential Impacts of Connected Vehicles: Mobility,Environmental, and Safety Perspectives

The connected vehicle is a rapidly emerging paradigm aimed at deploying and developing a fully connected transportation system that enables data exchange among vehicles, infrastructure, and mobile devices to improve mobility, enhance safety, and reduce the adverse environmental impacts of the transportation systems. This study focuses on micromodeling and quantitatively assessing the potential impacts of the connected vehicle (CV) on mobility, safety, and the environment. To assess the benefits of CVs, a modeling framework is developed based on traffic microsimulation for a real network located in the city of Toronto, Canada, to mimic communication between enabled vehicles. In this study, we examine the effects of providing real-time routing guidance and advisory warning messages to CVs. In addition, to take into account the rerouting in nonconnected vehicles (non-CVs) in response to varying sources of information such as apps, global positioning systems (GPS), variable message signs (VMS), or simply seeing the traffic back up, the impact of fraction of non-CV vehicles was also considered and evaluated. Therefore, vehicles in this model are divided into; uninformed/unfamiliar not connected (non-CV), informed/familiar but not connected (non-CV) that get updates infrequently every 5 minutes or so (non-CV), and connected vehicles that receive information more frequently (CV). The results demonstrate the potential of connected vehicles to improve mobility, enhance safety, and reduce greenhouse gas emissions (GHGs) at the network-wide level. The results also show quantitatively how the market penetration of connected vehicles proportionally affects the performance of the traffic network. While the presented results are pertinent to the specifics of the road network modeled and cannot be generalized, the quantitative figures provide researchers and practitioners with ideas of what to expect from vehicle connectivity concerning mobility, safety, and environmental improvements.     

地铁整合建设与广州市可持续发展

从城市可持续发展的角度出发,探讨了地铁与城市发展、地铁经济、交通网络、地下空间、地铁文化之间的整合建设.今后地铁开发应该做好规划,实施综合开发,改善乘车环境,充分发挥地铁对可持续发展的作用.