Browse Topic: High-speed rail systems

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Distributed Control Method and System of Formation Train Based on Multi-Objective Operation Curve Optimization2026-99-05557/10/2026
In order to improve the transportation efficiency of high-speed trains, reduce the operational energy consumption and ensure the on-time arrival of trains, the operation curve optimization is regarded as a key way to achieve the above objectives. In this paper, a distributed control method and system for grouped trains based on multi-objective running curve optimization is introduced. Firstly, the train dynamics equations are established by considering the combined forces during train operation and the train driving maneuvering strategy, combining with the line conditions, and dividing the train operating conditions; secondly, combining with the virtual grouping technology, the train units are kept in a high safety and smooth tracking operation with small intervals between the train units; and then the constraints, such as setting up safety protection distance and Then, the constraints of safety protection distance and space-time safety protection are set, and with energy-saving and comfort as the optimization goals, the multi-objective hiking optimization algorithm (MOHOA) is adopted to optimize the operation curve according to the train's working conditions; finally, the high-speed train tracking and operation system model is considered to have nonlinear and parameter-variable characteristics, and is susceptible to external factors. Finally, considering that the high-speed train tracking system model has nonlinear and time-varying characteristics and is easily affected by external disturbances, a distributed control law is designed for the optimized running curve, and a sliding mode control method is adopted for tracking operation. By optimizing the running curve of the train and realizing the precise protection strategy, the control method established based on the optimized curve can ensure the smooth running of the train while improving the efficiency of railroad transportation.
Jiang, Qiqi, Chen, Guangwu, Shi, Jianqiang, Wang, Dong, Si, Yongbo, Li, Peng, Zhang, Wentao, Yang, Yang
Design and Analysis of Orthogonal Excitation Eddy Current Brake for High-Speed Trains2026-99-05137/10/2026
As high-speed train technology advances, the demands on braking system performance have intensified. Known for their efficiency, reliability, and eco-friendliness, Linear Eddy Current Brakes (LECB) have become a focal point in the research and development of high-speed train braking systems. This paper presents an innovative Orthogonal Excitation Eddy Current Brake (OEECB), which enhances the braking force without modifying the overall dimensions of the conventional LECB. By adding a set of longitudinal excitation coils parallel to the rail surface, the OEECB creates an orthogonal excitation structure that augments the braking force. Initially, this paper outlines the design concept of the OEECB and then analyzes its working principle based on electromagnetic field theory. Subsequently, a finite element solver is employed to numerically model the electromagnetic characteristics of the OEECB. Finally, by comparing the performance differences between the conventional LECB and OEECB, the superiority of the OEECB in enhancing braking performance is demonstrated. The results indicate that under the same excitation current conditions, the OEECB increases the braking force by over 20 % while maintaining a controllable increase in attractive force.
Huang, Liuwen, Zuo, Jianyong, Zhang, Yu
Study on the Influence of Liquid Composite Swivel Arm Positioning Nodes on the Dynamic Performance of High-Speed Trains2025-99-025512/23/2025
Rubber components are an important part of the suspension system of high-speed trains, and the complex nonlinear characteristics of rubber parts have a significant impact on the vehicle dynamic performance. This paper establishes a nonlinear dynamics model of the liquid composite swivel arm positioning node, which can reflect the dynamic stiffness and dynamic damping characteristics of the rubber components that change nonlinearly with the frequency and amplitude, and also has a fast calculation speed. The vehicle dynamics simulation model considering the longitudinal stiffness nonlinear characteristics of the arm node is established, and the influence of the stiffness nonlinearity of the liquid composite arm positioning node on the dynamic performance of the vehicle, such as straight-line stability and curve passing ability, is studied in depth through numerical simulation.
Cheng, Junqiang, Yang, Chen, Li, Longtao, Cong, Rilong, Hu, Tingzhou
Analysis of the Effect of High-Speed Train Travel on The Characteristics of Flow Field Distribution Near Wrist Arm Insulators in Tunnels2025-99-032712/17/2025
With the continuous progress of modern high-speed railroad technology, the speed of train operation is increasing, and its aerodynamic effect when traversing the tunnel is also getting more and more attention from researchers. In this paper, we constructed a three-dimensional flow field model of the wrist-arm insulator in the tunnel and considered the train speed, tunnel structure, size and position of the wrist-arm insulator, and other factors, and then through the simulation software, we simulated the change of the airflow in the tunnel when the high-speed train enters the tunnel. Through the simulation analysis, we obtained the characteristics of the flow field distribution around the wrist-arm insulator in the tunnel when the high-speed train crosses the tunnel. The results show that when the train crosses the tunnel at a high speed, the airflow inside the tunnel is strongly squeezed and disturbed by the train, forming a complex airflow field. When the train passes by, the wrist insulator will be impacted and squeezed by the high-speed airflow generated from the train, resulting in significant changes in the airflow velocity and pressure distributions on its surface. These changes not only affect the electrical performance of the arm insulator but also have a direct impact on its structural stability and service life.
