Abstract
Six-stroke diesel engine proposed here has six processes in one cycle, and NO emission is expected to decrease owing to the direct EGR in the 2nd combustion process. However, weak mixing in the 2nd combustion process produced much soot. In this study, the six-stroke diesel engine was operated with low compression ratio in order to reduce NO emission. Moreover, high swirl ratio, supercharging and early injection were applied to promote mixing of air and fuel. As the results, high swirl ratio was effective in the reduction of soot emission. Under high swirl ratio condition, early injection with supercharging was effective in the reduction of soot emission due to well mixing of air and fuel.
