• Journal of the Korean Society for Railway
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• v.16 no.1
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• pp.14-19
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• 2013

Because excessive interior noise when riding a high-speed train leads to annoyances, fatigue and stress for passengers, interior noise reduction methods should be considered. In particular, a high-speed train operated in various operation environments, and in South Korea, these include open fields and tunnels. Therefore, a specific study about changes in interior noise characteristics according to different environments is necessary. For this reason, the interior noise characteristics on a KTX train and on the KTX-Sancheon train were analyzed from noise measurements using microphones in this paper. Vibrations on the axles, bogies and floor were also measured, are these area are structural paths for interior noise. From this research, the interior noise characteristics according to the driving speed were deduced and the effects on interior noise by driving environments such as open fields and tunnels were investigated. Furthermore, the effect on interior noise by axles, bogies and floor vibrations were analyzed from a transfer function analysis.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2010.10a
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• pp.309-309
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• 2010

한국은 산과 강이 많고 평야가 적은 지형적 특성상 터널 구간, 교량 구간 등이 많고 철도 차량이 이러한 구간들을 통과할 때 차량 내부에서 발생되는 과도 소음 또한 자주 발생하게 된다. 정상상태에서 소음에 비하여 과도상태에서 소음은 특성이 급격히 변화하여 승객들에게 더욱 큰 성가심을 유발할 수 있다. 특히 국내에서 운행중인 KTX 와 KTX 산천과 같은 고속철도의 경우 빠른 운행 속도로 인하여 과도 소음의 정도 또한 높아지게 된다. 따라서 더욱 정숙한 승객들의 승차 환경을 조성하기 위하여 과도상태에서의 실내소음 특성분석은 그 중요성이 더욱 커지고 있다. 본 연구에서는 고속철도가 감속 가속할 때, 터널을 통과할 때, 교량 위를 운행할 때, 차량이 교행할 때 등의 과도 상태에서의 실내 소음 특성을 음질평가의 방법으로 분석하고 정상상태에서의 소음 특성과 비교하였다.

• Journal of the Korean Society for Railway
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• v.15 no.4
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• pp.315-322
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• 2012

In a tunnel, interior noise of a high speed train increases by 5dB~7dB. The reason is that the sound intensity of the acoustic field in the tunnel significantly increases by the reflected waves occurred in the closed space. Especially, the incident acoustic power largely increases on the outside of the compartment side panel and large transmission of noise is available through the side panel and the glass window. In this paper, the sound insulation strategy in the tunnel is proposed for the next generation high speed train under development. Specimens of the aluminum extruded panels, layered panels and double glazed window are manufactured and intensity transmission loss is measured according to ASTM E2249-02. Based on the measured data, problems in the sound insulation performance are diagnosed and the sound insulation strategy is reviewed on each panel and layered structures.

• Journal of KSNVE
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• v.3 no.2
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• pp.95-102
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• 1993

고속철도를 포함한 철도운행에 있어서 소음문제는 중요한 환경문제의 하나 이다. 지금까지 철도소음에 관한 국내에서의 연구는 철도소음 기준과 관련된 일부 연구를 제외하고는 거의 없는 상황이다. 앞으로 고속철도의 성공적인 운행을 위하 여는 선로변에서의 소음저감 대책으로 지형과 궤도조건에 따른 소음피해 예측과 소음원 특성을 고려한 효과적인 방음설계에 대한 연구가 필요하다. 또한 경부고속 철도 노선에 터널이 많으므로 터널 미기압파의 발생과 그대책에 대한 연구가 필요할 것으로 생각된다. 이와 더불어 국산화 차량 개발을 위하여 차체와 판토그래프에서의 공력소음감소를 위한 공력해석, 전동소음과 구조물 소음 감소를 위한 차륜과 쾌도의 개선, 추진장치와 보조장치의 소음제어설계 등 각각의 소음발생원에 대한 이해와 소음저감 기술의 개발이 필요하다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2020.07a
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• pp.583-584
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• 2020

철도의 고속화 및 수송력 증대로 인하여 철도 터널 및 주변 환경에서 발생하는 소음 및 진동 공해는 커다란 사회문제로 대두되고 있으며, 도시의 고층화로 인해 차단벽을 이용한 방음 기술의 한계와 철도 차량의 고속, 경량화 추세로 인한 소음. 진동, 위험상황으로 인한 문제는 지속적으로 발생하고 있다. 본 논문에서는 IoT 기술을 결합한 안정성을 보장하는 IT 기반기술의 위험상황 감지, 철도 소음진동 분석, 모니터링 및 제어할 수 있는 시스템을 설계하고, 철도 인근지역 주민 또는 유관기관에 소음진동 수치에 따른 적합한 대응 시스템을 제공할 수 있는 IoT 기술 제어 분석 및 안정화 서비스 시스템을 설계하였다.