Zhang, Kangkang, Ma, Jianqiao
Modeling Internal Node Impedance in High-Speed Rail Passenger Hubs Based on Queuing Theory2025-01-71722/21/2025
High-speed railway (HSR) hubs play a pivotal role in the integrated transport system, efficiently connecting various modes of transport and facilitating transport integration. Characterized by their large scale, complex functional spatial layouts, and diverse interchange types, these hubs see a growing proportion of passenger traffic annually. Thus, studying the interchange impedance in high-speed railway passenger transport hubs is crucial for enhancing interchange efficiency and service quality. However, current research lacks a quantitatively comparable impedance model for high-speed railway hubs, particularly under peak passenger flow conditions. This paper addresses this gap by examining the internal node impedance at Nanjing South Railway Station, focusing on the entry gate turnstile node and security check node. It begins by analyzing passenger passing behavior at these nodes and then constructs a integrated queuing model for inbound gates and security checks, considering the interdependencies between these systems. The model parameters are calibrated, and operational indices are calculated using survey data from the case station. The findings reveal that the security check service node is a critical point in the joint queuing system. The results of the study can inform improvements in the operational and management efficiency of high-speed railway hub stations.
Zhang, Zhenyu, Wang, Jian
Evaluation of Friction Torque in Tapered Roller Bearings2024-01-30479/8/2024
A bearing is a mechanical component that transmits rotation and supports load. Depending on the type of rotating mechanism, bearings are categorized into ball bearings and tapered-roller bearings. Tapered-roller bearings are superior to ball bearings in load-bearing capabilities. They are used in applications where high loads, such as, the wheel bearings for commercial vehicles and trucks, aircraft, high-speed trains, and heavy-duty spindles for heavy machinery must be supported. The demand for reducing the friction torque in automobiles has recently increased owing to carbon-emission regulations and fuel-efficiency requirements. Therefore, research on the friction torque of bearings is essential; studies have been conducted on lubrication, friction, and contact in tapered-roller bearings. There have also been studies on lip friction, roller misalignment, and so on; however, research on the influence of roller geometries and material properties is scarce. This study investigated the friction torque of tapered-roller bearings taking roller geometries and material uncertainties into consideration. The friction torque of tapered-roller bearings subject to axial loads was calculated theoretically and compared to experimental results. A Monte Carlo simulation was performed to evaluate the influence of roller geometries and material uncertainties on the friction torque of the bearings. The results of the Monte Carlo simulation showed a distribution skewed to the left. A correlation analysis of the random variables suggested that the outer raceway half angle and rib angle had a significant impact on the friction torque. In conclusion, the method proposed in this study enables the identification of factors influencing the torque of tapered-roller bearings. It is anticipated that these results can be utilized in the design of tapered-roller bearings.
Lee, Seungpyo, An, Hyun Gyu
Using an Inerter-Based Suspension to Reduce Carbody Flexible Vibration and Improve Riding-Comfort10-07-02-00092/1/2023
The riding-comfort of high-speed trains affects the travel experience of passengers, and the lightweight design technology of the carbody increases the flexible vibration and reduces passenger comfort. To this end, a vertical dynamics model of railway vehicles is established to demonstrate the potential of using passive inerter-based suspensions to reduce the flexible vibration of the carbody and improve riding-comfort. According to the characteristics of the inerter component, an appropriate inerter-based suspension is applied to the railway vehicle to reduce low-frequency resonance. The sum of the comfort indexes of the three reference points of the carbody is optimized as the objective function to improve the passenger comfort of the whole vehicle. The results reveal that the inerter-based suspension applied to the primary or secondary suspension has different effects on vehicle vibration. Compared with the traditional suspension, the riding-comfort using the inerter in both the primary and secondary suspension is improved by 21.3%, 9.3%, and 6.6%, respectively.
He, X.L., Chen, J., Tang, D. Y., Peng, S., Tang, B.B.
Cradle-to-Gate Life Cycle Analysis of Origami-Based Sheet Metal for Automobile PartsSAE-PP-0030911/12/2022
The sustainability of sheet metal parts often has multiple facets depending on the phase under consideration. The work presented in this paper focuses on cradle-to-gate Life Cycle Analysis (LCA) of the Origami-based Sheet Metal (OSM) folding process. OSM is an emerging fabrication technique that utilizes the principle of folding sheet metal parts by creating Material Discontinuities (MD) along the bend line. MD enables sheet metal folding (i.e., bending) with minimal force requirements and machinery. The anticipated reduction in force and machinery will result in a reduction in the required manufacturing energy. In addition, the OSM has less dependency on dies and shape-dedicated equipment. Hence, the cost associated with sheet metal parts development is reduced. This study attempts to establish the environmental impacts of the OSM for sheet metal parts by utilizing cradle-to-gate life cycle analysis. Environmental impacts of OSM are highlighted by comparing the OSM with the conventional stamping process. In the LCA, consumed energy and emissions are considered environmental impact indicators. Energy and emissions data are collected from published literature, machinery manuals, and available empirical models for energy consumption. A case study of a vehicle floor panel is presented as an example. Finite element analysis (FEA) is employed to achieve a more accurate energy estimation since the LCA inventory data displays a significant discrepancy. The findings of this study reveal that OSM requires less energy and produces fewer emissions than the stamping process.
Qattawi, Ala, Albat, Muhammad Ali, Algamal, Anwar, Ramineni, Lakshmi , Ali, Majed, Almotari, Abdalmageed, Alafaghani, Ala’aldin, Sun, Jian-Qiao
Improving Overhead Equipment Devices for a New Era of Railway TransportationTBMG-4001410/1/2021
The railway network is the backbone of the transportation system in India, connecting remote villages and towns with metropolitan cities across the country. Recent government initiatives aim to revamp and modernize the entire network by 2030 and the past couple of years have brought many changes to the rail system.
