城市轨道交通高峰客流组织措施分析

随着城市化水平的不断提高和轨道交通的网络化发展,轨道交通客流的潮汐性特点越来越突出,高峰客流组织措施对地铁运营效率及乘客出行时间影响很大。文章以南京地铁一号线为例,对高峰运营现状及客流数据进行分析,发现存在列车运能不足、客流组织效率有待提高等问题,提出增设客运组织设备设施管理、合理安排人员和制定行车组织计划、改造列车车厢座椅增加运能、实行弹性票价调节客流等措施。该研究可以为其他城市轨道交通线路的高峰客流组织提供参考。

Aerodynamic performance analysis of trains on slope topography under crosswinds

This work used the computational fluid dynamics method combined with full-scale train tests to analyze the train aerodynamic performance on special slope topography. Results show that with the increment in the slope gradient, the aerodynamic forces and moment increase sharply. Compared with the flat ground condition, the lateral force, lift force, and overturning moment of the train on the first line increase by 153.2%, 53.4% and 124.7%, respectively, under the slope gradient of 20°. However, with the increment of the windward side's depth, the windbreak effect is improved obviously. When the depth is equal to 10 m, compared with the 0 m, the lateral force, lift force and overturning moment of the train on the first line decrease by 70.9%, 77.0% and 70.6%,respectively. Through analyzing the influence of slope parameters on the aerodynamic performance of the train, the relationships among them are established. All these will provide a basic reference for enhancing train aerodynamic performances under different slope conditions and achieve reasonable train speeds for the operation safety in different wind environments.

Research on the Effects of Train Operation Mode for Vehicle Energy Consumption

The research background is based on great consumption of urban rail transit energy, through summarizing the research of scholars at home and abroad, the comprehensive research including train operation pattern, the train traction characteristics and optimization design of integrated research has carried out in this paper, by using OPENTRACK software simulation to verify the optimization results according to different line features finally. The aim of this paper is to explore ways and methods of traction strategy optimization under the condition of trains timing energy saving. The main research contents of this paper are based on the research status at home and abroad, first of all, the different operating modes of the train running on the line are analysed, including the time saving mode, the energy saving mode and timing energy saving mode, and quantitative analysed the influence of different operation modes on vehicle energy consumption. The influence factors and traction calculation method of energy consumption of train running are studied. Firstly, the factors that affect the energy consumption of the train are analysed, including the basic facilities and transport organization mode. On the basis of this, the train load and running status of the train are analysed, and the model of the train movement and energy consumption are calculated. The OPENTRACK software is used to establish the actual circuit model, and the simulation is verified. The results show that the reasonable operation mode of the train operation mode can greatly reduce the energy consumption.

Determination method of load balance ranges for train operation safety under strong wind

The aerodynamic performances of a passenger car and a box car with different heights of windbreak walls under strong wind were studied using the numerical simulations, and the changes of aerodynamic side force, lift force and overturning moment with different wind speeds and wall heights were calculated. According to the principle of static moment balance of vehicles, the overturning coefficients of trains with different wind speeds and wall heights were obtained. Based on the influence of wind speed and wall height on the aerodynamic performance and the overturning stability of trains, a method of determination of the load balance ranges for the train operation safety was proposed, which made the overturning coefficient have nearly closed interval. A min(|A1|+|A2|), s.t. |A1|→|A2|(A1 refers to the downwind overturning coefficient and A2 refers to the upwind overturning coefficient)was found. This minimum value helps to lower the wall height as much as possible, and meanwhile, guarantees the operation safety of various types of trains under strong wind. This method has been used for the construction and improvement of the windbreak walls along the Lanzhou–Xinjiang railway(from Lanzhou to Urumqi, China).

Aerodynamic design for China new high-speed trains

High-speed trains have very complex running environments,which contain single-train running in open air,two-trains passing by in open air,single-train running in tunnel and two-trains passing by in tunnel.When the environment wind appears,crosswind effects must be considered.Aerodynamic design of high-speed trains mainly aims at the drag,lift,moment,impulse pressure waves,aerodynamic noise,etc.at typical running conditions.In the paper,the aerodynamic design processes of CRH380A and 380B are introduced and the aerodynamic performances of different designs are analyzed and compared.Wind tunnel experiments and running tests indicate that the new generation of high-speed trains have excellent aerodynamic performances.

Temperature-induced deformation of CRTS II slab track and its effect on track dynamical properties

Two finite-element models of the CRTS II slab track are presented to simulate temperature-induced deformations of the concrete track slab with no deterioration or with a deteriorated cement asphalt mortar(CAM).One model,which considers the fully bonding interface between the slab and the CAM layer,could applied to a track that is in good condition;the other model uses cohesive zone elements to simulate the deteriorated CAM with some possible interfacial separation and slip.Utilizing both of the models,temperature-induced warp deformations of track under various temperature loads are investigated.The influence of temperature deformation on the dynamic properties of the track is analyzed based on the train-track coupled dynamics.Numerical results show that the deteriorated CAM layer can significantly increase temperature deformations of a CRTS II track slab,which would produce tiny rail irregularities.There are clear differences between the deformation shapes of the track slabs that have an inseparable mortar layer and those have a separable mortar layer.The track slab with a deteriorated mortar layer showed more open curl distortion than the track slab in good condition.The dynamical response index of the slab track is intensified to a certain level due to the temperature deformation;with an increase of the train speed,the track dynamical responses increased linearly.However,rail irregularities due to the temperature deformations are very tiny.Even if a track is exposed to extreme temperature loads and the mortar layer is deteriorated,temperature deformation can have a negligible effect on the track’s dynamical properties.