• The Journal of the Acoustical Society of Korea
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• v.37 no.4
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• pp.223-231
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• 2018

Recently, due to various environmental problems, blast tracks in tunnel are replaced with concrete tracks, but they have more adverse effects on noise than blast tracks so that additional noise measures are needed. Among these measures, sound-absorbing blocks start to be used due to its easy and quick installation. However, the performance of sound absorption blocks need to be verified under real environmental and operational conditions. In this paper, interior noise levels in KTX train cruising in Dalseong tunnel are measured before and after the installation of sound-absorbing blocks and the measured data are analyzed and compared. Additionally, noise reduction are estimated by modeling the high speed train, the tunnel and absorption blocks. Measurement devices and methods are used according to ISO 3381 and the equivalent sound pressure levels during the cruising time inside the tunnel are computed. In addition to overall SPLs(Sound Pressure Levels), 1/3-octave-band levels are also analyzed to account for the frequency characteristics of sound absorption and equipment noise in a cabin. In addition, to consider the effects of train cruising speeds and environmental conditions on the measurements, the measured data are corrected by using those measured during the train-passing through the tunnels located before and behind the Dalseong tunnel. Analysis of measured results showed that the maximum noise reduction of 6.8 dB (A) can be achieved for the local region where the sound-absorbing blocks are installed. Finally, through the comparison of predicted 1/3-octave band SPLs for the KTX interior noise with the measurements, the understanding of noise reduction mechanism due to sound-absorbing blocks is enhanced.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.29-30
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• 2006

The interior noise of KTX in tunnel has become an issue since the commercial operating in April 2004. The analysis of the interior noise of KTX in tunnel with concrete track shows sharply increased noise level in the range of 80Hz that is the natural frequency of the KTX carbody. We know that the booming noise inside KTX in tunnel with concrete track is generated by noise outside gangway and rolling noise at the carbody natural frequency. In this Study noise reduction methods are discussed on the basis of the comparison of the KTX and KHST noise characteristics. Alternatively, the effect of the modified mud-flap on the interior noise is introduced.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.8
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• pp.3631-3637
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• 2013

Gangway bellows in this study is the double wrinkled neoprene rubber component to accept various deviations between the carriage end parts of the articulated type high speed railway vehicle(HSRV). The fatigue failure of the bellows has a harmful effect on the riding comfort for the passengers with the increase of noise and ringing in the ears due to air-tightness failure during pass through a long tunnel. In this study, to assure the safety of gangway bellows of the HSRV, non-linear analysis of the gangway bellows considering triaxial angular displacement(rolling /yawing/pitching) between the carriage end parts are performed. The non-linear properties of the rubber are determined by uniaxial tension and equi-biaxial tension test. Moreover, from the results of non-linear analysis, the effects of the angular displacements and frictional coefficients are evaluated.

• Journal of the Korean Society for Railway
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• v.16 no.6
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• pp.454-459
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• 2013

Pressure waves are generated and propagate in a tunnel when train enters tunnel high speed. A compression wave due to the entry of train head propagates along the tunnel and is reflected at tunnel exit as an expansion wave. An expansion wave due to the entry of the train tail propagates along the tunnel and is reflected at tunnel exit as a compression wave. These pressure waves are repeatedly propagated and reflected at the tunnel entrance and exit. Severe pressure changes causes ear-discomfort for passengers in the cabin and micro pressure waves around the tunnel exit. It is necessary to analyze the transient pressure phenomena in tunnels qualitatively and quantitatively, because pressure change rate is considered as one of the major design parameters for optimal tunnel cross sectional area and repeated fatigue force on car body. In this study, we developed a characteristics method based on a fixed mesh system and boundary conditions for crossing trains and analyzed this system using an X-t diagram. The results of the simulation show that offsetting of pressure waves occurs for special entry conditions of a crossing train.

• Journal of the Korean Society for Railway
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• v.15 no.5
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• pp.436-441
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• 2012

Pressure waves are generated and propagate in tunnel when train enters a tunnel with high speed. Compression wave due to the entry of train head propagates along the tunnel and is reflected at tunnel exit as expansion wave. While expansion wave due to the entry of train tail propagates along the tunnel and is reflected at tunnel exit as compression wave. These pressure waves are repeatedly propagated and reflected at tunnel entrance and exit. Severe pressure change per second causes ear-discomfort for passengers in cabin and micro pressure wave around tunnel exit. It is necessary to analyze the transient pressure phenomena in tunnel qualitatively and quantitatively, because pressure change rate is considered as one of major design parameters for an optimal tunnel cross sectional area and the repeated fatigue force on car body. In this study, we developed the characteristics method analysis based on fixed mesh system and compared with the results of real train test. The results of simulation agreed with that of experiment.