Aerodynamic Performance of Different Metro Train Geometries through a Straight Tunnel Based on Steady and Unsteady Reynolds-Averaged Navier-Stokes Modeling2020-01-50687/31/2020
Numerical RANS modeling has been carried out to assess the aerodynamics of different metro train geometries through a straight tunnel. A steady-state approach was first used to choose the best geometry out of seven alternatives in terms of drag reduction when compared with a typical blunt face train design representative of European metro networks. The proposed models have different edge-rounding characteristics at the front and rear faces. Afterward, the baseline and optimized geometries are compared at different train velocities, and the flow structure surrounding the models is discussed using unsteady RANS results. The study focuses on skin and pressure drag coefficients for trains traveling at 40 km h−1 in a straight tunnel with a blockage ratio of 0.69. All the considered alternatives show a drag reduction between 5% and 20% relative to the baseline case.
Croquer, Sergio, Fellouah, Hachimi, Poncet, Sébastien
Detection Method for Cavity Defects in Ballastless Track Structures of High-Speed Railways Based on Air-Coupled Ultrasonic Lamb Waves10-03-02-00107/2/2019
This study proposes a method for the rapid detection and location of cavity defects in ballastless track structures of high-speed railways in service. First, the propagation of air-coupled ultrasonic Lamb waves in the ballastless track structure is studied. Theoretical calculation results show that the ultrasonic Lamb wave group velocity of the A2 mode in the track plate is 4000 m/s. Then, the excitation and reception methods of the air-coupled ultrasound are studied. Theoretical and experimental results show that the A2 mode Lamb wave can be generated by the 3.8° oblique incidence of the ballastless track structure. Finally, an experimental system for air-coupled ultrasonic testing is constructed. A pair of air-coupled ultrasonic probes is used to provide excitation and reception Lamb wave signals at an inclined angle of 3.8°, 20 mm away from the surface of the track plate, and 40 mm/step along the scanning direction. Experimental data indicate that interaction between the Lamb wave and cavity conforms to the energy leakage principle, and the amplitude of the Lamb wave increases with the increase in cavity of the scanning path. The “position-amplitude” curve is drawn from the collected experimental data. Based on the quantitative relationship between the convex interval of the curve and the size of the cavity that can be calculated to obtain the cavity size, the detection error value is ±5 mm. Theoretical and experimental results show that noncontact rapid detection of cavities can be realized by using the air-coupled ultrasonic Lamb waves.
Wenfa, Zhu, Wei, Shao, Xingjie, Chen, Xiangzhen, Meng, Haiyan, Zhang
Impact of Dynamic Characteristics of Wheel-Rail Coupling on Rail Corrugation10-03-02-00097/2/2019
To gain a better understanding of the characteristics of corrugation, including the development and propagation of corrugation, and impact of vehicle and track dynamics, a computational model was established, taking into account the nonlinearity of vehicle-track coupling. The model assumes a fixed train speed of 300 km/h and accounts for vertical interaction force components and rail wear effect. Site measurements were used to validate the numerical model. Computational results show that (1) Wheel polygonalisation corresponding to excitation frequency of 545-572 Hz was mainly attributed to track irregularity and uneven stiffness of under-rail supports, which in turn leads to vibration modes of the bogie and axle system in the frequency range of 500-600 Hz, aggregating wheel wear. (2) The peak response frequency of rail of the non-ballasted track coincides with the excitation frequency of wheel-rail coupling; the resonance results in larger wear amplitude of the rail. The track lateral pinned-pinned frequency at 540 Hz contributes to the propagation of rail corrugation. (3) With wheel-rail contact friction coefficient of 0.3, simulation results of track lateral pinned-pinned frequency are consistent with the counterparts from field tests, successfully validating the numerical model. The model also shows that optimal design value of stiffness of the fastening system is 40 kN/mm. (4) The excitation frequency of the railway track at 500-600 Hz is the primary cause of rail corrugation. Increased axle load and high traffic density of high-speed trains also contributes to corrugation of the wheel-rail system. However, varying the train speed may help to reduce the rate of propagation of rail corrugation.
Gao, Xiaogang, Wang, Anbin, Gu, Xiaohan, Li, Wei
3D Design and Surface Mapping of Disc Brake Pad for High Speed Train Using FEA2018-01-08414/3/2018
Recurrently, the increase in production of high-speed trains worldwide has become a confirmed fact. Seeking to use the high-speed trains locally to link the capital of Egypt “Cairo” with the new industrial cities has become a national requirement. Modeling 3D surface maps using finite element analysis (FEA) is one of the most important mechanical design tools for frictional parts to facilitate the manufacture of brake systems for heavy duty vehicles, especially high-speed trains due to difficult working conditions. In this paper, we presented simulate 3D surface maps for proposed frictional material pad using FEA at certain design parameters and experimental result conductions. The typical surface characteristics of disc brake pad are compared with commonly used materials in railway and vehicle brakes in Egypt. The surface mapping of the pad materials are characterized by the analysis and distribution for profile deformation, stress as well as the thermal distribution at different thicknesses of the proposed brake pad. We also studied the safety factor of the proposed design. This work aims to explain the dynamic behavior phenomena to ensure the robustness of the proposed design to be studied to meet the standard requirements.
