Analysis of Multi-Pulse Injection Strategy for Diesel PCCI Combustion

摘要

Multi-pulse injection strategy for Premixed Charge Compression Ignition (PCCI) combustion was investigated in a four-valve, direct-injection diesel engine by CFD simulation using KIVA-3V code coupled with detailed chemistry. The effects of fuel splitting proportion, injection timing, spray angles, and injecting velocity were examined. The mixing process and formations of soot and NOx emissions were investigated as the main concern of the research. The results show that the fuel splitting proportion and the injection timing significantly impacted the combustion and emissions due to the considerable changes of the mixing process and fuel distribution in cylinder. While the spray including angle and injection velocity at the injector exit can be adjusted for improving mixing, combustion and emissions, appropriate injection timing and fuel splitting proportion must be jointly considered for optimum combustion performances.