抗侧滚扭杆对地铁车辆动力学性能影响的研究

国内外大部分高速客车转向架和地铁车辆转向架均采用了抗侧滚扭杆装置,以有效抑制车体侧滚角,降低车辆的柔度系数。但是,抗侧滚扭杆对其他动力学指标的影响易被忽视。通过建立某地铁车辆的动力学模型,仿真计算分析了车辆以80 km/h运行时,抗侧滚扭杆对车辆运行平稳性及车辆通过曲线时对柔度系数、倾覆系数、脱轨系数的影响。结果表明,抗侧滚扭杆装置虽然对降低车辆柔度系数有显著作用,但对车辆运行平稳性和车辆通过曲线时的倾覆系数、脱轨系数都有不利影响。因此,对于地铁车辆和中低速城轨车辆,应综合考虑二系悬挂的特性后再决定是否采用抗侧滚扭杆装置。     

二系单空气簧悬挂转向架的结构及动力学性能研究

对长春轨道客车股份有限公司目前正在执行的澳大利亚ED I626项目转向架结构进行了研究,根据实体结构运用动力学仿真软件建立相似动力学模型,计算并分析此类结构转向架的动力学性能。以计算结果为依据,研究该结构类型转向架在应用中的特性。     

转向车轮定位参数对车辆性能的影响

转向车轮四个定位参数,导致了轮胎与地面相互作用复杂化.所以,转向车轮定位参数对车辆性能的影响必须重视.本文比较了海南洋浦昌华运输有限公司在同一车型上变更车轮定位参数前后,一个年度内上下半年对车辆油耗和轮胎寿命的统计数据.并且列举了海口某机动车辆综合性能检测站对营运车辆进行检测时,一批车辆转向车轮侧滑量,证明新车或在用车辆,均必须保持正确匹配的车轮定位参数.     

偏侧风对风力机气动性能的影响

针对偏侧风对风力机气动性能影响的研究问题,用相对运动法作偏侧风的矢量分解,获得各风速分量的时间空间变化性质;在气动性能的计算模型中分离出偏侧风扰动项,分析了偏侧风对气动力的影响机理;用差值比较法在实例计算中得到偏侧风的气动推力和力矩,得出偏侧风对风力机具有周期性局部冲击的结论,为综合研究风力机风速风向变化下的气动特性及风电传动系统动力学行为提供了支持。     

地铁车辆车门开关对空调性能及车内温度的影响

在整车热工试验室对地铁车辆进行开关门测试,研究开关门过程空调性能及车内温度变化。频繁开关车门会造成整车空调系统能耗的增加。夏季制冷时,地铁车辆车内外温差不大,使空调系统能耗增加幅度不大。车门的频繁开关会造成车内温度变化。车门的开启和关闭使空调出风口的空气温度发生变化,进而改变地铁车辆内部的气温。门附近的气流变化很大,温度波动很大。     

汽油机气缸中滚动气流运动对发动机性能的影响

本文通过调整导气屏气阀位置产生大范围变化的缸内气流运动形式，用传统的稳流试验台和作者最近研制的测缸内滚流运动的稳流试验台对各种气流运动形式进行稳流试验，用二维激光多普勒测速仪在反拖的发动机缸内紊流运动的发展变化并用着火发动机的性能实验结果来分析各种气流形式的涡流、滚流和紊流特性。试验结果表明，在气缸中产生较强的横轴涡流即滚动或接近滚动气流运动时，燃烧室内的紊流强度可获得较大的提高，性能也有明显的改     

核岛侧常规岛主厂房山墙抗倒塌能力分析

常规岛主厂房是一种特殊的工业建筑结构,具有质量、刚度分布不均匀、多错层等特点,其靠近核岛一侧山墙抗倒塌性能会影响核岛的安全性,应进行细致的分析与设计。首先,通过静力推覆法对主厂房结构在SL-2级地震作用下的整体抗震性能进行了研究,然后,通过移除核岛侧山墙的关键构件,对核岛侧山墙抵御突发事件的能力进行了评估。结果表明:经过合理的设计,核岛侧山墙能够在地震作用和重要构件突然丧失承载力的作用下保持不倒塌,结构具有较大冗余度,能保证核岛安全。     

