• 한국철도학회:학술대회논문집
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• 한국철도학회 2003년도 추계학술대회 논문집(III)
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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.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2012년도 춘계학술대회 논문집
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• pp.499-504
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• 2012

The high-speed train enjoys widespread acceptance as environment-friendly means of medium- to long-distance transportation. The pursuit of higher speed and lighter weight in railroad vehicles has engendered higher noise level. In particular, the environmental noise places many restrictions in the operation of high-speed railroad vehicles. This research investigates the effect of installing a skirt onto a high-speed train bogie with the top speed of 400 km/hr and using High Speed EMU for the purpose of reducing the environmental noise. In order to analyze the effect of the interior noise and environmental noise due to installation of the skirt, sound level is calculated using the Ray method and Statical Energy Analysis method. The numerical calculation predicts a reduction of approximately 2 dB in the environmental noise level, but at the cost of increase of approximately 2.5 dB in the interior noise level of the vehicle.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 춘계학술대회논문집
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• pp.1093-1098
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• 2002

Dynamic behaviors of the Korean High-speed Train(KHST) have been analyzed to investigate the performance on the stability, the safety and the ride comfort. Multi-body dynamics analysis program using Recursive method, called RecurDyn, have been employed in the numerical simulation. To model the wheel-rail contact, the RecurDyn uses its built-in module which uses the square root creep law. The accuracy of the rail module in RecurDyn. however, decreases in the analysis of flange contact because it linearizes the shape of the wheel and rail. To solve this problem, a nonlinear contact theory have been developed that considers the profiles of the wheel and rail. The results show that the KHST still needs more stability. The problem should be solved by the examinations of module and modeling.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2010년도 추계학술대회 논문집
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• pp.302-307
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• 2010

Development of light-weight high speed train (HST) based on distributed motor control with the top speed of 350 km/hr has engendered a need for abatement of the interior noise of the train cabin. The development of noise abatement measures is crucial at the design stage of the train car since the noise transmission characteristics of the car structure directly influences the cabin interior noise. Since the transmission loss measurement using the entire car structure is often not feasible, especially at the initial stages of the train development, investigation of transmission characteristics using small-scale reverberation chamber can furnish useful alternative source of predicting the noise level. In the present study, white noise is generated at source and transmission loss estimated by performing measurement of a specimen in a scaled reverberation chamber. Comparison of measured values with the previously derived numerical values show good agreement in the overall trend but appreciable quantitative differences still remain.

• 한국소음진동공학회논문집
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• 제25권4호
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• pp.266-274
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• 2015

Vibration exposure of domestic high speed trains(KTX and ITX-saemaeulho) to passenger traveling on the Gyung-Bu line was measured to evaluate health effect which is based on ISO 2631-1. The vibration exposure was compared with the frequency weighted root mean square(r.m.s.) and vibration dose value(VDV) of the two trains’ vibration. It is concluded that vibration exposure of the two train during round trip of Busan-Seoul in single day is evaluated to be safe for the passenger’s health according to the health guidance caution defined on ISO 2631-1. Futhermore KTX’s vibration exposure is found to be significantly lower than ITX-saemaeulho thanks to lower vibration magnitude as well as shorter trip time.

• 한국산학기술학회논문지
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• 제14권8호
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• pp.3631-3637
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• 2013

갱웨이 벨로우즈는 관절형 고속철도차량 객차 끝단부 사이에 다양한 변위차를 고려하여 갱웨이 프레임에 장착된 이중 주름구조 네오프렌 고무부품이다. 실제 운행중의 벨로우즈의 파손은 터널 통과시 기밀 파손으로 인한 이명현상 발생과 함께 소음 증가로 승객의 승차감에 심각한 영향을 미친다. 본 연구에서는 고속철도차량 갱웨이 벨로우즈의 안전성 연구일환으로서, 차량주행시 차량 끝단부의 3축 회전변위(롤링, 요잉, 피칭변위차)를 고려한 갱웨이 벨로우즈의 비선형 해석을 수행하였다. 본 고무의 비선형 재료 특성은 단축인장 및 등2축 인장시험을 수행하여 구하였다. 또한, 비선형 해석결과로부터 회전변위 및 마찰계수의 영향을 평가하였다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문집
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• pp.104-109
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• 2002

The purpose of this study is to calculate transmission loss of KHST passenger vehicle's wall section accurately Typical transmission loss measurement of wall in the laboratory condition was carried out in advance, which is easier than KHST. Transmission loss results were compared with those by statistical acoustic method. Transmission loss values of KHST calculated by experimental method are compared with those from closed form solution.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문초록집
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• pp.317.2-317
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• 2002

Transmission loss of KHST passenger vehicle was calculated using measured acoustic data: In order to verify the transmission loss results for KHST case, similar experiment was carried out in laboratory condition, which result was compared those by geometric acoustic method. The computational results shows good agreement with the transmission loss magnitude from experiments. This paper also mentions items to obtain more accurate transmission loss values, i. e. how to assure reverberant field condition, the selection of source speaker' location.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2011년도 추계학술대회 논문집
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• pp.711-716
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• 2011

Today, high-speed trains enjoy wide acceptance as fast, convenient and environment-friendly means of transportation. However, increase in the speed of the train entails a concomitant increase in the aerodynamic noise, adversely affecting the passenger comfort. At the train speed exceeding 300 km/h, the effects of turbulent flows and vortex sheddding are greatly amplified, contributing to a significant increase in the aerodynamic noise. Drawing a biomimetic analogy from low-noise flight of owl, a method to reduce aerodynamic noise at inter-coach space of high-speed trains is investigated. The proposed method attempts to achieve the noise reduction by modifying the turbulent flow and vortex shedding characteristics at the inter-coach space. To determine the aerodynamic noise at various train speeds, wind tunnel testing and numerical CFD (Computational Fluid Dynamics) simulation for the basic inter-coach spacing model are carried out, and their results compared. The simulation and experimental results reveal that there are discrete frequency components associated with turbulent air flow at constant intervals in the frequency domain

• 한국철도학회논문집
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• 제5권1호
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• pp.26-31
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• 2002

The more sophisticated patterns of propagation model is presented in this paper, which includes three different source characteristics (spherical, cosine and dipole). The spherical, cosine and dipole radiation characteristics compared, and sound event level and the maximum sound level are calculated by experiment and calculation. It is shown that patterns of propagation have dipole characteristics for low speed range (below about 150Km/h) at electric multiple system. We know that push-pull high speed system has cosine characteristics of noise propagation at low speed range (below about 200Km/h).