Ali, Salah H. R., Azzam, Badr S N, Osman, Tarek, Moustafa, Ahmed
Biomimetics: nature leads the way on design16MEIP06_186/1/2016
That bird flight inspired Leonardo da Vinci to conceptualize “flying machines,” only to be developed centuries later by the Wright brothers by observing pigeons in flight, is quite well known. Such imitation of the models, systems, and elements of nature for the purpose of solving complex problems, otherwise known as biomimetics or biomimicry, is not new. Mother Nature is a great engineer that over the years has fascinated engineers and scientists alike, who have borrowed and applied its time-tested patterns and strategies. Technological advancements and continuous endeavors to push the limits of engineering have led to transformational innovations, as can be seen in some of the recent trends to catch up with nature's best assets. Velcro is perhaps the best known and commercially successful example of a nature-inspired design. After a hunting trip in the Alps in 1941, Swiss engineer Mestral's socks and dog were covered in burdock burrs. Intrigued by it, Mestral studied them under a microscope to understand the simple system of interlocking hooks and spent the next few years developing Velcro. Such mimicking of nature's precise and efficient shapes, structures, and geometries is referred to as the basic level of biomimicry, by American biologist Janine Benyus.
Setting the standard15AUTP02_042/1/2015
Meggitt CTO Emeritus begins term at helm of SAE International, seeks to encourage cross-sector relations, elevate image of SAE as aerospace industry leader. Providing leadership for a diverse organization is nothing new to Richard Greaves, Ph.D., SAE International's President for 2015. Prior to his semi-retirement in 2012, Greaves oversaw all of engineering and technology for Meggitt PLC, which specializes in aerospace equipment and has 11,000 employees operating at more than 40 sites worldwide. Now as Chief Technology Officer (CTO) Emeritus, Greaves oversees new technology for the $2.5 billion engineering business. Headquartered in the U.K., Meggitt is organized into five operating divisions-Meggitt Aircraft Braking Systems, Meggitt Control Systems, Meggitt Equipment Group, Meggitt Polymers and Composites, and Meggitt Sensing Systems-and generates revenues in excess of $2.5 billion per year. Customers include many of the major aircraft OEMs and engine suppliers, most notably the U.S. Department of Defense, Airbus, Boeing, Bombardier, GE Aviation, Gulfstream, Lockheed Martin, and Rolls-Royce.
Monaghan, Matthew
Trains: Theory and Applications of Ground Vehicle Aerodynamics118487/18/2014
This video summarizes Chapter 8 of the book, "Theory and Applications of Aerodynamics for Ground Vehicles", by Dr. T. Yomi Obidi, published by SAE International. Concepts covered include train classification by function and speed, drag effect on design, and lateral force.
Theory and Applications of Aerodynamics for Ground VehiclesR-3923/20/2014
This book provides an introduction to ground vehicle aerodynamics and methodically guides the reader through the various aspects of the subject. Those needing specific information or a refresher can easily jump to the material of interest. There is a particular emphasis on various vehicle types (passenger cars, trucks, trains, motorcycles, race cars, etc.). However, the book is focused on cars and trucks, which are the most common vehicles in the speed range in which the study of ground vehicle aerodynamics is beneficial. Readers will gain a fundamental understanding of the topic, which will help them design vehicles that have improved aerodynamics; this will lead to better fuel efficiency, improved performance, and increased passenger comfort. The author’s basic approach to the presentation of the material is complemented with review questions, application questions, exercises, and suggested projects at the end of most of the chapters, which helps the reader apply the information presented, either in the classroom or for self-study. Aside from offering a solid understanding of ground vehicle aerodynamics, the book also offers more thorough study of several key topics. One such topic is car-truck interaction, when one vehicle (usually the smaller one) is overtaking the other. There is a direct and instant benefit in terms of safety on the highway from understanding the forces at play when one vehicle passes the other in the same direction and sense. Chapters examine: • Drag • Noise and vehicle soiling • Wind tunnels and road/track testing • Numerical methods • Vehicle stability and control • Vehicle sectional design • Large vehicles: trucks, trailers, buses, trains • Severe service and off-road vehicles • Race cars and convertibles • Motorcycles • Concept vehicles
Obidi, T. Yomi
Characterisation of the Brake Pads Used in High-Speed Trains2013-01-20289/30/2013
It is essential to characterize the frictional properties of brake pads used in high-speed trains during the processes of development and manufacturing of the pads. This paper presents the test results of new developed composite and powder metallurgical brake pads at different sliding speeds and contact pressures with specially designed test rig. Test results show that the coefficient of friction was increased with the increasing of sliding speed up to 120km/h, but over 120km/h it was decreased with the increasing of sliding speed for the composite brake pads. For the powder metallurgical brake pads, sliding speeds had no significant effect on the friction coefficients of the brake pads. Contact pressure had significant effect on the friction coefficient of brake pads for both materials. Water on the braking contact surfaces had significant effect on the friction coefficient of powder metallurgical brake pads. Temperature had significant effect on the friction coefficient of the powder metallurgical brake pad 2-T5 but had no significant effect on 1-T5. The braking squeal generated from both brake pads of composite material and powder metallurgical material has been investigated. It has been observed that powder metallurgical braking pads were likely to generate squeal but composite brake pads were not. Both sliding speed and contact normal pressure play a significant role on the generation of braking squeal.