踏面下凹磨耗对地铁车辆动力学性能的影响

铁道车辆在运行的过程中由于各种因素的作用车轮踏面磨耗呈现下凹趋势,这种凹形磨耗称为下凹磨耗.为了表征踏面下凹磨耗对地铁车辆动力学性能的影响程度,针对某一地铁车辆建立了多体动力学仿真模型,计算分析了3种磨耗工况下列车运行稳定性、平稳性和安全性指标.分析结果表明,随着车轮踏面下凹磨耗深度的增大,列车稳定性、平稳性变差,且在一定程度的磨耗范围内这种下凹磨耗的趋势有利于列车曲线通过.     

峰谷分时电价对用户满意度影响的系统动力学分析

峰谷分时电价作为电力需求侧管理的一种有效调峰手段,其实施会对用户的用电方式满意度和电费支出满意度产生一定的影响,从而最终影响用户对峰谷分时电价的综合满意度。从系统和运动的观点出发,分析了不同影响因素间的因果关系,基于系统动力学方法构建了峰谷分时电价对用户满意度影响的系统流程图,从峰谷电量变化、用户电费节约及用户满意度3个方面分析了峰谷分时电价对用户满意度的影响,并对不同峰谷电价比和响应敏感型用户进行了敏感性分析。结果表明,模型合理、有效。     

挺柱转动对凸轮挺柱摩擦副抗擦伤性能影响的试验研究

本文对498Q发动机凸轮和与之配对的球面挺柱(R750mm、R2000mm)分别在凸轮轴转速为1500r/min和1050r/min两种工况下,在TM—1型凸轮挺柱磨损试验机上,进行了挺柱转动对凸轮挺柱摩擦副抗擦伤性能影响的试验。在试验的基础上对此摩擦副的接触应力、滑动速度等参数进行了理论计算;并利用电子探针、扫描电镜分析探讨了该摩擦副擦伤失效机理,以及挺柱转动速度、挺柱球面半径和凸轮轴转速对其抗擦伤性能的影响。     

铺轨车动力学性能仿真分析

为了解铺轨车的动力学性能,运用多体动力学软件,建立车辆系统的多体拓扑关系图,对ZK2转向架旁承、轴箱导框、心盘等非线性环节进行简化处理,构建非线性的动力学模型.通过动力学仿真结果可知,铺轨车的动力学性能主要由其2位端的ZK2转向架的性能所决定.     

Fuel cell-battery hybrid powered light electric vehicle (golf cart): Influence of fuel cell on the driving performance

A light electric vehicle (golf cart, 5 kW nominal motor power) was integrated with a commercial 1.2 kW PEM fuel cell system, and fuelled by compressed hydrogen (two composite cylinders, 6.8 L/300 bar each). Comparative driving tests in the battery and hybrid (battery + fuel cell) powering modes were performed. The introduction of the fuel cell was shown to result in extending the driving range by 63–110%, when the amount of the stored H₂ fuel varied within 55–100% of the maximum capacity. The operation in the hybrid mode resulted in more stable driving performances, as well as in the increase of the total energy both withdrawn by the vehicle and returned to the vehicle battery during the driving. Statistical analysis of the power patterns taken during the driving in the battery and hybrid-powering modes showed that the latter provided stable operation in a wider power range, including higher frequency and higher average values of the peak power.     

Experimental investigation on the dynamic performance of a hybrid PEM fuel cell/battery system for lightweight electric vehicle application

A hybrid system combining a 2 kW air-blowing proton exchange membrane fuel cell (PEMFC) stack and a lead–acid battery pack is developed for a lightweight cruising vehicle. The dynamic performances of this PEMFC system with and without the assistance of the batteries are systematically investigated in a series of laboratory and road tests. The stack current and voltage have timely dynamic responses to the load variations. Particularly, the current overshoot and voltage undershoot both happen during the step-up load tests. These phenomena are closely related to the charge double-layer effect and the mass transfer mechanisms such as the water and gas transport and distribution in the fuel cell. When the external load is beyond the range of the fuel cell system, the battery immediately participates in power output with a higher transient discharging current especially in the accelerating and climbing processes. The DC–DC converter exhibits a satisfying performance in adaptive modulation. It helps rectify the voltage output in a rigid manner and prevent the fuel cell system from being overloaded. The dynamic responses of other operating parameters such as the anodic operating pressure and the inlet and outlet temperatures are also investigated. The results show that such a hybrid system is able to dynamically satisfy the vehicular power demand.     

