• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.28 no.9
• /
• pp.1042-1050
• /
• 2004

Theoretical study has been conducted to clarify pressure characteristics of KTX(Korea Train eXpress) in tunnel. The severe pressure change in tunnel may give rise to the ear-discomfort for passenger and fatigue for car body. The external and internal pressure of rolling stock have been measured by using the running test with atmospheric pressure sensors and portable data acquisition system in high speed train. In this study, the tunnels from 200m to 4000m in length have been chosen for the investigation of tunnel length effects. We found that there are similar patterns of external pressure change for each critical tunnel length. The critical tunnel lengths are governed by train speed, train length and sonic velocity. And, the patterns of pressure wave in tunnel are classified into eight groups.

• Journal of KSNVE
• /
• v.8 no.1
• /
• pp.187-194
• /
• 1998

In order to predict the train noise propagation from a level railroad, this paper presents the model of train noise source and the prediction model based on the results by using the sound intensity method. The prediction model gives the effects of geometric attenuation, ground attenuation, and barrier attenuation of noise. There are several principal assumption in developing model: (a) the train noise is primarily rolling noise; (b) the rail head and wheels are in good condition; (c) the height of source is 10cm above track; (d) the directivity pattern of train noise sources is a dipole source. Calculated results based on this model are compared with available field data and good agreement has been obtained.

• Journal of KSNVE
• /
• v.10 no.4
• /
• pp.636-641
• /
• 2000

KHST(Korea High Speed Train) project plans to design and to build an high speed train. There are noise requirements in passenger room for the standing and running condition, which should be reached. Predicted noise calculated for the standing and running TM5(Motorized car) and TT4(Trailer car) train (v=300 km/h and v=350 km/h) to find out critical areas in or around the train. From the estimation in DWA IfS, actions of noise reduction are proposed to reach the requirements. This paper takes the review of the calculated results in DWA IfS to propose a new design of inner wall.

• Proceedings of the KSR Conference
• /
• 2001.10a
• /
• pp.62-73
• /
• 2001

The scope of this study is focused on the survey of new logistics transportation systems in railroad and case studies of new systems such as piggyback system, bi-modal system swapbody, and double stack train(DST). Piggyback system, bi-modal system, swapbody, and double stack train are reviewed in term of technological validity and economic validity in Korea. Piggyback - trailer does pass loaded weight limits but does not pass train limits and can not utilize the existing freight cars. Piggyback - cargo trunk does pass all the criteria and could be developed by a domestic technology. But this study suggests to expand the length of train cars to 18.300mm for accommodation of two cargo trucks. Bi-modal system and swapbody do also pass. Double stack train could only pass the loaded weights and does not meet the train limit and the possibility of using existing freight cars. Domestic technology could not development DST, due to civil engineering construction limits and low standard height of electric line, which could not afford to operate DST.

• Proceedings of the KSR Conference
• /
• 2000.11a
• /
• pp.571-577
• /
• 2000

This paper is designed for the identification system of the train using RFID(radio Frequency Identification) in the 134.2㎑. The reader of transmitter transmits an interrogation signal to the tag, then the tag of receiver retransmits the defined data to the reader after receiving the interrogation signal from it. The system is also applied to the reflection communication as a backscatter modulation and selected the passive Pouter system which does not need an active electrical power device. It is useful that ore can effectively manage and control of the information of train such as materials loaded in the train. We make the reader of the identification system for the train which can communicate with the tag installed under the train.

• Proceedings of the KSR Conference
• /
• 2000.11a
• /
• pp.712-719
• /
• 2000

This paper presents a new algorithm to analyze a train voltages of multi-trains in auto-transformer-fed AC railway systems, using electrical equivalent change. The train current will be divided into circulation and return currents, and these current values are the same. By evaluating each current independently, the result will be more precise. The train current flows through the all auto-transformer corresponding to track impedance. In analyzing the railway system, the algorithm is based on the K.C.L, K.V.L, superposition and circuit separation method. Multi-train's voltages are determined by calculating the catenary voltage at each train's position and adding up these train's voltage drop. Case studies use a field operational data, show that tile proposed method is easily applied.

• Journal of the Korean Society for Railway
• /
• v.1 no.1 s.1
• /
• pp.20-29
• /
• 1998

State of the art and current issues related with the RC and PSC structure system for the German magnetic levitation train "Transrapid" were investigated. The German magnetic levitation train adopted a new kind of a structure to enable high-speed transportation, which allows the use of the space over a ground. The loading from Transrapid is light-weight compared with a regular train due to load distribution to a supporting structure. Therefore, Transrapid is considered an economical and efficient transportation system, and is also an environmentally-sustainable structure. In this paper, the structural design and construction technology specific to a magnetic levitation train were discussed, and structural considerations related with an actual operation of the train were pointed out. In addition, the future research area of a magnetic levitation train was proposed.

• Proceedings of the KSR Conference
• /
• 2007.05a
• /
• pp.1890-1901
• /
• 2007

This paper explored train frequency of intercity rail station. Main factors to decide train frequency are location of station, social-economic index and land use of station area and travel demand. In this paper, we focused on travel demand which is critical factor to decide train frequency. Tests on a KTX case show that train frequency can be efficiently decreased in weekday to transport same demand. The work has shown many subjects that need further research. It is important to include various factors influencing on train frequency decision.

• Proceedings of the KSR Conference
• /
• 2007.05a
• /
• pp.162-168
• /
• 2007

The critical speed above which the vehicle become unstable should be fundamentally verified in the development of new train. In case of high speed tilting train, which require both higher critical speed and higher curving speed, the critical speed should be more carefully treated because the both requirements are conflicting each other in the conventional train design. This research has been performed to estimate the linear and non-linear critical speed of 200km/h Korean Tilting Train which has been developing. The newly developed self-steering mechanism was attached to the tilting train to secure critical speed under the lower yaw stiffness which was inevitable to secure higher curving performance. The simulation to predict critical speed was done by commercial vehicle dynamic S/W. Full scale roller rig test was carried out for the validation of numerical results and effectiveness of self-steering mechanism.

• Proceedings of the KSR Conference
• /
• 2010.06a
• /
• pp.1814-1820
• /
• 2010

Korean Train Express (KTX) has been commercially operating and achieving elevation on transport capacity since 2004. And the first hish-speed prototype test train, HSR-350x, was developed and succeeded in testing of running over 350km/h. Now KTX-II based on HSR-350x was started in service run. The new high-speed train development project, HEMU-400x project, has started since 2007. The protype train is being designed and manufactured. After the train are developed completely, it will run on the commercial line and will be test to verify the estimated performance. The authors devised the performance evaluation method and process of the HEMU-400x prototype system. And we introduce the definite performance test items and the method to vitrificate them in this paper.