• 한국철도학회논문집
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• 제13권1호
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• pp.44-50
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• 2010

본 연구에서는 튜브-열차 시스템의 기본적인 유동장의 특성을 파악하고, 튜브열차의 공기저항을 계산할 수 있는 보다 효율적인 수치 해법을 제시하고 계산 결과에 대한 타당성을 논하였다. 최소한의 계산 영역 내에선 정상상태의 해를 찾기 위하여 비정상 해석의 결과를 기준으로 하여 경계조건의 부여 방법을 변화시킨 정상 해석의 결과를 비교한 결과, 열차속도가 300 km/h일 경우에는 공기저항의 값이 정상해석 결과와 비정상해석 결과가 잘 일치하였으며, 동일 속도 대역에서의 고속열차 현장시험 결과와 비교한 결과 열차/터널 단면적비에 따라 공기저항의 비가 동일한 추세를 나타나는 것으로 나타났다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.774-779
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• 2007

The crash energy absorbers used in the trains normally are classified into two types. The first is the structure type, which mainly used in not only the primary structure of train but also the crash energy absorbers at the critical accidents. The second is the module type, which just absorbs the crash energy independently and attached onto the structures of the trains. The expansion tube is widely used as the module type of the crash energy absorbers, especially in the trains that have a heavy mass. Since the crash energy is absorbed by means of expanding the tube in the radial direction, the features of the expansion tube have the uniform load during the compression. As the uniform load remains in sudden impact, the expansion tube is effective to decrease acceleration of passengers when the train accident occur. The buckling instability of the expansion tubes is affected by the boundary conditions, thickness and length of tube. In this study, the effects of the length and thickness of the expansion tubes under the arbitrary load on the buckling are studied using the ABAQUS/standard and ABAQUS/explicit, a commercial finite element analysis program, and then presents the guideline to design the expansion tubes. The analysis processes to compute the buckling load consist of the linear buckling analysis and the nonlinear post-buckling analysis. To analysis the nonlinear post-buckling analysis, the geometry imperfections are introduced by applying the linear buckling modes to nonlinear post-buckling analysis.

• 한국철도학회논문집
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• 제13권5호
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• pp.516-520
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• 2010

튜브 구조물의 압력을 대기압 이하로 유지하는데에 사용될 진공 펌프의 용량을 설정하기 위한 파라메타 연구를 수행하였다. 최근 철도 기술 연구자들은 초고속 수송 시스템의 하나인 튜브 열차 시스템에 관심을 가지게 되었다. 초고속을 달성하기 위하여 튜브 내부를 저압으로 유지할 필요가 있는데, 저압에서는 공기 저항이 극단적으로 줄어들기 때문이다. 진공 펌프 시스템은 튜브 내부를 저압으로 만들고, 누설을 보충하는 역할을 한다. 일련의 연구결과, 다양한 파라메타에 대한 진공 펌프의 용량을 구하였다. 이 결과들은 공기 저항 저감 효과를 분석하는데에 적용될 것이다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.1454-1460
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• 2009

Ultra-speed tube train, which runs in vacuum atmosphere to overcome aero-dynamic dragging force, is considered as a high-speed ground transportation system to back up long-distance air travel. To realize the ultra-speed tube train, feasibility study of currently available Maglev technologies especially for propulsion and levitation system is needed. Propulsion by linear synchronous motor(LSM) and levitation by electro-dynamic suspension(EDS) which are utilized in the Japan's MLX system could be one of candidated technologies for ultra-speed tube train. In the LSM-EDS system, the key component is superconducting magnet, and its reliability and performance is very important to guarantee the safe-operation of Maglev. As the initiative of the feasibility study, this paper deals with the basic structure of superconducting magnet and core technologies to design and operate it. And by surveying the current R&D achievement in Korea, the nation's capability to develop advanced superconducting magnet for Maglev is presented.

• 한국철도학회논문집
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• 제4권3호
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• pp.94-101
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• 2001

One of the best methods to evaluate crashworthiness of a full rake trainset is to analyse 1-dimensional dynamic model using dampers, nonlinear springs and bars, and masses. In this study, the crashworthiness of KHST has been evaluated by analysing a nonlinear dynamic model made up of springs/bars-dampers-masses. The numerical results show that the KHST can absorb more kinetic energy at lower impact forces and lower accelerations in case of heavy collisions, if compared with KTX. Also, the KHST can be protected from any damage in its car-body and electric components except the energy absorbing tube in case of light collisions, like train-to-train accidents at speed under 8 kph. On the other hand, the KTX may be more damaged in the light collisions because there is no energy absorbing tube.