电感和电阻对DC-ERTG母线电压的影响

保持直流母线电压的稳定是确保DC-ERTG正常工作的前提。通过实验测试了直流母线的电感和电阻对母线电压的影响,并对一个实际DC-ERTG系统进行了仿真,结果可供类似系统的设计参考。     

余热锅炉动态特性的数值计算

本文对单压余热锅炉的动态特性进行了数值计算。分析了当燃气轮机排烟温度和流量发生扰动时,余热锅炉出口参数随时间的变化规律。研究结果为联合循环余热锅炉控制系统的设计提供了理论依据。     

Effects of drivetrain hybridization on fuel economy,performance and costs of a fuel cell hybrid electric vehicle

Fuel cell hybrid electric vehicles (FCHEVs) are considered to be the most attractive long-term option for passenger cars. Several barriers, such as cost, durability and hydrogen refueling infrastructure, must be overcome for a wider use of FCHEVs. In this paper, a mid-sized FCHEV is modeled and simulated in ADVISOR to analyze the influence of hybridization factor on vehicle performance and costs. The results are compared with those of the Toyota Mirai in order to find the optimum size of the fuel cell stack and the number of battery modules that meet various driving requirements, minimize hydrogen consumption and vehicle cost. The best results are obtained by reducing the fuel cell stack power by 58%. A 7.7% increase in equivalent fuel economy (71.6 MPGe) and a reduction of 25% in the vehicle cost is achieved.     

轴箱悬挂参数对高速动车动力学性能的影响

以采用转臂式轴箱定位的某型高速动车组为原形,通过多刚体动力学软件SIMPACK建立了完整的动力学模型,着重分析了一系纵、横、垂向刚度的变化对动车组稳定性、平稳性及曲线通过性能的影响。通过各参数的优化分析,发现合理的参数配置可以实现高速稳定性与曲线通过性能的理想配置,充分体现了轴箱转臂式定位的优越性。在仿真中,轮轨接触采用LMA踏面与Rail60kg／m钢轨的匹配,轨道不平顺采用德国高速低干扰线路轨道谱。     

两种常用漂浮式风力机平台动态特性分析

分别针对MIT/NREL TLP和Umaine-Hywind Spar两种海上风力机浮式平台主体的水动力特性进行研究,旨在分析两者的系泊稳定性.基于海洋水动力学和结构动力学理论,建立了平台/缆索系统耦合模型,在水深和外界载荷激励相同的情况下,利用有限元分析ANSYS软件中的水动力学计算模块进行时域、频域响应分析,研究了两种平台在海风、海流和随机波联合作用下的动态响应,并分析了两种平台随波浪频率的响应变化.结果表明:MIT/NREL TLP平台的动态响应较大,而Umaine-Hywind Spar平台动态响应较小;两平台均在低频波浪作用下产生响应峰值.     

Numerical study of enhancing vehicle radiator performance using different porous fin configurations and materials

A vehicle radiator is used for cooling down the hot working fluid with airflow passing over its flow passages and fins. The proper design of the radiator is very important due to space and weight limitations in automobiles. In this study, a numerical investigation has been conducted on the improvements, which can be obtained by implementing different porous fins in the radiator channels. The effects of different porous fin configurations with the same porous media volume on the heat transfer rate and pressure drop were investigated. The coefficient of performance values were presented for evaluating the overall performance. The investigated geometries included horizontal, vertical, corrugated, and wavy‐corrugated configurations. The results showed that the corrugated pattern had the best thermal performance among these geometries while the horizontal configuration presented the lowest pressure loss, even though the best overall performance belonged to wavy‐corrugated configuration. After selecting this configuration, the influence of different porous materials on the radiator performance was studied. Finally, the radiator with the optimum porous media configuration and material was compared to a conventional radiator. It was found that implementing this porous media in the radiator channels improves its overall thermal performance factor up to 237%.