4-밸브 SI엔진에서 텀블,스월 유동의 영향에 따른 화염전파 과정

Abstract

The effects of tumble and swirl flows on the combustion were experimentally investigated in a 4-valve SI engine. The tumble flows were generated by various intake ports of different entry angle; 25°, 20° and 15°. Inclined tumble(swirl) flows were induced by two different swirl control valves. The initial flame propagation was visualized by an ICCD camera and its images were analyzed to compare the enflamed area and displacement of initial flames. The combustion duration was also calculated by heat release analysis.It was found that there is a correlation between the stronger tumble during induction and turbulence levels at the time of ignition resulting in faster flame development. Inclined tumble was proved to be more beneficial than the pure tumble for faster and stable combustion under lean mixture conditions, which was confirmed by faster propagating flame images and shorter combustion durations.