Development of the Analysis Model for Overhead Contact Line and Pantograph by EN Standard

2011 ◽  
Author(s):  
Jin-Hee Lee ◽  
Tae-Won Park ◽  
Sung-Pil Jung
Keyword(s):  
Contact Line ◽  
High Speed ◽  
Simulation Method ◽  
Railway Vehicle ◽  
Vehicle Speed ◽  
Analysis Model ◽  
Beam Elements ◽  
Sliding Joint ◽  
Multibody Dynamic ◽  
Catenary System

The evaluation of the contact loss of the catenary system is the highlight issue for the high-speed railway vehicle. In this paper, using the multibody dynamic analysis techniques including a flexible body, the simulation method of the catenary system is proposed. The pantograph and overhead contact line are developed by using rigid body and ANCF (Absolute Nodal Coordinate Formulation) beam elements, respectively. And relative motions are constrained by sliding joint. Using this analysis model, contact force and loss of contact are calculated according to vehicle speed. The results of the simulation are evaluated by EN 50318 that is the international standard with regard to validation of the dynamic interaction between pantograph and overhead contact line.

Analysis on Impact Loading at Rail Welds at High Speed

2008 ◽  
Author(s):  
Guangwen Xiao ◽  
Xinbiao Xiao ◽  
Zefeng Wen ◽  
Xuesong Jin
Keyword(s):  
Impact Loading ◽  
High Speed ◽  
Hertzian Contact ◽  
Railway Vehicle ◽  
Vehicle Speed ◽  
Explicit Integration ◽  
Normal Forces ◽  
Rail Irregularity ◽  
Multi Body ◽  
The Impact

When a railway vehicle passes through a track with different weld irregularities at high speed, the impact loading of the vehicle coupled with the track is investigated in detail using a coupled vehicle/track model. In this model, a half vehicle is considered and modeled as a multi-body system. In the track model, a Timoshenko beam resting on discrete sleepers is applied to model each rail. Each sleeper is modeled as a rigid body accounting for its vertical, lateral, roll motions. A moving sleeper support model is used to simulate the interaction of the vehicle and the track. The ballast bed is replaced with equivalent masses. The equivalent dampers and springs are used to replace the connections between the parts of the vehicle and track. In calculating the coupled vehicle and track dynamics, Hertzian contact theory and the creep force theory by Shen et al. are, respectively, used to calculate the normal forces and the creep forces between the wheels and the rails. The motion equations of the vehicle-track are solved by means of an explicit integration method. The weld rail irregularity is modeled by setting a local track vertical deviation at a rail weld joint, which is described with a simplified cosine function. In the numerical analysis the effect of the different wavelength, depth, the position of the welded joint in a sleeper span, and vehicle speed is taken into account. The numerical results obtained are greatly useful in the tolerance design of welded rail profile irregularity caused by damage and hand-grinding after rail welding.

Derailment Analysis of High-Speed Railway Vehicle Bogies

2011 ◽  
Vol 110-116 ◽  
pp. 186-195 ◽  
Author(s):  
Yung Chang Cheng ◽  
Chern Hwa Chen ◽  
Che Jung Yang
Keyword(s):  
High Speed ◽  
Lateral Displacement ◽  
Vertical Displacement ◽  
Creep Model ◽  
Railway Vehicle ◽  
Vehicle Speed ◽  
Nonlinear Creep ◽  
Bogie Frame ◽  
Suspension Parameters ◽  
Yaw Angle

Based on the heuristic nonlinear creep model, the nonlinear coupled differential equations of the motion of a 12 degree-of-freedom (12-DOF) bogie system which takes account of the lateral displacement, vertical displacement, the roll angle and the yaw angle of the each wheelset and the bogie frame, moving on curved tracks are derived. The nonlinear creep forces and moments are constructed via the saturation constant of the nonlinear creep model in completeness. The effect of the suspension parameters of a bogie system on the derailment quotient is investigated. Results obtained in this study show that the derailment quotient of a bogie system increases as the vehicle speed increases. In addition, the derailment quotient of a bogie system is generally decreased with the increasing values of suspension parameters.

