• 환경영향평가
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• 제20권4호
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• pp.443-453
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• 2011

The purpose of present study is to develop a noise map around Korean Train Express (KTX) line. It is also to evaluate the high speed railway noise influence in neighboring areas around KTX. In order to develop the noise map, noise source modeling and 3-D noise radiation simulation have been performed by means of SoundPLAN program. The result of the noise map has been verified in comparison with the measured noise level. Noise measurements have been performed at 15 locations around KTX line. At each locations, 6 microphones were located 1.5m and 3m above the ground at each of 25m, 50m and 75 m distances from a center of the KTX track. The noise map showed clearly the high speed railway noise influence in neighboring areas around KTX line. The present study has also showed the noise could be reduced by using noise barriers constructed at severely noise-exposed locations.

• 한국철도학회논문집
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• 제19권3호
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• pp.271-279
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• 2016

팬터그래프의 공력소음은 열차가 고속으로 주행할 때 발생하는 소음의 주요한 원인이다. 본 연구에서는 팬터그래프에 의한 공력소음 기여도를 분석하기 위하여 차세대고속열차(HEMU-430X)를 이용하여 시험을 수행하였다. 실제차량에서의 팬터그래프에 의한 소음의 주파수 특성을 분석하기 위하여, 350km/h와 400km/h 주행 시 전체차량의 음장가시화를 144채널 마이크로폰 어레이를 이용하여 수행하였다. 음장가시화 분석결과 팬터그래프의 소음은 250~400Hz 대역의 저주파 소음이 주로 기여함을 확인하였다. 또한 팬터그래프의 소음 기여도를 분석하기 위하여 팬터그래프의 올림 및 내림 시 소음도 차이를 단일 마이크로폰 시험을 통하여 비교분석하였다. 단일 마이크로폰 시험을 통한 팬터그래프 소음의 주요 주파수 특성은 315~400Hz와 1000~1250Hz 대역임을 확인 하였으며 이는 기존의 연구 결과 및 음장가시화 결과와 잘 일치하였다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 1998년도 창립기념 춘계학술대회 논문집
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• pp.273-279
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• 1998

This study represents the technique about the noise reduction of HVAC equipment for high speed train(HST) operating at 200km/h. HST is different from the low speed train in the various points as well as the speed. Especially, the noise of cabin is closely related to the comfort of passenger and the noise from HVAC is one of main noise source in the cabin. In this study, the noise from HVAC was reduced by 5 dB(A) using the concept of multiple resonator and guide vein. Therefore, the noise of cabin decreased from 60 dB(A) to 55 dB(A) at the center of the cabin.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.899-902
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• 2007

The KTX train which brings April 2004 high-speed railroad commerce operation time is operated currently Kyungbu line Seoul-Gwangmyeong-Daejeon-Dongdaegu-Pusan and Honam line Youngsan-Gwangmyeong-Seodaejeon-Kwangju/Mokpo. The high-speed railroad opening to traffic after KTX train interior noise follows in railway line quality change and it is changing together. From the research which it sees until opening to traffic after present time of the KTX vehicle it executed an interior noise quality change from Kyungbu line.

• 한국소음진동공학회논문집
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• 제11권7호
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• pp.253-260
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• 2001

A Study of interior noise reduction in the magelv train is presented. Tarin speed of interest is low such that aero-dynamic noise is negligible and power supply system is a dominant noise source. Based on the measurements of interior noise and acceleration levels during running and zero speed conditions, dominant noise sources are identified. After spectra characteristics of noise sources are investigated several noise reducing methods are studied such as STL increasement of floor panels. sealing. and absorption treatment It is found that the most important noise sources are VVVF inverter and SLM in running condition, whereas air conditioner and DC/DC converter are dominant in zero speed. Sine the major noise sources are under the floor complete sealing and high STL of the floor panel are shown to be the most crucial factors in noise reduction After sound absorbing material, which is polyurethan foam of 50 mm thickness, is thickness, is attached to the downward side of the floor in addition to sealing treatment, the interior noise is reduced by 3~4 dB.

