강제 변위 제어와 곡면 비교를 고려한 선체 외판 열간 곡가공 정보의 정밀화

학위논문(박사) --서울대학교 대학원 :조선해양공학과,2009.2.Docto

Differential Evolution을 利用한 船舶用 部材의 블록單位 네스팅

학위논문(석사)--서울대학교 대학원 :조선해양공학과,2004.Maste

소 바이러스성 설사병 바이러스 국내 분리주의 5`-untranslated region 염기서열 분석에 관한 연구

Thesis (master`s)--서울대학교 대학원 :수의학과 수의미생물학전공,2002.Maste

A Comparative Study on North Adolescent Migrants and South Korean Adolescents Political Attitude: Focused on political efficacy and political trust

학위논문 (박사)-- 서울대학교 대학원 : 사회교육과(일반사회전공), 2011.2. 모경환.Docto

Assessment of Diesel and JP-8 on Direct Injection Diesel Engine

An experimental study has been carried out to investigate the effect of diesel and JP-8 fuel on engine performance and emissions in a single cylinder heavy-duty diesel engine equipped with a production type cylinder head and a high pressure common-rail injection system, while macroscopic spray images were captured. Experiments were performed at various engine speed, injection pressure and injection timing for both fuels. It was found that spray tip penetration with JP-8 fuel is shorter than diesel fuel due to low viscosity characteristics of JP-8 fuel from macroscopic spray images analysis. Peak heat release rate was higher and premixed bum duration was longer with JP-8 fuel due to its better vaporization characteristics when fuel injection pressure was 300 bar. The result also showed that increase of injection pressure to 1400 bar was more dominant factor which influences combustion characteristics than difference of vaporization due to viscosity characteristics between diesel and JP-8 fuel

Design of a Heat Exchanger to Reduce the Exhaust Temperature in a Spark-Ignition Engine

Design of experiments (DOE) technique has been used to design an exhaust heat exchanger to reduce the exhaust gas temperature under high load conditions in a spark-ignition engine. The DOE evaluates the influence and the interaction of a selected eight design parameters of the heat exchanger affecting the cooling performance of the exhaust gas through a limited number of experiments. The heat exchanger was installed between the exhaust manifold and the inlet of the close-coupled catalytic converter (CCC) to reduce thermal aging. To maximize the heat transfer between exhaust gas and coolant, fins were implemented at the inner surface of the heat exchanger. The design parameters consist of the fin geometry (length, thickness, arrangement, and number of fin), coolant direction, heat exchanger wall thickness, and the length of the heat exchanger. The acceptable range of each design parameter is discussed by analyzing the DOE results