4-밸브 SI엔진에서 텀블, 스월 유동이 연소에 미치는 영향

Abstract

The effects of tumble and swirl flows on the combustion were investigated experimentally in a 4-valve SI engine. The tumble flow patterns were generated by various intake ports of different entry angle; 25°, 20° and 15°. Inclined tumble(swirl) flows were induced by three different swirl control valves. The initial flame propagation was visualized by an ICCD camera and its image were analyzed to compare the enflamed area and displacement of initial flames. The combustion duration was calculated by heat release analysis of the pressure in an operating engine. 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 combustion durations.