Wang, Shuwen, Zhang, Jing-Ming, Yang, Zhenning, Chen, Kang
Genesis of the Third-Body at the Pad-Disc Interface: Case Study Of Sintered Metal Matrix Composite Lining Material2009-01-305310/11/2009
During braking, third-body flows and layers govern friction mechanisms, which are fully responsible of the friction coefficient and wear. In the context of development of brake friction pairs, the involved tribological circuit has to be well understood and mastered. This paper concerns a sintered metal matrix composite used for TGV very high speed train. A series of low-energy stop brakings allows a detailed study of the third-body formation at the pad-disc contact. The pin surface is observed after each test. The evolution of the rubbing-area expansion all along the series is explained, and the friction behaviour, typical of the studied friction material, is related to the formation of a well-established third body at the pad-disc interface.
Desplanques, Yannick, Degallaix, Gérard
Manufacturing of the Composite Chassis of the Superbus and Assembly Strategy2009-01-03504/20/2009
The Superbus was introduced as one of the option for the Zuiderzeelijn, a fast connection between Amsterdam and Groningen and resulted to be the best option; the others being three different types of high speed train and the magnetic levitation train. In order evaluate the feasibility of its implementation, the Dutch Ministry of Transport and Water Management has decided to fund the realization of a demonstrator. The Superbus is sustainable, fast, lightweight, and appealing and transports passengers and goods from point to point and drives at high speed (250 km/h) on its dedicated and relatively cheap infrastructure. The Superbus is 15 meter long, 2.5 m wide, 1.6m high and weighs less than 9 ton when fully loaded. The vehicle has to be able to brake or avoid an obstacle (detected by the navigation and control system) within a distance of 240m. Alongside that, static and dynamic loading conditions have rendered the structural design targets very demanding. For that, a new design has been implemented, which a uses cross-beams type of structure resulting in octagonal doors. Also, lightweight materials and construction processes have been implemented.
Terzi, Antonia, Ockels, Wubbo
Large Eddy Simulations of a Typical European High-Speed Train Inside Tunnels2004-01-02293/8/2004
This article presents our results of external aerodynamics, obtained with Large Eddy Simulations (LES), about a typical European passenger-stock inside tunnels. The focal points are the aerodynamic forces and their typical frequencies applied to the tail. Two train lengths and three tunnels are employed in the study to model the conditions of double and single-track bores. Owing to the relatively high numerical cost associated with LES for external train aerodynamics we could only afford sufficient spatial grid resolution on our shortest train. The flow simulations confirm the existence of coherent structures alongside the body that give rise to continuously propagating pressure disturbances. These disturbances with a relatively small amplitude and high spatial frequency cannot affect the ride comfort. Still, they are found to influence the flow separation about the tail, which is regarded as one of the candidate mechanisms to impair the ride comfort and running stability.
Diedrichs, Ben, Berg, Mats, Krajnović, Siniša
Vehicle-Bridge Interaction DynamicsB-WSP-0051/1/2004
The commercial operation of the bullet train in 1964 in Japan marked the beginning of a new era for high-speed railways. Because of the huge amount of kinetic energy carried at high speeds, a train may interact significantly with the bridge and even resonate with it under certain circumstances. This book is unique in that it is devoted entirely to the interaction between the supporting bridges and moving trains, the so-called vehicle-bridge interaction (VBI). It provides an up-to-date coverage of research conducted on various aspects of the VBI problems. Using the series of VBI elements derived, the authors study a number of frontier problems, including the impact response of bridges with elastic bearings, the dynamic response of curved beam to moving centrifugal forces, the stability and derailment of trains moving over bridges shaken by earthquakes, the impact response of two trains crossing on a bridge, the steady-state response of trains moving over elevated bridges, and so on. Contents: Moving Load Problems: Impact Response of Simply-Supported Beams Impact Response of Railway Bridges with Elastic Bearings Mechanism of Resonance and Cancellation for Elastically-Supported Beams Curved Beams Subjected to Vertical and Horizontal Moving Loads Interaction Dynamics Problems: Vehicle-Bridge Interaction Element Based on Dynamic Condensation Vehicle-Bridge Interaction Element Considering Pitching Effect Modeling of Vehicle-Bridge Interactions by the Concept of Contact Forces Vehicle-Rails-Bridge Interaction - Two-Dimensional Modeling Vehicle-Rails-Bridge Interaction - Three-Dimensional Modeling Stability of Trains Moving over Bridges Shaken by Earthquakes
Yau, J. D., Wu, Y. S., Yang, Y. B.
Numerical Investigation of Dynamic Wind Loading on High Speed Ground Vehicle During Crossing Event2003-01-12513/3/2003
In order to study unsteady wind loading on high speed trains passing by each other, a three-dimensional inviscid numerical method based on three types of domain decomposition techniques is developed. After the validation of the code to a single track train/tunnel interaction problem on three dimensional configuration, numerical simulations of the trains passing by on the double-track are conducted using 3 basic parameters in order to understand basic nature of the crossing event. From the practical viewpoint, variational parametric study is carried out to understand the effects of the velocity of the train, the gap between the train and the blockage ratio.
