Abstract
In order to extend the HCCI high load operational limit, the effects of the distributions of temperature and fuel concentration on pressure rise rate were investigated through theoretical and experimental methods. The Blowdown Supercharge (BDSC) system and the EGR guide parts are employed simultaneously to enhance thermal stratification inside the cylinder. Also, direct fuel injection system was also used to control the distribution of fuel concentration. As a result, pressure rise rate during high load HCCI operation was successfully reduced with the thermal stratification enhanced by the EGR guide. It is also found that the uniformed fuel concentration distribution generated by a direct fuel injection had less effective to reduce pressure rise rate. Because directly injected fuel into hot EGR gas decreased EGR gas temperature leading to reduce thermal stratification generated by the EGR guide.
