Empirical relation between the typhoon surge deviation and the corresponding typhoon characteristics: a case study in Taiwan

The relation between typhoon surges and typhoon characteristics measured at Kenfang Tidal Station on the northeast coast of Taiwan was studied in this paper. Typhoon characteristics include the typhoon center atmospheric pressure, the typhoon near-center wind speed, the typhoon storm radius, the distance between the typhoon center and the tidal station, and the typhoon approach tracks. The results show that the typhoon surge deviation is strongly dependent on typhoon characteristics. An empirical typhoon surge formula is proposed in terms of the typhoon wind speed, the typhoon storm radius, and the distance between the typhoon center and the tidal station. The coefficients in the empirical formula were evaluated, based on the measured typhoon surge data at Kenfang Tidal Station. The storm surge deviations at Kenfang Station during Typhoons Doug (1994) and Herb (1996) estimated using the proposed empirical formula were compared with the measured data as well as with the results of a numerical study.     

离心压气机叶轮出口气体流动演变规律数值仿真研究

采用全三维仿真计算方法,针对离心压气机叶轮出口位置,进行了气体流动演变规律研究。研究结果表明:相同转速下,随着流量的减小,叶轮出口绝对气流角增加,且增加的范围主要集中在叶轮流道中心以下区域,叶顶区域变化不明显;相同转速下,叶轮出口总压比呈逐渐增加趋势;相同转速下,流量的减小使得叶轮顶部的效率损失减小而主流区的效率损失增加,压气机的最终效率取决于间隙流和主流流动损失的耦合作用。     

考虑传力杆位置偏差的刚性路面接缝传荷预估模型

针对刚性路面传力杆空间位置偏差问题,建立了Winkler地基上考虑层间接触状况的等平面尺寸双层路面结构模型,计算了传力杆位置偏差(水平偏角、竖直偏角和埋深偏差)对接缝传荷能力的影响,并通过三元非线性回归构建了接缝传荷能力预估模型,提出了模型的荷载修正系数η1并推荐了其取值范围.经FWD实测弯沉传荷系数的验证,修正后的预估模型较好地反映了位置偏差传力杆刚性路面的接缝传荷能力.传力杆水平偏角对弯沉传荷系数影响较小,随着竖直偏角的增大,传荷系数呈线性较小,水平偏离15°时,传荷系数降低约12％.传力杆布置于面层中部时,传荷能力最大,埋设位置偏上或偏下都将引起传荷系数的下降,偏下2 cm时降幅可达10％.     

考虑横向干扰的交叉跟驰模型研究

在传统跟驰模型的基础上,对车辆横向位置分布进行了实地调查,分析了周边交通场景对跟随车的横向干扰特性。引入最大转移速度和疏散路程参数,建立了交叉跟驰模型并进行了交通仿真。统计分析结果表明:行驶车辆横向位置分布基本符合正态分布,跟随车的行为变化与车辆偏离中心线的距离大小有关,交叉跟驰模型可以更加准确地反映实际道路交通场景。此模型的建立能够揭示车辆微观交互行为,对保障车辆运行安全和交通流稳定性具有重要的现实意义。     

郑武线轨道不平顺的相关性分析

根据轨道不平顺相关函数的数据处理方法,基于郑武线轨道不平顺实测数据,对郑武线轨道不平顺的相关性进行分析,得出郑武线轨道高低、方向及水平不平顺的相关函数的具体表达式;此外,得出郑武线轨道水平不平顺状态最差,方向不平顺次之,高低不平顺相对较好;郑武线轨道高低、方向及水平不平顺彼此独立,因而可将某单一不平顺或几种不平顺组合作为车-轨系统振动分析激扰。     

履带式摊铺机直线行驶跑偏量的理论计算及检测控制

对履带式摊铺机直线行驶性能进行了分析，提出了一种检测实际跑偏量的方法。利用此方法，结合实际施上作业工况更高的精度要求，对其相应跑偏量的检测控制进行了详细计算及分析。     

中亚机车通风过滤系统的改进设计

对南车资阳机车有限公司出口到中亚如土库曼斯坦、哈萨克斯坦机车的通风过滤系统存在的问题进行了分析,对现车的改进提出了四个方面的措施,介绍了新开发的适用于风沙地区的机车模块化结构的独立通风方案。     

和谐HX_D1型机车构架侧梁立板焊缝X射线探伤工艺的研究

分析了用现有探伤工艺透照HXD1型机车构架立板不等厚对接焊缝存在的问题,根据X射线管辐射侧倾效应,提出把射线焦点中心向厚板方向平移适当距离,并在普通透照电压的基础上适当提高管电压,用以增加透照厚度宽容度而不降低照相灵敏度的工艺方法。通过多次现场试验,探索出HXD1型机车构架立板不等厚对接焊缝的最佳工艺参数。     

基于绝对位置编码的列车定位技术

介绍在轨道交通中常用的列车定位技术，分析各种技术的优缺点，提出一种基于绝对位置编码的列车定位技术。利用优序列（最大周期线性反馈移位寄存器序列）对轨道线路上的绝对位置进行编码，当列车在线路上运行时，通过车载阅读器顺序检测设置在轨道线路上的二值标记，在不同位置上读到的标记在移位存储器中构成唯一的位置编码，以此位置编码值作为地址与车载阅读器所处位置的坐标信息相对应，就可以实现列车的绝对定位。二值标记可以根据列车定位精度的需要等间隔或不等间隔布置，既可以对整条轨道线路统一编码，也可以与既有应答器相结合应用，每段应答器之间的轨道线路采用相同的编码。该定位方法具有高精度、高可靠性、低成本、抗干扰能力强的优点。     

Simulating pedestrian movements at signalized crosswalks in Hong Kong

This paper presents a new pedestrian simulation (PS) model for signalized crosswalks in Hong Kong. This PS model is capable of estimating the variations of walking speed particularly on the effects of bi-directional pedestrian flows so as to determine the minimum required duration of pedestrian crossing time. Video records taken from the observational surveys at the selected crosswalk in urban area were used to extract the required data for model calibration. It was found that the design walking speed for signalized crosswalks should be varied by the effects of the bi-directional pedestrian flows. It was also interesting to note that the negative impact of the bi-directional flow effects (ranging from uni-directional to bi-directional pedestrian flows) on the chance of pedestrian crossing the crosswalk is increasing from free-flow to at-capacity flow conditions. The new PS model is also validated using an independent data set so as to examine the reliability of the simulation results. The validation results show that the new PS model can provide an accurate evaluation on the changes of walking speed and its standard deviation under different scenarios with particular emphasis on the effects of the bi-directional pedestrian flows. The advancement of this PS model can be applied to assess the effects of each improvement measure and to evaluate the benefits of each scenario in practice.