It is well known that a lean burn engine caused by stratified mixture formation has many kinds of advantages to combustion characteristics, such as higher thermal efficiency and lower CO, NOx levels than conventional homogeneous mixture combustion. Although this combustion can achieve low fuel consumption technology, it produces much unburned hydrocarbon and soot because of heterogeneous equivalence ratio in the combustion chamber. Therefore, the stratified mixture formation technology is very important to obtain the stable lean combustion. In this paper, fundamental studies for stratified combustion were carried out using a constant volume combustion chamber. The local effect of mixture formation according to control air-fuel distribution in the chamber was examined experimentally. In addition, the effect of turbulence on stratified charge combustion process was observed by schlieren photography. From this study, we found that the flame propagation speed increase with swirl flow and the swirl promotes the formation of fuel and air mixture.
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