Areas of Research

Mie-scattering method and Entropy analysis for observing the spray characteristics such as diesel nozzle and gasoline direct injector and observing the spray impinging behavior. The entropy analysis study is developed a laser scattering image detection system, and measured the macro scale fuel spray characteristics such as spray penetration length, spray angle and vorticity. An entropy analysis method based on the concept of statistical thermodynamics has been developed, and the fuel distribution was analyzed by this method. In impinging spray behavior, the influence of the wall temperature and ambient pressure and impingement distance on impinging spray on the wall was examined. The spray growth velocity and path spray penetration at various wall conditions were analyzed, and the spray path penetration was investigated experimentally. The path penetration after impingement was predicted with using the Ebara’s empirical equation.

- PDA measurement for measuring the spray velocity, spray droplet diameter, and spray momentum, kinetic energy. The aim of this investigation is to describe detailed the spray characteristics such as drop size, velocities, penetration length, and spray cone angle. In addition, it was classified the measured droplet sizes into several groups in order to characterize atomization process of droplet at high shear flow region and spray tip by means of relative velocity of each size-classified droplet and Weber number. Finally, the measured droplet size data was compared with Nukiyama-Tanasawa and Rosin-Rammler distribution function to investigate which distribution function is more useful to predict the drop size distribution of pressure swirl injector. From the results, the global spray structure and quantitative characteristics of high-pressure swirl injector are clarified and the factors influencing the breakup mechanism of fuel droplets were investigated with the classification of droplet size and time.

- Heterodyne interferometry method. The methodology technique developed the laser heterodyne interferometry system spark-plug-in optic sensor was measured in cylinder temperature in accordance with crank angle phase. The developed heterodyne interferometry used the spark-plug-in fiber-optic sensor has a good feasibility to measure the unburned and burned temperature history.

Combustion and new combustion technology

- New Combustion Technology of gasoline engine such as CAI(controlled Auto-ignition) engine, SCCI(Stratified Charged Compression Ignition) engine, HCCI(Homogeneous Charged Compression Ignition)engine. Stratified charge compression ignition (SCCI) combustion, which is developed to extend the HCCI (homogeneous charge compression ignition) operating range, has a good potential to improve fuel economy and to reduce emissions. In this study, SCCI combustion and emission characteristics were investigated in a single-cylinder gasoline engine with a direct-injection system. From the experimental results, we elucidated the effects of air-fuel ratio, intake temperature and injection timing including early and late injection on the attainable SCCI combustion region. CAI combustion was realized using a single cylinder gasoline DI engine. In this study, the camshafts were modified in order to restrict the gas exchange process. We investigated the effects of air-fuel ratio, residual EGR rate and injection timing on the CAI combustion area. In addition, the effect of injection timing on combustion factors such as the start of combustion, its duration and its heat release rate was also investigated.

Role of Large project PM (Project Manager) as acquired the Project of Development of SCR System in a 650kW Marine Diesel Engine (2011.04-2012.04)

SCR system development for satisfying Emission regulation in a marine engine

1) DCU (Dosing Control Unit) algorithm development

2) Urea Nozzle Control logic and calibration / mapping system development

3) Urea Dosing control algorithm and DPF Control algorithm

4) 1D/3D Simulation of SCR / DPF system

Role of project PM (Project Manager of Experimental development) as acquired the Project of Development of 22HLX Diesel Engine in a Marine engine with AVL. Ltd. (2009.02-2010.12)

Role of Project PM (Project Manager) as acquired the project of Corporation development of 17AHX Diesel Engine in a Marine Engine with STX engine (Korea) and NIGATA Power System (Japan), (2010.02-2011.07)

Role of Project PL (Project Leader of System Engineering) as acquired the project of SCR System in a 10MW Low-speed Marine Engine (2012.10 – Present)

Interest fields in Geothermal energy in the Renewable energy field

The geothermal energy is also free of producing the carbon dioxide and high price of fossil fuel with limited resources. With these advantages, the geothermal heat pump system is expected to expand its application. However, research on the geothermal system is insufficient to have efficient and optimized system. Thermal Performance Evaluation on Standing Column Well Type Borehole Heat Exchanger and Borehole Size Effect on Geothermal Heat Exchanger and Characteristic Analysis and Evaluation of Bleeding Effect on Standing Column Well (SCW) Type Geothermal Heat Exchanger.