• 대한조선학회논문집
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• 제46권4호
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• pp.373-381
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• 2009

The running attitude of a high-speed planing craft may change significantly depending on its speed in seaway. Other variables that may influence its running attitude are its weight, center of gravity, sea conditions, and so on. In this paper, planing craft model tests were carried out with respect to above variables in SNU towing tank, and vertical motion responses of a planing craft in regular head waves were analyzed. The experimental results in regular waves were compared with those in calm water, and compared with the theoretical estimations. Finally, the effects of running speeds of a planing craft on its motion amplitudes are confirmed.

• 한국철도학회논문집
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• 제5권4호
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• pp.231-236
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• 2002

Todays, crash safety requirements of the railway vehicle structures become important design criterion according to the increased driving speed and the lightweight construction. Although the crash analysis using computer simulation can be effectively applied to predict the crash performance of the railway vehicles in the early design stage, the optimized design w.r.t the crash safety could be realized by the crash tests with actual prototype vehicles. However, it is very expensive and time-consuming task to perform the crash test of the railway vehicles. As a measure to cope with the problem, in this paper, the scale modeling technique is suggested and experimentally verified to predict the impact energy absorption characteristics of full scale model of aluminum extrusions sub-structures and the high-speed railway vehicle structure.

• 신재생에너지
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• 제7권4호
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• pp.42-49
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• 2011

The objective of this paper is to suggest a new method of a wind turbine performance test. The performance test of a wind turbine is generally carried out in a wind tunnel. The test needs not only a high-accuracy measuring system but also durable structure to withstand high speed turbine rotation and wind flow. Therefore, we tried turbine performance test using a towing tank to improve stability and reliability. Because a turbine rotates more slowly and generates more torque in the water than in the wind tunnel under similarity conditions. In this study, we developed turbine performance test systems and verified the turbine test method using a towing tank through comparing results of the wind tunnel and the towing tank test.

• 한국철도학회논문집
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• 제17권6호
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• pp.415-422
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• 2014

철도에서 강화노반은 궤도의 변형에 직접적인 영향을 주는 중요한 노반층이다. 따라서 강화노반재료의 거동에 대한 깊은 이해가 요구된다. 이에 본 연구에서는 철도의 강화노반재료로 사용되는 재료를 대상으로 입도 특성과 시공조건 및 하중조건에 따른 회복탄성계수에 대한 실험적 연구를 대형삼축압축시험으로 수행하였다. 시험 결과 최대입경, 입도분포, 다짐함수비 등이 회복탄성계수로 평가된 재료 성능에 영향을 미치지만 하중 주파수는 큰 영향이 없다는 것을 확인할 수 있었다. 열차 운행 환경에 적합한 시험 결과를 제시하여 향후 강화노반 재료의 해석 등의 유용한 자료로 활용할 수 있을 것으로 판단된다. 또한 제한적이지만 회복탄성계수 예측 모델에 대한 상수값을 제시하여 다양한 하중조건에 따라 회복탄성계수를 적용하도록 하였다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 1998년도 추계학술대회 논문집
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• pp.361-368
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• 1998

This paper sums up the study of the soundproof facilities to be placed on the test track section within the Seoul-Pusan H.S.T project. The objective of this study is to determine optimum design of soundproof including height, length, location, sound absorbing materials for test track(chonan-taejon). This paper shows the model to design the shape and materials of noise barrier for high speed trains(TGV, ICE, etc). Noise prediction is to be conducted by MITHRA. Various parameters affecting the noise propagation outdoors are surveyed and discussed in relation to H.S.T. noise.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2003년도 춘계전력전자학술대회 논문집(2)
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• pp.886-890
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• 2003

This paper introduces the combined test results of the traction system for KHST(Korean High Speed Train: hereafter refer to KHST). The main purpose of this combined test is to verify the performance of the traction system that is designed to operate up to maximum 350km/h speed. Combined test system consists of a traction transformer, two AC-DC PWM converters, a PWM Inverter, two traction motors and flywheel system. Flywheel system represents equivalent model of the train inertia. Also traction control system and MASCON Interfaces are included. Various kinds of experiments are performed to prove total traction system performance and detail waveforms are described

• 한국가시화정보학회지
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• 제20권3호
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• pp.128-135
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• 2022

Cavitation occurs inevitably in marine propellers rotating at high speed in the water, which is a major cause of underwater radiated noise. Cavitation-induced noise from propellers rotating at a specific frequency not only reduces the sonar detection capability, but also exposes the ship's location, and it causes very fatal consequences for the survivability of the navy vessels. Therefore cavity inception speed (CIS) is one of the important factors determining the special performance of the ship. In this study, we present a method using computer vision that can detect and quantitatively estimate tip vortex cavitation on a propeller rotating at high speed. Based on the model test results performed in a large cavitation tunnel, the effectiveness of this method was verified.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2003년도 추계학술대회 논문집
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• pp.60-63
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• 2003

Resistance performance of 3 G/T class coastal leisure boat is experimentally investigated at high speed ranges and the effect of a fin attached at hull side is studied together. Wave patterns are observed to make clear the relation between the resistance performances and the wave characteristics.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 추계학술대회 논문집
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• pp.372-379
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• 2008

In the case of pantograph, three models of HSR350X(G7), KTX-I and KTX-II have been already introduced into the field of domestic high speed train. This thesis intends to explain performance test result of the conditionally purchasing pantograph that is progressing up to now. The pantograph is being developed to localize pantograph that was applied to KTX-I. Also, it consider criteria that applied for verification of design contents and method of dynamic test that verify pantograph's current collecting performance.

• 대한조선학회논문집
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• 제48권1호
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• pp.8-14
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• 2011

RIB(Rigid Inflatable Boat) is widely used for coastal transportation in the commercial use and for ISR(Intelligence, Surveillance, Reconnaissance) in the military use. Since RIB is around 10 meters in length and over 30 knots in speed, its motion characteristics in waves is quite different from a large scale ship. When it turns, large roll occurs and heeling direction is opposite to the large ship's case. Currently, many countries are developing USV(Unmanned Surface Vehicle) of which type is RIB. In order to develop high performance autopilot and way point controller, it is very important to identify RIB's motion characteristics. In this paper, sea trial test results of a 7-meter RIB such as speed, turning, zig-zag, and way point control tests were represented and its resistance and propulsion model was identified by using sea trial data and Savitsky's formula. In addition, the state space model which will be used in the identification of the four-degree-of-freedom dynamics in the next step was formulated and the identification procedure was proposed.