http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
오늘 본 자료
하성도(Ha Seong-Do),송달호(Song Dahl-Ho) 한국철도학회 1999 한국철도학회 학술발표대회논문집 Vol.- No.-
Development of the personal rapid transit system is reviewed from its invention stage to its current development stage in the world. Also, the special features of each PRT system and the reasons of delay of PRT application in cities are described briefly.
고속으로 주행하는 열차 주위의 3차원 비정상 유동장 해석
하성도,Ha, Seong-Do 한국기계연구원 1997 硏究論文集 Vol.27 No.-
The 3-dimensional unsteady compressible flows around the high speed train have been simulated for the train entering a tunnel and for passing another train. The simulation method employs the implicit approximation-factorization finite difference algorithm for the inviscid Euler equations in general curvilinear coordinates. A moving grid scheme is applied in order to resolve the train movement relative to the tunnel and the other train. The velo-city and pressure fields and pressure drag are calculated to study the effects of tunnel and the other train. The side directional force which is time dependent is also computed for the passing train. Pressure distribution shows that the compression wave is generated in front of the train noise just after the tunnel entrance and proceeds along the inside of tunnel.
하성도,김유일,Ha, Seong-Do,Kim, Yu-Il 한국기계연구원 1995 硏究論文集 Vol.25 No.-
At the running speed higher than 250 km/h, several aerodynamic problems such as the increase of aerodynamic resistance, aerodynamic noise, pressure fluctuation at the tunnel entry, impulsive wave at the tunnel exit bring about the power consumption, deterioration of riding quality, and severe environmental noise. To solve these aerodynamic problems, the flow phenomena around the high speed train have to be analyzed in detail. In this study, the flow around the train is modelled as the 2-dimensional viscous compressible flow and the flow field is calculated numerically for the three different types of geometry and running speed. The aerodynamic drag coefficient and the pressure coefficient are evaluated each case.
허신,하성도,Heo, Sin,Ha, Seong-Do 한국기계연구원 1997 硏究論文集 Vol.27 No.-
The dynamic design process for the articulated bogie of light rail vehicle(LRV) was studied to design a primary and secondary suspension elements. Suspension stiffness and damping is selected on the basis of the ride quality and suspension stroke trade-off. LRV was modeled as a 2 d.o.f linear system for the design of vertical suspension characteristics and a 4 d.o.f linear system for the design of lateral suspension characteristics. FRA's class-4-track irregularity was used for the exciting disturbance on track. The optimum value of primary and secondary suspension characteristics was determined using this design process.