• 한국유체기계학회 논문집
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• 제18권1호
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• pp.29-36
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• 2015

Recently, Stirling engines are emerging as a key device for power conversion of renewable energy or waste energy. This study develops a LTDSE(Low Temperature Differential Stirling Engine) using a water spray for higher heat transfer and performs load performance tests for various flow rates and temperatures of hot water spray for variable engine loads emulated by a mechanical friction device. Internal temperature and pressure, working frequency and inlet and outlet temperature of the supply water are measured. As a result, the increases in flow rate and temperature of hot water respectively enhance the power output, efficiency and the working frequency, while the increasing engine load leads to decreases in working frequency but increases in the pressure amplitude. Eventually, it is revealed there exists a maximum shaft power of the test engine.

• 한국유체기계학회 논문집
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• 제15권4호
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• pp.27-32
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• 2012

Gas turbines for an aircraft have the start and restart capabilities within their flight envelop. It is an important item for engine qualification and substantiated with the test. Experimental investigations were carried out to find the relation between the corrected torque and the corrected rotating speed of an air turbine starter in this study. A dedicated air supply system for the air turbine starter and a special device to measure the torque and the rotating speed of the air turbine starter were developed and installed at the altitude engine test facility in Korea Aerospace Research Institute. Experimental results show that the relations between the corrected torque and the corrected rotating speed of the air turbine starter are linear and the inlet temperature and pressure conditions for the air turbine starter were found out to provide minimum required torque for the engine qualification test at various altitude. The start and restart tests for the currently developing engine were successfully performed using this experimental results.

• 한국산업융합학회 논문집
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• 제27권3호
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• pp.629-634
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• 2024

The Korea Research Institute of Ships and Ocean Engineering (KRISO) has developed a test module that can vertically ascend and descend with a buoyancy engine to verify the performance of the developed buoyancy engine. The independent test module has been tested in the Ocean Engineering Basin(C.M.Lee et al., 2023). After that, more tests were performed in the Deep Ocean Engineering Basin and at sea. In the 50-meter depth pit test of the Deep Ocean Engineering Basin, there were no problems with the ascent and descent operations, but the buoyancy engine was not properly maintained due to various problems in the independent test module, resulting in a difference between the calculated results using the solution of the equations of motion and the actual measurement results. The East Sea test was conducted at a depth of approximately 110 meters north-east of Pohang, with a dive to 100 meters. The difference between the pressure sensor value and the calculated value was observed, but after checking the results of the underwater position tracking device(USBL, Ultra Short Base Line system), it was estimated that the difference was caused by the influence of the current.

• International Journal of Naval Architecture and Ocean Engineering
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• 제9권2호
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• pp.199-208
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• 2017

We perform an experiment on lacquer formation with simple test device. The anti-lacquer is one of important issues to increase durability, and to improve performance in the engines because the lacquer formation cause sticking of fuel injection pump, scuffing of cylinder liners, and increase of lubricant oil consumption in the marine diesel engines. We suggest this simple test in order to save enormous experimental cost in marine diesel engines, and in order to have ease in performing the various tests. The influences of the Base Number (BN) of lubricant oils and the sulfur content of fuel oils in the formation of lacquer are investigated. In order to investigate physical and chemical properties of lacquer, we perform a variety of tests such as, visual inspection, EDS. In addition, we investigate adhesion of lacquer by pull-off test quantitatively, and perform dissolution test with dilute sulfuric acid.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2008년도 제31회 추계학술대회논문집
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• pp.31-35
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• 2008

본 시험장치는 가스터빈 관련 교육기관, 연구소 등에 가스터빈 엔진의 작동 원리와 구조에 대한 기초지식을 제공하고 가스터빈 엔진의 이론적 열역학 계산을 실제 성능시험을 통하여 비교해 볼 수 있도록 개발되었다. 추력 30lbf급 마이크로 터보제트 엔진을 대상으로 하여 NI DAQ(데이터 수집)장치와 LabVIEW 프로그램으로 각 구성품의 온도, 압력과 추력, 연료유량, 공기유량 등의 실시간 데이터를 모니터링 및 획득할 수 있도록 시험장치를 구성하였다.