• 한국소음진동공학회논문집
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• 제12권10호
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• pp.758-765
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• 2002

KITECH and ODS performed a study of internal and external noise prediction of the Korean high speed prototype test train(HSR 350X). The object of this study was 3 kinds of cars, trailer car(TT2), motorized car(TMI ) and power car(TPI) and the predicted noise was for the two different driving speeds in free field and tunnel conditions. Data of carbody design and noise sources were delivered from manufactures. Some of noise sources which were not available in the project team, were chosen by experiences of ODS. Internal noise level of each car was predicted for two cases i.e, at 300 km/h and 350 km/h. In addition sound transmission path and dominant noise sources were also investigated for each section of the car, which is circular shell typed part of whole carbody. In case of TT2, the dominating sound transmission path is the (floor in terms of structure-borne noise and air-borne noise. The main noise sources are structure-borne noise from the yaw-damper and air-borne noise from the wheel/rail contact, whereas the dominating sound transmission path of TMI are floor and sidewall below the window in terms of structure-borne noise. The main noise sources of TMI are structure-borne noise from motor/gear unit and the yaw-damper in the free field, and air-borne noise from the wheel/rail contact and structure-borne noise from motor/gear unit in the tunnel. Through the external noise prediction for the KHST test train formation, the noise form the wheel/rail contact is estimated as one of the major sources. In addition, the noise specification of sub-component was proposed for managing each sub-surpplier to reach the KHST noise requirement. The specification provide the sound power of machinery part and transmission loss of component of carbody structure. The predicted noise level in each case exceeded the required limit. Through this study, the noise characteristics of the test train were investigated by simulation, and then the actual test will be performed in near future. Both measured and calculated data will be compared and further work for noise reduction will be continued.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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• pp.174-177
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• 2007

In this paper the noise characteristics of metro train is investigated experimentally. It is primarily aimed at observing the squealing noise radiation of each wheel when the vehicle pass the curve sections. This will be used to understand the noise excitation mechanism at the contact area between squealing wheels and rails which induce squeal noise at curve sections. To identify the related key parameters and boundary conditions on-board monitorings of the noise, vibration of the wheel and bogie and displacement behaviour of the wheels and rails have been done. In this paper only noise measurement and results are discussed. From spectrogramms squeal noise due to creepage and noise due to flange contact of the wheels could be identified. At the moment of the curve passing the highest squeal levels are found on the front inner wheel. However since curve noise depends on variable factors more analyses will be followed to identify the squealing wheels and the noise excitation.

• 소음진동
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• 제3권1호
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• pp.47-55
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• 1993

In order to maintain comfortable life environment around railroad site, noise from train itself, and to train & rail interaction, and the vibration transmitted through the ground should be controlled to the extent of permissible level. In order to achieve this, the basic railroad noise & vibration data such as magnitude and frequency characteristics of them are necessary to establish the counterplan for railroad noise & vibration. In this study, we measured and analysed the characteristics of time variation, frequency, direction and distance attenuation of noise and vibration of the railroad between Seoul and Pusan.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 춘계학술대회 논문집
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• pp.338-343
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• 2005

The Korean high speed train(KHST), developed since 1996, is presently undergoing commissioning tests on the high-speed track as well as on the conventional track since 2002. The purpose of the commissioning test is twofold: first to verify the performance of the train-set and equipments, and to demonstrate system reliability. Last December, KHST has reached the maximum speed of 350km/h and a number of data proving the performance of the train has been acquired. Among the data noise level and pressure variation in a cabin are important factors effecting passenger's comfort. Discussed in this paper are interior noise and pressure variation when the train passes tunnels during the 350km/h test.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.73-80
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• 2007

In this paper, the characteristics of noise and vibration of high speed train is analyzed depending on its speed. The speed is a very important parameter because it can affect the interaction between the train and the environment as well as the characteristics of the train itself. To measure its characteristics, we analyzed the signals from microphones and accelerometers which were attached to the passenger car of the high speed train. The signals from each sensor were stored in the recorder, and then analyzed by using the signal processing program. The data from each sensor are analyzed with the spectrogram. From the spectrogram, we found some distinct characteristics of the passenger car. Also, the characteristics of the noise propagation were inferred from the spectrogram.