• Title/Summary/Keyword: Interior noise

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A Study on the Interior Noise Reduction of EMU by Contribution Analysis (기여도 분석에 의한 전기동차 실내소음 저감대책 연구)

  • 문경호;김재철;유원희
    • Proceedings of the KSR Conference
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    • pp.218-225
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    • 1999
  • Speed-up and mass reduction of EMU(Electrical multiple unit) causes increase of interior noise. One of the best ways to reduce the interior noise is to identify noise sources. In this study, we evaluated interior noise by contribution analysis. This method is to predict the interior noise contribution of carbody by using transfer function between acceleration and sound pressure. The plan of the interior noise reduction based on the test results was also presented.

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A Study on Interior Noise Characteristics of High-speed Trains (고속철도 차량의 실내소음 특성 연구)

  • Noh, Hee-Min;Choi, Sunghoon;Kim, Seog-Won;Hong, Suk-Yoon
    • 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.

Analysis of Interior Noise for KTX in Tunnel with Concrete Track (콘크리트 궤도 터널 내 KTX 차량의 실내소음 특성 분석)

  • Kim, Jae-Chul;Lee, Chan-Woo
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.25-28
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    • 2005
  • The interior noise of KTX in tunnel is becoming the problem since the commercial operating in April 2004. The major sources of interior noise for High speed train ate known as the aerodynamic noise and rolling noise generally. We measure the noise and vibration inside KTX in tunnel in order to find the cause of the interior noise of KTX. The analysis results show that the interior noise of KTX in tunnel with concrete track is increased sharply by a low frequency below 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 aerodynamic noise outside ganqway and rolling noise at the carbody natural frequency.

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Comparison of Interior Noise for High Speed Trains in Korea (국내 고속철도 차량의 실내소음 특성 비교)

  • Kim, Jae-Chul;Lee, Chan-Woo;Jeong, Soon-Chul
    • Proceedings of the KSR Conference
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    • pp.90-94
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    • 2007
  • There are the high-speed train of two types in Korea, KTX and KHST(Korean High Speed Train). The characteristics of interior noise appear differently because the car bodies of the trains are designed with the different materials. In this study, we measure the interior noise for KTX and KHST. The experimental results show that the interior noise of KTX is equal to KHST in open territory and tunnel and interior noise in tunnel with concreted track increase about $3{\sim}4dB(A)$ compared to tunnel with ballasted track. We also know that interior noise level of KHST is higher then KTX in range of high frequency (above 630Hz).

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Analysis of Noise Contribution using Frequency Response Function and Measurements of Noise Distribution for Railway Interior Noise (주파수 응답 함수를 이용한 철도차량 실내소음 기여도 분석 및 분포도 측정)

  • 김재철;유원희
    • Journal of KSNVE
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    • v.9 no.5
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    • pp.949-954
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    • 1999
  • Speed-up and mass reduction of railway vehicle usually causes increased of the interior noise. One of the best ways to control the interior noise is to identify the noise level radiated from each of parts in the cabin. In this paper, we describe the method to estimate the interior noise nad evaluate the noise contribution to each of parts. This method is based that the sound pressure can be calculated by using the frequency response function and acceleration. According to analysis of the noise contribution, we validated that the noise radiated from the floor is the higher in the cabin. We also measured the noise distribution for the side and floor by using the microphone array in order to analyze the effect of the noise flowing into the cabin from the outdoors. Finally, we presented the plan of the interior noise reduction based on the noise levels radiated from each of parts.

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Analysis of Interior Noise of KTX in Tunnel with Concreted Track (콘크리트 궤도 터널 내 KTX 차량의 실내소음 특성 분석)

  • Kim, Jae-Chul;Lee, Chan-Woo
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.17 no.11
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    • pp.1037-1042
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    • 2007
  • KTX trains show a high interior noise level in tunnel with concreted track at 300 km/h. Generally, the concreted track has higher sound emissions compared with ballasted track due to the reduced absorption and the major sources of interior noise for KTX are known as the aerodynamic noise and rolling noise. Therefore, It is necessary to find out noise source and noise components to affect interior noise in tunnel with concreted track. In this study, we measure the noise and vibration inside KTX in tunnel in order to find the cause of the interior noise of KTX. The analysis results show that the interior noise of KTX in tunnel with concreted track is increased sharply by a low frequency below 80 Hz. We know that the low frequency noise inside KTX in tunnel with concreted track is generated at the natural frequency of carbody by aerodynamic noise outside gangway and rolling noise. In order to reduce the noise level at 80 Hz, modification of mud-flap length between carbodys is suggested and the effect of noise reduction is examined in tunnel with concreted track.

Analysis of Interior Noise for KTX Train using SEA (통계적 에너지 해석법을 이용한 KTX차량의 실내소음 해석)

  • Kim Jae-Chul;Lee Chan-Woo;Choi Sung-Hun
    • Proceedings of the KSR Conference
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    • pp.783-788
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    • 2004
  • Recently, Statistical Energy Analysis(SEA) is being increasingly applied to describe vibro-acoustic behavior of complex structures, such as air plane, automobile, ship, building. In this paper, we discuss the application of SEA to predict the interior noise for KTX train. To validate the SEA model of KTX train, calculated the interior noise for motorized car is compared to measured one. Finally, the reduction measures of interior noise for KTX are also discussed.

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An interior noise analysis of KTX vehicles on various operating conditions (한국형 고속철도 차량의 운행조건에 따른 차내 소음 분석)

  • Choi Sunghoon;Kim Jae-Chul;Lee Chan-Woo;Moon Kyung-Ho
    • Proceedings of the KSR Conference
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    • pp.138-142
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    • 2003
  • The conditions for measurement of the interior noise should meet the international standards. However, due to the limitations in test conditions the possible errors in measurement equipment, reliability of the measurement results has been questioned. Hence, the test procedure for the interior noise measurement of KTX vehicles are reviewed and investigated with the reference of international standards. Furthermore, the acceptable tolerance is inspected through the analysis of the factors that influence the interior noise of the KTX vehicle.

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Objective Evaluation of Vehicle Interior Noise in Operation (주행중 차실 내부 소음의 평가)

  • Jeong, Hyuk;Ih, Jeong-Guon
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.47-52
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    • 1996
  • Interior noise, engine speed and vehicle speed are measured under road-load condition and interior noise signal is transformed by using the transient signal analysis methods such as the spectrogram and wavelet transform. Using the analyzed results, subjective noise criteria such as the loudness, noisiness and articulation index at each vehicle speed can be estimated and characteristics of interior noise for various running mode can be discussed in the viewpoint of noise quality.

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Noise Prediction of Train Using Ray Tracing Method and Statistical Energy Analysis (음선추적법과 통계적 에너지 분석법을 이용한 철도차량 실내 소음 해석)

  • Park, Hee-Jun
    • Proceedings of the KSR Conference
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    • pp.942-946
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    • 2010
  • As the major sources of interior noise of train at running condition are the wheel/rail contact noise, the traction motor's noise and the driving gear's noise and these noise sources are transmitted through the car body, the noises of HVAC and air duct can be ignored. But the interior noise of train at standstill condition is decided by HVAC's noise and noise from the diffuser through the air duct. the interior noise prediction of train at standstill condition should be performed considering the shape of air duct, the air velocity and noise reduction property inside the air duct. But it is hard to estimate the interior noise level by the numerical method. Therefore train maker predict the interior noise level using The commercial noise prediction program. This paper introduce the noise prediction method of the train at standstill condition using the commercial program appling the ray tracing method and statistical energy analysis.

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