• 한국산학기술학회논문지
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• 제21권7호
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• pp.38-45
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• 2020

아진공 튜브 안을 부상한 상태로 주행하는 캡슐트레인은 공기저항력 및 마찰력을 획기적으로 줄임으로써 초고속 주행이 가능하다. 캡슐트레인에서 부상방식으로 사용되는 초전도 유도 반발식 부상은 부상 공극이 커서 인프라 건설비용이 저렴하고 별도의 부상제어가 필요 없는 장점이 있지만, 부상·안내 공극의 변화가 크고 부상 및 안내력에 댐핑 특성이 작아 주행 안정성 및 승차감을 악화시킬 수 있다. 본 연구에서는 초전도 유도 반발식 부상방식에 기반한 캡슐트레인의 동특성 해석 모델을 구축하고 이를 활용하여 캡슐트레인의 주행 특성을 분석하였다. 먼저 초전도 유도 반발식 부상에 있어서 동특성에 중요한 영향을 미치고 속도 및 공극 변화에 따라 비선형적인 특성을 보이는 부상 및 안내 강성을 도출하였고, 이러한 강성이 반영된 캡슐트레인의 3D 동특성 해석 모델을 구축하였다. 구축된 모델을 이용하여 캡슐트레인의 속도별 주행 특성이 승차감에 미치는 영향과 곡선 주행, 튜브 처짐 및 튜브 연결부 단차 등과 같은 주행 환경이 차량의 동특성 및 주행 안정성에 미치는 영향을 검토하였다.

• 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 2006년도 추계학술대회 논문집
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• pp.941-946
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• 2006

It followed in system development and SMRT(Seoul Metropolitan Rapid Transit Co)System reached to an automatic train operation(ATO) and driverless operation(DLM) from the manual operation due to the train driver. The train like the general bus or the car vehicle was not serial riding in a car and the Parallel concept which the numerous passenger rides in a car simultaneously occur frequently the charge of the train driver unmanned bitterly from existing manual handling was a possibility of doing, train open door control(ODM) which bites also ATO, it handles it minimized. Like this ATO/DLM, the control system which bites being a Wayside to Train communication for immediacy, it is a system of the Vital concept the immediacy of the citizen Data evil the radio information transmission and the train of the interface which is accurate from unmanned operation and, will decipher, will accomplish it will guarantee. It respects the passenger accident prevention and an air question environment improvement from subway platform and phul leys the screen door of Platform(PSD) with the fire tube frost it refers and part it treats and to sleep it does, ODM which bites is accuracy and immediacy of altitude and when seeing from the viewpoint which demands the trust of altitude, ODM system the trust of car incest interface in the equipment construction which is safe and the comparative analysis back of the system analysis against the control which bites and case study and other subway system it leads from the research which it sees and signal - train in base grudge to sleep it contributes it does.

• 대한기계학회논문집B
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• 제21권9호
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• pp.1095-1104
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• 1997

When a high-speed railway train enters a tunnel, a compression wave is generated ahead of the train and propagates along the tunnel, compressing and accelerating the rest air in front of the wave. At the exit of the tunnel, an impulsive wave is emitted outward toward the surrounding, which causes a positive impulsive noise like a kind of sonic boom produced by a supersonic aircraft. With the advent of high-speed train, such an impulsive noise can be large enough to cause the noise problem, unless some attempts are made to alleviate its pressure levels. For the purpose of the impulsive noise reduction, the present study investigated the effect of a vertical bleed duct on the compression wave propagating into a model tunnel. Numerical results were obtained using a Piecewise Linear Method and testified by experiment of shock tube with an open end. The results showed that the vertical bleed duct reduces the maximum pressure gradient of compression wave front by about 30 percent, compared with the straight tunnel without the bleed duct. As the width of the vertical bleed duct becomes larger, reduction of the impulsive noise is expected to be greater. However the impulsive noise is independent of the height of the vertical bleed duct.