http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
디젤 엔진 분무의 액적 미립화 모델 및 벽면 충돌 모델에 관한 연구
김홍석,성낙원,Kim, Hongsuk,Sung, Nakwon 대한기계학회 1999 大韓機械學會論文集B Vol.23 No.1
In this research computational methods for the droplet atomization and spray wall impingement are studied for the non-evaporating diesel fuel spray. The TAB(Taylor Analogy Breakup) model and Wave model are compared with experiments in order to describe droplet atomization process. The Watkins model and O'Rourke model are compared to simulate the spray wall impingement. As a result, It is found that the application of the Wave model has a good agreement with the experimental data in the case of high pressure injection. With regard to wall Impingement phenomena, it is found that the Watkins model is appropriate to the high temperature cylinder wall condition, while the O'Rourke model is appropriate to cold starting problem.
전기히터방식 매연여과장치의 재생특성 향상을 위한 흡기드로틀링 연구
김홍석(Hongsuk Kim),한승환(Hanseung Han),조규백(Gyubaek Cho),정용일(Youngil Jeong),강봉균(Bong-Gyun Kang),임인혁(In-hyuk Im) 한국자동차공학회 2004 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-
Application of an electric heater to a DPF system is one of attractive methods for active regeneration, but limitation of electric power available in vehicles has been a problem to be solved. In this study, intake throttling was studied to reduce the required electric energy of an electric heated DPF system. This study showed the decrease of 30-50% of intake air mass flow rate and increase of 20-60℃ of exhaust gas temperature by the intake throttling.<br/> When intake throttling was applied with the condition of EGR OFF, required electric energy for soot regeneration was reduced due to the effect of exhaust gas temperature increase.
ELPI와 SMPS를 이용한 디젤엔진 입자상물질 측정 특성 비교
김홍석(Hongsuk Kim),이상수(Sangsu Lee),조규백(Gyubaek Cho),성낙원(Nakwon Sung),정용일(Youngil Jeong) 한국자동차공학회 2003 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-
The measurement characteristics of ELPI and SMPS were compared. The qualitative comparison between ELPI and SMPS showed acceptavle similarities for the size distributions of particles in ambient air, KCI aerosol, and diesel emission, but the quantitative comparison showed great differences. Stable results were obtained by both SMPS and ELPI in the repeated measurements for diesel particles, but SMPS showed more relianle results for different engine load conditions in the steady state operation.
디젤엔진 NOx 저감을 위한 고체암모늄 SCR 시스템 타당성 연구
김홍석(Hongsuk Kim),이호열(Hoyeol Lee),윤천석(Cheon Seog Yoon),우세종(Seajeong Woo),정용일(Youngil Jeong) 한국자동차공학회 2012 한국자동차공학회 학술대회 및 전시회 Vol.2012 No.11
One of most effective NOx control technology of modern diesel engines is SCR with ammonia. Current NOx reduction systems are being designed to use a solution of urea dissolved in water as a source of ammonia. However, there is a lot of demand for alternative ammonia source, because the urea solution supply systems are expensive and complicate. The aim of this study is to show the feasibility of solid ammonium SCR. This study compares the decomposition characteristics of ammonium carbonate and soild urea with vapor pressure test and TGA analysis. As a result, it is shown that the ammonium carbonate is more suitable for alternative ammonia source than solid urea. It also shown that the proper temperature and pressure condition of the reactor for decomposition of the ammonium carbonate are ~120℃ and ~6 bar. The nearly same NOx reduction performance was archived with the solid ammonium SCR compared with liquid urea SCR in the diesel engine application.
중형엔진에 적용되는 전기히터/촉매 복합 재생방식 매연여과장치의 성능에 관한 연구
김홍석(Hongsuk Kim),정용일(Youngil Jeong),황재원(Jae-Won Hwang),한상명(Sangmyeong Han) 한국자동차공학회 2005 한국자동차공학회 춘 추계 학술대회 논문집 Vol.2005 No.11_1
The passively regenerated DPF systems applied to midium duty diesel engines usually do not properly work due to the low exhaust gas temperature. This study shows the performance of an electrical heated CDPF system for a midium duty Diesel engine. The electrical heated CDPF system showed PM conversion efficiency of 96% during DN-13 mode and it's BPT ranged from 330 to 350℃ depending on the engine speeds. The electrical current supplied to the heater was determined by the capacity of the engine alternator at each engine operating condition. The electrically heated CDPF system in this study showed favorable back pressure characteristics during the test mode which simulated city driving conditions.
[디젤엔진부문] 선형 안정성 이론을 이용한 액체 제트의 미립화 모델에 관한 연구
김홍석(Hongsuk Kim),성낙원(Nakwon Sung) 한국자동차공학회 2000 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-
The characteristics of unstable waves are investigated using a linear instability theory and an atomization model is proposed for a non-reacting high-speed liquid jet. In this study the effect of injection parameters, such as Weber number, Reynolds number, and density ratio, on the wave characteristics are investigated. In the atomization model, the droplet sizes after breakup were determined by the wavelengths of fast growing waves, and the mass of the shed droplets was determined by the breakup time derived by O'Rouke et al. As a result, it is found that in comparison with measurements and a empirical equation of diesel fuel spray the results of calculation have a similar trend of the decrease of overall SMD with Reynolds number increase.