Hwang, Jaeho, Kim, Ik-Hwan, Lee, Dong-ho
Light Weight Design for High Speed and MAGLEV Trains2001-01-325410/1/2001
High-speed trains today operate at speeds between 200 and 320 km/h and MAGLEV trains between 400 and 500 km/h, whereas world record stands at 515 km/h for trains on wheels and 552 km/h for MAGLEV trains. This speed level can only be reached economically when light weight design is systematically used. Low axle load is crucial for the useful life of the infrastructure and low overall weight is necessary to reduce traction power and braking efficiency. The influence of train configuration on the mass per passenger seat is shown. For a given train configuration finally light weight design is compulsory despite the fact that requirements for structural stiffness, sound dampening, thermal insulation and other comfort items need additional mass. A number of high-speed trains such as TGV Duplex, Talgo Pendular, ETR 500, Pendolino WCML, ICN are presented and compared with the MAGLEV train TR08. A special aspect in this comparison will be passenger safety and as part of it crash-worthiness of the vehicles. Development trends for the future are given.
Zehnder, Jürg
Reliability Verification of Computer Based Control and Diagnosis Algorithm2001-01-332210/1/2001
From December of 1996, KERI is participating a project whose goal is to develop the Korean High Speed Train(KHST) with maximum speed of 350kph. KERI's responsibility is the electrical system engineering that includes engineering design of an on-board computer system for diagnosis and control of train set and electrical/mechanical devices. A system engineering approach of the design is performed in order to guarantee safety and reliability. This paper presents the simulation of on-board computer system's control and diagnosis algorithm using CASE tool. The simulation is focused on reliability verification of control and diagnosis algorithm for KHST prototype trainset's on-board computer system.
Lee, J-H, Jeon, J-W, Jeong, P-G, Park, D-Y, Kim, Y-J
Design of Network Based On-Board Computer System2001-01-325810/1/2001
Currently KERI is participating a project whose goal is to develop the Korean High Speed Train(KHST) with maximum speed of 350kph. KERI's responsibility is the electrical system engineering that includes engineering design of an on-board computer system for diagnosis and control of trainset and electrical/mechanical devices. A system engineering approach of the design is performed in order to guarantee the passenger safety and economically viable train for construction, operation and maintenance. This paper presents the engineering design and test of on-board computer system that ensures the safety and reliability of KHST. The design is focused at Train Communication Network(TCN) interfaced distributed processing system.
Lee, J-H, Cho, C-H, Lee, J-D, Park, D-Y, Kim, Y-J
An Improved Re-adhesion Control Method for High-speed Railways2001-01-325510/1/2001
Induction motor drive with pulse-width modulated (PWM) inverter control has been developed for the Korean High-Speed Railway. This paper describes a re-adhesion control system to improve tractive efficiency and to reduce wheel abrasion. The adhesion characteristics of the high-speed train are analyzed to get maximum adhesion effort and the re-adhesion control system is designed as a subsystem of the induction motor control. In order to verify the performance of the proposed system, a downscaled re-adhesion control simulator is set up and running tests are executed.
Hwang, Don-Ha, Kim, Moon-Sup, Ryoo, Hong-Je, Lee, Joo-Hoon, Park, Doh-Young, Kim, Yong-Joo, Kim, Dong-Hee
Fiber Reinforced Ceramic Composite for Brake Discs2000-01-276110/1/2000
From the family of CMC's a short fibre reinforced SiC-material (C/SiC) has been developed for lightweight brake discs with high thermal load and long life time. The patented material combines good physical, mechanical and friction properties, such as corrosion resistance, low CTE and Young's Modulus, high abrasion and temperature resistance and high and constant friction characteristics in wet, cold and hot conditions. First applications in sports cars and high-speed trains have been realized. The paper shows the way of production with a high potential for serial applications and the comparison of properties between brake rotor material like grey iron, Alu-MMC, Carbon/Carbon and C/SiC. The history of the development of the first life time brake disc for the new Porsche 911 Turbo is given as well as further projects for high speed luxury cars and high speed trains like ICE and TGV. Friction properties in combination with a selection of brake pad materials like organic, sinter and semi metallic are shown.
Krupka, Mario, Kienzle, Andreas
Methods to Estimate the Confidence Level of the Experimentally Derived Statistical Energy Analysis Model: Application to Vehicles9719695/20/1997
The effectiveness of vehicle design' modifications based on an experimental SEA model will strongly depend on the confidence one can have in the identified model. This paper deals with the estimation of the variances of the experimentally derived internal and coupling loss factors, allowing to assess the confidence levels of the SEA predictions. The theory concerning the statistical aspects of the Power Injection Method (PIM) is outlined and the derived analytical expressions are validated based on a Monte-Carlo variability analysis. The statistical formulas are then applied to a railway carriage of a high-speed train, illustrating that the calculation of confidence levels is a very useful tool to assess the accuracy of the experimental SEA model.
Hermans, L., De Langhe, K., Demeestere, L.
The French High Speed Train (TGV) Pantograph's Aeroacoustics9719185/20/1997
After 300 kph the aerodynamics noise emitted by the French High Speed Train T.G.V. (Train Grande Vitesse) becomes preponderant. The pantograph and roof environment located in the top of the rear power car are one of the sources which participate in the overall noise of the train. Investigations in an anechoi'c wind tunnel are performed firstly with a real pantograph, secondly with a fine 117 scale power car model. After a trainborne Velocimetry Laser Doppler campaign, the real turbulent boundary layer is simulated in the wind tunnel. The decreasing of the radiated noise level is obtained by modifying the geometry of both the pantograph and the roof and by adding devices on the pantograph itself. These results suggest that close attention needs to be paid to the roof geometry.