• 한국추진공학회지
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• 제26권4호
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• pp.10-20
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• 2022

한국항공우주연구원의 자유제트형 지상추진시험설비인 스크램제트 엔진 시험설비의 마하 5 조건에서 스크램제트 엔진 흡입구의 성능분석 시험을 진행하였다. 스크램제트 엔진 흡입구의 대표적인 성능 인자인 전압력 회복률, 공기 포획율 측정을 위하여 격리부 후방에 설치되는 피토/정압 레이크가 설계 제작되었다. 격리부 후방에 장착된 레이크가 전방의 흡입구 램프와 격리부에 미치는 영향과 레이크로 측정된 흡입구의 성능 인자 분석 그리고 흡입구의 받음각 변화에 따른 벽면 정압력 분포 변화에 대한 분석이 수행되었다. 끝으로 연소기에서의 압력 상승을 모사하는 장치인 흡입구 후방 배압 조정 장치를 이용하여 흡입구 불시동이 발생하는 시점을 확인하였으며, 본 논문에는 그 결과를 정리하였다.

• 한국추진공학회지
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• 제26권1호
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• pp.77-87
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• 2022

한국항공우주연구원 스크램제트 엔진 시험설비를 활용한 스크램제트 엔진 흡입구 지상 시험을 수행하기 위하여 일반적으로 진행하는 시험 가능 여부 확인 절차를 소개하였다. 스크램제트 흡입구 시험을 수행하기 위하여 새롭게 제작된 마하 5 노즐의 설계 과정을 정리하였으며, 노즐의 코어 유동 분포를 확인하기 위한 장치를 설명하고 코어 유동 시험 분석 결과를 기록하였다. 일련의 시험 결과를 통하여 흡입구가 신규 마하 5 노즐 코어에 위치하는 것을 확인하였다.

• 한국산업융합학회 논문집
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• 제21권5호
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• pp.241-246
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• 2018

The engine cooling system is a device that keeps the temperature of the engine room at a proper level by driving the cooling fan when the engine room temperature that occurs during driving is above a certain temperature. Recently, the vehicle cooling system has been changed to electronic system. Therefore, in this paper, we will analyze the clutch operation characteristics for designing a superior electronic fan clutch. For this purpose, an electronic fan clutch was designed and a test bed for performance evaluation was constructed and analyzed.

• 한국수소및신에너지학회논문집
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• 제23권4호
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• pp.373-381
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• 2012

To determine the performance characteristics of motorcycle engine using biogas for practical use, the intake system of a 110 cc motorcycle engine is properly modified to operate with biogas as a fuel. Biogas is a potentially renewable fuel for replacing gasoline in future, but it has high percentage of $CO_2$ that could lead to slow the burning rate of biogas-air mixture and cause instability in combustion. Thus, the performance characteristics of biogas-fueled motorcycle engines could be different from those of gasoline motorcycle engines. In this paper, the important parameters of performance characteristics (such as: power output, thermal efficiency, fuel consumption, exhaust emission,${\cdots}$) of biogas-fueled motorcycle engine are studied and estimated with change of engine speed and load. The obtained results when operating with biogas are used to compare with that of gasoline fuel under the same operating conditions. Engine speed in the experimental is changed from 1500 rpm (idle-mode) up to 3500 rpm by a step of 500 rpm. Engine load is changed from zero to maximum load with the help of an exciting voltage device from generator-type dynamometer. The experimental results show that the tested engine operated with richer biogas-air mixture than that of gasoline-air mixture under the same test conditions. Biogas-fueled engine gives a higher fuel consumption and lower thermal efficiency under the same power output. Brake thermal efficiency of biogas engine is found to be about 3% lower than gasoline-fueled motorcycle engine for whole range of speed. Exhaust emission of biogas-fueled motorcycle engine (such as: CO, HC) is found to be lower than the limitation level of the emission standards of Vietnam for motorcycle engines (CO <4.5% HC <1200 ppm).

• Journal of Positioning, Navigation, and Timing
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• 제11권2호
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• pp.119-126
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• 2022

This paper presents a method to reduce the vibration-induced noise effect of an inertial measurement device mounted on a self-driving vehicle. The inertial sensor used in the GNSS/INS integrated navigation system of a self-driving vehicle is fixed directly on the chassis of vehicle body so that its navigation output is affected by the vibration of the vehicle's engine, resulting in the degradation of the navigational performance. Therefore, these effects must be considered when mounting the inertial sensor. In order to solve this problem, this paper proposes to use an in-house manufactured vibration suppression device and analyzes its impact on reducing the vibration effect. Experimental test results in a static scenario show that the vibration-induced noise effect is more clearly observed in the lateral direction of the vehicle, but can be effectively suppressed by using the proposed vibration suppression device compared to the case without it. In addition, the dynamic positioning test scenario shows the position, speed, and posture errors are reduced to 74%, 67%, and 14% levels, respectively.