Abstract
The development of new energy engine is important to overcome the social problems of global warming and energy crisis. However, in the most recent future, it is important to improve the thermal efficiency of conventional gasoline engine also. As one of the countermeasures, the HCCI combustion applying negative valve overlap (NVO) has been evaluated in the many literatures. So far, we evaluated the normal spark-ignition combustion applying NVO, and we reported the effectiveness to lean limit extension. In this paper, the effectiveness to thermal efficiency is reported.
