• International Journal of Railway
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• 제1권3호
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• pp.89-93
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• 2008

Reliability of onboard power supply systems on rolling stock is a very important issue for the railway operator. While a failure of the HVAC supply results in a loss of comfort for the passengers, a failure of the supply for air compressors or for the traction cooling systems results in towing the train. This is, looking at the required availability of a train, not acceptable. An active redundancy concept for the onboard power supply maximizes the availability of the system. This paper describes such a system under the aspect of $\cdot$ Weight reduction $\cdot$ Continuous operation when changing from normal to redundant operation $\cdot$ Flexibility in train design.

• 한국자동차공학회논문집
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• 제24권1호
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• pp.82-89
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• 2016

This paper presents computational fluid dynamics (CFD) analysis on passenger thermal comfort in a train. Human thermal comfort in vehicles depends mainly on air temperature, mean radiant temperature, air velocity, humidity, and direct solar flux, as well as the level of activity and thermal properties of clothing and seat. The velocity and temperature distribution in a train with and without passengers are reported. The thermal comfort in a passenger train are also presented based on PMV and PPD indices with 16 segments of the human body.

• 대한기계학회논문집B
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• 제21권8호
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• pp.963-972
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• 1997

As a high-speed train enters a tunnel, a compression wave is generated ahead of it due to the piston action of train. The compression waves propagate along the tunnel and reflect at the exit of tunnel. A complex wave phenomenon appears in the tunnel, because of the successive reflections of the pressure waves at the exit and entrance of tunnel. The pressure waves give rise to large pressure transients which impose the fluctuating loads on the running train. It is highly needed that the pressure transients should be predicted to design the train body and to improve the comfortableness of the passengers in the train. In the present study, the pressure transients were calculated numerically for a wide range of train speed and compared with the previous tunnel tests. The calculation results agreed with ones of the tunnel tests, and the mechanism of pressure transients was made clear.

• 대한기계학회논문집B
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• 제21권8호
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• pp.983-995
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• 1997

As a high-speed train enters a tunnel, a compression wave is generated ahead of it due to the piston action of train. The compression waves propagate along the tunnel and reflect backward at the exit of tunnel. A complex wave phenomenon appears in the tunnel, because of the successive reflections of the pressure waves at the exit and entrance of tunnel. The pressure waves can give rise to large pressure transients which impose the fluctuating loads on the running train. It is highly needed that the pressure transients should be predicted to design the train body and to improve the comfort for the passengers in the train. In the present study, the pressure transients and aerodynamic drag for two-trains running in a tunnel were calculated numerically for a wide range of train speed, and compared with the results of the previous tunnel tests and calculations for one train. The present calculation results agreed with ones of the tunnel tests, and the mechanism of pressure transients was made clear.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.1187-1190
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• 2009

CURVE SQUEAL NOISE IS THE INTENSE HIGH FREQUENCY TONAL THAT CAN OCCUR WHEN A RAILWAY VEHICLE TRAVERSES A CURVE OR A SWITCH. THE HIGH NOISE LEVEL CAUSES ANNOYANCE FOR PEOPLE WHO LIVE IN THE NEIGHBOURHOOD OF THE SQUEALING RAILWAY TRACK AS WELL AS FOR THE PASSENGERS IN CARS WITH CURVES. THIS PAPER EXAMINES THE SPECTRAL SOUND DISTRIBUTION IN CURVES FOR KTX TRAIN. THE FREQUENCY RANGE IS FROM AROUND 4,000 TO ALMOST 16,000Hz, WITH NOISE LEVELS UP TO 92dB IN CURVE R400.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 추계학술대회 논문집
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• pp.258-262
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• 2004

In this paper, the hazard factors on voltage rising effect between the rail and the earth were reviewed in subway system of AC traction line according to moving condition and location of the train. Site measuring of voltage rising between conductor part of train and station floor was performed to ascertain the risk level on the passenger. Plans for preventing hazard of rail-voltage rising and electrical shock on the passengers at platform were proposed.

• 한국철도학회:학술대회논문집
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• 한국철도학회 1999년도 추계학술대회 논문집
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• pp.398-404
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• 1999

Safety of passengers in the Korean High Speed Train, KHST, was evaluated under the different accident scenarios. Preliminary occupant analysis has been performed based on the TGV-K train seat characteristics. The influence of the vehicle deceleration and passenger type, seating positions, effectiveness of compartmentalization have been evaluated in terms of occupant injury criteria. This study is the final result of the occupant analysis of KHST project at 1st stage 3rd year.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 춘계학술대회 논문집
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• pp.551-556
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• 2004

The Korean Train eXpress(KTX) which started in last April has got many complaints of passengers. This is caused by weak connections between KTX and traditional trains. This paper shows the methods to increase the connection in 3 points of view; business, operation and rolling stocks. For the flexible business, it is necessary that the connecting trains must be multi-purposefully for the satisfaction of KTX transferring passengers and existing commuting passengers. And the expanding of free class is needed. A free class is the base of business flexibility. In an operation point of view, I show the method that can decrease pains for getting transfer. Finally, for the effective using of rolling stocks, I propose that TC(trailer with control) car is added to existing locomotive and passenger coach set. In concluding, KTX needs strong connections with traditional trains. This will bring more competitive power with other transportation systems. And that method must get flexible and various service, in addition to effective and minimizing investment.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.321-326
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• 2008

Light weight of vehicles by composite materials makes possible high speed, energy saving, and low repair cost. As Bimodal Tram and Tilting Train eXpress(TTX) use carbon composite material for their bodies, safety for passengers and electrical devices against unexpected failures has been issued more than ever. Lightning strike which generates high voltages and large currents is the worst case for the safety of passengers and devices. With this background, we experimentally investigated the insulation breakdown phenomena on carbon composite materials by the application of lightning surge voltage and current. From the experimental results, we could estimate whether the composite body is safe or not for the inside passengers and devices against lightning strikes.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2006년도 추계학술대회 논문집
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• pp.192-195
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• 2006

With increasing concerns of indoor air quality, $CO_2$ concentration in the public transportation, such as train, bus, and subway, draws big interests. The $CO_2$ concentration in the indoor air is regarded as index of ventilation status rather than that of adverse health effect. In this study, we measured the time-series of $CO_2$ concentrations in the KTX cabin during the journey of Gyongbu-line (Seoul-Busan) and Honam-line (Seoul-Mokpo) with the number of passengers on board. At the same time, the concentration of particulate matter (PM), temperature, humidity and gaseous pollutants including HCHO and VOCs were monitored. It is found that the $CO_2$ concentration was correlated linearly with number of passengers and was highly correlated with tunnel regions where the ventilation unit (flap) was closed.