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유경현,오영택,Ryu, Kyung-Hyun,Oh, Young-Taig 한국자동차공학회 2007 한국 자동차공학회논문집 Vol.15 No.3
Three diesel engines were fueled with BDF 20, a blend of 80% diesel fuel and 20% biodiesel fuel by volume, and run in excess of 200 h to evaluate their combustion characteristics and durability. The engines used for this study were a 4-cylinder 2476-cc displacement IDI diesel engine(Engine 1), a 4-cylinder l732-cc displacement IDI diesel engine(Engine 2), and a single cylinder 673-cc displacement DI diesel engine(Engine 3). Engine dynamometer testing was performed on each engine at regularly scheduled intervals to monitor the performance and exhaust emissions, which were sampled at 1h intervals for analysis, The peak combustion pressure with BDF 20 increased in Engines 1 and 3 over that measured when burning pure diesel fuel, but that in Engine 2 remained constant. Combustion parameters, such as the maximum combustion pressure and corresponding crank angle, did not change over the long-term dynamometer testing. The BSFC with BDF 20 in Engine 1 was less than that measured with pure diesel fuel. The amount of smoke produced with BDF 20 was less for all engines ; the greatest reduction was observed for Engine 3. The NOx emissions were lower in the IDI engines than the DI engine. The traditional trade-off between smoke and NOx emissions was maintained for BDF 20 fuel for Engines 1 and 3. There was not a big difference in the $CO_2\;and\;O_2$ emissions for BDF 20, as compared to pure diesel fuel, but more $CO_2$ was exhausted by Engine 1 than by Engines 2 or 3 and less $O_2$ was exhausted by Engine 1 than by Engines 2 or 3. The engine parts remained clean, except for some carbon attached to the area surrounding the nozzle hole of the DI diesel engine.
바이오디젤유(미강유 에스테르)를 이용한 농업용 디젤기관의 연소 특성
유경현,윤용진,오영택,Ryu, Kyung-Hyun,Yun, Yoong-Jin,Oh, Young-Taig 대한기계학회 2003 大韓機械學會論文集B Vol.27 No.2
Biodiesel fuel as an alternative fuel for diesel engine has a great possibility to solve the problems such as air pollution. It is a domestically produced, renewable fuel that can be manufactured from vegetable oils, used vegetable oils, or animal fats. In this study, the usability of biodiesel fuel derived from rice bran oil as an alternative fuel for diesel engines was investigated in agricultural diesel engine. Emissions were characterized with neat biodiesel fuel and with a blend of biodiesel fuel and conventional diesel fuel. Since the biodiesel fuel includes oxygen of about 11%, it could influence the combustion process strongly. So, the use of biodiesel fuel resulted in lower emissions of carbon monoxide, carbon dioxide, and smoke emissions without any increase of oxides of nitrogen. It is concluded that biodiesel fuel can be utilized effectively as a renewable and an environmentally Innocuous fuel for diesel engine.
흡기관내로의 물 분사에 의한 디젤기관의 연소특성 (I)
유경현,윤용진,오영택,Ryu, Kyung-Hyun,Yun, Yoong-Jin,Oh, Young-Taig 대한기계학회 2002 大韓機械學會論文集B Vol.26 No.12
To effectively meet current regulations on the exhaust emissions of diesel engine required to control the deterioration of air pollution in the whole world, this study is to investigate the effects of water induction through the air intake system on the characteristics of combustion and exhaust emissions in IDI diesel engine. A method fur supplying water through the air intake system to reduce the exhaust emissions has been considered with other methods such as water introduction in the form of water-in-fuel emulsion or water injection directly into the combustion chamber, but it has not been studied about the effects of water on the combustion concepts and the characteristics of exhaust emissions in detail until now. In this study, the formation of NOx was significantly suppressed by decreasing the gas peak temperature during the initial combustion process because the water play a role as a heat sink during evaporating in the combustion chamber, but the smoke was slightly increased by increasing water amount.
유경현(Kyung-hyun Ryu) 한국공학교육학회 2011 공학교육연구 Vol.14 No.6
This paper explores and proposes the evaluation criteria of design projects in the entry-level design course. In the entry-level engineering design course the students proceeds various design projects to understand the concept of engineering design process and to develop the creativity. The evaluation criteria of design projects is very important component because the outcome of students in the engineering design course are effected from the evaluation criteria that enforces the students to focus on doing their task. According to this case study the evaluation criteria can be good solution to evaluate the design projects. By the outcome standard of ABEEK on the entry-level engineering design course the evaluation criteria was selected with the results of design projects such as design plan, report, handicrafts, objectives.
글라스 울(Glass Wool) 생산용 스피너의 토출 홀 방향에 따른 응력해석
정관용(Gwan-Yong Jeong),유경현(Kyung-Hyun Ryu),김상영(Sang-Young Kim) 대한기계학회 2019 대한기계학회 춘추학술대회 Vol.2019 No.11
The spinner used in the production of glass wool is a key part that makes glass molten metal of 1000degrees or more in the form of thread by high-speed rotation of 2,000rpm. Accordingly, this study aims to analyze the cause of failure of the existing model through stress analysis of the spinner and to extend the life of the spinner by changing the design. As a result of the stress analysis, the existing model showed stress concentration between the holes and the cracks growing through the holes. This is similar to the actual failure pattern of existing spinners. As a result of stress analysis by using a model in which the direction of the discharge hole of the spinner was changed, it was confirmed that the model having a 10 ° tilt angle of the hole in the direction of rotation of the spinner showed a longer life and durability than the original spinner. In the model where the angle of the hole is 10° in the direction of gravity, it is confirmed that the stress is more concentrated as the thickness of the stress concentration portion becomes thinner. These results are expected to contribute not only to the durability and life span of the spinner, but also to the productivity of the product.