In the past, the U.S. NRC(Nuclear Regulatory Commission) strictly required testing of the EDG for NPP through Reg.Guide 1.108 Rev 1. However, these test requirements acted as a deterioration and wear factor for diesel engines, and are now applying Reg.Guide 1.9 Rev 3, which relaxed regulatory requirements and improved performance monitoring. After applying the new regulatory guidelines in this study, the EDG analyzed the performance of the combustion chamber. As a result, there were no signs of deterioration or decreased performance of the current EDG. This is due to slow start, short operation time, the use of high quality fuel oil and proper maintenance. On the other hand, if the performance is proven, it is judged that proper period extension of cylinder maintenance is possible.

The effects of intake system on turbulent kinetic energy for the in-cylinder flow of a four-valve SI engine were studied. For this study, the same head, cylinder, and the piston were used to examine turbulence characteristics in two different intake systems. In-cylinder flow measurements were conducted using three dimensional LDV system. The measurement method, which simultaneously collects 3-D velocity data, allowed a evaluation of turbulent kinetic energy inside a cylinder. High levels of turbulent kinetic energy were found in regions of high shear flow, attributed to the collisions of intake flows. These specific results support the more general conclusion that the slightly offset direction of the intake system produced higher in-cylinder velocities on the +x-axis side of the cylinder which caused some asymmetric flow patterns about the z-axis. Higher levels of turbulent kinetic energy prevailed in zones of mean velocity collisions and regions where significant directional changes in the mean velocity patterns occurred.

In-cylinder flows in a motored 3.5L four-valve SI engine are investigated quantitatively using three-dimensional LDV system to determine how intake system affects the flow field. For this study, the same engine head, cylinder, and piston are used. The purpose of this work is to develop quantitative methods which correlate in-cylinder flows to engine performance. The LDV results reveal that collision regions and zones around vortices can be traced as the origins of turbulent kinetic energy. High levels of turbulent kinetic energy are found in regions of high shear flow, attributed to the collisions of intake flows. These specific results support the more general conclusion that the inlet conditions play the dominant role in the generation of the turbulence fields during the intake stroke.

In recent years, the regulation of exhaust gas of automobiles has been strengthened, and various high-tech technologies have been applied to cope with exhaust gas regulations. Especially, in case of gasoline vehicles, by injecting gasoline direct injection, a large amount of carbon deposits are adsorbed in intake / exhaust valves and combustion chambers, Which is a cause of combustion. Therefore, in this study, we developed the cleaning liquid and related special tools to remove carbon deposits in the combustion chamber, and developed the cleaning process of the combustion chamber and tried to understand the effect on the engine performance improvement. In order to prevent the release of heavy metals after burning, the cleaning effect of the cleaning liquid was investigated by temperature and the influence of the knocking of the engine on the cleaning performance.