포트 마스킹과 밸브 타이밍에 따른 연소 현상 해석 및 연비와 Cyclic NOx 배출 특성

Abstract

A swirl motion in cylinder has been used to enhance the combustion quality due to charge stratification and better mixture formation in internal combustion engines. So, reduction in fuel consumption can be achieved by engine operation with lean A/F ratio conditions without negative effects in combustion stability. Also, a variable valve timing system is widely used for the fuel economy and better torque in gasoline engines. In this study, swirl ratio was measured by steady-flow impulse torque swirl meter to compare intensities of swirl according to the masked ratio of intake port. Moreover, actual engine experiments is performed to determine swirl effect by port masking with various intake valve timing and A/F ratio to enhance combustion stability, fuel economies and to reduce exhaust gases, especially cyclic NOx with fNOx 400.