Fages, A., Bertrand, C.
Superconducting Maglev and its Electromagnetic Characteristics9519228/1/1995
A new test line of superconducting maglev is under construction, reflecting the results of Miyazaki test line. The null flux levitation system arranging 8-figured levitation coils on the sidewall is installed about 2km long in the middle part of the 7km guideway. The characteristics of the levitation, guidance and propulsion system have been tested with the test vehicle MLU002N. The results agreed well with analytical ones. As levitation and guidance forces were larger than those of normal flux system, lower take-off speed was attained on this section. The new test line of 42.8km long adopts this null flux system, implementing those results. Vehicle and coils to be tested on the new test line are summarized as far as they are related to electromagnetic characteristics are concerned.
Fujiwara, Shunsuke
SERAPHIM: A Propulsion Technology for Fast Trains9519248/1/1995
The Segmented Rail Phased Induction Motor (SERAPHIM) is a compact, pulsed linear induction motor (LIM) offering a unique capability for very high speed train propulsion. It uses technology developed for the Sandia coilgun, an electromagnetic launcher designed to accelerate projectiles to several kilometers per second! Both aluminum cylinders and plates were accelerated to a kilometer per second (Mach 3) by passing through a sequence of coils which were energized at the appropriate time. Although this technology was developed for ultra-high velocity, it can be readily adapted to train propulsion for which, at sea level, the power required to overcome air resistance limits the operational speed to a more modest 300 mph. Here, the geometry is reversed. The coils are on the vehicle and the “projectiles” are fixed along the roadbed. In the 1970's, the Federal Railroad Administration tested a 200 mph train riding on passive wheels and powered by a conventional LIM. In a LIM, electrical windings generate a backward moving wave of magnetic flux in a conducting reaction rail, producing a forward force. SERAPHIM operates not by embedding flux in a conductor, but by excluding it. In this propulsion scheme, pairs of closely spaced coils on the vehicle straddle a segmented aluminum reaction rail. A high frequency current is switched on as a coil pair crosses an edge and remains off as they overtake the next segment. This induces surface currents which repel the coil. In essence, the pulsed coils push off segment edges because at the high frequency of operation, the flux has insufficient time to penetrate. In contrast to conventional LIMs, the performance actually improves with velocity, even for a minimal motor consisting of a single coil pair reacting with a single plate. With either distributed onboard power, a passive wheeled train powered by a SERAPHIM is an attractive alternative to one which is levitated using superconducting magnets (MAGLEV) and propelled by switched electrified coils in the roadbed. This paper will present results of proof-of-principle tests, electromagnetic computer simulations, and systems analysis. It is concluded that this new linear induction motor can be implemented using existing technology and is a promising alternative propulsion method for very high speed rail transportation.
Kelley, Bruce, Turman, Bob, Marder, Barry, Rohwein, Gerald, Aeschliman, Dan, Cowan, Bill
CFD Aerodynamics of the French High-Speed Train9203432/1/1992
This paper presents the CFD activities performed for the analysis of the aerodynamic phenomena related to the nose shape of the French High-Speed train and the results obtained on a reference shape. The methodology focuses on nose shape optimization associated to the reduction of drag and to the damping of the pressure waves generated during tunnel entry. Two main approaches are detailed. On one side, Finite Element Navier-Stokes simulations are used to analyze the main free field features, the results being compared to those obtained on a scale mock-up. On the other side, a specific technique, involving adaptive remeshing with Finite Elements, solving the Euler equations, is developed and used in order to simulate the generation of pressure waves due to tunnel entry.
Aϊta, S., Tabbal, A., Mestreau, E., Montmayeur, N., Masbernat, F., Wolfhugel, Y.F., Dumas, J.C.
Maglev System Design Considerations9116248/1/1991
The characteristics of maglev systems being considered for implementation in the United States are speculative. A conference was held at Argonne National Laboratory on November 28-29, 1990, to discuss these characteristics and their implications for the design requirements of operational systems. This paper reviews some of the factors considered during that conference.
Coffey, Howard T.