Research of Modern Railway Vehicle Structure Fatigue Design Method Based on Multibody Dynamic Simulation

2010 ◽  
Vol 118-120 ◽  
pp. 327-331 ◽  
Author(s):  
Bing Rong Miao ◽  
Wei Hua Zhang ◽  
L.M. Zhang ◽  
Tao Zhu ◽  
H.T. Yin
Keyword(s):  
High Speed ◽  
Optimization Problems ◽  
Design Method ◽  
Parallel Optimization ◽  
Railway Vehicle ◽  
Local Vibration ◽  
Integrated Method ◽  
Durability Analysis ◽  
Multibody Dynamic ◽  
Vehicle Structure

For high-speed railway carbody structure durability analysis problems in China, one integrated method based on MBS (multibody simulation) is proposed here. Firstly, one EMU (Electricity Multiple Unit) full vehicle was performed to dynamic modeling and simulation. The numerical simulation results were applied to illustrate the vehicle dynamic characteristics. And the relationships between structural strength, stiffness, and frequency characteristics were also studied. Secondly, the multidisciplinary design technique was used to solve multi-mode coupled vibration of carbody structure on the cumulative effects of local vibration and damage effects, as well as structure light-weighting and other parallel optimization problems. Finally, the effective measures were proposed to control carbody structure’s physical failure.

Dynamic Analysis for Derailment Safety of High-Speed Railway Vehicle Bogies

2011 ◽  
Vol 199-200 ◽  
pp. 239-242
Author(s):  
Chern Hwa Chen ◽  
Yung Chang Cheng ◽  
Shun Chin Yang ◽  
Yuh Yi Lin ◽  
Cheng Hsin Chang ◽  
...  
Keyword(s):  
High Speed ◽  
Lateral Displacement ◽  
Vertical Displacement ◽  
Creep Model ◽  
Railway Vehicle ◽  
Vehicle Speed ◽  
Nonlinear Creep ◽  
Suspension Parameters ◽  
Derailment Safety ◽  
Yaw Angle

Based on the heuristic nonlinear creep model, the nonlinear coupled differential equations of the motion of a 12 degree-of-freedom (12-DOF) bogie system which takes account of the lateral displacement, vertical displacement, the roll angle and the yaw angle of the each wheelset and the bogie frame, moving on curved tracks are derived. The nonlinear creep forces and moments are constructed via the saturation constant of the nonlinear creep model in completeness. The effect of the suspension parameters of a bogie system on the derailment quotient is investigated. Results obtained in this study show that the derailment quotient of a bogie system increases as the vehicle speed increases. In addition, the derailment quotient of a bogie system is generally decreased with the increasing values of suspension parameters.

scholarly journals Influence of suspension parameter for derailment analysis of a full railway vehicle model cruising on a curved track

2021 ◽  
Author(s):  
Yamika Patel ◽  
◽  
Vikas Rastogi ◽  
Wolfgang Borutzky ◽  
◽  
...  
Keyword(s):  
High Speed ◽  
Research Work ◽  
Creep Model ◽  
Railway Vehicle ◽  
Vehicle Speed ◽  
Nonlinear Creep ◽  
Pitch Motion ◽  
Proposed Model ◽  
Curved Track ◽  
Creep Models

The main intention of this research work is to study the derailment response of high speed railway vehicle (HSRV) cruising on a curved track. In previous research work, lower degree of freedom (DOF) has been considered for the derailment analysis which may not give more accurate results. Hence, a 31 DOF bondgraph model of HSRV has been developed which consist of carbody, two truck frames and two selfsame wheelsets for each truck frame. Vertical, lateral, roll, yaw and pitch motion are considered for carbody and bogie and except pitch motion all the other motion are considered for wheelsets. Non-linearities in terms of heuristic nonlinear creep model and flange contact has been employed to simulate the derailment response at high speed. The effect of vehicle speed running on a curved track was investigated for derailment quotient. The main aim of present research work to evaluate derailment quotient at the speed range of 150 kmph to 600 kmph for hard and soft suspension parameter. Derailment quotient has been calculated for both linear and nonlinear creep models and it is seen that DQ for linear model has a lower value compare to non linear creep. The major advantages of the proposed model are that, the presented model can actively predict the derailment of a railway vehicle, and also precisely determine the nonlinear critical hunting speeds.

Wetting contact line modeling in high-speed jet coating

2005 ◽  
Vol 20 (2) ◽  
pp. 217-226 ◽  
Author(s):  
Alfa Arzate ◽  
Philippe A. Tanguy
Keyword(s):  
Contact Line ◽  
High Speed

scholarly journals CFD Simulation of a Hyperloop Capsule Inside a Low-Pressure Environment Using an Aerodynamic Compressor as Propulsion and Drag Reduction Method

2021 ◽  
Vol 11 (9) ◽  
pp. 3934
Author(s):  
Federico Lluesma-Rodríguez ◽  
Temoatzin González ◽  
Sergio Hoyas
Keyword(s):  
Shock Waves ◽  
Power Consumption ◽  
High Speed ◽  
Cfd Simulation ◽  
Aerodynamic Drag ◽  
Flow Behavior ◽  
Critical Conditions ◽  
Vehicle Speed ◽  
Blockage Ratio ◽  
The Cost

