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회귀 분석과 수치 최적화 방법을 이용하여 디젤엔진의 흡기 및 연료분사 제어 최적화
김영근 ( Youngkun Kim ),김웅일 ( Woongil Kim ),박상기 ( Sangki Park ),이기형 ( Kihyung Lee ) 한국액체미립화학회 2016 한국액체미립화학회 학술강연회 논문집 Vol.2016 No.-
Recently insufficient of fossil fuels and global warming have been issued. So interest of improving fuel efficiency and reducing exhaust emission is increased. Especially in case of diesel engine, the number of control parameters has been increased because of after treatment system. The calibrations are more complex and need detail. Therefore present method of diesel engine calibration spend a lot of time and expense, consequentially engineers feel too much pressure. This study focus on the engine modeling, predictability and accuracy using DOE. In addition intake and fuel control parameters are optimally calibrated by using regression model and numerical optimization.
에탄올/가솔린 혼합연료의 물리적 특성에 따른 분무 특성 비교
김웅일,김영근,이황복,이기형,Kim, Woong Il,Kim, Youngkun,Lee, Hwang Bok,Lee, Kihyung 한국액체미립화학회 2017 한국액체미립화학회지 Vol.22 No.3
The aim of this study is to investigate the effect of physical properties of fuels on spray characteristics in the gasoline direct injection system. Injection rate, spray visualization, and spray pattern experiments were performed to analyze the spray characteristics of ethanol, gasoline, and ethanol/gasoline blends. We measured injection rate of each fuel via the Bosch method. The spray visualization experiment was also carried out at atmospheric pressure using a high-speed camera. Finally, the average of drop surface area per unit volume was measured using the optical patternator. The experimental results from Bosch method showed that peak injection rate increased when the volume fraction of ethanol increased. In addition, higher viscosity of ethanol than that of gasoline leads to longer injection delay. At the initial injection region before reaching 0.8 ms, the spray tip penetration becomes longer as increasing the volume fraction of ethanol, but reversely shorter after 0.8 ms. It was found that ethanol makes spray angle become larger. The surface area per unit volume of the drop was decreased as the distance from the injection tip or the concentration of the gasoline increased.
백병훈 ( Byunghoon Baek ),김웅일 ( Woongil Kim ),김영근 ( Youngkun Kim ),민병혁 ( Byounghyouk Min ),이기형 ( Kihyung Lee ) 한국액체미립화학회 2018 한국액체미립화학회 학술강연회 논문집 Vol.2018 No.-
At the time the need to use alternative fuels that can reduce harmful emissions is increasing, ethanol has a simple chemical structure compared to gasoline and diesel, so that it is possible to reduce harmful emissions, and the oxygen atoms contained in ethanol have a merit of performing a good function for combustion. In the overseas market, the production of FFVs (Flexible Fuel Vehicle) using ethanol-gasoline blended fuel is increasing, and it is possible to use ethanol-gasoline blended ratio differently depending on the driving tendency. Since there is a disadvantage that the combustion characteristics vary depending on the blended ratio, it is necessary to evaluate the spray of the blends in order to optimize the combustion of the target engine. In GDI (Gasoline Direct injection) systems that inject directly into an engine cylinder, fuel must be injected at high pressure to be atomized for efficient combustion. As the fuel is injected at a high pressure, the amount of fuel vaporized due to the promotion of fuel atomization increases, and since the area of the vaporized fuel also affects the engine combustion, it is necessary to observe the spray characteristics of the liquid and vapor regions of the injected fuel. The BOS (Background Oriented Schlieren) is the method using the difference in density by the fuel injected into the measurement area through the pattern image of the background and has advantage of measuring it with the existing spray visualization experiment equipment. In this study, the vaporization characteristics of ethanol-gasoline blended fuels were observed by the spray visualization experiment using the BOS technique, and the rate of vaporization was increased as the ambient temperature increased.