Development Research of Gasoline HCCI Engine

-The Effect of Combustion during NVO (Negative Valve Overlap) on Thermal Efficiency-

Abstract

The effect of NVO combustion on thermal efficiency was investigated with a cycle simulation software realizing an HCCI combustion analysis. As a result, it was found that shorter NVO duration with NVO combustion was able to ensure better thermal efficiency keeping ignitability. It is necessary to set EVC, IVO, and the NVO fuel split ratio in consideration of the ignition timing, the pumping loss, and the expansion ratio of NVO combustion to obtain the best thermal efficiency in the case of NVO combustion.