One of the most restrictive conditions in ground transportation at high speeds is aerodynamic drag. This is even more problematic when running inside a tunnel, where compressible phenomena such as wave propagation, shock waves, or flow blocking can happen. Considering Evacuated-Tube Trains (ETTs) or hyperloops, these effects appear during the whole route, as they always operate in a closed environment. Then, one of the concerns is the size of the tunnel, as it directly affects the cost of the infrastructure. When the tube size decreases with a constant section of the vehicle, the power consumption increases exponentially, as the Kantrowitz limit is surpassed. This can be mitigated when adding a compressor to the vehicle as a means of propulsion. The turbomachinery increases the pressure of part of the air faced by the vehicle, thus delaying the critical conditions on surrounding flow. With tunnels using a blockage ratio of 0.5 or higher, the reported reduction in the power consumption is 70%. Additionally, the induced pressure in front of the capsule became a negligible effect. The analysis of the flow shows that the compressor can remove the shock waves downstream and thus allows operation above the Kantrowitz limit. Actually, for a vehicle speed of 700 km/h, the case without a compressor reaches critical conditions at a blockage ratio of 0.18, which is a tunnel even smaller than those used for High-Speed Rails (0.23). When aerodynamic propulsion is used, sonic Mach numbers are reached above a blockage ratio of 0.5. A direct effect is that cases with turbomachinery can operate in tunnels with blockage ratios even 2.8 times higher than the non-compressor cases, enabling a considerable reduction in the size of the tunnel without affecting the performance. This work, after conducting bibliographic research, presents the geometry, mesh, and setup. Later, results for the flow without compressor are shown. Finally, it is discussed how the addition of the compressor improves the flow behavior and power consumption of the case.

Numerical Simulation of Flowfield around High Speed Trains Passing by each other at the same Speed

2011 ◽  
Vol 97-98 ◽  
pp. 698-701
Author(s):  
Ming Lu Zhang ◽  
Yi Ren Yang ◽  
Li Lu ◽  
Chen Guang Fan
Keyword(s):  
Numerical Simulation ◽  
Wind Tunnel ◽  
Flow Field ◽  
Point Source ◽  
High Speed ◽  
Stokes Equations ◽  
Field Structure ◽  
Vehicle Speed ◽  
Mesh Method ◽  
High Speed Trains

Large eddy simulation (LES) was made to solve the flow around two simplified CRH2 high speed trains passing by each other at the same speed base on the finite volume method and dynamic layering mesh method and three dimensional incompressible Navier-Stokes equations. Wind tunnel experimental method of resting train with relative flowing air and dynamic mesh method of moving train were compared. The results of numerical simulation show that the flow field structure around train is completely different between wind tunnel experiment and factual running. Two opposite moving couple of point source and point sink constitute the whole flow field structure during the high speed trains passing by each other. All of streamlines originate from point source (nose) and finish with the closer point sink (tail). The flow field structure around train is similar with different vehicle speed.

A real-time control method-based simulation for high-speed trains on large-scale rail network

2017 ◽  
Vol 28 (10) ◽  
pp. 1750126 ◽  
Author(s):  
Yutong Liu ◽  
Chengxuan Cao ◽  
Yaling Zhou ◽  
Ziyan Feng
Keyword(s):  
Real Time ◽  
Traffic Flow ◽  
High Speed ◽  
Large Scale ◽  
Simulation Method ◽  
Real Time Control ◽  
Rail Network ◽  
Time Control ◽  
High Speed Trains ◽  
Rail Traffic

In this paper, an improved real-time control model based on the discrete-time method is constructed to control and simulate the movement of high-speed trains on large-scale rail network. The constraints of acceleration and deceleration are introduced in this model, and a more reasonable definition of the minimal headway is also presented. Considering the complicated rail traffic environment in practice, we propose a set of sound operational strategies to excellently control traffic flow on rail network under various conditions. Several simulation experiments with different parameter combinations are conducted to verify the effectiveness of the control simulation method. The experimental results are similar to realistic environment and some characteristics of rail traffic flow are also investigated, especially the impact of stochastic disturbances and the minimal headway on the rail traffic flow on large-scale rail network, which can better assist dispatchers in analysis and decision-making. Meanwhile, experimental results also demonstrate that the proposed control simulation method can be in real-time control of traffic flow for high-speed trains not only on the simple rail line, but also on the complicated large-scale network such as China’s high-speed rail network and serve as a tool of simulating the traffic flow on large-scale rail network to study the characteristics of rail traffic flow.

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