• Journal of Advanced Marine Engineering and Technology
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• 제36권2호
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• pp.230-237
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• 2012

최근 엔진 메이커들은 원유가 인상 및 대기환경 규제에 대응하기 위하여 디젤엔진의 대안으로서 가스엔진 개발에 대한 관심이 증가되고 있다. 이에 STX는 22HLX 디젤엔진을 기초로 한 1.6MW급 가스엔진을 개발하였다. 예연소실 방식의 개발된 가스엔진은 엔진속도가 1000rpm에서 제동평균유효압력이 21bar이고 질소산화물 배출량이 50ppm(공기 중 산소함유 15% 기준)의 우수한 성능을 가진다. 특히 열효율 45%의 우수한 연료 경제성을 가지며 이산화탄소 배출량은 디젤엔진의 약 75%수준으로 온실가스 저감에도 효과적이다.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2007년도 제29회 추계학술대회논문집
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• pp.339-342
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• 2007

스마트무인기의 추진동력계통은 터보프롭 항공기와 유사한 피치 가버닝 개념으로 조종사가 엔진동력을 직접 입력하고 제어기는 프로펠러의 RPM을 일정하게 유지하는 방식을 사용한다. PW206C 엔진은 회전익 항공기에 맞게 개발된 전자식 엔진제어기(Electronic Engine Control)를 갖춘 터보축엔진으로 스마트무인기에서 요구되는 엔진제어개념과는 맞지 않는다. 따라서 기존 EEC의 엔진상태 모니터링 기능은 사용하되 엔진 출력은 수동방식으로서 전기식 작동기를 엔진의 Power Lever Arm(PLA)에 연결하여 조절한다. 본 논문에서는 엔진성능계산프로그램을 사용하여 비행고도 및 속도변화에 대한 엔진성능을 계산하여 각 비행조건에서의 PLA 작동범위를 예측하였다.

• 한국자동차공학회논문집
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• 제14권1호
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• pp.144-152
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• 2006

Split injection has been known to reduce total hydrocarbon (THC) emission level and increase engine performance under certain operating conditions 1, 2). Exhaust Gas Recirculation (EGR) is a common technique adopted for nirtric oxides (NOx) reduction by the dilution of intake air, despite a sacrifice of simultaneous increase in THC and decrease in engine performance3). Thus, using split injection with adequate EGR may improve the emission level of UBHC, NOx and the engine performance compared to that of single-injection with or without EGR cases. The purpose of this study is to investigate the engine performance and emission levels at various engine operating conditions and injection methods when it is applied with EGR. The characteristics of single-injection and split-injection were investigated with various engine loads and EGR rates. The engine speed is changed from 800rpm to 1200rpm to investigate how the combustion characteristics are changing with increasing engine speed.

• 임산에너지
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• 제7권1호
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• pp.28-36
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• 1987

To know the possibility of fuel substitution for Diesel engine with the seed oil of Evodia daniellii, which is one of the native oil seed trees in Korea. the refined seed oil mixed with light oil in the various rates was tested in the 8 PS Diesel engine: the output, the fuel consumption rate, the governor performance, the rpm stability in the total loading condition. the content of graphite in the burned gas, and the traction coefficients at the different gear stages were maintained The following results were discussed. 1. The output at the normal revolution (2200rpm)was increased as the percent seed oil increased. At the lower rpm (2000-1500rpm )there were no consistent difference in the outputs among fuels of the different percent seed oil 2. The rate of fuel consumption was inclosed as the percent seed oil increased in each loading condition. 3. The more percent sud oil was mixed in the fuel. the better governor performance appeared at both the instantaneous and stable speed. 4. The more percent seed oil was mixed In the fuel, the more stable rpm ratio was maintained 5. The graphite content In the burned gas was increased as the load increased, but there was no apparent difference in the content at each load among the 100$\%$ seed oil, the 100$\%$ light oil, and the mixtures in various rates. 6. In all fuel mixtures the maximam traction coefficent appeared at the third transmission gear stage. Generally in over all transmission gear stages the fuel mixtures of the seed oil:light oil ratio from 7:3 to 5:5 resulted greater traction force than the other fuels.

• 산업기술연구
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• 제17권
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• pp.339-344
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• 1997

DOHC gasoline engine(4-cylinder in line type, 1600cc) is modified for the experiment to develope an alternative fuel. The modified engine is tested with the various combination of gasoline and methanol. Pollutant emissions of CO and HC are measured at the end of exhaust manifold. The concentration of CO and HC in exhaust gas is greatly reduced with the increase of coolant temperature of engine. HC concentration is reduced until methanol content reaches to thirty percent and then increased with the volumetric percentage of methanol in fuel. On the other hand, the concentration of CO is reduced as the methanol centent is increased up to 20 percent and then it becomes constant even though the methanol content is raised. The effect of engine RPM on the HC and CO exhaust is investigated. HC concentration is reduced as the engine RPM is increased but the typical trends of variation are not found in the measured value of CO concentrations.