MagLev and High Speed Rail System Environmental Energy and Economic Benefit Evaluation in Florida: A Comparative Analysis9014778/1/1990
The analysis reported on in this paper examines environmental, energy and economic benefits for specific, though different, proposed state wide high speed rail (HSR) systems combined with a regional maglev proposal under review in Florida. One of the HSR proposals and the maglev system are projected to be fully permitted within the next eighteen months and operational by the 1994-96 period. The specifics of each applicants proposals are integrated into a complex computer model which reflect different; 1) technologies and speeds, 2) energy demands and other resource needs, 3) system service level characteristics, 4) ridership levels, 5) modal splits combined with 6) other system differences. This computer model then integrates the unique a) fuel consumption and b) emission levels of the actual electrical generation grid supplying the HSR and maglev systems in central and south Florida. Finally, the model quantitatively combines this data with equivalent emissions, energy and other system information on auto and airplane transportation modes. This data and pertinent user characteristics enable the model to estimate precise environmental, energy and economic benefits (expressed in 1990 dollars) for each unique HSR and maglev transportation system for the year 1999 alone. The results of this Florida specific analysis conclude that implementation of a HSR proposal and the maglev system will annually result in: Economic and Energy Benefits - Time savings valued to $85 million. Automobile wear and maintenance savings valued to $37.4 million. Property and injury loss savings valued to $8 million. Reduction in annual transportation energy consumption of between 1.13 to 1.69 trillion Btus. Reduced dependence of $28.4 million on fossil fuel to power our transportation systems. Reduction of $23.5 million in imported oil thereby strengthening this nation's domestic economy by A) reducing negative balance of payments, B) increasing reliance on domestic sources of energy, and C) increasing domestic security. Reduce the annual economic damages (externalities) from transportation air pollution emissions. Additionally HSR/maglev systems will result in Savings in new highway construction costs exceeding $1 billion. Up to 217,979 man year direct and indirect construction employment. Up to $20 billion in indirect construction income. As much as 9,908 annual permanent operations jobs created both direct and indirect. Over $300 million annually in direct and indirect operation employment income. - Enhanced transportation productivity by a factor of three over current modes. Environmental Emissions Benefits and Costs - Annual reductions of between 555 to 633 tons/year of Volatile Organic Carbons (VOC) emissions. Annual reductions of between 3,035 to 4,746 tons (2753 to 4305 mtons) year of Carbon Monoxide (CO). Annual reductions of between 53,890 to 54,467 tons (48878 to 49402 mtons) year of Carbon Dioxide (CO2). Annual reductions of between 877 to 1,184 tons (795 to 1074 mtons) year of Nitrogen Oxides (NOx). Annual reductions of between 57 to 84 tons (52 to 76 mtons) year of Total Suspended Particulate (TSP) matter. Annual reductions of between 49 to 78 tons (44 to 71 mtons) year of tire wear particulate matter. Annual increases of between 132 to 173 tons (120 to 157 mtons) year of Sulfur Oxides (SOx). Total non-CO2 auto and airplane emissions exceed HSR and maglev emissions by a factor of 14. Total automobile and airplane emissions (including CO2) exceed HSR and maglev emissions by 200%. With proper mitigation measures, environmentally related noise impacts can be resolved. Growth in all Benefits/Costs All of these HSR/maglev social benefits will rise by a factor of 1.75 of any percentage improvements in trip times while ridership revenues to system owners could rise by a factor of 2.7.
Lynch, Tim
An Opportunity for High Speed Rail in Canada8917018/1/1989
This paper examines the efficiency of a high speed rail system relative to the air system over distances where rail offers a competitive transit time. As an example we consider the corridor between Toronto and Montreal. The basic result is that high speed rail is the low cost technology over relatively low demand levels. The profitability of a HSR investment is evaluated using the criterion of Net Present Value. Given the structure of our analysis, the Net Present Value is very sensitive to the revenue assumption. This suggests a role for public sector financial involvement.
Hurley, W. J., Jones, J., Wood, G.
Utilization of Membranes for H 2 0 Recycle System8513947/1/1985
Conceptual studies of closed ecological life support systems (CELSS) carried out at NAL in Japan for a water recycle system using membranes1) are reviewed. The system will treat water from shower room, urine, impure condensation from gas recycle system, and so on. The H2 O recycle system is composed of pre-filter, ultrafiltration membrane, reverse osmosis membrane, and distillator. Some results are shown for a bullet train of toilet-flushing water recycle equipment with an ultrafiltration membrane module. The constant value of the permeation rate with a 4.7m2 of module is about 70 1/h after 500h of operation. Thermovaporization with porous polytetrafluorocarbon membrane is also proposed to replace the distillator.
Ohya, Haruhiko, Oguchi, Mitsuo
Urban Rapid Rail Vehicle and Systems Program Progress7504442/1/1975
This paper describes the content, objectives, and status of the U.S. Dept. of Transportation's Urban Mass Transportation Administration's Urban Rapid Rail Vehicle and Systems Program (URRVS). The URRVS Program includes the following separate but interrelated programs: 1. BART Monitor. 2. State-of-the-Art Cars (SOAC). 3. Advanced Concept Train (ACT-1). 4. Advanced Subsystems Development Program (ASDP). 5. Advanced Concept Train Future Planning (ACT-3).
Hervey, David E.
High Speed Train Noise Control7206392/1/1972
This paper presents the tracked air cushion vehicle from a noise control point of view. The study, of the different sources of noise, points out that it is possible when using a linear induction motor to reduce the noise level to value as low as possible. In the case of very high speed vehicules other types of propulsion can be used. However it remains possible to reach acceptable noise levels.
Duthion, L., Doyotte, C.
High-Speed Railway Transportation Today and Tomorrow7001852/1/1970
The present generation of high-speed trains in various parts of the world has demonstrated improved performance and increased passenger and shipper patronage. Their performance is compared to the technical performance of future high-speed rail vehicles likely to be developed in the next decade. Market data and economic projections are analyzed to determine the cost and performance level trade offs for future generation trains and their likely competitors. An assessment of the overall impact to society is made regarding the widespread application of high-speed railway technology in the future.
Cripe, Alan R.
HIGH SPEED TRAINS3700231/1/1937
Henkle, Thomas H.
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