• 동력기계공학회지
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• 제9권3호
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• pp.5-9
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• 2005

A study on the performance and exhaust emissions of diesel engine with reducing exhaust gas temperature is performed experimentally. In this paper, experiments are performed at engine speed 2200rpm, 2600rpm and load 0%, 25%, 50%, 75% and 100% by test engine with F.W. cooler passing through exhaust gas. Main measured & analyzed parameters are exhaust gas temperature, specific fuel consumption, NOx and soot emissions etc. The obtained conclusions are as follows. (1) Specific fuel consumption is the least value at load 75% and it is decreased 1.5% after remodeling F.W. cooler. (2) NOx emission is the most value at load 100% and it is increased 30.1% after remodeling F.W. cooler. (3) Soot emission is the most value at load 100% and it is decreased 20.0% after remodeling F.W. cooler.

• 한국자동차공학회논문집
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• 제17권5호
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• pp.16-25
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• 2009

Testing engine performance using an engine dynamometer requires high technical researchers and many facilities. Nowadays, different variables of CAE program are used for identifying the engine performance instead of engine dynamometer test. This is more convenience, as it does not necessitate an abundance of engine dynamometer experiments and, in addition, produces better results. However, CAE programs also contain various variables which can affect engine performance. Those are coupled with each other, thus making it difficult to determine the effectiveness of different variables on engines. DoE (Design of Experiments) methodology is an efficient way to verify the magnitude of effectiveness on engine performance as well as making responses to be optimized at once without trial & error. This study used data from WAVE simulations, which modeled the DOHC SI engine with in-line 4 cylinders at 1500, 3000 and 4500rpm. DoE methodology is designed properly to determine the effectiveness of five variables on power, BSFC, and volumetric efficiency, as well as to find the optimal response conditions at each rpm through a minimized number of experiments. After finishing DoE process, all the results are examined concerning the reliability of test through a verification experiment.

• Journal of Advanced Marine Engineering and Technology
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• 제28권3호
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• pp.551-558
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• 2004

Recently, fuel prices have been continually raised in diesel engine. Such a change in the fuel price influences enormously the development trend of marine diesel engines for slow speed, In other words, the focus was shifted from large diameter and high speed to low fuel consumption. Accordingly, more efforts are being made for engine manufacturing and development to develop highly efficient engines. In this study. a single cylinder 4 stroke cycle DI slow speed diesel engine was designed and manufactured, a 4 stroke cycle was configured and basic performances were evaluated. The results are as follows. The optimal fuel injection timing had the lowest value when specific fuel consumption was in BTDC 8~$10^{\circ}$, a little more delayed compared to high speed diesel engines. Cycle variation of engines showed about 5% difference at full loads. This is a significantly small value compared to the cycle variation in which stable operation is possible, showing the high stability of engine operation is good. The torque and brake thermal efficiency of engine increased with an increase of engine 250-450 rpm. but fuel consumption ratio increased from the 450 rpm zone and thermal efficiency abruptly decreased. Mechanical efficiency was maximally 70% at a 400 rpm that was lower than normal engines according to the increase of mechanical frictional loss for cross head part. The purpose of this study was to get more practical engines by comparing the above results with those of slow speed 2 stroke cycle diesel engines.

• International journal of advanced smart convergence
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• 제4권1호
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• pp.54-63
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• 2015

Increasing air pollution levels and the global oil crisis has become a major hindrance in the growth of our automobile sector. Traditional Internal Combustion engines running on non-renewable fuels are proving to be the major culprit for the harmful effects on environment. With few modifications and also with assistance of few additional components current small SI engines can be modified into a pneumatic engine (commonly known as Compressed Air Engines) without much technical complications where the working fluid is compressed air. The working principle is very basic as adiabatic expansion of the compressed air takes place inside the cylinder pushing the piston downwards creating enough MEP to run the crank shaft at decent RPM. With the assistance of new research and development on pneumatic engines can explore the potential of pneumatic engines as a viable option over IC engines. The paper deals with analysis on RPM variation with corresponding compressed air injection at different crank angles from TDC keeping constant injection time period. Similarly RPM variation can also be observed at different injection pressures with similar injection angle variation. A setup employing a combination of magnetic switch (reed switch), magnets and solenoid valve is used in order to injection timing control. A conclusive data is obtained after detailed analysis of RPM variation that can be employed in newly modified pneumatic engines in order to enhance the running performance. With a number of benefits offered by pneumatic engine over IC engines such as no emissions, better efficiency, low running cost, light weight accompanied by optimized injection conditions can cause a significant development in pneumatic engines without any major alteration.

• 대한기계학회논문집B
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• 제35권2호
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• pp.137-143
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• 2011

본 연구는 4실린더 커먼레일 디젤엔진에 바이오디젤 혼합 디젤연료를 적용하였을 경우 엔진의 연소특성과 배출물 저감효과를 실험적으로 구한 것이다. 실험 연료는 바이오디젤 20%와 디젤연료 80%(체적분율)를 혼합한 BD20과 저유황디젤연료(ULSD)를 사용하였으며, 연료분사압과 엔진회전수를 변수로하여 실험을 수행하였다. 실험결과 B20과 ULSD 모두 연료분사압력이 증가함에 따라 NOx 배출농도는 증가하고, Soot 배출량은 감소하는 경향을 나타내었다. 특히 BD20의 경우 ULSD와 비교하여 NOx 배출농도는 다소 증가하였으나, Soot 배출량은 현저하게 감소하였다. 또한, 회전속도가 1000rpm에서 2000rpm으로 증가함에 따라 NOx 배출농도는 감소하고, Soot 배출량은 낮은 분사압력에서 현저히 증가하는 경향을 나타내었다.